Genetic basis of channelopathies and cardiomyopathies in Hong Kong Chinese patients: a 10-year regional laboratory experience

Hong Kong Med J 2018 Aug;24(4):340–9  |  Epub 2 Mar 2018
DOI: 10.12809/hkmj176870
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
ORIGINAL ARTICLE
Genetic basis of channelopathies and cardiomyopathies in Hong Kong Chinese patients: a 10-year regional laboratory experience
Chloe M Mak1; Sammy PL Chen2; NS Mok3; WK Siu2; Hencher HC Lee2; CK Ching2; PT Tsui3; NC Fong4; YP Yuen2; WT Poon2; CY Law2; YK Chong2; YW Chan2; TC Yung5; Katherine YY Fan6; CW Lam7
1 Chemical Pathology Laboratory, Kowloon West Cluster Laboratory Genetic Service, Department of Pathology, Princess Margaret Hospital, Laichikok, Hong Kong
2 Department of Pathology, Princess Margaret Hospital, Laichikok, Hong Kong
3 Department of Medicine, Princess Margaret Hospital, Laichikok, Hong Kong
4 Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Laichikok, Hong Kong
5 Department of Paediatric Cardiology, Queen Mary Hospital, Pokfulam, Hong Kong
6 Department of Cardiac Medicine, Grantham Hospital, Wong Chuk Hang, Hong Kong
7 Department of Pathology, The University of Hong Kong, Pokfulam, Hong Kong
 
Corresponding author: Dr Chloe M Mak (makm@ha.org.hk)
 
 Full paper in PDF
 
Abstract
Introduction: Hereditary channelopathies and cardiomyopathies are potentially lethal and are clinically and genetically heterogeneous, involving at least 90 genes. Genetic testing can provide an accurate diagnosis, guide treatment, and enable cascade screening. The genetic basis among the Hong Kong Chinese population is largely unknown. We aimed to report on 28 unrelated patients with positive genetic findings detected from January 2006 to December 2015.
 
Methods: Sanger sequencing was performed for 28 unrelated patients with a clinical diagnosis of channelopathies or cardiomyopathies, testing for the following genes: KCNQ1, KCNH2, KCNE1, KCNE2, and SCN5A, for long QT syndrome; SCN5A for Brugada syndrome; RYR2 for catecholaminergic polymorphic ventricular tachycardia; MYH7 and MYBPC3 for hypertrophic cardiomyopathy; LMNA for dilated cardiomyopathy; and PKP2 and DSP for arrhythmogenic right ventricular dysplasia/cardiomyopathy.
 
Results: The study included 17 male and 11 female patients; their mean age at diagnosis was 39 years (range, 1-80 years). The major clinical presentations included syncope, palpitations, and abnormal electrocardiography findings. A family history was present in 13 (46%) patients. There were 26 different heterozygous mutations detected, of which six were novel—two in SCN5A (NM_198056.2:c.429del and c.2024-11T>A), two in MYBPC3 (NM_000256.3:c.906-22G>A and c.2105_2106del), and two in LMNA (NM_170707.3:c.73C>A and c.1209_1213dup).
 
Conclusions: We characterised the genetic heterogeneity in channelopathies and cardiomyopathies among Hong Kong Chinese patients in a 10-year case series. Correct interpretation of genetic findings is difficult and requires expertise and experience. Caution regarding issues of non-penetrance, variable expressivity, phenotype-genotype correlation, susceptibility risk, and digenic inheritance is necessary for genetic counselling and cascade screening.
 
 
New knowledge added by this study
  • We characterised the genetic heterogeneity in channelopathies and cardiomyopathies among Hong Kong Chinese patients and described 26 mutations with six novel variants.
  • This is the first case series of cardiac genetics in Hong Kong.
Implications for clinical practice or policy
  • This study provides genetic information for variant interpretation and insight into the clinical application of genetic testing for channelopathies and cardiomyopathies.
 
 
Introduction
Cardiac genetics is evolving rapidly and many new insights have recently been achieved. Genetic causes are found in various potentially lethal channelopathies and cardiomyopathies including long and short QT syndrome (LQTS and SQTS), Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia (CPVT), hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C), Barth syndrome, and left ventricular non-compaction.1 Knowledge of genetics deepens the understanding of pathophysiology and remarkably changes the diagnosis, treatment, and genetic counselling for recurrence risk and family planning. This group is highly genetically heterogeneous (Table 12).
 

Table 1. Common channelopathy- and cardiomyopathy-associated genes2
 
The genetic basis of inherited cardiac diseases in the Hong Kong Chinese population is largely unknown. The Princess Margaret Hospital provides a comprehensive cardiac genetic service. We conducted this study to review the clinical and genetic findings of 28 unrelated positive cases encountered between January 2006 and December 2015.
 
Methods
Diagnosis of the cardiac conditions was based on clinical assessments by a cardiologist and practice guidelines.3 4 5 The patients were referred by cardiologists from various public hospitals for genetic analysis. Only patients with positive genetic findings are reported in this study. There were seven patients with LQTS, two with Brugada syndrome, two with CPVT, nine with HCM, four with DCM, and four with ARVD/C. Local ethics board approval was obtained. Peripheral blood samples were collected from the proband after informed consent was obtained. Genomic DNA was extracted using a QIAamp Blood Kit (Qiagen, Hilden, Germany). The coding exons and the flanking introns (10 bp) of each gene were amplified by polymerase chain reaction. The primer sequences and protocol are available on request. Sanger sequencing was performed in the following order and stopped once a positive finding was detected: KCNQ1, KCNH2, KCNE1, KCNE2, and SCN5A for LQTS; SCN5A for Brugada syndrome; RYR2 for CPVT; MYH7 and MYBPC3 for HCM; LMNA for DCM; and PKP2 and DSP for ARVD/C. The order was based on prevalence according to the literature and local experience. All coding exons were amplified for each gene except selected exons 3, 8, 14, 45, 46, 47, 49, 88, 89, 90, 93, 96, 97, 100, 101, and 103 for RYR2.6 The GenBank accession numbers are shown in Table 2. The pathogenicity of novel missense variants was analysed by Alamut Visual (Interactive Biosoftware, Rouen, France) with Polymorphism Phenotyping v2 (PolyPhen-2), Sorting Intolerant from Tolerant (SIFT), MutationTaster, and Assessing Pathogenicity Probability in Arrhythmia by Integrating Statistical Evidence (APPRAISE, https://cardiodb.org/APPRAISE/) and that of novel splicing variants by Splice Site Finder-like, MaxEntScan, NNSPLIC, GeneSplicer, and Human Splicing Finder, wherever appropriate. Splicing variants were considered to be damaging if there was a >10% lower score when compared with the wild-type prediction. Allele frequencies among populations were referred to the Exome Aggregation Consortium (ExAC; http://exac.broadinstitute.org/).
 

Table 2. Targeted genes in Sanger sequencing analysis
 
Results
During the 10-year study period more than 90 patients with channelopathies or cardiomyopathies were referred for genetic analysis. Among them, 28 unrelated patients had positive genetic results, comprising 17 males and 11 females. Their mean age at diagnosis was 39 years (range, 1-80 years). The major clinical presentations included syncope, palpitations, and abnormal electrocardiography (ECG) findings. Four patients were asymptomatic and were diagnosed following an incidental abnormal finding related to other medical issues. A family history was present in only 13 (46%) patients. All detected mutations were heterozygous, and 26 different heterozygous mutations were detected. These encompassed 11 missense, two nonsense, and five splicing mutations, as well as eight small insertions and deletions. There were six novel mutations—two in SCN5A (NM_198056.2:c.429del and c.2024-11T>A), two in MYBPC3 (NM_000256.3:c.906-22G>A and c.2105_2106del), and two in LMNA (NM_170707.3:c.73C>A and c.1209_1213dup) [Table 3]. All were considered pathogenic or likely pathogenic according to the Practice Guidelines for the Evaluation of Pathogenicity and the Reporting of Sequence Variants in Clinical Molecular Genetics by the Association for Clinical Genetic Science.7 Further clinical details and genotypes are shown in Table 3.
 

Table 3. Clinical and genetic findings of 28 Chinese patients with channelopathies and cardiomyopathies
 
There were seven patients with LQTS, two with Brugada syndrome, two with CPVT, nine with HCM, four with DCM, and four with ARVD/C. Three patients with LQTS had mutations in KCNQ1 (cases 1-3) and four had mutations in KCNH2 (cases 4-7). Two patients (cases 8 and 9) with Brugada syndrome had mutations in SCN5A, including two novel mutations. Two patients (cases 10 and 11) with CPVT had mutations in RYR2. Four patients with HCM (cases 12-15) had MYH7 mutations and five (cases 16-20) had MYBPC3 mutations, including two novel mutations. Four patients with DCM (cases 21-24) had LMNA mutations, including two novel mutations. Finally, three patients with ARVD/C had PKP2 mutations (cases 25-27) and one had a DSP mutation (case 28).
 
Discussion
This is the first report of a cardiac genetic case series among Hong Kong Chinese patients with channelopathies and cardiomyopathies. A total of 28 patients are reported, and 26 different mutations and six novel mutations have been identified. Wide genetic diversity is observed, with no common mutation found. Hereditary channelopathies and cardiomyopathies are mainly inherited in an autosomal dominant manner. Mutations can be either inherited or de novo. Risk to proband sibling(s) and first-degree relatives depends on the genetic status of the parents. Offspring of the proband have a 50% risk of inheriting the mutation. Siblings of the proband have the same risk if the mutation is transmitted from either parent. Patients carrying a mutation of these sudden arrhythmia death syndromes show incomplete penetrance. In general, a mutation carrier will show symptoms/signs in 80% of those with CPVT, 20% to 50% of ARVD/C patients, 18% to 63% of LQTS patients, 80% to 94% of SQTS patients, and 80% of patients with Brugada syndrome who have abnormal ECG findings when challenged with a sodium channel blocker.8 No exact figure is available for HCM. The data could be more specific if a particular mutation was considered alongside clinical findings and family history. Pre-symptomatic testing of at-risk family members cannot be used to predict age of onset, severity, type of symptoms, or rate of progression. Detailed clinical, ECG, and genetic characterisation of affected and unaffected family members is helpful.
 
Long QT syndrome
Long QT syndrome is genetically heterogeneous, with at least 12 genes involved. Mutations in the four genes, KCNQ1, KCNH2, KCNE1, and KCNE2, are detected in 46%, 38%, 2%, and 1% of affected patients, respectively.8 A small proportion of patients (3%) have double heterozygous mutations in more than one disease loci.9 Specific arrhythmogenic triggers are associated with a particular subtype, such as exertion, swimming, and near-drowning for LQT1; auditory triggers and cardiac events occurring in the postpartum period for LQT2; and cardiac events during sleep or at rest for LQT3. Three patients had KCNQ1 mutations. Case 1 had recurrent syncope induced by exercise and swimming, but genetic testing confirmed LQTS type 1. Other patients had no specific provoking factor. LQTS type 2 caused by KCNH2 mutations accounts for about 38% of all LQTS.8 Four patients (cases 4-7) carried KCNH2 mutations and two (cases 4 and 6) presented with Torsades de pointes and one (case 7) had survived cardiac arrest requiring an implantable cardioverter defibrillator. Case 6 was the youngest patient, presenting at age 1 year. Genotype-guided treatment in LQTS is recommended and LQT1 responds best to beta-blockers.10 11
 
Brugada syndrome
Brugada syndrome is characterised by cardiac conduction abnormalities (ST-segment abnormalities in leads V1-V3 on ECG and a high risk for ventricular arrhythmias) that can result in sudden death. The Shanghai Score System has been recently published for the diagnosis of Brugada syndrome.12 13 The prevalence of Brugada syndrome or its characteristic ECG pattern is reportedly higher among Asians, such as Japanese (0.14%-1.22%).14 15 16 17
 
Brugada syndrome is genetically heterogeneous and can be attributed to defects in at least 23 genes at the time of reporting.8 Mutations in SCN5A are detected in 11% to 14% of affected individuals in Japan and <10% in Taiwan where mutations in CACNA1C account for 1% to 7%.18 Approximately 65% to 70% of patients remain genetically undiagnosed. Expressivity is variable and penetrance is incomplete and low.
 
Conventionally, Brugada syndrome has been described as a monogenic disease that has autosomal dominant inheritance with incomplete penetrance; it is caused by rare genetic variants with a large effect size. Most individuals diagnosed with Brugada syndrome have an affected parent. The proportion of cases caused by a de-novo mutation is approximately 1%. Recent studies indicate that genetic inheritance is likely more complex, and models of an oligogenic disorder or susceptibility risk/genetic predisposition have been suggested.19 20 21 22
 
Among the two patients in this series, none had a positive family history. Symptoms were more non-specific, such as palpitation and syncope. It is noteworthy that convulsion can be a presentation of channelopathies (case 8). Clinical suspicion should be higher with more specific investigations, such as exercise-stress ECG and flecainide challenge tests, are required in order to reveal the real culprit. Sudden cardiac death can be the first presenting symptom in Brugada syndrome.
 
Two novel mutations are described in SCN5A: c.429del and c.2024-11T>A. The former is predicted to cause a frameshift and premature protein truncation. The latter is predicted to abolish the acceptor splice site and create a cryptic site upstream. At the time of reporting, both are absent from controls in the Exome Sequencing Project, 1000 Genomes Project, and ExAC. SCN5A mutations can cause either LQTS or Brugada syndrome.
 
Catecholaminergic polymorphic ventricular tachycardia
Catecholaminergic polymorphic ventricular tachycardia can present with syncope and sudden death during physical exertion or emotion, due to catecholamine-induced bidirectional ventricular tachycardia, polymorphic ventricular tachycardia or ventricular fibrillation. The reported mean age of onset is between 7 and 12 years.8 Exercise stress testing or an adrenaline provocation test may induce ventricular arrhythmia and enable a clinical diagnosis. About half of these cases are related to a dominantly inherited RYR2 gene mutation, with a small proportion (1%-2%) related to recessively inherited CASQ2 gene mutations. RYR2 is a large gene with 105 exons. Tier testing has been proposed by Medeiros-Domingo et al.6 First-tier RYR2 genetic testing of the 16 selected exons allows identification of about 65% of CPVT cases. There were two paediatric CPVT patients (cases 10 and 11) in our series, with two known disease-causing mutations detected, namely NM_001035.2(RYR2):c.11836G>A (p.Gly3946Ser)23 24 25 26 and c.14848G>A (p.Glu4950Lys).23 24 Both mutations were detected in first-tier screening.
 
Hypertrophic cardiomyopathy
Hypertrophic cardiomyopathy is the most prevalent hereditary cardiac disease, causing about one third of sudden cardiac deaths in young athletes. Its prevalence in China is approximately 1 in 1250.27 The clinical manifestations are markedly variable, ranging from asymptomatic to sudden cardiac death. Genetic testing provides an accurate diagnosis in the probands and enables screening of asymptomatic family members. Although the genetic background of HCM is heterogeneous, involving at least 30 genes, MYH7 and MYBPC3 are the most common and each accounts for approximately 40%.8
 
Nine patients with HCM are reported here: four had known MYH7 mutations and five had MYBPC3 mutations, including two novel mutations. NM_000256.3:c.906-22G>A was detected in case 16 and was a novel variant. Neither population frequency nor known pathogenicity have been reported. In-silico analysis showed creation of a novel acceptor site and insertion of 20 nucleotides into exon 10. This conceivably would lead to a frameshift and premature protein termination. Exon 10 of MYBPC3 is a microexon in which the stability of its original splicing site is easily disrupted by intronic variants. A similar mutation has been reported as c.906-36G>A.28 Nonetheless, cDNA analysis was not performed. NM_000256.3(MYBPC3):c.1223+1G>A at the critical canonical +1 splice site is also novel. In addition, other known disease-causing splicing mutations affecting the same nucleotide have been reported.26 29 30 Case 19 had two variants detected in MYBPC3 (c.2215G>A and c.3624del). The small deletion c.3624del is a mutation known to cause HCM in the Chinese population31 and predicted to cause a frameshift and premature termination of the protein. The missense variant c.2215G>A is as yet unreported and is predicted by in-silico analyses to cause an amino acid change from glutamate to lysine at codon 739 and probably damage. At the time of reporting, the variant is absent from controls in the Exome Sequencing Project, 1000 Genomes Project, and ExAC databases. This variant is considered to have uncertain significance. The mother of the patient in case 19 was available for testing. She was 48 years old at the time of genetic testing, asymptomatic, and heterozygous for c.3624del only. Hence, the two variants c.2215G>A and c.3624del of MYBPC3 were in-trans in the patient and elder brother of the patient in case 19. Both had a more severe form of HCM, with a younger onset.
 
Dilated cardiomyopathy
Familial DCM is a group of genetically heterogeneous disorders. Laminopathy can manifest as several allelic disorders affecting muscle, nerve, adipose, and vascular tissues; one of them is cardiomyopathy, dilated 1A. We identified four patients with DCM, two of whom also had proximal muscle weakness. Two novel mutations in LMNA were detected (c.73C>A and c.1209_1213dup). NM_005572.3(LMNA):c.73C>A is a novel variant that is predicted to be deleterious by SIFT, probably causing damage according to PolyPhen-2 and disease-causing according to MutationTaster. Other missense mutations have been reported in the same amino acid codon.32 33 34 NM_005572.3(LMNA):c.1609-1G>A is predicted to significantly affect splicing by in-silico analysis. At the time of reporting, all variants are absent from controls in the Exome Sequencing Project, 1000 Genomes Project, and ExAC. In case 22 with NM_005572.3(LMNA):c.73C>A, one of the parents died of chronic heart failure in the fourth decade of life, and one sibling died of heart block and chronic heart failure with a diagnosis of muscular dystrophy at age 38 years. Nonetheless, there was no sample left for genotyping.
 
Arrhythmogenic right ventricular dysplasia/cardiomyopathy
Arrhythmogenic right ventricular dysplasia/cardiomyopathy is associated with fibrofatty replacement of cardiomyocytes, ventricular tachyarrhythmias, and sudden cardiac death. Although the right ventricle is primarily affected in this condition, left-dominant arrhythmogenic cardiomyopathy has also been described, and mutations have been identified in DSP as well as in other genes.35 Four patients are reported here, with three having mutations in PKP2 and one in DSP. Interestingly, the patient in case 26 presented at age 80 years with episodic palpitations. His ECG results showed paroxysmal ventricular tachycardia. He had a deletion in PKP2, c.1125_1132del (p.Phe376Alafs*8), resulting in a truncated incomplete protein product. Age of onset in patients with PKP2 mutations is older than that of the patient with DSP mutation. The latter patient (case 28) died at age 23 years, with sudden collapse as the first presentation.
 
Primary arrhythmogenic disorders including LQTS/SQTS, CPVT, Brugada syndrome, and cardiomyopathies account for about one third of sudden cardiac deaths in the young.36 Identification of a pathogenic variant can solve the diagnostic mystery, provide relief to the family, and enable family screening and counselling for other at-risk family members. In some developed countries, molecular autopsy is an essential part of a formal forensic investigation in unexplained sudden death.37 We support the implementation of molecular autopsy in routine autopsy investigation of sudden cardiac death victims. Our group has conducted the first local prospective study to determine the prevalence and types of sudden arrhythmia death syndrome underlying sudden cardiac death among local young victims through clinical and molecular autopsy of sudden cardiac death victims and clinical and genetic evaluation of their first-degree relatives (http://www.sadshk.org/en/medical_research.php). Such data can serve as the groundwork for the feasibility of implementation of such investigations in Hong Kong.
 
Genetic tests for cardiac conditions can aid diagnosis and guide treatment. Nonetheless, there are limitations that complicate the translational use of genetic results in patient care, such as incomplete penetrance, variable expressivity, and findings of variants of uncertain significance. In addition, since the genetic heterogeneity is large among cardiomyopathies and channelopathies and more genes are yet to be discovered, a negative genetic finding does not necessarily exclude a genetic basis of disease in patients.
 
Major limitations of the current study include its small sample size, incomplete family data for co-segregation study, and lack of functional study of novel variants. We observed a lower rate of use of genetic tests in early years that might have been due to insufficient awareness among clinicians about the clinical usefulness of such tests for channelopathies and cardiomyopathies. Clinical indications published in an expert consensus statement on the state of genetic testing for channelopathies and cardiomyopathies from the Heart Rhythm Society and European Heart Rhythm Association provide a good reference to determine when a genetic test should be requested.5 In our hospital, referral information can be accessed on http://kwcpath.home/genetics/ and more information about genetic service provision in public hospitals is available in the Hong Kong Hospital Authority Genetic Test Formulary (http://gtf.home/). A comprehensive system of cardiac genetics service is required for an efficient referral system, resource funding, training, and appropriate long-term follow-up.
 
Conclusions
We present the phenotypic and genotypic characteristics of 28 unrelated Hong Kong Chinese patients diagnosed across a 10-year period. For each disease entity, it was beyond our reach in the past decade to exhaustively screen for all known genes. We therefore focus on the most common ones when investigating cardiac genetics. Even so, genetic analysis can provide an accurate diagnosis and is of utmost importance for the management of patients and their families. Non-penetrance, variable expressivity, phenotype-genotype correlation, susceptibility risk, and digenic inheritance have been reported. Genetic testing also allows for genetic counselling on the recurrence risk. Correct interpretation of genetic findings for careful genetic counselling requires professional expertise with relevant experience in both clinical medicine and molecular genetics. Next-generation sequencing will improve diagnostic performance in this genetically heterogeneous group of channelopathies and cardiomyopathies, and could become a mainstay diagnostic tool.
 
Author contributions
All authors have made substantial contributions to the concept or design of this study; acquisition of data; analysis or interpretation of data; drafting of the article; and critical revision for important intellectual content.
 
Funding/support
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
Declaration
All authors have no conflicts of interest to disclose. All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.
 
Ethical approval
Local ethical approval of this study was obtained (KW/EX/09-155).
 
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Ambulance use affects timely emergency treatment of acute ischaemic stroke

Hong Kong Med J 2018 Aug;24(4):335–9  |  Epub 30 Jul 2018
DOI: 10.12809/hkmj177025
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
ORIGINAL ARTICLE
Ambulance use affects timely emergency treatment of acute ischaemic stroke
KK Lau, FRACP, FHKAM (Medicine)1; Ellen LM Yu, BSc (Stat & Fin), MSc (Epi & Biostat)2; MF Lee, BS (Nursing), MSc1; SH Ho, BS (Nursing)1; PM Ng, BS (Nursing), MSc1; CS Leung, FHKCEM, FHKAM (Emergency Medicine)3
1 Department of Medicine and Geriatrics, Princess Margaret Hospital, Laichikok, Hong Kong
2 Clinical Research Centre, Princess Margaret Hospital, Laichikok, Hong Kong
3 Accident and Emergency Department, Princess Margaret Hospital, Laichikok, Hong Kong
 
Corresponding author: Dr KK Lau (laukk2@ha.org.hk)
 
 Full paper in PDF
 
Abstract
Introduction: For acute ischaemic stroke patients, treatment with intravenous tissue plasminogen activator within a 4.5-hour therapeutic window is essential. We aimed to assess the time delays experienced by stroke patients arriving at the emergency department and to compare ambulance users and non-ambulance users.
 
Methods: We performed a prospective cohort study in a tertiary hospital in Hong Kong. All acute stroke patients attending the emergency department from January to June 2017 were recruited. Patients who were in hospital at the time of stroke onset and those who transferred from other hospitals were excluded. Three phases were compared between ambulance users and non-ambulance users: phase I, between stroke onset and calling for help; phase II, between calling for help and arriving at the emergency department; and phase III, between arriving and receiving medical assessment.
 
Results: Of 102 consecutive patients recruited, 48 (47%) patients arrived at the emergency department by ambulance. The percentage of stroke patients attending emergency department within the therapeutic window was significantly higher for ambulance users than for non-ambulance users (64.6% vs 29.6%; P<0.001). For phases I, II and III, the median times were significantly shorter for ambulance users (77.5, 32 and 8 min, respectively) than for non-ambulance users (720, 44.5 and 15 min, respectively; all P<0.001).
 
Conclusion: Transport of patients to the emergency department by ambulance is important for timely and effective stroke treatment.
 
 
New knowledge added by this study
  • Significantly more ambulance users received medical consultation at the emergency department within the therapeutic window than non-ambulance users.
  • Time intervals between stroke onset, help seeking, arrival at the emergency department and medical consultation were significantly shorter for ambulance users than for non-ambulance users.
  • Non-ambulance users who had visited a general practitioner arrived at the emergency department significantly later than ambulance users after seeking help; those who did not visit a general practitioner were not significantly different from ambulance users.
Implications for clinical practice or policy
  • The public should be educated to promptly call the emergency services after stroke onset.
 
 
Introduction
Treatment for acute ischaemic stroke by intravenous tissue plasminogen activator (TPA) was introduced in 1995.1 Early attendance is essential, as the effectiveness of TPA has been shown to decrease over time.2 3 Stroke patients are recommended to receive TPA within 4.5 hours after stroke onset.1 2 In Hong Kong, TPA has been available since early 2010. It typically takes 1 hour to complete the necessary examination, blood tests, brain computed tomographic scan, and preparation of TPA for administration. Therefore, stroke patients should receive a medical consultation at an emergency department (ED) within the therapeutic window of 3.5 hours after onset. In 1999, a study in Hong Kong investigated how patients attended EDs after stroke.4 At that time, stroke was classified as category II, and patients were not treated as urgent. Therefore, such stroke patients were often seen several hours after arrival. The study suggested that stroke should be treated as category I, and that immediate treatment should be given.4 Public education on recognising the signs and symptoms of stroke was also recommended.4 A collective effort at the social and administrative levels, aimed at shortening the duration between onset and arrival has been proposed.5 The aim of the present study was to investigate stroke patients’ means of transportation to the ED after stroke. The percentage of stroke patients receiving medical consultation at the ED within the therapeutic window was compared between ambulance users and non-ambulance users.
 
Methods
This was a prospective cohort study conducted by the Accident and Emergency Department and the Department of Medicine and Geriatrics, Princess Margaret Hospital, Hong Kong. All stroke patients admitted to the acute stroke unit via the ED from 1 January 2017 to 30 June 2017 were included. Patients who were in hospital at the time of stroke onset, or who transferred from other hospitals were excluded. Patients were invited to join this study after receiving stroke treatment, including TPA when applicable. Stroke patients were divided into two groups: ambulance users who called the emergency services and were brought to hospital by emergency ambulance; and non-ambulance users who sought alternate help and attended by other means of transportation. Non-ambulance users were further divided into those who visited a general practitioner (GP) before attending the ED, and those who did not. The onset time, arrival time, and time of medical consultation in the ED were collected from patient interviews and electronic admission records. The collected data were cross-checked by relatives or a GP. Three time intervals were studied: phase I was between stroke onset and calling for help (calling the emergency services for ambulance users or other calls for help for non-ambulance users); phase II was between calling for help and arriving at the ED; and phase III was between arriving at the ED and receiving medical consultation. The percentage of stroke patients receiving a medical consultation within the therapeutic window (210 minutes from stroke onset) was compared between ambulance users and non-ambulance users using Pearson’s Chi squared test. The time intervals of the three phases were reported as median (interquartile range) and were compared between the two groups using the Mann-Whitney U test.
 
Results
A total of 102 patients were eligible and were consecutively recruited. Of these patients, 48 (47.1%) were brought to the ED by ambulance. Patient demographic data, including age, sex, and co-morbidities are presented and compared between ambulance users and non-ambulance users in Table 1. No statistical difference was found between the two groups except hypertension (P=0.016).
 

Table 1. Demographic characteristics of non-ambulance users and ambulance users
 
The proportion of stroke patients arriving within the therapeutic window was significantly higher in ambulance users (64.6%; 31/48) than that in non-ambulance users (29.6%; 16/54) [P<0.001]. Of the 12 non-ambulance users who visited a GP before going to the ED, only one (8.3%) arrived within the therapeutic window, compared with 15 out of 42 (35.7%) patients from the non-ambulance user group.
 
Table 2 shows the comparison of the different time intervals between ambulance users and non-ambulance users. There were significant differences between the two groups for all phases (P<0.001). The median time for phase I for ambulance users was 77.5 minutes, whereas for non-ambulance users it was 720 minutes. The non-ambulance user group, whether the patient visited a GP or not, had a longer phase I interval than the ambulance user group (1470 [720-3165] min; P=0.001 for those who visited a GP and 440 [75-3023] min; P=0.004 for those who did not visit a GP). For phase II, the median travel time for ambulance users (32 min) was significantly shorter than that for non-ambulance users (44.5 min) [P<0.001]. Compared with ambulance users, non-ambulance users who had visited a GP had a significantly longer travel time (76 [56.25-123] min; P<0.001), whereas the travel time for those who did not visit a GP was not significantly different (31.5 [19.5-52.5] min; P=0.743). After arrival at the ED, the time to medical consultation for ambulance users was 8 minutes and that for non-ambulance users was 15 minutes (P<0.001). The time from onset of stroke to medical consultation in the ED for ambulance users was 120 minutes, whereas that for non-ambulance users was 1182 minutes (P<0.001).
 

Table 2. Time interval comparison between ambulance users and non-ambulance users
 
Of the 102 patients, 34 patients were treated with TPA. The reasons for not giving TPA were: uncertain onset time (n=8), therapeutic window exceeded (n=13), low National Institutes of Health Stroke Scale (NIHSS) score of <5 (n=52), high NIHSS score of >25 (n=16), intracerebral haemorrhage (n=16), convulsions (n=2), patient refused TPA (n=2), and poor pre-morbidity (n=6). There may be more than one reason per patient for not giving TPA. At 3 months after administration of TPA, five patients had excellent results (ie, reduction of ≥8 points in NIHSS score), 11 had good results (ie, reduction of ≥4 points in NIHSS score), 14 were static (ie, change of <4 points in NIHSS score), and four deteriorated (ie, increase of ≥4 points in NIHSS score).
 
Discussion
In Hong Kong, calls to the emergency services are answered by the Police Force and the Fire Services Department, which provides ambulance and fire-fighting services. Our study found that overall time intervals were shorter in ambulance users than in non-ambulance users. Significantly more ambulance users had a medical consultation within the therapeutic window than did non-ambulance users. For phase I, ambulance users might have more awareness and called for help earlier than the non-ambulance users. Compared with ambulance users, phase II was significantly longer for non-ambulance users who visited a GP, but not for patients who did not visit a GP. This might be because non-ambulance users who did not visit a GP went directly to the ED after calling for help. Ambulance users had a shorter phase III than did non-ambulance users. Non-ambulance users who did not visit a GP had shorter phase II, phase III, and overall time from onset to medical consultation than did those who visited a GP.
 
A study in Australia showed that fewer than 50% of stroke patients who called for an ambulance could correctly identify stroke from the symptoms.6 A study in Germany on calling for emergency assistance showed similar findings.7 An important finding in these papers was the importance of advice and assistance immediately after stroke onset6 7; one third of these patients were unable to make decision themselves.6 How stroke patients interpreted their symptoms, developed coping mechanisms, and engaged others prior to an emergency call for help was unclear.6 The process of seeking “lay referral” to call for an ambulance was not studied.6
 
In North America, a study to compare hospital arrivals showed no major differences between the situation in 2002 and that in 2009.8 The Get With The Guidelines–Stroke Program included over 413 147 ischaemic stroke patients from 287 hospitals; of these, 26.8% of patients arrived at the ED in ≤3.5 hours. The percentage of stroke patients who arrived within the therapeutic window did not change during the studied period. The authors suggested that further effort would be necessary to increase the proportion of patients arriving within the therapeutic window.8
 
Our findings are important for clinical applications. In our literature search, we could not find study from Hong Kong on how to shorten the time prior to hospital arrival. We believe that appropriate education can change the mindset of the public. If patients can recognise the signs and symptoms of stroke, they are more likely to call an ambulance in a timely manner, and thus will have a higher chance of receiving TPA treatment within the therapeutic window.
 
There are several limitations to the present study. The study was conducted in a single centre within a 6-month period. Although the sample size was limited by the study period, significant results were found. The study involved asking patients to recall the time of stroke onset, time of calling for help, and time of arrival at the ED. To mitigate any potential recall bias, the recalled information was cross-checked by relatives or a GP, and the time interval was short.
 
In recent years, the Hong Kong Stroke Fund has provided much public education, promoting recognition of acute stroke using the mnemonic “FAST” (談笑用兵). Here, “F” (face, 笑) refers to facial asymmetry, “A” (arms, 用) refers to weakness or numbness of the limbs, “S” (speech, 談) refers to slurring of speech, and “T” (time, 兵) refers to calling for immediate assistance.9
 
A study in Japan compared the effectiveness of different media on how to improve public knowledge of stroke. The authors found that television was more effective than printed newspapers.10 A combination of different media was found to be most effective.10 Structured community-based public education can improve public knowledge on stroke.10
 
Some patients voluntarily mentioned their reasons for not calling the emergency services for an ambulance. Some years ago, there was a publicity campaign to reduce ambulance misuse.11 Although the original message was not to misuse the ambulance service, the effect was long-lasting. Some patients still believe that there is always someone who is in greater need of an ambulance. Thus, these patients believe that they can travel to the ED themselves and are unaware of the urgency. Because these patients are unaware of the therapeutic window, they do not hurry to the ED. Public education, especially to encourage proper use of ambulance services is required.12 Public education on recognition of the symptoms and signs of stroke and on how to better utilise the emergency services is of the utmost importance.
 
Conclusion
The present study shows that the means of transport to the ED is an important aspect in effective stroke treatment. Stroke patients who call the emergency services are more likely to be treated effectively with TPA within the therapeutic window. Increasing public awareness of the signs and symptoms of acute stroke, and of the need to call the emergency services in case of stroke is critical.
 
Acknowledgement
Thanks to all patients and their relatives, without their support this study could not be completed.
 
Author contributions
All authors have made substantial contributions in designing the study, collecting data, analysis and interpretation of data, drafting, and critical revision of the article.
 
Funding/support
This research has received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
Declaration
All authors have disclosed no conflict of interest. All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.
 
Ethical approval
This study was approved by the Ethics Committee, Kowloon West Cluster (REC no. KW/EX-16-183(105-10)). Written informed consent was provided by all patients.
 
References
1. National Institute of Neurological Disorders and Stroke rt-PA Stroke Study Group. Tissue plasminogen activator for acute ischemic stroke. N Engl J Med 1995;333:1581-7. Crossref
2. Hacke W, Donnan G, Fieschi C, et al. Association of outcome with early stroke treatment: pooled analysis of ATLANTIS, ECASS, and NINDS rt-PA stroke trials. Lancet 2004;363:768-74. Crossref
3. Strbian D, Ringleb P, Michel P, et al. Ultra-early intravenous stroke thrombolysis: do all patients benefit similarly? Stroke 2013;44:2913-6. Crossref
4. Lau KK, Yeung KM, Chiu LH, et al. Delays in the presentation of stroke patients to hospital and possible ways of improvement. Hong Kong J Emerg Med 2003;10:76-80. Crossref
5. Hachinski V, Donnan GA, Gorelick PB, et al. Stroke: working toward a prioritized world agenda. Cerebrovasc Dis 2010;30:127-47. Crossref
6. Mosley I, Nicol M, Donnan G, Patrick I, Dewey H. Stroke symptoms and the decision to call for an ambulance. Stroke 2007;38:361-6. Crossref
7. Handschu R, Poppe R, Rauss J, Neundörfer B, Erbguth F. Emergency calls in acute stroke. Stroke 2003;34:1005-9. Crossref
8. Tong D, Reeves MJ, Hernandez AF, et al. Times from symptom onset to hospital arrival in the Get With the Guidelines–Stroke Program 2002 to 2009: temporal trends and implications. Stroke 2012;43:1912-7. Crossref
9. Hong Kong Stroke Fund. Acute Stroke Management— FAST. 2017. Available from: http://www.strokefund.org/eng/prevention_part1.php. Accessed 22 Sep 2017.
10. Miyamatsu N, Okamura T, Nakayama H, et al. Public awareness of early symptoms of stroke and information sources about stroke among the general Japanese population: the acquisition of stroke knowledge study. Cerebrovasc Dis 2013;35:241-9. Crossref
11. Hong Kong’s Information Services Department.「切勿濫用救護車」標語創作比賽. 2009. Available from: http://www.info.gov.hk/gia/general/200906/16/P200906160205.htm. Accessed 22 Sep 2017.
12. Becker K, Fruin M, Gooding T, Tirschwell D, Love P, Mankowski T. Community-based education improves stroke knowledge. Cerebrovasc Dis 2001;11:34-43. Crossref

The first pilot study of expanded newborn screening for inborn errors of metabolism and survey of related knowledge and opinions of health care professionals in Hong Kong

Hong Kong Med J 2018 Jun;24(3):226–37 | Epub 4 Jun 2018
DOI: 10.12809/hkmj176939
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
ORIGINAL ARTICLE
The first pilot study of expanded newborn screening for inborn errors of metabolism and survey of related knowledge and opinions of health care professionals in Hong Kong
Chloe M Mak, MD, FHKAM (Pathology)1; Eric CY Law, PhD, FHKAM (Pathology)2,3; Hencher HC Lee, MA, FRCPA1; WK Siu, PhD, FHKAM (Pathology)1; KM Chow, FRCOG, FHKAM (Obstetrics and Gynaecology)4; Sidney KC Au Yeung, FRCOG, FHKAM (Obstetrics and Gynaecology)5; Hextan YS Ngan, FRCOG, FHKAM (Obstetrics and Gynaecology)6; Niko KC Tse, FHKCPaed, FHKAM (Paediatrics)7; NS Kwong, FHKCPaed, FHKAM (Paediatrics)8; Godfrey CF Chan, FHKCPaed, FHKAM (Paediatrics)9; KW Lee, FRCOG, FHKAM (Obstetrics and Gynaecology)4; WP Chan, MB, ChB, FHKAM (Obstetrics and Gynaecology)4; SF Wong, FRCOG, FHKAM (Obstetrics and Gynaecology)5; Mary HY Tang, FRCOG, FHKAM (Obstetrics and Gynaecology)6; Anita SY Kan, MRCOG, FHKAM (Obstetrics and Gynaecology)6; Amelia PW Hui, FRCOG, FHKAM (Obstetrics and Gynaecology)6; PL So, FRCOG, FHKAM (Obstetrics and Gynaecology)5; CC Shek, FHKCPaed, FHKAM (Paediatrics)7; Robert SY Lee, FHKCPaed, FHKAM (Paediatrics)7; KY Wong, FHKCPaed, FHKAM (Paediatrics)9; Eric KC Yau, FHKCPaed, FHKAM (Paediatrics)7; KH Poon, MRCP(UK), FHKCPaed8; Sylvia Siu, MB, ChB, FHKAM (Paediatrics)8; Grace WK Poon, FHKCPaed, FHKAM (Paediatrics)9; Anne MK Kwok, FHKCPaed, FHKAM (Paediatrics)9; Judy WY Ng, BAppSc(Nurs), MSSc (Counselling)4; Vera CS Yim, FHKAN (HKCMW), MSC5; Grace GY Ma, BSN, MHSM (Health Services Management)6; CH Chu, MS10; TY Tong, MSc1; YK Chong, FHKCPath, FHKAM (Pathology)1; Sammy PL Chen, FRCPA, FHKAM (Pathology)1; CK Ching, FRCPA, FHKAM (Pathology)1; Angel OK Chan, MD, FHKAM (Pathology)3; Sidney Tam, FRCP, FHKAM (Pathology)4; Ruth LK Lau, MB, ChB, FHKAM (Pathology)11; WF Ng, MB, ChB, FHKAM (Pathology)11; KC Lee, MB, ChB, FHKAM (Pathology)1; Albert YW Chan, MD, FHKAM (Pathology)1; CW Lam, PhD, FHKAM (Pathology)2
1 Chemical Pathology Laboratory, Department of Pathology, Princess Margaret Hospital, Kwai Chung, Hong Kong
2 Department of Pathology, The University of Hong Kong, Queen Mary Hospital, Pokfulam, Hong Kong
3 Division of Clinical Biochemistry, Queen Mary Hospital, Pokfulam, Hong Kong
4 Department of Obstetrics and Gynaecology, Princess Margaret Hospital, Kwai Chung, Hong Kong
5 Department of Obstetrics and Gynaecology, Tuen Mun Hospital, Tuen Mun, Hong Kong
6 Department of Obstetrics and Gynaecology, Queen Mary Hospital, Pokfulam, Hong Kong
7 Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Kwai Chung, Hong Kong
8 Department of Paediatrics and Adolescent Medicine, Tuen Mun Hospital, Tuen Mun, Hong Kong
9 Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, Pokfulam, Hong Kong
10 Department of Pathology, United Christian Hospital, Kwun Tong, Hong Kong
11 Department of Pathology, Yan Chai Hospital, Tsuen Wan, Hong Kong
 
Corresponding author: Dr CW Lam (ching-wanlam@pathology.hku.hk)
 
 Full paper in PDF
 
Abstract
Introduction: Newborn screening is important for early diagnosis and effective treatment of inborn errors of metabolism (IEM). In response to a 2008 coroners’ report of a 14-year-old boy who died of an undiagnosed IEM, the OPathPaed service model was proposed. In the present study, we investigated the feasibility of the OPathPaed model for delivering expanded newborn screening in Hong Kong. In addition, health care professionals were surveyed on their knowledge and opinions of newborn screening for IEM.
 
Methods: The present prospective study involving three regional hospitals was conducted in phases, from 1 October 2012 to 31 August 2014. The 10 steps of the OPathPaed model were evaluated: parental education, consent, sampling, sample dispatch, dried blood spot preparation and testing, reporting, recall and counselling, confirmation test, treatment and monitoring, and cost-benefit analysis. A fully automated online extraction system for dried blood spot analysis was also evaluated. A questionnaire was distributed to 430 health care professionals by convenience sampling.
 
Results: In total, 2440 neonates were recruited for newborn screening; no true-positive cases were found. Completed questionnaires were received from 210 respondents. Health care professionals supported implementation of an expanded newborn screening for IEM. In addition, there is a substantial need of more education for health care professionals. The majority of respondents supported implementing the expanded newborn screening for IEM immediately or within 3 years.
 
Conclusion: The feasibility of OPathPaed model has been confirmed. It is significant and timely that when this pilot study was completed, a government-led initiative to study the feasibility of newborn screening for IEM in the public health care system on a larger scale was announced in the Hong Kong Special Administrative Region Chief Executive Policy Address of 2015.
 
 
New knowledge added by this study
  • The feasibility of the OPathPaed service model was evaluated in 2440 neonates. The main focus was on parental education, consent, sampling, sample dispatch, dried blood spot preparation and testing, reporting, recall, and counselling.
  • Of 210 health care professionals who responded to a survey, 73.6% were unaware of newborn screening for inborn errors of metabolism (IEM), 87.6% urged for more education, and 91.3% supported implementing expanded newborn screening for IEM immediately or within 3 years.
Implications for clinical practice or policy
  • The OPathPaed service model for implementing expanded newborn screening for IEM is feasible for local public hospital settings.
  • Health care professionals support implementation of newborn screening for IEM. In addition, there is a substantial need of more education.
 
 
Introduction
The expansion of newborn screening (NBS) for various genetic disorders with a focus on inborn errors of metabolism (IEM) has become a mandatory part of health care policy worldwide. Multiplex testing by tandem mass spectrometry has extended the scope of NBS far beyond the traditional ‘one test for one disease’ paradigm, requiring only a tiny blood sample, obtained by a simple heel prick.1 2 As a result, many inherited diseases are now screened for to allow early diagnosis and intervention and thereby prevent permanent damage or potential deaths.
 
Inborn errors of metabolism are a group of rare metabolic diseases with heterogeneous clinical presentations and genetic aetiologies. They are individually rare but collectively common. In 2011, Lee et al3 reported a 5-year retrospective review on the laboratory diagnosis of amino acid disorders, organic acidurias, and fatty acid beta-oxidation defects in three regional hospitals. The overall local incidence of classical IEM was 1 in 4122 live births.3 No phenylketonuria was identified through the screening of 18 000 newborns in the early 1970s.4 Hyperphenylalaninaemia was the second most common amino acid disorder reported by Lee et al,3 with an incidence of 1 in 29 542 live births. Another study by Hui et al5 reported the overall incidence of common IEM as 1 in 5400. According to the Hong Kong Paediatric Metabolic Registry, there were two cohorts, the first one with 20 years from 1982 to 2002 with 89 IEM patients and the second one with 14 years from 1996 to 2010 with 120 IEM patients. The estimated incidence of IEM was 1 in 7580 (unpublished data); however, as that was a voluntary case-finding study from several hospitals, the incidence was likely to be an underestimate. These figures are similar to those reported worldwide, such as 1 in 5800 in mainland China,6 1 in 5882 in Taiwan,7 and 1 in 4000 in America.8
 
In 2000, a mandatory NBS programme for hyperphenylalaninaemia, congenital hypothyroidism, and congenital deafness was implemented in mainland China.9 In 2006, the American College of Medical Genetics recommended 29 metabolic diseases (IEM) for which screening should be mandated.10 Since then, the scope of this recommendation has been expanding (Recommended Uniform Screening Panel, the Secretary of the Department of Health and Human Services11).12 In Hong Kong, population screening for congenital hypothyroidism and glucose-6-phosphate dehydrogenase (G6PD) deficiency using umbilical cord blood has been mandatory since March 1984 under the Neonatal Screening Unit of the Clinical Genetic Service, Department of Health. This programme has resulted in a significant reduction in related morbidities and mortalities.
 
In 2008, a coroner inquest was called to investigate the sudden death of a 14-year-old boy with a postmortem genetic diagnosis of glutaric acidaemia type II.13 The Coroners’ Report demanded that “The Department of Health, the Hospital Authority, the Faculty of Medicine of various universities and others concerned should carry out a feasibility study to see whether universal check may be carried out on all newborn babies for congenital metabolism defect.”14
 
To be effective, an expanded NBS programme needs to be coupled with improved general awareness of IEM and NBS. Educational support and training are required for frontline clinicians engaged in the diagnosis and care of patients with IEM.15 Several studies have shown that health care professionals do not have satisfactory awareness and knowledge of IEM.15 16 17 18 Therefore, a better understanding of the awareness of IEM among health care professionals in Hong Kong is needed.
 
We have conducted the first feasibility pilot study on the expanded NBS service model in a hospital setting in Hong Kong and the first survey on the knowledge and opinions on NBS for IEM among health care professionals in Hong Kong.
 
Methods
This prospective pilot study was conducted in phases from 1 October 2012 to 31 August 2014, involving three public hospitals and The University of Hong Kong (HKU), with over 40 collaborators from departments of pathology, paediatrics, and obstetrics. Phases 1 and 2 involved a single-site study conducted at Princess Margaret Hospital from 1 October 2012 to 31 October 2013 and then at Tuen Mun Hospital from 1 November 2013 to 31 March 2014. Phase 3 was university (HKU)-based and the recruitment was open to the public from 3 March 2014 to 31 August 2014. Phase 4 was a two-site study at the Tuen Mun Hospital and Queen Mary Hospital from 4 April 2014. Phase 5 was carried out at all three hospitals from 2 July 2014 until 31 August 2014. The OPathPaed model for expanded NBS was used for evaluation.19 The OPathPaed model includes 10 steps: parental education, consent, sampling, sample dispatch, dried blood spot (DBS) preparation and testing, reporting, recall and counselling, confirmation test, treatment and monitoring, and cost-benefit analysis (Fig 1).
 

Figure 1. OPathPaed service model for delivery of expanded NBS for IEM in Hong Kong
 
Pilot study to investigate the feasibility of the 10-step OPathPaed model
Step 1: Parental education
Educational talks were delivered by chemical pathologists during antenatal visits. With the help of the Save Babies Through Screening Foundation, we added Chinese subtitles to the video titled “Newborn Screening Saves Babies One Foot at a Time”. The video is available online (https://www.youtube.com/watch?v=dxFit_a601w). DVDs and a locally designed pamphlet with an email address and telephone number for enquiries were distributed to expectant mothers (Fig 2). In order to raise public awareness, several interviews with the media were arranged and reports were published in several newspapers20 21 22 and radio and television programmes.23 24
 

Figure 2. Chinese version of pilot study pamphlet on newborn screening for inborn errors of metabolism
 
Step 2: Obtaining consent
A consent form was designed for NBS for IEM (data not shown). Educational videos and pamphlets were used to inform the parents. Written informed consent was collected during a postnatal talk after the education session. The talk was conducted in group presentation for the mothers by chemical pathologists.
 
Step 3: Sampling
Paediatricians or pathologists organised training for phlebotomists on the heel prick technique, in compliance with the Clinical and Laboratory Standard Institute guidelines.25 An instruction sheet with photographs of valid and invalid DBS samples was provided as guidance for the phlebotomists (Fig 3). Samples were collected from neonates aged between 24 hours and 28 days.
 

Figure 3. Instruction guide with examples of valid and invalid dried blood spot samples
 
Step 4: Dried blood spot dispatching
Drying racks and special boxes designed for specimen transport before complete drying were delivered to the testing sites. Complete drying of blood spots was ensured for valid sample integrity. The blood spot cards were dried perpendicular to each other above and below the rack position to avoid contact contamination between blood spots of different patients.
 
Step 5: Dried blood spot preparation and testing
Two commercial DBS assay kits: (1) MassChrom Amino Acids and Acylcarnitines from Dried Blood/Non-derivatised (Chromsystems Instruments & Chemicals GmBH, Gräfelfing, Germany); and (2) NeoBase Non-derivatized MSMS kit (with succinylacetone assay; PerkinElmer, Waltham [MA], US) were validated for use in the study. In addition to a manual puncher and an autopuncher for DBS preparation, a fully automated online extraction system (DBS-MS 500; CAMAG, Muttenz, Switzerland) was also evaluated. The precision and local reference intervals of the commercial assay kits are listed in Table 1. Our laboratory has participated in the Newborn Screening Quality Assurance Programme organised by the US Centers for Disease Control and Prevention (CDC) since 2011. The disease panel included in the study is shown in Table 2.8 10 11
 

Table 1. Precision performance and local reference intervals for full-term babies for two commercial assay kits (NeoBase, MassChrom)
 

Table 2. Disease panel included in the study11
 
Step 6: Reporting
Chemical pathologists were responsible for reporting of positive results to the paediatricians. The CDC cut-off for clinical decision (https://wwwn.cdc.gov/NSQAP/Restricted/CDCCutOffs.aspx) and the Region 4 Stork Collaborative Project (https://www.clir-r4s.org/) data interpretation tools were applied during interpretation of the results.
 
Step 7: Recall and counselling
Newborn Screening ACT Sheets and Confirmatory Algorithms by the American College of Medical Genetics (https://www.ncbi.nlm.nih.gov/books/NBK55827/) were followed for patient recall. All abnormal results were examined by chemical pathologists. These chemical pathologists were also responsible for contacting the parents for post-test counselling and for arranging subsequent hospital referrals for care by paediatricians.
 
Step 8: Confirmation test
Confirmation of diagnosis was provided by regional laboratories through measurements of functional metabolites (mainly plasma amino acid levels, plasma acylcarnitine levels, and urine organic acid levels) and genetic diagnosis by DNA sequencing wherever appropriate.
 
Step 9: Treatment and monitoring
Admission logistics and treatment protocols for neonatal units with on-call rosters were established by hospital paediatricians. The same regional laboratories mentioned in Step 8 continued to provide biochemical diagnostic services.
 
Step 10: Cost-benefit analysis
A cost-benefit analysis has been conducted and published previously.26 Hyperphenylalaninaemia due to 6-pyruvoyl-tetrahydropterin synthase deficiency was used as an example to evaluate the costs and benefits of implementing an expanded NBS programme in Hong Kong. Assuming an annual birth rate of 50 000 and hyperphenylalaninaemia incidence of 1 in 29 542 live births, the annual medical costs and adjusted loss of workforce would be HK$20 773 207. The implementation and operational costs of an expanded NBS programme are expected to be HK$10 473 848 annually. Thus, implementing the expanded NBS programme is expected to result in an annual saving of HK$9 632 750.26
 
Survey of health care professionals’ knowledge and opinions of newborn screening for inborn errors of metabolism
A questionnaire was distributed by convenience sampling to 430 health care professionals who worked in hospitals and were not involved in the pilot study. These self-administered questionnaires were distributed to local health care professionals including medical doctors, nurses, and other allied health care professionals either in person with returning envelopes or via email to department heads for further distribution. The self-administered questionnaire in English was modified from a previously published questionnaire that was tested among parents.27 The self-administered questionnaire included 13 questions that covered the local practice of the existing NBS programme, as well as knowledge and opinions of an expanded NBS programme. No personal identifiers were included in the questionnaire and questions were mostly in a closed-ended format. Data analyses were performed using Excel 2000 (Microsoft Corp. Redmond [WA], US) and GraphPad QuickCalcs (http://graphpad.com/quickcalcs/ConfInterval1.cfm). Percentages for each question were calculated as the number of replies divided by the total number of respondents for that question. The questions and corresponding responses are shown in Table 3.
 

Table 3. Survey questions on knowledge and opinions of newborn screening for inborn errors of metabolism and responses from health care professionals in Hong Kong (n=210)
 
Results
Pilot study recruitment
By 31 August 2014, 2440 neonates had been recruited. The DBSs were collected from neonates aged 24 to 48 hours (n=2064, 84.6%), 3 to 5 days (n=331, 13.6%), 5 to 7 days (n=9, 0.4%), and 7 to 28 days (n=36, 1.5%). The participation rate was 86.6% on the days when blood samples were collected. There were no recorded DBS sampling or dispatch failures. The method validation and results of the DBS amino acids and acylcarnitine assays have been published elsewhere28; further details are available from the corresponding author on request. Overall, no true-positive cases were found in this pilot study, likely because of the limited sample size. Six (0.25%) false-positive cases were detected in 2440 neonates; of these, two had mild elevations in long-chain acylcarnitine levels, two had high tyrosine levels, one had a high citrulline level, and one had a low free carnitine level. Subsequent laboratory findings were all normal. No false-negative cases were reported from the IEM clinics of the involved hospitals within 2 years after project completion. However, patients who emigrated or received treatment at private institutions could not be followed up.
 
Health care professionals’ knowledge and opinions of newborn screening for inborn errors of metabolism
A total of 430 questionnaires were distributed and 210 (48.8%) completed responses were received. Results are shown in Table 3. Of the respondents, 50.0% were nurses and 32.9% were doctors. The doctors worked mainly in departments of paediatrics (47.8%), pathology (21.7%), and obstetrics (17.4%). Most (89.6%) respondents were aware of the existing NBS programme for hypothyroidism and G6PD deficiency; however, 47.5% did not know about IEM and 73.6% had not heard of expanded NBS for IEM. Most (87.6%) respondents agreed that more education on IEM and NBS is needed.
 
Discussion
This is the first prospective pilot study on NBS for IEM in Hong Kong, and it has successfully evaluated the feasibility of the OPathPaed model. This study is also the first to investigate the knowledge and opinions on NBS for IEM of local health care professionals.
 
To implement an expanded NBS programme for IEM successfully in Hong Kong, there are several important points that need to be addressed. First, awareness and knowledge of NBS for IEM among the general public and among health care professionals should be improved.27 Second, comprehensive data on the local disease spectrum and incidence should be made available; such data were not available until recently.3 5 Third, free flow of information and sharing of experiences among colleagues working in the acute care and public health sectors should be facilitated. Fourth, more emphasis should be given to regular updates on NBS health care policy, confirmatory investigation service support, and treatment protocols. Last, the use of umbilical cord blood samples in the existing programme is unsuitable for an expanded NBS programme for IEM because of unacceptably high false-negative rates.29 The metabolites associated with many amino acid disorders, organic acid disorders, and fatty acid oxidation disorders are not elevated in cord blood. In 2013, the hospital-based OPathPaed model was published for the implementation of an expanded NBS programme suitable for a local setting.19 The present study further confirms the feasibility of the OPathPaed model for use on a larger scale. The OPathPaed model integrates expert input from obstetricians, pathologists, and paediatricians. Because babies born in Hong Kong are normally delivered in hospitals, the OPathPaed model approach should be able to achieve full coverage.
 
The success of an expanded NBS programme for IEM would depend not only on the diagnostics but also on how well patients diagnosed with IEM could be managed. It is difficult to accumulate experience and the many metabolic diseases can easily cause confusion. In addition, sophisticated management requires individualised drug formulations, which may not be easily accessible or may involve off-label prescriptions. Overseas studies have identified significant knowledge gaps among clinicians involved in the follow-up care of newborns with IEM identified by NBS.15 16 17 18 Some were poorly prepared to follow up the initial diagnosis, provide appropriate counselling, or make appropriate clinical referrals.17 In our study, 73.6% of 210 health care professionals (who were not involved in the pilot study) were unaware of the expanded NBS programme, and 47.5% of respondents did not know what IEM were. The majority of respondents (87.6%) agreed that better education was needed and 91.3% supported expanding NBS for IEM immediately or within 3 years. According to a parental survey among 172 parents regarding NBS for IEM,27 over 89% had never heard of NBS for IEM or metabolic disorders. Although some IEM may be incurable, 97% of parents supported an expanded NBS programme and 82.8% of parents supported implementation of this expansion immediately or within 3 years.27
 
The present study also provides the first local evaluation of the fully automated DBS-MS 500 system. The DBS is directly eluted into the extraction chamber, with an online extraction system connecting with the tandem mass spectrometer. There is no need for DBS card punching. Together with the integrated optical card recognition and barcode reading module, this automation minimises the risk of sample misidentification during manual processing. The precision and accuracy demonstrated are comparable to those of conventional procedures. However, because the DBS-MS 500 system requires application of an internal standard solution before extraction, the financial cost per extraction would be higher than that for conventional methods. In addition, special DBS cards are required for the extraction chamber. Third-party DBS cards of a specific quality may not easily fit into the system. The throughput of up to 500 DBS cards per run is more than adequate for local needs, as there are about 50 000 live births annually in Hong Kong.
 
The limitations of the pilot study include small and non-representative sample size, a relatively short study period that may have been inadequate for follow-up to confirm true negatives, and the convenience sampling and low response rate of the health care professional survey.
 
Conclusion
The present pilot study investigated the feasibility of an expanded NBS for IEM in Hong Kong, and surveyed health care professionals for their knowledge and opinions on NBS for IEM. We successfully evaluated the OPathPaed model on a larger scale than has been attempted previously and demonstrated that health care professionals have a favourable opinion of implementing an expanded NBS programme in Hong Kong. It is timely that, as this pilot study was completed, the needs of parents and health care workers were addressed in the Hong Kong Special Administrative Region Chief Executive’s Policy Address of 2015, when a government-led initiative was announced to study the feasibility of NBS for IEM in the public health care system on a large scale.
 
Author contributions
All authors have made substantial contributions to the concept or design of this study; acquisition of data; analysis or interpretation of data; drafting of the article; and critical revision for important intellectual content.
 
Acknowledgement
We acknowledge all collaborators, doctors, nurses, medical technologists, phlebotomists, information technologists, and parents for their efforts and support. We thank the Save Babies Through Screening Foundation for allowing us to use their video for educational purpose. We thank CAMAG Germany for providing technical support during the evaluation of the DBS-MS 500. The CAMAG had no role in the study design, data collection, analysis, reporting, or manuscript preparation.
 
Funding/support
This work was funded by the SK Yee Medical Foundation. The funder had no role in study design, data collection, analysis, interpretation, or manuscript preparation.
 
Declaration
All authors have no conflicts of interest to disclose. All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.
 
Ethical approval
Local ethical approval was obtained from each of the regional hospitals involved in this study.
 
References
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2. Carpenter KH, Wiley V. Application of tandem mass spectrometry to biochemical genetics and newborn screening. Clin Chim Acta 2002;322:1-10. Crossref
3. Lee HC, Mak CM, Lam CW, et al. Analysis of inborn errors of metabolism: disease spectrum for expanded newborn screening in Hong Kong. Chin Med J (Engl) 2011;124:983-9.
4. Davies DP. Hong Kong Reflections: Health, Illness and Disability in Hong Kong Children. Hong Kong: The Chinese University Press; 1995.
5. Hui J, Tang NL, Li CK, et al. Inherited metabolic diseases in the Southern Chinese population: spectrum of diseases and estimated incidence from recurrent mutations. Pathology 2014;46:375-82. Crossref
6. Gu X, Wang Z, Ye J, Han L, Qiu W. Newborn screening in China: phenylketonuria, congenital hypothyroidism and expanded screening. Ann Acad Med Singapore 2008;37(12 Suppl):107-10.
7. Niu DM, Chien YH, Chiang CC, et al. Nationwide survey of extended newborn screening by tandem mass spectrometry in Taiwan. J Inherit Metab Dis 2010;33(Suppl 2):S295-305. Crossref
8. Chace DH, Kalas TA, Naylor EW. The application of tandem mass spectrometry to neonatal screening for inherited disorders of intermediary metabolism. Annu Rev Genomics Hum Genet 2002;3:17-45. Crossref
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11. Recommended Uniform Screening Panel, The Advisory Committee on Heritable Disorders in Newborns and Children, US Department of Health and Human Services. Available from: https://www.hrsa.gov/advisorycommittees/mchbadvisory/heritabledisorders/recommendedpanel/. Accessed 1 Aug 2017.
12. Therrell BL, Johnson A, Williams D. Status of newborn screening programs in the United States. Pediatrics 2006;117(5 Pt 2):S212-52. Crossref
13. Lee HC, Lai CK, Siu TS, et al. Role of postmortem genetic testing demonstrated in a case of glutaric aciduria type II. Diagn Mol Pathol 2010;19:184-6. Crossref
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15. Gennaccaro M, Waisbren SE, Marsden D. The knowledge gap in expanded newborn screening: survey results from paediatricians in Massachusetts. J Inherit Metab Dis 2005;28:819-24. Crossref
16. Wells AS, Northrup H, Crandell SS, et al. Expanded newborn screening in Texas: a survey and educational module addressing the knowledge of pediatric residents. Genet Med 2009;11:163-8. Crossref
17. Kemper AR, Uren RL, Moseley KL, Clark SJ. Primary care physicians’ attitudes regarding follow-up care for children with positive newborn screening results. Pediatrics 2006;118:1836-41. Crossref
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Three-dimensional versus two-dimensional laparoscopy for ovarian cystectomy: a prospective randomised study

Hong Kong Med J 2018 Jun;24(3):245–51 | Epub 31 May 2018
DOI: 10.12809/hkmj176846
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
ORIGINAL ARTICLE
Three-dimensional versus two-dimensional laparoscopy for ovarian cystectomy: a prospective randomised study
MW Lui, MB, BS, MRCOG; Vincent YT Cheung, MB, BS, FRCOG
Department of Obstetrics and Gynaecology, Queen Mary Hospital, The University of Hong Kong, Pokfulam, Hong Kong
 
Corresponding author: Dr MW Lui (luimanwa@gmail.com)
 
 Full paper in PDF
 
Abstract
Introduction: Three-dimensional (3D) laparoscopy is now available as an alternative to conventional two-dimensional (2D) laparoscopy for ovarian cystectomy. However, the clinical value of 3D laparoscopy in benign gynaecological surgery remains uncertain. This study evaluated whether 3D laparoscopy had any advantages over 2D laparoscopy for ovarian cystectomy for apparently benign ovarian cysts.
 
Methods: This prospective randomised study involved patients undergoing laparoscopic ovarian cystectomy. The primary outcomes were the duration of cystectomy and surgeon’s Global Operative Assessment of Laparoscopic Skills (GOALS) score. The secondary outcomes were the preferences, perceptions, and adverse effects reported by the participating surgeons.
 
Results: There were 38 patients assigned to the 2D laparoscopy group and 37 patients assigned to the 3D laparoscopy group. Participating surgeons in the 2D group reported more efficient tissue handling than did those in the 3D group (mean [standard deviation] rating score, 4.2 [0.8] vs 3.8 [0.8]; P=0.033). Duration of cystectomy (47.6 [32.0] min vs 51.6 [36.2] min; P=0.198) and overall GOALS score (20.8 [3.9] vs 20.1 [3.3]; P=0.393) were similar between both groups. Participating surgeons in the 2D group reported nausea, dizziness, ocular fatigue, and blurring of vision less frequently than did those in the 3D group (5.3% vs 45.9%; P<0.001).
 
Conclusion: There were no significant benefits to using 3D laparoscopy compared with conventional 2D laparoscopy for ovarian cystectomy, and 3D laparoscopy may cause more frequent adverse effects in surgeons.
 
 
New knowledge added by this study
  • For ovarian cystectomy, there is no significant benefit to using three-dimensional laparoscopy rather than conventional two-dimensional laparoscopy.
  • Three-dimensional laparoscopy permits binocular vision and depth perception; however, surgeons using three-dimensional laparoscopy more frequently reported adverse effects such as ocular fatigue, nausea, dizziness, and blurring of vision.
Implications for clinical practice or policy
  • Clinical use of three-dimensional laparoscopy in more complex surgical procedures, such as laparoscopic suturing, or with more experienced surgeons may be beneficial; therefore, further investigation is worthwhile.
 
 
Introduction
Laparoscopy has replaced laparotomy in most gynaecological procedures, and laparoscopic cystectomy is currently the mainstay of treatment for apparently benign ovarian cysts. However, the absence of depth perception and limited instrument dexterity are major drawbacks of laparoscopy. Advances in three-dimensional (3D) video imaging technology allow 3D laparoscopy to provide better precision than conventional two-dimensional (2D) laparoscopy, especially in depth perception and spatial orientation. This increased precision may help improve surgeon’s performance during laparoscopic surgery.
 
Studies have shown that 3D laparoscopy objectively1 2 and subjectively3 4 improves surgical performance, especially during complex tasks.5 In addition, 3D laparoscopy lessens the learning curve for beginners.6 The durations of laparoscopic cholecystectomy and pelvic lymphadenectomy have also been shortened when performed using 3D technologies.7 8 However, the clinical value of 3D laparoscopy in benign gynaecological surgery remains uncertain. This study aimed to evaluate any advantages of using 3D laparoscopy over 2D laparoscopy for ovarian cystectomy.
 
Methods
This prospective randomised study was conducted from May 2014 to May 2016 at the Queen Mary Hospital, Hong Kong, a teaching hospital affiliated with The University of Hong Kong. Women with apparently benign ovarian cysts who were scheduled for elective laparoscopic ovarian cystectomy and who were eligible for the study were invited at the pre-admission clinic to enrol in the study. Inclusion criteria were being older than 18 years; ability to understand Cantonese, Putonghua, or English; and ability to understand the study information during the consent process. Patients who were intra-operatively found to have no ovarian cyst were excluded from further analysis.
 
Patients were allocated by block randomisation to undergo surgery with 2D laparoscopy (2D group) or 3D laparoscopy (3D group) according to a computer-generated random sequence, in blocks of five. The group allocation for each patient was disclosed to the surgeon on the day before the surgery using a consecutively numbered, opaque, sealed envelope. Demographic data of patients and duration of surgeries were collected by a research nurse.
 
A pneumoperitoneum was created using a Veress needle to provide visually guided closed access. For 3D laparoscopy, a 10-mm 3D telescopic videoscope was used (Endoeye Flex 3D; Olympus, Center Valley [PA], US). All surgeons were trained for 3D laparoscopy using a pelvic trainer with standardised tasks including peg transfer, precision cutting, duct cannulation, and suturing with knot tying. The 3D laparoscopy training was continued until the surgeons could confidently operate using 3D images. All non-specialist surgeons were supervised by a laparoscopist accredited at the advanced level in gynaecological laparoscopic surgery, according to the Hong Kong College of Obstetricians and Gynaecologists.9 At their discretion, surgeons were allowed to switch from 3D laparoscopy to traditional 2D laparoscopy if difficulty was encountered during surgery. All 2D laparoscopies were performed using a 10-mm laparoscope (26033AP; Karl Storz Endoscopy-America Inc, Culver City [CA], US). The same 32-inch high-definition monitor (LMD-3215MT; Sony Corporation, Tokyo, Japan) was used for all operations. In the 2D and 3D groups, cystectomy was performed in the usual manner, using two or three 5-mm accessory ports inserted in the lower abdomen under direct vision. The start time of the operation (first skin incision), insertion of primary trocar, completion of cystectomy, and end of operation (final skin closure) were recorded by the research nurse.
 
After the operation, all surgeons were required to self-evaluate their performance by using the Global Operative Assessment of Laparoscopic Skills (GOALS) assessment tool.10 The five-item GOALS score includes assessment of depth perception, bimanual dexterity, efficiency, tissue handling, and autonomy. Any operator discomfort encountered during the surgery, any need to convert to 2D laparoscopy, and the surgeon’s preference for the type of laparoscopy based on experience were also recorded. Demographic data and operative findings, such as size and laterality of cysts, operative duration, and presence of adhesions were analysed. Duration of cystectomy was defined as the time from completion of primary port insertion to separation of the cyst from the ovary and completion of haemostasis. The time spent on specimen retrieval was not included, owing to variations in the specimen retrieval method with or without use of a specimen bag.
 
The primary outcome of the present study was the difference between the GOALS score of 2D and 3D groups. The secondary outcomes were the duration of cystectomy and surgeon’s preferences and reported adverse effects. Subgroup analysis was performed to compare the outcomes for different experience levels among the surgeons. The surgeons were categorised according to their experience in performing laparoscopic surgery (≤5 years or >5 years). Surgeons with more than 5 years of experience had achieved competency in gynaecological laparoscopic surgery to at least an intermediate level, according to the Hong Kong College of Obstetricians and Gynaecologists, and had completed a required number of laparoscopic operations as requested by the College.9
 
A sample size of 36 patients was required in each group, as calculated using an alpha of 0.05 and a beta of 0.2 for detection of a difference in the sum of four items of the GOALS score (excluding tissue handling) of 13 (interquartile range [IQR], 11-16) in the 2D group and 16 (IQR, 12-18) in the 3D group, as based on a previous study,11 using a two-sided test. To allow for a 10% dropout rate, 40 patients were recruited into each group. For randomised patients whose operations were subsequently rescheduled outside the study period, treatment assignment numbers were reallocated to subsequent eligible patients who provided consent. Statistical analysis was performed using SPSS Windows version 21.0 (IBM Corp, Armonk [NY], US). Data were presented as proportions or mean and standard deviation. Student’s t test and Chi squared test were used for statistical analyses. A P value of <0.05 was considered statistically significant.
 
Results
Of the 83 patients recruited into the study from May 2014 to May 2016, operations were rescheduled for three patients who were therefore withdrawn from the study; 80 patients completed the trial (Fig). Of these 80 patients, two from the 2D group and three from the 3D group were excluded from analysis because no cysts were identified. Finally, 38 patients in the 2D group and 37 patients in the 3D group were included for analysis. Patient characteristics and surgical outcomes are presented in Table 1. There were no significant differences between the 2D and 3D groups in terms of patient age, laterality of the ovarian cyst, histological diagnosis of the cyst, presence of severe adhesions, volume of blood loss, and experience level of the surgeon. Three accessory ports were used in four patients in the 2D group and in five patients in the 3D group. In all other patients, two accessory ports were used. The mean (standard deviation) diameter of the ovarian cyst was smaller in the 3D group than that in the 2D group (5.1 [2.1] cm vs 6.1 cm [2.1] cm; P=0.031). Body mass index in the 2D group was significantly higher than that in the 3D group (23.4 [4.4] kg/m2 vs 21.3 [2.6] kg/m2; P=0.011). Severe adhesion was defined as a score of >20 for adnexal adhesion unilaterally12 or a score of >40 for endometriosis,13 according to the American Society for Reproductive Medicine classifications.
 

Figure. Recruitment flowchart in this study
 

Table 1. Patient characteristics and surgical outcomes
 
The differences between 2D and 3D groups in terms of GOALS score and duration of cystectomy are presented in Table 2. A total of 15 surgeons participated in the study and there were 13 in each group: 11 in both, while two for each were involved in 2D and 3D groups, respectively. Participating surgeons in the 2D group reported more efficient tissue handling than did those in the 3D group. Adverse effects, including nausea, dizziness, ocular fatigue, and blurring of vision were reported less frequently by participating surgeons in 2D group than those in 3D group (Table 3). However, none of the participating surgeons requested intra-operative conversion from 3D to 2D laparoscopy. At the end of surgery, more participating surgeons in the 3D group expressed a preference for 2D laparoscopy (43.3%) than for 3D laparoscopy (18.9%), whereas 37.8% had no preference. A subgroup analysis of participating surgeons in the two groups did not show statistically significant differences in terms of GOALS score (2D vs 3D; 28.9 [5.1] vs 28.2 [46.0]; P=0.585), tissue handling (4.2 [0.8] vs 3.9 [0.8]; P=0.060), and duration of cystectomy (93.7 [46.1] min vs 97.7 [52.2] min; P=0.737).
 

Table 2. Differences between the 2D and 3D laparoscopy groups in terms of surgeon’s GOALS score and duration of cystectomy
 

Table 3. Adverse effects reported by participating surgeons
 
Subgroup analyses according to the experience level of the surgeon and the presence of dense adhesions are shown in Tables 4 and 5, respectively. Two of the surgeons in the 3D group and three of the surgeons in the 2D laparoscopy are accredited at the advanced level in gynaecological laparoscopic surgery by the Hong Kong College of Obstetricians and Gynaecologists. Surgeons with more than 5 years of laparoscopic experience reported lower scores in tissue handling and efficiency when using 3D laparoscopy. There were no differences in terms of GOALS score and duration of cystectomy in the subgroup with dense adhesions.
 

Table 4. Comparison between the 2D and 3D groups in terms of surgeon’s GOALS score and duration of cystectomy according to the experience level of the surgeon
 

Table 5. Comparison between the 2D and 3D groups in terms of surgeon’s GOALS score and duration of cystectomy according to presence of severe adhesions
 
Discussion
Three-dimensional laparoscopy is gaining popularity in modern gynaecological surgery owing to improved depth perception and spatial orientation compared with 2D laparoscopy. Improved effectiveness using 3D laparoscopy has been shown extensively in training models, especially when performing complex tasks5 and in beginners.6 8 14 However, our study was unable to show an improvement in terms of GOALS score and duration of operation (Table 2) despite the 3D laparoscopy group having a smaller mean ovarian cyst diameter (Table 1). This finding contradicts a recent meta-analysis that 3D laparoscopy was associated with shortened surgical time and hospital study, less blood loss, and fewer perioperative complications.15
 
The addition of binocular vision and depth perception in 3D laparoscopy is associated with more frequent adverse effects such as ocular fatigue, nausea, and dizziness.16 In the present study, participating surgeons in the 3D group more frequently reported nausea, dizziness, ocular fatigue, and blurring of vision than did those in the 2D group. However, this result may be because the participating surgeons were unfamiliar with 3D images; with experience, this discomfort may be lessened. Maintaining stability of the telescope is of utmost importance during 3D laparoscopy; therefore, familiarity with 3D images is important for assistants to mitigate adverse effects. Furthermore, maintaining an appropriate distance between the screen and the surgeon also alleviates nausea and ocular fatigue.16
 
Previous studies have shown that 3D laparoscopy is beneficial for less experienced surgeons6 8 14 and for any surgeon performing complex tasks.5 However, in our subgroup analysis, we were unable to confirm any benefits of 3D laparoscopy in relation to the experience level of the surgeons. All participating surgeons were much more familiar with 2D laparoscopy and, thus, the difference between groups might simply reflect the surgeon’s assessment of what they are used to. This familiarity effect may explain the lower scores in tissue handling and efficiency with 3D laparoscopy attained by the more experienced surgeons.
 
The surgeon’s preference for 2D laparoscopy and the heterogeneity of the participating surgeons and patients make the subgroup analyses underpowered and represents a constitute limitation of the present study. The differences in mean diameter of the ovarian cysts and body mass index between the two groups also suggest ineffective randomisation. Other limitations include ineffective randomisation, withdrawal of patients after randomisation, and surgeon’s lack of experience with 3D laparoscopy. During data analysis, there were also no controls for possible confounding factors, such as experience of each surgeon with 3D laparoscopy or significant differences in patient characteristics between the groups.
 
In conclusion, the results show that there is no significant benefit to using 3D laparoscopy for ovarian cystectomy compared with conventional 2D laparoscopy. Moreover, 3D laparoscopy is associated with more frequent adverse effects for surgeons. However, it is possible that more complex procedures, such as those involving laparoscopic suturing and knot tying, might be easier to perform with 3D laparoscopy than with 2D laparoscopy. Therefore, further evaluation of the clinical performance of 3D laparoscopy in operations of different complexities and of surgeons with different experience levels are warranted.
 
Author contributions
All authors have made substantial contributions to the concept of this study; acquisition of data; analysis or interpretation of data; drafting of the article; and critical revision for important intellectual content.
 
Acknowledgement
We wish to thank Ms Wai-ki Choi for helping in patient recruitment and data collection.
 
Funding/support
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
Declaration
The authors have no conflicts of interest to disclose. All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity. The study was presented as oral presentation in the 25th Asian and Oceanic Congress of Obstetrics and Gynaecology, 16 June 2017, Hong Kong.
 
Ethical approval
Ethical approval was obtained from the Institutional Review Board of the University of Hong Kong/Hospital Authority Hong Kong West Cluster. Written informed consent was obtained from all participating patients and surgeons. The study was registered with ClinicalTrials.gov (NCT02775344).
 
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Evaluation of a multiplex flow immunoassay versus conventional assays in detecting autoantibodies in systemic lupus erythematosus

Hong Kong Med J 2018 Jun;24(3):261–9 | Epub 25 May 2018
DOI: 10.12809/hkmj177007
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
ORIGINAL ARTICLE
Evaluation of a multiplex flow immunoassay versus conventional assays in detecting autoantibodies in systemic lupus erythematosus
Elaine YL Au, MB, BS, FHKAM (Pathology)1; WK Ip, PhD1; CS Lau, MB, ChB, FHKAM (Medicine)2, YT Chan, MB, BS, FHKAM (Pathology)1
1 Division of Clinical Immunology, Department of Pathology, Queen Mary Hospital, Pokfulam, Hong Kong
2 Division of Rheumatology and Clinical Immunology, Department of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
 
Corresponding author: Dr Elaine YL Au (elaineauyl@gmail.com)
 
 Full paper in PDF
 
Abstract
Introduction: Conventional diagnostic assays are being replaced with automated multiplex assays, but their performance needs to be evaluated. We compared a multiplex flow immunoassay with conventional techniques in the detection of antinuclear antibodies (ANAs) and antibodies to specific extractable nuclear antigens (ENAs) in serum samples from patients with systemic lupus erythematosus.
 
Methods: A total of 140 consecutive Chinese patients with systemic lupus erythematosus and 41 healthy controls were included. The automated BioPlex 2200 ANA Screen assay (Bio-Rad Laboratories, Hercules [CA], US) was compared with indirect immunofluorescence. In addition, use of BioPlex 2200 to detect anti-ENA antibodies was compared with in-house assays of countercurrent immunoelectrophoresis (CIEP), enzyme-linked immunosorbent assay (ELISA), and line blot.
 
Results: The sensitivity and specificity of BioPlex in detecting ANAs (91.4% and 95.1%, respectively) were comparable to those of indirect immunofluorescence (90.7% and 85.4%, respectively). Overall, BioPlex achieved the best agreement with ELISA in detecting anti-ENA antibodies: agreement was >90% for most antibody types (κ=0.79-0.94). In contrast, agreement was poorest with CIEP, ranging from 85.6% (κ=0.33) for anti-Sm antibodies to 93.9% (κ=0.88) for anti-Ro antibodies. Overall, BioPlex and ELISA had the highest sensitivity, whereas CIEP had the highest specificity. In terms of disease association, anti-Sm detected by CIEP had the best positive predictive value and specificity for lupus nephritis.
 
Conclusions: In a local lupus cohort, BioPlex showed comparable sensitivity to indirect immunofluorescence in detecting ANAs and comparable performance to ELISA in detecting anti-ENA antibodies. However, CIEP was the best method in terms of disease specificity.
 
 
New knowledge added by this study
  • The sensitivity of the BioPlex 2200 ANA Screen was comparable to that of indirect immunofluorescence.
  • The BioPlex 2200 multiplex platform has a comparable performance to the enzyme-linked immunosorbent assay in the detection of antibodies to specific extractable nuclear antigens, but it is less specific than conventional gel precipitation (countercurrent immunoelectrophoresis).
Implications for clinical practice or policy
  • The performance of newer multiplex platforms for autoantibody detection may be different from that of conventional methods, and disease specificity of autoantibodies may change according to the test method.
  • This variation may have a significant impact on the interpretation of results and on patient management.
 
 
Introduction
Connective tissue disease is a group of disorders characterised by the presence of antinuclear antibodies (ANAs) and clinical autoimmune phenomena. The investigations that are performed depend on both purpose and performance characteristics. For example, to rule out a diagnosis, a test with high sensitivity is needed, such as testing for the absence of ANAs to rule out systemic lupus erythematosus (SLE). In contrast, to establish a diagnosis, a test with high specificity is more desirable, such as testing for antibodies to double-stranded DNA (dsDNA) or anti-Sm antigens in SLE. Therefore, after an initial positive ANA test result, subsequent tests for specific antibodies, such as those against dsDNA and certain extractable nuclear antigens (ENAs), are necessary.
 
Conventionally, ANAs are detected by indirect immunofluorescence (IIF). This method is sensitive and essentially detects all antibodies against cellular constituents, with antibody profile having varying clinical significance. However, it is labour-intensive, and technical interpretation of the results can be subjective. The enzyme-linked immunosorbent assay (ELISA), which can be automated and high-throughput–enabled, is gaining popularity over IIF. When ELISA is used to screen for ANAs, the source of antigens has major implications on the sensitivity and specificity of the assay. Although the ELISA technique has improved with time, concerns over false-negative ANA cases persist. Therefore, the American College of Rheumatology (ACR) still recommends IIF as the gold standard in ANA testing.1
 
To detect antibodies against ENAs, gel precipitation assays have been used for more than five decades, and countercurrent immunoelectrophoresis (CIEP) has been accepted as the reference method for anti-ENA antibody testing. Positive results from CIEP are highly specific. The majority of the literature on autoantibodies and disease association has been established with this technique.2 However, other methods such as ELISA, immunoblot, and line blot are gradually replacing CIEP. In recent years, multiplex assays have been introduced. The BioPlex 2200 ANA Screen assay (Bio-Rad Laboratories, Hercules [CA], US) is an automated multiplex immunoassay using flow cytometry to detect a panel of autoantibodies, including ANAs and antibodies against ENAs. There are a few published studies showing reasonable agreement between this system and ELISA.3 4 5 6 7
 
Conventional assays are being replaced with newer automated high-throughput assays. However, the performance of the newer techniques may not be equivalent to that of conventional assays. This difference will have important implications to clinicians, who may base their clinical judgement on their knowledge of how conventional assays perform.8 9 10 11 12 13 14 15 16 In this study, we evaluate the performance of BioPlex 2200 using serum samples from a local cohort of SLE patients, and compare it with the performance of three established techniques (CIEP, ELISA, line blot) in terms of anti-ENA antibody detection. The sensitivity of BioPlex 2200 ANA Screen assay was also compared with IIF.
 
Methods
Study setting and participant recruitment
This cross-sectional study was conducted at the Queen Mary Hospital, Hong Kong, a tertiary university teaching hospital. Patients were recruited from the hospital’s lupus clinic from 1 December 2013 to 31 December 2013. All patients attending the clinic underwent routine serology screening during their visit. Of 160 consecutive patients, 140 with adequate serum stored in the clinical immunology laboratory were recruited. All patients had an established diagnosis of SLE, according to the ACR classification criteria.17 Patients who were <18 years or >80 years and pregnant patients were excluded from the study. Data of serum samples in 41 healthy controls, who were mainly laboratory staff and had given verbal consent for the blood donation were also included; their age ranged from 18 to 54 years. All stocked serum was stored at -70°C.
 
Assessment of clinical variables
Electronic and written medical records of the recruited patients were reviewed, and relevant clinical and laboratory data were collected. Global disease activity was assessed according to the SLE disease activity index,18 19 and cumulative organ damage was assessed in terms of the Systemic Lupus International Collaborating Clinics/ACR Damage Index score.20
 
Antinuclear antibody detection
BioPlex 2200 automated system
The BioPlex 2200 ANA Screen system was used to detect 13 types of autoantibodies simultaneously in one test—namely, those against dsDNA, chromatin, centromere B, Scl-70, RNP (RNP-A, RNP-68), Sm, RNP/Sm, Ro (SSA-52, SSA-60), SSB/La, Jo-1, and ribosomal P protein. For BioPlex results, anti-RNP was reported separately from anti-RNP/Sm; the kit’s RNP antigen is a recombinant antigen (RNP-A and RNP-68) whereas RNP/Sm is an affinity-purified antigen, which is similar to the antigen used for the RNP test in ELISA and line blot in this study.
 
The presence of anti-dsDNA antibody was classified as negative if levels were ≤4 IU/mL, indeterminate if 5 to 9 IU/mL, and positive if ≥10 IU/mL, as recommended by the manufacturer. For the other autoantibodies, the results were expressed as an antibody index (AI). An AI of 1.0 was the cut-off concentration that corresponded to approximately the 99th percentile of values obtained from a nondiseased population in the manufacturer’s study. Results of ≥1.0 were reported as positive (range, 0.2-8.0 AI). A test result was considered positive for ANAs if one or more of the antibody tests in the panel was positive.
 
Indirect immunofluorescence
The IIF assay was adopted as the reference method for ANA detection. All serum samples were diluted in 1:80 in phosphate-buffered saline and tested on slides pretreated with substrate from a human epithelial cell line (Kallestad HEp-2 Cell Line Substrate Slides; Bio-Rad Laboratories, Hercules [CA], US) according to the manufacturer’s instructions. The slides were read using the same microscope and setting as routine clinical samples by a single observer. Slides that were negative for ANA by IIF were reviewed by an independent second observer to confirm negativity. In cases of discrepancy, a third adjudicator was sought.
 
Anti–extractable nuclear antigen antibody detection
The performance of BioPlex in the detection of anti-ENA antibodies was compared with that of the following assays.
 
Countercurrent immunoelectrophoresis
The CIEP assay used in this study was optimised in-house. Rabbit thymus extract (ImmunoVision Inc, United States) was used for typing of anti-Sm, anti-RNP, and anti-La, whereas human spleen extract (ImmunoVision Inc) was used as a source of Ro antigen.
 
Line blot
The EUROASSAY test kit (EUROIMMUN, Lübeck, Germany) was used as the line blot immunoassay in this study. The kit qualitatively assessed the presence of human immunoglobulin G (IgG) autoantibodies against six different antigens: RNP, Sm, SS-A, SS-B, SCl-70, and Jo-1. On the basis of signal intensity, the results were categorised as negative, borderline, and positive.
 
Enzyme-linked immunosorbent assay
The QUANTA Lite ENA Profile EIA kit (INOVA Diagnostics, San Diego [CA], US) was used for ELISA in this study. The kit qualitatively screened for the presence of IgG autoantibodies against specific ENAs—namely, SSA (60 and 52 kDa), SSB, Sm, RNP/Sm, Scl-70, and Jo-1. The results were calculated using the following formula (where OD = optical density at 450 nm):
 
 
Results of <8 U/mL were classified as negative, 8 to 12 U/mL as equivocal, and >12 U/mL as positive.
 
Statistical analysis
The diagnostic performance of BioPlex versus that of IIF was compared for the detection of ANAs in the SLE cohort and controls. Assay sensitivity and specificity were calculated and compared using a paired McNemar’s test. Cohen’s kappa coefficient and percentage of observed agreement were also calculated for the two methods.
 
For individual anti-ENA antibodies (against RNP, Sm, Ro, La, Scl-70, and Jo-1), agreement analysis was calculated for the four laboratory methods. Fleiss’ kappa coefficient with its 95% confidence interval and the percentage of observed agreement were calculated to assess overall agreement among the four methods. Pairwise agreement analysis for the four methods was also performed by calculating Cohen’s kappa coefficient and percentage of observed agreement. Weak and borderline results in the ELISA and line blots were treated as negative in the analysis.
 
The diagnostic value of anti-ENA antibody detection to predict various disease manifestations was examined, along with comparisons between the different methods. In particular, we studied diagnostic performance for the association of anti-Sm antibodies with nephritis, anti-RNP antibodies with Raynaud’s phenomenon, and anti-Ro/La antibodies with photosensitivity, discoid rash, Sicca symptoms, leukopenia, and lymphopenia.21 22 23 24 25 26 Sensitivity, specificity, positive and negative predictive values, and diagnostic accuracies were calculated.
 
The SPSS (Windows version 20.0; IBM Corp, Armonk [NY], US) and Microsoft Excel 2010 for Windows were used for statistical analysis and calculation of confidence intervals, respectively. P values of <0.05 were regarded as statistical significance. The STARD 2015 guidelines were used during the writing of this article.27
 
Results
Patients and autoantibodies
All 140 SLE patients were local Chinese patients, with a female predominance (n=128, 91.4%). The mean age was 46.8 (range, 24-69) years and the median disease duration was 17 years (Table 1). The majority of our cohort had at least one anti-ENA antibody present (n=114, 81.4%) as detected by the BioPlex method (Table 2). Anti-Ro antibody was the most commonly detected antibody, ranging from 50.7% to 62.9% of the cohort depending on the assay method (Table 2). Methods other than CIEP had a positivity rate of 1.4% to 5.0% for anti–Scl-70 antibody and 0.7% to 2.1% for anti–Jo-1 antibody.
 

Table 1. Baseline characteristics of participants
 

Table 2. Detection of anti-ENA antibodies for SLE patients and controls, by assay method
 
BioPlex antinuclear antibody screen versus indirect immunofluorescence
The sensitivity of the BioPlex 2200 ANA Screen assay in the SLE cohort was 91.4%, which was comparable to that of IIF (90.7%; Table 3). The specificity of BioPlex among healthy controls was high, reaching 95.1%, compared with 85.4% for IIF, although the difference was not statistically significant. The agreement between BioPlex and IIF was moderate (κ=0.657). Eight patients tested positive by IIF, but negative by BioPlex. The IIF patterns of these cases were either weak homogeneous or weak fine-speckled. Nine patients were negative by IIF, but positive by BioPlex; these included two with a low titre of anti-dsDNA antibodies, one with anti-Sm antibodies, one with anti-RNP antibodies, and five with anti-Ro antibodies. Four patients tested ANA-negative by both methods; all four had a long-standing history of SLE (12-40 years). All had had severe disease manifestations, including cerebral lupus and lupus nephritis, and all had been taking powerful immunosuppressants for years, although the disease had become stable and inactive in recent years. Interestingly, they had been ANA-positive in the past. Possible changes in their serology after a long period of heavy immunosuppression for disease control may have accounted for the observed results.
 

Table 3. Diagnostic accuracy of antinuclear antibody test by BioPlex versus indirect immunofluorescence as reference
 
Agreement between assays for antibodies to extractable nuclear antigens
In terms of agreement between different methods, BioPlex achieved the best agreement with ELISA, of >90% for the detection of most of the antibodies tested by ELISA (Table 4). The agreement between BioPlex and ELISA was 95.6% for anti-RNP/Sm antibodies (κ=0.89), 93.9% for anti-Sm (κ=0.79), 97.2% for anti-Ro (κ=0.94), and 95.6% for anti-La (κ=0.87). In contrast, the agreement between BioPlex and CIEP was not as strong. Agreement was 84.5% for detection of anti-RNP antibodies (κ=0.57), 85.6% for anti-Sm (κ=0.33), 93.9% for anti-Ro (κ=0.88), and 89.0% for anti-La (κ=0.6). Overall, the CIEP tended to agree better with the line blot assay than with ELISA or BioPlex.
 

Table 4. Agreement between four assay methods to detect anti-ENA antibodies
 
Performance of assays for antibodies to extractable nuclear antigens
Overall, BioPlex and ELISA had a higher sensitivity in detecting autoantibodies in the SLE cohort than the other two methods (Table 2). There were a few positive cases of anti–Scl-70 and anti–Jo-1 antibody detection in the cohort by all assays except CIEP, although the clinical significance of these antibodies in patients with SLE is uncertain.
 
In the healthy control group, CIEP had the highest specificity; none of the healthy subjects had anti-ENA autoantibodies when tested by CIEP (Table 2). With BioPlex, however, 2.4% (1/41) of the controls for each were positive for anti-La and anti–Scl-70 antibodies. For the line blot, if a weak borderline band were considered positive, then 4.9% (2/41) of the subjects were positive for anti-La antibodies (data not shown). If a weak borderline band were considered negative, then none of the healthy controls tested positive. For ELISA, if borderline results were counted negative then 2.4% (1/41) of the healthy controls still tested positive for anti-Sm antibodies.
 
Antibodies to extractable nuclear antigens and disease manifestations
Among the panel of anti-ENA autoantibodies tested, anti-Sm antibody had the best predictive value for the presence of lupus nephritis. However, the predictive value was method-dependent (Table 5). Anti-Sm antibody detection by CIEP had the best positive predictive value for lupus nephritis, reaching 87.5%. The specificity of anti-Sm antibody detection by CIEP for lupus nephritis was high, reaching 98.6%, although the sensitivity was only 10.4%. Anti-Sm antibody detection by BioPlex in nephritis had a higher sensitivity of 26.9%, however, the specificity and positive predictive value were lower than those achieved by CIEP (78.1% and 52.9%, respectively).
 

Table 5. Diagnostic performance of predicting clinical manifestations of SLE by detection of anti-ENA antibodies, according to assay method
 
Anti-RNP antibody detection by CIEP had a specificity of 84.1% for Raynaud’s phenomenon, whereas the specificity by other methods was lower (69.2% for ELISA, 78.5% for line blot, and 65.4% for BioPlex). As the prevalence of Raynaud’s phenomenon in the cohort was not high, the positive predictive value was at best 37.0% only, by CIEP.
 
BioPlex generally had a higher sensitivity than the other methods, with the trade-off of lower specificity. However, CIEP generally performed better than BioPlex in disease-antibody associations (Table 6). The superiority of CIEP over BioPlex was most obvious in the diagnostic accuracy of linking anti-RNP antibody detection to Raynaud’s phenomenon (71.4% for CIEP vs 62.9% for BioPlex; P<0.001). Detection of antibodies to RNP (recombinant) and RNP/Sm by BioPlex did not differ significantly in diagnostic accuracy for association with Raynaud’s phenomenon.
 

Table 6. Diagnostic accuracy of predicting clinical manifestations of SLE by detection of anti-ENA antibodies, according to assay method
 
Discussion
In recent years, the multiplex method has been introduced in ANA testing. However, on the basis of the existing literature, this method is considered suboptimal in sensitivity compared with IIF, and its false-negative rate is similar to that of ELISA, ranging from 0.2% to 41.5% in the different populations studied.4 7 28 29 30 When Tozzoli et al31 compared the detection of ANAs between IIF using a 1:80 cut-off and BioPlex 2200 ANA Screen in a cohort of 95 SLE patients, they found that IIF had superior sensitivity over BioPlex (85/95 [89.5%] positive vs 77/95 [81.1%] positive, respectively). Generally, multiplex methods are considered to be simple to operate, have potential for automated and high-throughput processing, and can detect multiple specific antibodies simultaneously. Nonetheless, the main limitation is that such methods do not detect all the autoantibodies that can be detected by IIF. Hence, multiplex systems are considered to be insufficient in sensitivity and negative predictive value, and IIF remains the reference method of ANA testing.32 33
 
For our cohort, the BioPlex system demonstrated good sensitivity (91.4%), comparable to that of IIF (90.7%), with an agreement of 86.2% (κ=0.657). The specificity of BioPlex was slightly higher than that of IIF (95.1% vs 85.4%) but the difference did not reach statistical significance, perhaps because of the relatively small control group. Notably, a large proportion (6 of 9 cases) of the BioPlex-positive IIF-negative cases were actually positive for anti-Ro antibodies. Although IIF is the preferred method for ANA screening, as recommended by the ACR and the European Autoimmunity Standardisation Initiative, inconsistency among IIF assays exists.33 Slides from different vendors vary in sensitivity, especially for anti-SSA/Ro antibody detection.34 Moreover, the reading and interpretation of slides are reader- and skill-dependent.
 
Overall, BioPlex as used in our study showed a higher performance when compared with other studies. This difference could be due to different cohort characteristics, disease activities, and ethnicities. For example, the vast majority of the literature reports on studies of Caucasian populations, and studies of Chinese populations are scarce. In addition, we recruited only patients with SLE, but not other autoimmune diseases, thereby precluding direct comparisons. We also had a relatively small number of SLE cases; hence, some ANA staining patterns (eg, nuclear dots, proliferating cell nuclear antigen, nuclear lamina) were not encountered in the cohort, which limits the evaluation. Given the available literature and international recommendations, IIF remains the preferred method for ANA test until more supportive data for BioPlex are available.
 
In our study, CIEP performed best in terms of specificity, with none of the healthy controls testing positive for anti-ENA antibodies. In contrast, the specificity of the other platforms, especially ELISA and BioPlex, was less optimal, and positivity for antibodies to Sm (ELISA), Scl-70 (BioPlex), and La (BioPlex) was recorded. In addition, anti–Scl-70 and anti–Jo-1 antibodies were detected in assays other than CIEP in the SLE group. If appropriate disease controls, such as vasculitis, rheumatoid arthritis, and chronic infections are included, the performance of these assays would be better characterised.
 
There were several important limitations in our study. First, this was a cross-sectional study, and the clinical features and manifestations were retrospectively reviewed. The reviewer of the medical records was not blinded to the results of assays, which may have led to potential bias in record review and data extraction. Second, the performance of BioPlex was not evaluated in other rheumatic or autoimmune disease groups, which limits the generalisability of the results in other settings. Third, the number of participants included, especially that of healthy controls, was relatively small; disease controls were not included; and the controls were not age- and sex- matched with cases. These limitations may have led to bias in the evaluation of anti-ENA antibody assays. Finally, autoantibodies may precede clinical manifestations for years. A prospective study with parallel assessment of cases referred to the laboratory for ANA and anti-ENA antibody assessment by different techniques, as well as follow-up of the clinical manifestations and diagnosis, may provide a better assessment of the BioPlex system.
 
Conclusions
The BioPlex 2200 ANA Screen demonstrated comparable sensitivity to IIF in a local SLE cohort. The detection of specific antibodies, including those against ENAs, by the BioPlex system was more sensitive than that by CIEP, although with less specificity. Overall performance of BioPlex resembled that of the conventional ELISA technique, but with higher speed and turnaround time. Hence, BioPlex can be considered as a high-throughput ELISA-like assay for the detection of anti-ENA antibodies in SLE.
 
Author contributions
All authors have made substantial contributions to the concept or design of this study; acquisition of data; analysis or interpretation of data; drafting of the article; and critical revision for important intellectual content.
 
Funding/support
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
Declaration
All authors have no conflicts of interest to disclose. All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.
 
Ethical approval
This study was approved by The University of Hong Kong/Hospital Authority Hong Kong West Cluster Institutional Review Board (Ref No. UW14-442). The requirement for patient consent was waived by the ethics board.
 
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Clinical and biochemical characteristics of infants with prolonged neonatal jaundice

Hong Kong Med J 2018 Jun;24(3):270–6 | Epub 25 May 2018
DOI: 10.12809/hkmj176990
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
ORIGINAL ARTICLE
Clinical and biochemical characteristics of infants with prolonged neonatal jaundice
Sylvia LY Siu, MB, ChB, FHKAM (Paediatrics)1; Lilian WM Chan, MB, BS, FHKAM (Paediatrics)2; Albert NS Kwong, MB, BS, FHKAM (Paediatrics)1
1 Department of Paediatrics and Adolescent Medicine, Tuen Mun Hospital, Tuen Mun, Hong Kong
2 Ha Kwai Chung Child Assessment Centre, Kwai Chung, Hong Kong
 
Corresponding author: Dr Sylvia LY Siu (siulys@ha.org.hk)
 
 Full paper in PDF
 
Abstract
Introduction: Protocols for investigating neonatal prolonged jaundice vary and the yield from screening has not been assessed. International guidelines recommend establishing cholestasis before proceeding to investigate the underlying pathology. However, in most hospitals administered by the Hospital Authority, full liver function is checked at the first neonatal jaundice clinic visit. To study the diagnostic yield of this approach, we carried out a retrospective study of all infants referred for prolonged jaundice.
 
Methods: Attendance records from the neonatal jaundice clinic at the Tuen Mun Hospital, Hong Kong, the clinical management system, and electronic patient records were used to retrieve epidemiological, clinical, and laboratory data, and patients’ clinical progress.
 
Results: During the 8-month study period from 8 July 2015 to 8 March 2016, 1164 infants were referred to the neonatal jaundice clinic for prolonged jaundice. Among them, 16 (1.4%) had conjugated hyperbilirubinaemia. Diagnoses included biliary atresia (n=1), cytomegalovirus (CMV) infection (n=3), neonatal hepatitis syndrome (n=2), and transient cholestasis (n=10). In total, 98 (8.4%) infants had elevated alanine transaminase levels. Diagnoses included biliary atresia (n=1), hepatic congestion related to congestive heart failure (n=1), CMV infection (n=5), neonatal hepatitis syndrome (n=16), and non-specific elevated alanine transaminase (n=75). In total, 59 infants had elevated alkaline phosphatase levels.
 
Conclusions: A stepwise approach is recommended, in which full liver function is checked and the underlying cause of jaundice is investigated only after confirming cholestasis.
 
 
New knowledge added by this study
  • Among healthy infants with physiological or breastmilk jaundice, a transitional stage of cholestasis may occur when the jaundice is resolving. The lower conjugated bilirubin level and the downtrend of total bilirubin help to differentiate these infants from those with pathological cholestasis.
  • Breastfed infants usually have mild elevation of alanine transaminase which may reflect higher metabolism instead of pathology. Therefore, checking alanine transaminase levels at the first neonatal jaundice clinic visit is not recommended because of the potential detrimental effect on breastfeeding rates.
  • Late preterm infants with prolonged jaundice are at risk for osteopenia of prematurity.
Implications for clinical practice or policy
  • A stepwise approach is recommended, checking full liver function and investigating the underlying cause only after confirming cholestasis.
  • Bone profile blood test (alkaline phosphatase, albumin, calcium, and phosphate) is recommended for late preterm or low birth weight infants to screen for osteopenia of prematurity at the first neonatal jaundice clinic visit.
 
 
Introduction
All newborns have elevated unconjugated bilirubin concentrations relative to normal adult values. Two thirds or more of breastfed infants have unconjugated hyperbilirubinaemia that extends into the second and third weeks of life, and often up to age 8 to 12 weeks.1 Guidelines on the evaluation of cholestasis in infants recommend establishing cholestasis before proceeding to investigate the underlying pathology.2 3 However, of the hospitals administered by the Hong Kong Hospital Authority that care for newborns, most check full liver function at the first Neonatal Jaundice Clinic (NNJC) visit.
 
The Food and Health Bureau established the Committee on Promotion of Breastfeeding in Hong Kong in 2014. Since then, there has been a substantial improvement in exclusive breastfeeding rates and a continuous upward trend in ever-breastfeeding rates.4
 
The Tuen Mun Hospital is a regional hospital in the New Territories West region of Hong Kong. An outpatient Neonatal Jaundice Clinic is available every Monday to Friday from 14:00 to 17:00 to treat infants with jaundice. The increasing breastfeeding rates have led to increasing numbers of infants with prolonged jaundice being referred to the NNJC.
 
The present study aimed to learn about the clinical and biochemical characteristics of prolonged neonatal jaundice, and to study the diagnostic yield of a full liver function check at first NNJC visit. We reviewed the clinical and laboratory records of infants visiting the NNJC between 8 July 2015 and 8 March 2016. On the basis of the findings, we propose a more effective evaluation procedure for prolonged neonatal jaundice.
 
Methods
Attendance records maintained by the NNJC included the registration number, sex, and attendance date of the patients. Using the recorded patient registration numbers, gestational age, birth weight, glucose-6-phosphate dehydrogenase (G6PD) deficiency status, mode of feeding, phototherapy history, liver function test results, and clinical progress were retrieved from the clinical management system and electronic patient record. The study period was chosen for convenience. All infants who visited the NNJC during the study period were included to prevent possible selection bias. All suspicious data were verified by revisiting the electronic patient record to ensure data accuracy.
 
For gestational age, completed weeks of gestation were recorded. Preterm births were categorised as very preterm (before 34 weeks of gestation) or late preterm (between 34 weeks and 36 weeks 6 days of gestation). Full-term births were those at 37 weeks of gestation or later. Birth weights were categorised as very low (<1500 g), low (1500-2499 g), normal (2500-3999 g), or high (>3999 g). Modes of feeding were categorised as exclusive breastfeeding, mixed feeding, or exclusive formula feeding.
 
Data analysis
The SPSS for Windows version 15.0 (SPSS Inc, Chicago [IL], United States) was used for all statistical analyses. Student’s t test and univariate analysis of variance (ANOVA) were used in comparing the outcomes between groups. Tukey’s test was used for pairwise comparisons in ANOVA. Cross-tabulation was used to measure associations between binary outcome variables and binary predictor variables.
 
Results
Demographic characteristics
In total, 1164 infants (663 males, 501 females; male-to-female ratio=1.3:1) with prolonged jaundice were referred to the NNJC during the 8-month study period. The gestational ages of the infants ranged from 29 to 41 weeks, and there were eight (0.69%) very preterm infants and 94 (8.08%) late preterm infants. The birth weights of the infants ranged from 1425 g to 4670 g. The sample included only one (0.09%) very low birth weight infant, in addition to 80 (6.87%) low birth weight infants and 13 (1.12%) high birth weight infants. In total, 34 (5.13%) male infants and two (0.40%) female infants had G6PD deficiency. The mode of feeding was exclusive breastfeeding in 648 (55.70%) infants, mixed feeding in 400 (34.36%) infants, and exclusive formula feeding in 114 (9.79%) infants; the mode of feeding was not recorded in two infants. Among the 114 exclusively formula fed infants, 24 (21.10%) had a history of breastfeeding. At the first NNJC visit, 70 (6.01%) infants were 2 weeks old, 156 (13.40%) 3 weeks old, 758 (65.12%) 4 weeks old, 165 (14.18%) 5 weeks old, 10 (0.86%) 6 weeks old, and three (0.26%) 7 weeks old. One (0.09%) infant first visited at 8.7 weeks old and another (0.09%) first visited at 11.4 weeks old.
 
Full liver function test
At the first NNJC visit, 1139 (97.90%) infants received a full liver function test, which included taking measurements of alkaline phosphatase (ALP), calcium, and phosphate. In seven infants, low transcutaneous bilirubinometer readings were observed (peak reading, 42-86 μmol/L). Therefore, blood tests were not performed in these infants. At the first NNJC visit, 17 infants were seen by a doctor who adopted the stepwise approach and who screened only for cholestasis; one infant visiting on day 14 had only total bilirubin (TB) checked.
 
Influence of breastfeeding on liver biochemistry
There was a significant effect of mode of feeding on TB (F2,1155=18.058; P<0.01). The mean (M) TB levels in the exclusive breastfeeding group (M=146.73) were significantly higher than those in the mixed feeding group (M=131.05) and in the exclusive formula feeding group (M=121.21). Tukey’s test showed significant differences in TB levels between the exclusive breastfeeding and the mixed feeding groups (P<0.01) and between the exclusive breastfeeding and the exclusive formula feeding groups (P<0.01). There was no significant difference in TB level between the mixed feeding and exclusive formula feeding groups.
 
There was a significant effect of feeding on alanine transaminase (ALT) levels (F2,1133=15.015; P<0.01). The ALT levels in the exclusive breastfeeding group (M=21.79) were significantly higher than those in the mixed feeding group (M=18.97) and in the exclusive formula feeding group (M=16.55). Tukey’s test showed significant differences in ALT levels between the exclusive breastfeeding and the mixed feeding groups (P<0.01) and between the exclusive breastfeeding and the exclusive formula feeding groups (P<0.01). There was no significant difference in ALT levels between the mixed feeding and exclusive formula feeding groups.
 
There was a significant effect of feeding on ALP (F2,1135=6.276; P<0.01). The ALP levels in the exclusive breastfeeding group (M=348.83) were significantly higher than those in the mixed feeding group (M=329.08) and in the exclusive formula feeding group (M=327.76). Tukey’s test showed a significant difference in ALP level between the exclusive breastfeeding and the mixed feeding groups (P<0.01). There was no significant difference in ALP levels between the exclusive breastfeeding and the exclusive formula feeding groups (P=0.07) or between the mixed feeding and the exclusive formula feeding groups (P=0.99).
 
There was a significant effect for infants who had received phototherapy (t(1141)=3.57; P<0.01). Infants who had received phototherapy had higher TB levels (M=147.12) than those who had not (M=135.06).
 
There was no significant difference in TB levels between male and female infants. There was also no statistically significant difference in TB levels between G6PD-deficient and G6PD-sufficient infants.
 
Cholestasis
At the first NNJC visit, 16 (1.4%) infants had conjugated hyperbilirubinaemia. Diagnoses included biliary atresia in one, cytomegalovirus (CMV) infection in three, neonatal hepatitis syndrome in two, and transient cholestasis in 10 infants (Table 1). All infants were thriving well and did not have dark urine or pale stool at their first NNJC visit.
 

Table 1. Demographic and laboratory characteristics of cholestatic infants
 
Elevated alanine transaminase level
At the first NNJC visit, 98 (8.4%) infants had elevated ALT levels. The reference range used for ALT level is 5 U/L to 33 U/L. The proportion of infants that were followed up increased with increasing ALT level, as shown in Figure 1. Specific causes for elevated ALT level included biliary atresia in one infant, hepatic congestion related to congestive heart failure in one infant, and CMV in five infants (Table 2). Of the remaining 91 infants with elevated ALT levels, 16 had neonatal hepatitis syndrome and 75 had non-specific elevated ALT levels.
 

Figure 1. Infants with elevated ALT at the first visit
 

Table 2. Specific pathology of elevated alanine transaminase level
 
Urine tests revealed CMV infection in five infants with elevated ALT levels; CMV infection was believed to be acquired postnatally. These infants were all full-term births of normal birth weight and were asymptomatic. Of these five infants, four were exclusively breastfed and one was fed a mix of breastmilk and formula. After their elevated ALT levels resolved, three infants were discharged from the NNJC and the other two were followed up for coincidental findings (developmental concern in one and familial small head in the other) and not for concern over CMV infection. These five infants and the 75 infants with non-specific elevated ALT were all healthy and asymptomatic and had good weight gain; their elevated ALT levels resolved without treatment.
 
In this study, inflammation of the liver occurring in early infancy that could not be attributed to a specific cause of liver disease was termed neonatal hepatitis syndrome. The peak ALT levels and the duration of elevated ALT levels in 16 infants with neonatal hepatitis syndrome are shown in Figure 2. The duration of elevated ALT level ranged from 13 to 69 weeks and was shorter than 28 weeks in only four infants. Infants with neonatal hepatitis syndrome were followed up until ALT levels returned to normal and then for an average of 1 month longer.
 

Figure 2. Peak and duration of elevated ALT levels in 16 infants with neonatal hepatitis syndrome
 
In 75 infants who were otherwise healthy, non-specific elevated ALT levels were within double the usual upper limit. These infants were either not followed up or their liver function was monitored periodically (time intervals in months determined on case-by-case basis) with limited diagnostic testing.
 
Elevated alkaline phosphatase level and low phosphate level
The mode of feeding, gestational age, and birth weight were all found to affect ALP levels. Among 132 preterm or low birth weight infants, 21 (15.9%) had elevated ALP, compared with 31 (3.0%) among 1032 full-term and normal birth weight infants. For preterm or low birth weight infants versus term infants with birth weight >2499 g, the odds ratio for elevated ALP was 6.109 (95% confidence interval=3.394-10.994) [Table 3]. Among 1139 infants who underwent full liver function tests, 10 had low phosphate levels: seven had concomitant high ALP and low phosphate levels, and the remaining two late preterm infants and one full-term infant had isolated low phosphate levels.
 

Table 3. Infants with isolated elevated alkaline phosphatase and low phosphate
 
Discussion
We found that TB levels were significantly higher in the exclusive breastfeeding and mixed feeding groups than in the exclusive formula feeding group. Eight infants that were exposed to breastmilk and two exclusively formula-fed infants had transient cholestasis. Our findings also revealed that ALT levels were significantly higher in the exclusive breastfeeding and mixed feeding groups than in the exclusive formula feeding group. Besides, preterm or low birth weight infants had increased odds of high ALP levels compared with term infants with birth weight >2499 g.
 
Cholestasis
Breast milk jaundice (BMJ) was first described by Newman and Gross in 1963.5 Subsequently, BMJ has been reported to be associated with increased conjugated and unconjugated bilirubin levels.6 In 1991, investigators in Japan studied 58 breastfed infants with indirect hyperbilirubinaemia and found that 18 (31%) with BMJ had elevated ALP, gamma-glutamyltranspeptidase or serum bile acid, reflecting alterations in the hepatobiliary system.7 The serum bile acid levels in patients with BMJ are similar to those with cholestatic jaundice caused by diseases such as extrahepatic biliary atresia.7 This finding suggests that BMJ may be caused by hepatic dysfunction related to cholestasis. Moreover, for infants with BMJ and increased fasting serum bile acid levels, discontinuation of breastfeeding did not cause a rapid normalisation of the serum TB levels.7 This observation suggests that hyperbilirubinaemia in infants with increased serum bile acid levels is not directly related to breastfeeding. Our finding of transient cholestasis in 1.75% (2/114) of exclusive formula feeding infants versus 0.76% (8/1048) exclusive breast milk feeding and mixed feeding infants supported the hypothesis that cholestasis is not related to breastfeeding.
 
In this study, we used the term ‘transient cholestasis’ to describe the delay in the decline of conjugated bilirubin levels, as observed in 10 infants. Because TB levels declined first without a concomitant decline or even with an increase in conjugated bilirubin levels, there seemed to be a transitional stage of cholestasis. When TB levels decreased further, the conjugated bilirubin levels then decreased. Moreover, the conjugated bilirubin levels in these 10 infants were lower than those with biliary atresia or hepatitis. This finding supports the use of direct bilirubin as a surrogate marker in assessing the severity of cholestasis to ensure optimal timing of hepatobiliary scanning.8
 
Elevated alanine transaminase level
In 1981, Landaas et al9 first reported a significant difference in ALT levels between breastfed and formula-fed infants. They proposed a normal range for ALT level of 14 to 84 IU/L until 4.5 months of age. In 1984, Gómez et al10 examined 2099 out-patient children and found that ALT levels (40-97 IU/L, 3rd to 97th percentile) were higher in children <1 year than in older children. In 2003, investigators in Denmark found higher mean serum bilirubin, albumin, and aspartate transaminase (AST) levels in healthy exclusively breastfed full-term infants; they also found a strong positive association between AST and insulin-like growth factor-1 levels at 2 months (r=0.47; P=0.004).11 Protein levels in breast milk are lower than those in infant formulas. Serum albumin levels have been used to evaluate the adequacy of protein levels in infant formula. Thus, the finding of higher serum albumin levels in breastfed infants than formula feeding infants suggests that there were no protein deficiencies or abnormalities affecting albumin production in breastfed infants.11 Insulin-like growth factor-1 is an anabolic hormone in infants; thus, those authors believed that the most likely explanation for the elevated AST values among breastfed infants is a stimulation of liver metabolism through one of several growth factors in human milk.11 Therefore, the higher AST levels in breastfed infants were believed to be a reflection of a higher liver metabolism, rather than a reflection of liver cell damage. Alanine transaminase is present primarily in the liver and thus is a more specific marker of hepatocellular cell injury. Aspartate transaminase is present in the liver and other organs, a less specific marker of hepatocellular function. The aforementioned study used AST in a restrictive sense to reflect liver biochemistry. Therefore, the higher ALT levels among breastfed infants should logically be interpreted by the same token as reflection of higher liver metabolism rather than liver cell injury.
 
In the present study, other than those in which CMV was identified, findings were negative. Elevated ALT concentrations resolved in all infants other than the infant with biliary atresia. These findings support the hypothesis that elevated ALT in breastfed infants is a reflection of higher metabolism rather than of any pathology.
 
Isolated elevated alkaline phosphatase level and low phosphate level
Serum ALP is derived predominately from the liver and bones. In the present study, elevated ALP in seven infants was of hepatic origin. Tests of ALP’s heat stability index revealed that 52 infants with isolated ALP elevation were of bone origin.
 
In this study, 21 (15.9%) preterm or low birth weight infants had isolated elevated ALP (Table 3). Among the eight very preterm infants, only one had isolated elevated ALP and none had low phosphate. Among 94 late preterm infants, 20 (21.3%) had isolated elevated ALP and among these, six (30%) also had low phosphate.
 
The biochemical characteristics of high ALP and low phosphate are compatible with osteopenia of prematurity. During pregnancy, calcium and phosphorus are actively transferred from the mother to the fetus, reaching a peak accretion rate at 32 to 36 weeks of gestation. The third trimester is the period of most active growth and the increased accretion rate is in response to the higher fetal needs for the developing skeleton. As a result, in preterm infants, calcium and phosphate requirements increase with decreasing gestational age, to compensate for the loss of accretion of these minerals. In the present study, very preterm infants were managed in neonatal wards for long durations; therefore, this need for increased mineral supplements was recognised and addressed. However, late preterm infants may not be clearly distinguished from full-term infants, and their need for additional minerals may not be apparent or addressed during their short hospital stay.
 
Diagnostic yield of full liver function test at first neonatal jaundice clinic visit
Breastfed infants have been reported to acquire CMV via breastmilk.12 13 Cytomegalovirus excreted in breastmilk is likely caused by reactivated infection in the presence of maternal antibody transferred transplacentally.12 This type of milk-borne CMV infection apparently protects children from CMV diseases and the seropositivity for CMV may protect the next generation from CMV inclusion disease.
 
Poddighe et al14 reported a full-term breastfed infant with prolonged jaundice who had undergone extensive tests but with negative findings. Liver function test results returned to normal by age 7 months when breastmilk intake was significantly reduced. The authors14 then proposed that, in otherwise healthy infants and in the absence of risk factors, elevated ALT levels should be monitored for 7 months before performing further sophisticated tests. If this proposal were applied to the present study, only four infants had elevated ALT for less than 7 months and would have avoided further tests.
 
Proposed prolonged neonatal jaundice evaluation
The above discussion suggests that measuring ALT levels at the first NNJC visit is of limited benefit. For jaundiced infants, repeated follow-up examinations for elevated ALT levels may increase the risk of premature cessation of breastfeeding and of development of vulnerable child syndrome.15 Therefore, we propose measuring ALT levels only after noting cholestasis.
 
In the present study, late preterm infants were identified to be at high risk of having ALP elevation. Preterm or low birth weight infants accounted for <10% of those visiting the NNJC. In addition to cholestasis screening at the first NNJC visit, ALP, albumin, calcium, and phosphate should be checked for late preterm or low birth weight infants.
 
Vitamin D deficiency has been reported in 18% of Hong Kong women.16 In this study, the prevalence of elevated ALP was 4.6%. The recently published global consensus on prevention and management of nutritional rickets recommends vitamin D supplementation at 400 IU daily in all infants, independent of their mode of feeding in the first year of life.17 Therefore, the best way to protect infants may be to educate pregnant mothers to take vitamin D supplements during pregnancy and to give 400 IU daily vitamin D supplements to their infants.17
 
Limitations
Information bias and selection bias are two potential limitations of our study. First, for simplicity, all infants taking just one mouthful of breastmilk and those taking just one mouthful of formula were classified in the mixed feeding group. In the mixed feeding group, this information bias may mask the effect of breastfeeding on liver biochemistry. Second, the study period was chosen for convenience and not at random. This may create selection bias because outbreaks of diseases in infants tend to create clusters of clinic visits within a certain timeframe.
 
Conclusions
For full-term and normal or high birth weight infants, the most effective way to manage prolonged neonatal jaundice is to screen for cholestasis before full liver function examination. For late preterm or low birth weight infants, the most effective way to manage prolonged neonatal jaundice is to screen for cholestasis and to check bone profile (ALP, albumin, calcium, and phosphate) at the first NNJC visit.
 
Author contributions
All authors have made substantial contributions to the concept or design of this study; acquisition of data; analysis or interpretation of data; drafting of the article; and critical revision for important intellectual content.
 
Acknowledgement
The authors thank Ms CK Ho and Mr WF Wu for maintaining the neonatal jaundice clinic attendance records that made this retrospective study possible.
 
Funding/support
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
Declaration
All authors have disclosed no conflicts of interest. All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity. This paper was presented orally in Joint Annual Research & Scientific Meeting 2017, 19 August 2017, Hong Kong.
 
Ethical approval
Ethical approval for the study was obtained and patient/parental consent was waived by the New Territories West Cluster Clinical and Research Ethics Committee.
 
References
1. Academy of Breastfeeding Medicine Protocol Committee. ABM clinical protocol #22: guidelines for management of jaundice in the breastfeeding infant equal to or greater than 35 weeks’ gestation. Breastfeed Med 2010;5:87-93. Crossref
2. Fawaz R, Baumann U, Ekong U, et al. Guideline for the evaluation of cholestatic jaundice in infants: joint recommendations of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition and the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition. J Pediatr Gastroenterol Nutr 2017;64:154-68. Crossref
3. Moyer V, Freese DK, Whitington PF, et al. Guideline for the evaluation of cholestatic jaundice in infants: recommendations of the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition. J Pediatr Gastroenterol Nutr 2004;39:115-28. Crossref
4. Family Health Service, Department of Health, HKSAR Government. Breastfeeding Survey 2017.
5. Newman AJ, Gross S. Hyperbilirubinemia in breast-fed infants. Pediatrics 1963;32:995-1001.
6. Winfield CR, Macfaul R. Clinical study of prolonged jaundice in breast- and bottle-fed babies. Arch Dis Child 1978;53:506-7. Crossref
7. Tazawa Y, Abukawa D, Watabe M, et al. Abnormal results of biochemical liver function tests in breast-fed infants with prolonged indirect hyperbilirubinaemia. Eur J Pediatr 1991;150:310-3. Crossref
8. Siu LY, Wong KN, Li KW, et al. Outcome of hepatobiliary scanning: preterm versus full-term cholestatic infants. J Paediatr Child Health 2013;49:E46-51. Crossref
9. Landaas S, Skrede S, Steen JA. The levels of serum enzymes, plasma proteins and lipids in normal infants and small children. J Clin Chem Clin Biochem 1981;19:1075-80. Crossref
10. Gómez P, Coca C, Vargas C, et al. Normal reference-intervals for 20 biochemical variables in healthy infants, children and adolescents. Clin Chem 1984;30:407-12.
11. Jørgensen MH, Ott P, Juul A, et al. Does breast feeding influence liver biochemistry? J Pediatr Gastroenterol Nutr 2003;37:559-65. Crossref
12. Minamishima I, Ueda K, Minematsu T, et al. Role of breast milk in acquisition of cytomegalovirus infection. Microbiol Immunol 1994;38:549-52. Crossref
13. Hamprecht K, Maschmann J, Vochem M, et al. Epidemiology of transmission of cytomegalovirus from mother to preterm infants by breastfeeding. Lancet 2001;357:513-8. Crossref
14. Poddighe D, Castelli L, Marseglia GL, et al. Prolonged, but transient, elevation of liver and biliary functions tests in a healthy infant affected with breast milk jaundice. BMJ Case Rep 2014;pii:bcr2014204124. Crossref
15. Kemper K, Forsyth B, McCarthy P. Jaundice, terminating breast-feeding and the vulnerable child. Pediatrics 1989;84:773-8.
16. Woo J, Lam CW, Leung J, et al. Very high rates of vitamin D insufficiency in women of child-bearing age living in Beijing and Hong Kong. Br J Nutr 2008;99:1330-4. Crossref
17. Munns CF, Shaw N, Kiely M, et al. Global consensus recommendations on prevention and management of nutritional rickets. J Clin Endocrinol Metab 2016;10:394-415. Crossref

Plasma soluble cluster of differentiation 147 levels are increased in breast cancer patients and associated with lymph node metastasis and chemoresistance

Hong Kong Med J 2018 Jun;24(3):252–60 | Epub 25 May 2018
DOI: 10.12809/hkmj176865
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
ORIGINAL ARTICLE
Plasma soluble cluster of differentiation 147 levels are increased in breast cancer patients and associated with lymph node metastasis and chemoresistance
YH Kuang, PhD1; YJ Liu, MSc2; LL Tang, PhD2; SM Wang, PhD2; GJ Yan, BSc2; LQ Liao, PhD2
1 Department of Dermatology, Xiangya Hospital, Central South University, Changsha, Hunan, China
2 Department of Breast Surgery, Hunan Clinical Meditech Research Center for Breast Cancer, Xiangya Hospital, Central South University, Changsha, Hunan, China
 
Corresponding author: Dr LQ Liao (aq301981@163.com)
 
 Full paper in PDF
 
Abstract
Introduction: Cluster of differentiation 147 (CD147) contributes to breast cancer invasion, metastasis, and multidrug resistance. Recent studies have shown that peripheral soluble CD147 (sCD147) is increased in hepatocellular tumour and multiple myeloma patients and correlated with disease severity. This study aimed to assess the level, as well as the biological and clinical significance of sCD147 in breast cancer.
 
Methods: We tested plasma sCD147 levels in 308 breast cancer patients by enzyme-linked immunosorbent assay between February 2014 and February 2017. A subset of 165 cases of benign breast diseases was included as control group at the same period. We analysed the clinical significance of plasma sCD147 with relevance to clinicopathological factors of breast cancer patients.
 
Results: Plasma sCD147 levels were significantly higher in patients with primary breast cancer than those with benign breast diseases (P=0.001), in patients with locally advanced breast cancer (T3-T4 tumour) than those in early breast cancer (T1-T2 tumour; P=0.001), in patients with lymph node metastasis than in those without (P<0.001), and in patients with high recurrence risk than those with medium recurrence risk (P<0.001). Plasma sCD147 levels were also significantly higher in the chemotherapy-resistant group than in the chemotherapy-sensitive group (P=0.040). Plasma sCD147 was an independent predictor for lymph node metastasis in breast cancer patients (P=0.001).
 
Conclusion: This is the first study to demonstrate that plasma sCD147 levels are elevated in breast cancer patients. Soluble CD147 is also associated with tumour size, lymph node metastasis, high recurrent risk, and chemoresistance. Our findings support that plasma sCD147 is an independent predictive factor for lymph node metastasis.
 
 
New knowledge added by this study
  • Plasma sCD147 levels are elevated in breast cancer patients and are associated with tumour size, lymph node metastasis, high recurrent risk, and chemoresistance.
  • Plasma sCD147 is an independent predictive factor for lymph node metastasis.
Implications for clinical practice or policy
  • Plasma sCD147 may be used as the predictive factor to evaluate lymph node metastasis, recurrence risk, and chemoresistance of breast cancer.
  • Plasma sCD147 may contribute to the development of optimal adjuvant therapy for individual breast cancer patients.
 
 
Introduction
Breast cancer is the most common malignant tumour and the leading cause of cancer-related deaths among females in developing countries.1 Breast cancer displays heterogeneity: it comprises distinct pathologies and histological features and can have different chemotherapy responses and clinical outcomes.2 The identification of tumour-related factors that can predict tumour behaviour is important. Predictive factors can help identify as early as possible not only patients who have a high risk of recurrence and metastasis, but also patients who can benefit from different types of adjuvant therapy.3 Conventional predictive factors of high risk of recurrence and metastasis include relatively large (>5 cm) tumour size and high nuclear grade; negativity for oestrogen receptor and progesterone receptor; human epidermal growth factor receptor 2 (HER2) overexpression; and increased lymph node involvement at the time of breast cancer diagnosis.4 Recent advances in genetic profiling of tumours have extended our understanding of breast cancer biology and have allowed the use of several prognostic gene signatures to select patients at highest risk of early recurrence and those who may benefit from certain adjuvant treatment.2 5 6 However, despite receiving standard treatments routinely guided by predictive factors, more than 30% of breast cancer patients develop metastatic disease and have poor survival.7 8 As such, it is essential and urgent to identify reliable predictive factors to assist in diagnosis, staging, evaluation of recurrence risk, and development of new treatment modalities.
 
Cluster of differentiation 147 (CD147), a transmembrane glycoprotein that belongs to the immunoglobulin superfamily, can promote tumour invasion and metastasis, and mediate breast cancer drug resistance.9 10 11 12 13 Expression of CD147 is significantly correlated with axillary lymph node involvement; tumour, node, and metastasis staging; and shorter progression-free survival and overall survival.14 Previous data demonstrated that CD147 exists in both membrane-bound and soluble forms in many solid tumours, and soluble CD147 (sCD147) can be detected in the conditioned medium of tumour cells and peripheral blood of cancer patients.15 16 17 Overexpression of the CD147 gene in human breast cancer cells can increase the sCD147 level, indicating that sCD147 release is correlated with the degree of CD147 expression in tumour cells.15 16 17 Full-length CD147 may be exported into the microenvironment from tumour cells by microvesicle shedding or by matrix metalloproteinase (MMP)–dependent cleavage, thereby stimulating MMP expression in fibroblasts.18 19 20 In turn, sCD147 derived from tumour cells acts in a paracrine fashion on stromal cells that are both adjacent and distant to tumour sites, so as to further stimulate the production of MMPs and CD147. This additional CD147 consequently contributes to tumour angiogenesis, tumour growth, and metastasis.16 21 Importantly, several studies investigating the role of sCD147 level in patients with tumours have suggested that sCD147 may offer a useful approach in diagnosis, as it is correlated with disease severity.15 22 However, little is known about the level of sCD147 in patients with breast cancer. Furthermore, the biological and clinical significance of sCD147 in breast cancer has not been investigated.
 
In this study, we measured plasma sCD147 levels in patients with breast cancer and evaluated the results with respect to clinicopathological factors. We aimed to demonstrate the association between plasma sCD147 levels with tumour size, lymph node metastasis, recurrence risk, and chemoresistance in breast cancer patients.
 
Methods
Patients and samples
The results of this study are presented in accordance with the reporting recommendations for tumour marker prognostic studies.23 We conducted the study between February 2014 and February 2017 in the Affiliated Xiangya Hospital of Central South University in Changsha of Hunan Province, China. We collected peripheral blood samples from consecutive patients with breast cancer, including primary breast cancer, during their first hospital admission. To be eligible for this study, patients had to be adult females who had no other malignant diseases or severe systemic diseases, especially rheumatic, inflammatory, and cardiovascular diseases. The peripheral blood of consecutive patients with palpable benign breast masses, including fibroadenoma and adenopathy, was also collected to serve as control samples during the same period. All blood samples were centrifuged at 3000 rpm at 4°C for 5 minutes, and the plasma samples were stored at -70°C for later plasma sCD147 testing. All the patients’ clinicopathological findings were supplied by the Xiangya Hospital of Central South University. Breast cancer subtypes were identified according to the St Gallen Consensus 2013 classification system.24 Recurrence risk of breast cancer was evaluated according to the St Gallen Consensus 2007 criteria.25
 
The association between chemotherapy response and plasma sCD147 level was retrospectively analysed. The patients included in this analysis had to meet all of the following criteria: (1) had a confirmed diagnosis of invasive ductal breast carcinoma by pathology and had consented to undergo neoadjuvant chemotherapy; (2) had operable breast cancer consisting of a large tumour (>2 cm) that fulfilled the criteria for breast conserving surgery except tumour size, or triple-negative breast cancer (TNBC; ie, negative for oestrogen/progesterone receptors and HER2) with small (T1 stage) tumours; (3) had received no previous treatment; (4) had received only four cycles of pirarubicin-cyclophosphamide/epirubicin-cyclophosphamide (AC/EC)–based neoadjuvant chemotherapy before surgery; and (5) had complete hospital records that included evaluation of chemotherapy efficacy. Clinical response to AC/EC-based chemotherapy was evaluated by the decrease in tumour size and classified according to response evaluation criteria in solid tumours (RECIST criteria).26 Patients with complete remission or partial remission were classified as chemotherapy-sensitive, whereas patients with stable disease or progressive disease were classified as chemotherapy-resistant.
 
Enzyme-linked immunosorbent assay
The concentrations of plasma sCD147 were measured by enzyme-linked immunosorbent assay (ELISA). Plasma sCD147 levels were assessed using the EMMPRIN/CD147 ELISA kit (R&D Systems, Minneapolis [MN], US) according to the manufacturer’s protocol. The concentration of the sample in each ELISA well was determined by interpolation from a standard curve. Each sample was tested in duplicate.
 
Statistical analysis
The Mann-Whitney U test was used to compare levels of plasma sCD147 in different groups according to variable clinicopathological factors. The Chi squared contingency test with Yates correction was used to determine the relationship between clinicopathological factors of breast cancer patients and lymph node status or chemotherapy sensitivity. Binary logistic regression was used to assess clinicopathological factors (plasma sCD147, tumour size, and HER2) that were associated with lymph node metastasis or chemoresistance in invasive breast cancer. All multivariable logistic regression models used backward stepwise procedures, and only datasets complete for every outcome analysed were used. Receiver operating characteristic (ROC) curve analysis was performed to calculate the area under the curve and evaluate the optimal cut-off point, which was given by the maximum of the Youden index. Statistical significance was set at P<0.05. The GraphPad Prism 6 software (GraphPad Software, La Jolla [CA], US) and SPSS (Windows version 19.0; IBM Corp, Armonk [NY], US) were used for statistical analysis.
 
Results
Patient’ characteristics
Among all eligible patients with complete records, 165 had benign breast disease (age range, 22-68 years) and 308 had primary breast cancer (age range, 24-77 years). There was no significant difference in age between the two groups (P=0.381). Breast cancer patients comprised 11 with ductal carcinoma in situ and 297 with invasive ductal carcinoma. Retrospective analysis of the association of plasma sCD147 level with response to neoadjuvant chemotherapy included 175 patients who met all the inclusion criteria (Fig)—luminal A in 39, luminal B in 70, HER2-positive in 28, and TNBC in 38. In all, 170 patients had T2-T4 tumours and five had T1 TNBC tumours. Using the RECIST criteria, we assigned the 175 patients to two groups: chemotherapy-sensitive (n=126) and chemotherapy-resistant (n=49).
 

Figure. Patient flowchart
 
Plasma soluble CD147 levels in breast cancer patients
According to ELISA results, plasma sCD147 levels were significantly higher in patients with primary breast cancer than in those with benign breast disease (median [interquartile range; IQR], 8629.81 pg/mL [7426.33-10 309.20 pg/mL] vs 7625.99 pg/mL [6739.20-9140.04 pg/mL]; P=0.001). However, there was no significant difference in plasma sCD147 levels between patients with invasive breast cancer and those with ductal carcinoma in situ (8618.91 pg/mL [7404.81-10 358.50 pg/mL] vs 9185.79 pg/mL [7671.15-9626.47 pg/mL]; P=0.787). Regarding cancer subtypes of the 297 patients with invasive breast carcinoma, median (IQR) plasma sCD147 levels were significantly higher in patients with HER2-positive breast cancer (10 042.34 pg/mL [7772.01-11 058.48 pg/mL]) than in those with luminal A tumours (7991.05 pg/mL [7101.72-10 237.4 pg/mL]; P=0.007), luminal B tumours (8629.81 pg/mL [7200.45-9953.32 pg/mL]; P=0.017), and TNBC tumours (8585.16 pg/mL [7884.27-10 545.51 pg/mL]; P=0.027).
 
Association between plasma soluble CD147 and clinicopathological factors
The association between plasma sCD147 level and clinicopathological factors in patients with invasive breast cancer is summarised in Table 1. Plasma sCD147 levels increased with tumour size: median (IQR) levels were significantly higher in patients with locally advanced (stage T3-T4) than those with early (stage T1-T2) breast cancer (10 093.26 pg/mL [7974.73-11 451.21 pg/mL] vs 8561.45 pg/mL [7169.41-9952.90 pg/mL]; P=0.001). Plasma sCD147 levels were also elevated in patients with lymph node metastasis compared with those without (median [IQR], 9991.42 pg/mL [8154.61-11 452.84 pg/mL] vs 7814.78 pg/mL [6936.82-9516.85 pg/mL]; P<0.001). In addition, plasma sCD147 levels were significantly higher in patients with a high risk of recurrence than in those with a medium risk (median [IQR], 10 093.26 pg/mL [8135.35-11 679.71 pg/mL] vs 8134.68 pg/mL [7151.41-9616.68 pg/mL]; P<0.001). Although plasma sCD147 levels were elevated for the HER2- positive breast cancer subtype as compared with other breast cancer subtypes, there was no significant difference between HER2-positive and HER2-negative patients (median [IQR], 9254.34 pg/mL [7157.63-11 199.38 pg/mL] vs 8568.83 pg/mL [7448.34-10 070.42 pg/mL]; P=0.160).
 

Table 1. Association between plasma soluble CD147 and various clinicopathological factors (n=297)
 
Plasma soluble CD147 as an independent predictor for lymph node metastasis
Because plasma sCD147 was associated with lymph node status and recurrent risk, we speculated that plasma sCD147 may be a predictor for lymph node metastasis of breast cancer. Univariate analysis showed that tumour size and HER2 status may be involved in lymph node metastasis (Table 2). We subsequently used binary logistic regression analysis to identify clinicopathological factors associated with lymph node metastasis in invasive breast cancer. Our data showed that plasma sCD147 (P<0.001), HER2-positive tumours (P=0.001), and tumour size T3-T4 (P=0.005) were independent predictors of lymph node metastasis of breast cancer (Table 3). When we analysed ROC curves to evaluate use of plasma sCD147 as a diagnostic biomarker for lymph node metastasis, the area under the curve was 0.745 (95% confidence interval, 0.676-0.813) and the optimal cut-off point of plasma sCD147 was 8577 pg/mL, which provided a sensitivity of 70.9% and a specificity of 61.7%.
 

Table 2. Association between clinicopathological factors and lymph node involvement (n=297)
 

Table 3. Results of multivariable analysis of clinicopathological factors and lymph node metastasis
 
Association of plasma soluble CD147 levels with chemotherapy response
Table 1 shows that plasma sCD147 levels in the chemotherapy-resistant group were significantly higher than those in the chemotherapy-sensitive group (median [IQR], 10 093.26 pg/mL [7974.73-11 261.88 pg/mL] vs 8585.16 pg/mL [7789.74-9868.87 pg/mL]; P=0.040). Univariate analysis revealed that tumour size and HER2 status may be involved in chemotherapy response (Table 4). Binary logistic regression analysis demonstrated that plasma sCD147 was not an independent predictor for chemotherapy response of breast cancer patients, but tumour size of T3-T4 was (P=0.001) [Table 5].
 

Table 4. Association between tumour characteristics and chemotherapy response (n=175)
 

Table 5. Results of multivariable analysis of clinicopathological factors and chemotherapy resistance
 
Discussion
The tumour microenvironment plays a proactive role in malignant disease progression, including the transition from ductal carcinoma in situ to invasive cancer, tumour cell proliferation, dissemination, and metastasis.27 CD147 has been found to be overexpressed in breast cancer, associated with tumour size and staging, and predictive of poor prognosis.28 29 30 31 Tumour cells express molecules, either secreted or presented on the cell surface, that interact with surrounding stromal cells. Soluble CD147 may be released from membrane-associated CD147 as a result of both MMP proteolytic activity and microvesicle shedding in the tumour microenvironment. Soluble CD147 may then act in a paracrine fashion on stromal cells to further trigger production of MMPs and CD147; the latter contributes to tumour angiogenesis, tumour growth, and metastasis.16 19 21
 
Wu et al15 reported that serum sCD147 enhances the secretion of MMP-2 from hepatocellular carcinoma cells by activating extracellular signal-regulated kinase and focal adhesion kinase, as well as phosphoinositide-3-kinase/Akt signalling, indicating that sCD147 may contribute to hepatocellular carcinoma progression. Moreover, serum sCD147 was elevated in patients with hepatocellular carcinoma compared with healthy individuals, and sCD147 level was associated with tumour size and Child-Pugh score.15 Gross et al22 also reported that sCD147 levels were elevated in patients with multiple myeloma, and elevated levels were associated with refractory disease and shortened progression-free survival, indicating that sCD147 may be a new prognostic factor for patients with multiple myeloma.
 
A previous study demonstrated that CD147 was overexpressed in human breast cancer.10 In this study, we measured plasma sCD147 levels by ELISA and found that plasma sCD147 levels were significantly elevated in breast cancer patients compared with control patients who had benign breast diseases. We also found that plasma sCD147 was significantly elevated in lymph node metastasis in breast cancer patients. Taken together, these data show that plasma sCD147 may be released from tumour cells and promote lymph node metastasis of breast cancer. Some studies have reported that sCD147 has been detected in patients with inflammatory diseases31 or cardiovascular diseases.32 33 To eliminate interference from other diseases and conditions, we excluded patients with inflammatory or cardiovascular diseases and ensured patients in each group had a similar age distribution.
 
Previous studies have shown that membrane-bound CD147 may correlate with HER2 expression. Yan et al34 reported that CD147 induces angiogenesis by stimulating vascular endothelial growth factor production, invasiveness by stimulating MMP production, and multidrug resistance by hyaluronan-mediated upregulation of HER2 signalling. Xue et al30 reported that CD147 expression was positively correlated with HER2 overexpression. In a recent study, CD147 knockdown was shown to improve the antitumour efficacy of trastuzumab in HER2-positive breast cancer cells.35 Although we found that plasma sCD147 levels were significantly higher in the HER2-positive breast cancer subtype than in luminal A, luminal B, and TNBC subtypes, plasma sCD147 had no association with expression of HER2 or oestrogen/progesterone receptors in breast cancer. The reason for this finding is that there are four breast cancer subtypes—luminal A, luminal B, HER2-positive, and TNBC—according to oestrogen/progesterone receptor, HER2, and Ki67 status. The luminal B subtype includes some breast cancers that are positive for oestrogen/progesterone receptor and HER2. Hence, patients who are HER2-positive (Table 1) include those with HER2-positive subtype and also luminal B subtype; plasma sCD147 levels in patients who were ‘HER2-positive’ were different from those with a HER2-positive subtype.
 
It is essential to establish predictive factors to allow evaluation of the recurrence risk of breast cancer, so that optimal adjuvant therapy can be selected for individual patients.3 36 Larger tumour size at diagnosis, high proliferation factors, absence of oestrogen/progesterone receptors and HER2 overexpression, and lymph node metastasis are related to a high risk of recurrence and poor survival, and are commonly recognised as prognostic and predictive factors for breast cancer recurrence risk.4 37 38 Consistent with these findings, we found that plasma sCD147 levels were significantly increased in patients with locally advanced lymph node metastasis and a high risk of breast cancer recurrence. We also found that plasma sCD147 was positively associated with tumour size, lymph node metastasis, and high recurrence risk of invasive breast cancer.
 
Lymph node status, which confers different strategies for patients at different tumour stages, is critical information for the treatment of breast cancer, and the accurate prediction of lymph node status is a prerequisite for treatment decision. Our binary logistic regression analysis showed that plasma sCD147, HER2 positive subtype, and tumour size (T3-T4) were independent predictors for lymph node metastasis of breast cancer patients. Taken together, these data suggest that plasma sCD147 may be a new factor for the evaluation of breast cancer recurrence risk. Our ROC analysis demonstrated that plasma sCD147 could be a biomarker for distinguishing breast cancer patients with lymph node metastasis from those without; however, the sensitivity and specificity were not high (70.9% and 61.7%, respectively). The relatively low sensitivity and specificity suggest that using plasma sCD147 as the sole biomarker may result in substantial numbers of false positives and false negatives. Therefore, it may be necessary to investigate whether the combination of plasma sCD147 and other biomarkers can improve efficacy.
 
According to the data of 303 patients who were followed up for 3 to 38 months (median, 20 months), 11 patients had relapse: two had local recurrences and nine had distant metastases. The mean time of recurrence/metastasis was 23.6 months, with no difference between patients with relapse and those without (Table 6). We were not able to investigate the relationship between plasma sCD147 and disease-free survival or overall survival, because of the short median follow-up period.
 

Table 6. Follow-up data on relapse status
 
Previous data have shown that CD147 is one of the apoptosis-related proteins and it may mediate adriamycin chemoresistance in breast cancer by affecting the cellular localisation and dimerisation of the protein ABCG2 (ATP-binding cassette subfamily G member 2).10 In this study, we studied the relationship between plasma sCD147 and chemotherapy response in invasive breast cancer. All patients were given four cycles of AC/EC-based chemotherapy. We also found that plasma sCD147 levels were significantly higher in the chemotherapy-resistant group than in the chemotherapy-sensitive group, and such levels were positively associated with chemotherapy resistance. Although our data also showed that plasma sCD147, tumour size (T3-T4), and HER2 positive subtype may be involved in chemotherapy response, binary logistic regression demonstrated that tumour size (T3-T4) was an independent predictor for chemotherapy response of breast cancer patients, but plasma sCD147 was not. Owing to the small number of cases in the chemotherapy-resistant group, the statistical analysis of data may be underpowered.
 
In addition to the small sample of study and short median follow-up period, there were other limitations in this study. This study was conducted in one centre, and the researchers who extracted the data and conducted the analysis were not blinded to the study hypothesis. There may have increased selection and information bias. Furthermore, as the design of this study was relatively simple, there may be insufficient control for potential confounding factors in the multivariable analysis.
 
In conclusion, our study found that plasma sCD147 levels were elevated in breast cancer patients compared with controls with benign breast disease, and plasma sCD147 level was associated with tumour size, lymph node metastasis, high recurrence risk, and AC/EC-based chemoresistance. Moreover, our study supports that plasma sCD147 is an independent predictive factor for lymph node metastasis and is a feasible marker to distinguish breast cancer patients with lymph node metastasis from patients without.
 
Author contributions
Concept or design: LL Tang, LQ Liao.
Acquisition of data: YJ Liu, YH Kuang, SM Wang, GJ Yan.
Analysis or interpretation of data: LL Tang, LQ Liao.
Drafting of the article: YH Kuang, LQ Liao.
Critical revision for important intellectual content: YH Kuang, LQ Liao.
YH Kuang, YJ Liu, and LL Tang contributed equally to this study.
 
Funding/support
This study was supported by two grants from the National Natural Science Foundation of China (No. 81101654, awarded to LQ Liao, and No. 81573049, awarded to YH Kuang).
 
Declaration
The authors have no conflicts of interest to disclose. All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.
 
Ethical approval
The research protocols for the use of human tissue were approved by and conducted in accordance with the policies of the Institutional Review Boards at Central South University (Ref No. 201403152), which were formulated based on the 1964 Helsinki Declaration and its later amendments. Written informed consent was obtained from all participants.
 
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Outcomes of salvage radiotherapy for recurrent prostate cancer after radical prostatectomy

Hong Kong Med J 2018 Jun;24(3):218–25 | Epub 21 May 2018
DOI: 10.12809/hkmj176888
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
ORIGINAL ARTICLE
Outcomes of salvage radiotherapy for recurrent prostate cancer after radical prostatectomy
Eric KC Lee, MB, ChB, FHKAM (Radiology); WH Mui, MB, BS, FHKAM (Radiology); Adrian W Chan, MB, BS, FRCR; Y Tung, MB, BS, FHKAM (Radiology); Frank CS Wong, MB, ChB, FHKAM (Radiology)
Department of Clinical Oncology, Tuen Mun Hospital, Tuen Mun, Hong Kong
 
Corresponding author: Dr Eric KC Lee (leekachai2000@yahoo.com.hk)
 
 Full paper in PDF
 
Abstract
Introduction: Salvage radiotherapy (SRT) provides effective biochemical control for patients with prostate cancer who have prostate-specific antigen (PSA) failure after radical prostatectomy. However, the effect of SRT on long-term clinical outcomes remains unknown. Therefore, we report the natural history of patients treated with SRT.
 
Methods: We identified 84 Chinese patients with prostate cancer treated with SRT to the prostatic fossa alone during 2006-2017 at Tuen Mun Hospital, Hong Kong. Survival was calculated using Kaplan-Meier method. Log rank test and Cox regression were used to determine significance of clinical parameters with outcomes.
 
Results: Median SRT dose given was 70 Gy (range, 64-76 Gy). Median pre-SRT PSA level was 0.4 ng/mL (0.2-7.4 ng/mL). After SRT, 47 (56%) patients had undetectable (<0.1 ng/mL) PSA levels. After median follow-up of 48 months (2 months to 10 years), 25 (30%) patients had further biochemical progression. Subsequently, 12 patients received androgen deprivation therapy and nine (11%) developed distant metastasis. The 5-year biochemical progression–free survival, androgen deprivation therapy–free survival and metastasis-free survival were 62.7%, 83.5% and 86.7%, respectively. Early PSA failure after radical prostatectomy (hazard ratio=7.4), negative surgical margin (hazard ratio=2.7), positive extracapsular extension (hazard ratio=4.6), and detectable PSA levels after SRT (hazard ratio=17.3) were associated with lower biochemical progression–free survival after SRT.
 
Conclusions: High-dose SRT with intensity-modulated radiotherapy/volumetric modulated arc radiotherapy is an effective local treatment that can prevent distant metastasis and avoid the need for androgen deprivation therapy in Chinese patients who have PSA failure after radical prostatectomy.
 
 
New knowledge added by this study
  • Better biochemical progression–free survival after salvage radiotherapy (SRT) can be achieved through higher radiation doses and better selection of patients.
  • Patients with prostate-specific antigen (PSA) failure ≤24 months after radical prostatectomy, negative surgical margin, positive extracapsular extension, or detectable PSA after SRT are more likely to develop biochemical progression after SRT.
Implications for clinical practice or policy
  • Distant metastasis is more likely to occur in patients with extracapsular extension, patients who cannot achieve biochemical complete response, and patients who develop biochemical progression within 1 year of SRT.
  • For these patients, close monitoring for distant metastasis may be needed.
 
 
Introduction
Prostate cancer (PCa) is the most common non-cutaneous malignancy among men in western countries, and is the third most common cancer among men in Hong Kong.1 Increasing public awareness in the Chinese community, as well as the common use of prostate-specific antigen (PSA) tests by primary health physicians, have led to detection of PCa at an earlier stage, when it is amenable to either radical surgery or radiotherapy (RT).2 Because of recent advancements in operative management, such as robotic-assisted laparoscopic prostatectomy,3 many patients have found radical prostatectomy (RP) the preferred treatment option. Nevertheless, adjuvant radiotherapy (ART) to the prostatic fossa is indicated postoperatively in cases with positive surgical margin (SM), or residual disease from extracapsular extension (ECE). Alternatively, patients may receive salvage radiotherapy (SRT) when there is PSA failure, defined as any detectable and rising PSA level after RP.
 
Currently, ART is still being compared with SRT in three randomised controlled trials (RADICALS, RAVES, GETUG-AFU 17).4 5 6 While the results of these European and Australasian studies are still pending, the American Society for Radiation Oncology/American Urological Association guidelines recommend that physicians offer SRT to patients with PSA or local recurrence after RP in whom there is no evidence of distant metastasis (DM).7 Patients should be advised that SRT should be administered at the earliest sign of PSA recurrence. Approximately 60% of patients who are treated with SRT before the PSA level rises to >0.5 ng/mL will achieve an undetectable PSA level, providing long-term PSA control in nearly half of them.8
 
However, after SRT, some patients may still experience further clinical progression, including DM and cancer-related death. The effect of SRT on the long-term outcomes including metastasis-free survival (MFS) and overall survival—especially in Chinese patients—is not well understood. Herein we report the long-term survival data of patients at a single institution in Hong Kong who received SRT to the prostatic fossa using modern RT techniques.
 
Methods
Patient selection
Using the MOSAIQ system (version 2.62, IMPAC Medical Systems, Inc.; Sunnyvale [CA], US), we identified 91 Chinese patients treated with postoperative RT to the prostatic fossa at Tuen Mun Hospital, Hong Kong, between 2006 and 2017. The treatment records and clinical data of these patients were reviewed. Two patients who received ART with undetectable PSA were excluded. Patients who had received androgen deprivation therapy (ADT) prior to SRT were also excluded. These selection criteria yielded 84 evaluable individuals who received SRT to the prostatic fossa alone for PSA failure (defined as detection of PSA concentration at 0.2 ng/mL, with a second confirmatory level detected at 0.2 ng/mL) more than 3 months after RP.
 
Radiation therapy techniques
A planning computed tomographic scan was performed for each patient with 3-mm slice thickness, and the clinical target volume was determined with reference to one of the published consensus guidelines.9 10 11 The usual boundaries of the clinical target volume are: inferiorly, 5 mm below the urethral anastomosis; anteriorly, the posterior aspect of the symphysis pubis or the posterior third of the bladder; laterally, the medial border of the obturator internus and levator ani muscles; posteriorly, the anterior mesorectal fascia; and superiorly, 5 mm above the surgical bed. The planning target volume was defined as clinical target volume with a margin of 4 to 5 mm posteriorly and 0.7 to 1 cm in all other directions. Organs at risk, including the rectum, bladder, and bilateral femoral heads were contoured. Conformal radiotherapy or inverse planning techniques with intensity-modulated radiotherapy (IMRT) using seven to nine static beams were used before October 2010. After that, volumetric modulated arc radiotherapy (VMAT) was employed using the Pinnacle treatment planning system (Philips Medical Systems, Fitchburg [WI], US) with treatment delivered through one to two dynamic cone arcs.
 
Variable definition
Clinical data included age at SRT, time from surgery to RT (≤24 months vs >24 months), SRT dose, pre-SRT PSA level, and post-SRT nadir PSA. Pathological data consisted of pathological T stages (T2a vs T2b vs T2c vs T3a or T3b), ECE, seminal vesicle invasion, SM, and pathological Gleason scores (≤7 or ≥8).
 
Outcome definition
After SRT, patients were followed up with PSA level checks every 3 months in the first 2 years, every 6 months from year 3 to year 5, then annually. A complete response was defined as an undetectable nadir PSA (<0.1 ng/mL). Biochemical progression (PSA failure) was defined as a rise of PSA level by 0.2 ng/mL above the nadir with a second confirmation at least 1 week apart.12 Biochemical progression-free survival (bPFS) was defined as the date from SRT completion to the first date of biochemical progression. Patients who showed biochemical progression or symptoms suggestive of metastasis received imaging studies at the discretion of the oncologist. Metastasis-free survival was defined as the date from SRT completion to the date of occurrence of metastasis on imaging. Patients who showed biochemical progression with or without metastasis were counselled on the use of ADT; ADT-free survival was defined as the date of SRT completion to the first date of ADT administration.
 
Statistical analyses
The Kaplan-Meier method was used to estimate bPFS, MFS, and ADT-free survival. Log-rank tests and Cox regression analysis were used to test the association between groups and oncologic outcomes. Covariates consisted of continuous variables, including patient age at SRT, SRT dose, and pre-SRT PSA, and discrete variables including post-SRT nadir PSA (detectable vs undetectable), pathological T stages (T2a vs T2b vs T2c vs T3a vs T3b), pathological Gleason score (≤7 vs ≥8), SM (negative vs positive), ECE (negative vs positive), seminal vesicle invasion (negative vs positive), and time of SRT (≤24 months after RP or >24 months after RP). Only variables that were significantly associated with outcomes on univariate analyses were further tested for association in multivariate analyses.
 
Statistical analyses were performed using IBM SPSS Statistics for Windows, version 24.0 (IBM Corp, Armonk [NY], US), and numerical data were presented according to Cole.13
 
Results
Patients
The median age of the 84 patients was 68 years (range, 52-79 years) when they received SRT. The patients’ median pre-SRT PSA level was 0.4 ng/mL (range, 0.2-7.4 ng/mL). Of the patients, 63 (75%) had positive SM in their prostatectomy specimens. Extracapsular extension was detected in 25 (29.8%) patients. Pelvic lymph nodes of 41 patients were sampled during RP and were all found to be negative for malignancy. These and other pathological characteristics are summarised in Table 1. The median time from surgery to start of SRT was 18.4 months (range, 3.8-121 months).
 

Table 1. Patient and RP pathological characteristics (n=84)
 
Treatment delivery
Before October 2010, one patient was treated with conformal RT and 10 patients were treated with IMRT. Subsequently the other 73 patients were treated with VMAT. The median dose given to the prostatic fossa was 70 Gy (range, 64-76 Gy), with 66 (79%) patients receiving a dose of ≥70 Gy. The mean dose delivered using VMAT (69.5 Gy) was slightly higher than that delivered using IMRT/conformal RT (68.1 Gy) [independent-samples t test, t=2.1; P=0.028].
 
Treatment outcome
Of 84 patients, 47 (56%) had undetectable PSA levels (complete response; <0.1 ng/mL) after SRT. After a median follow-up of 48 months (range, 2-120 months), 25 (30%) patients had biochemical progression with an estimated 5-year bPFS of 62.7% (95% confidence interval [CI], 50.1-75.3%) [Fig 1a]. Among the 25 patients who developed biochemical progression after SRT, seven were found to have DM and subsequently received ADT, and five started ADT in the absence of DM, two of whom later developed DM and had their disease became castration-resistant. Overall, 12 patients received ADT and nine (11%) patients developed DM. The 5-year ADT-free survival and MFS were 83.5% (95% CI, 73.7-93.3%) and 86.7% (95% CI, 77.7-95.7%), respectively (Fig 1b, c). Notably, only six patients died, all from causes other than PCa.
 

Figure 1. (a) Biochemical progression–free survival, (b) androgen deprivation therapy–free survival, and (c) metastasis-free survival of patients after salvage radiotherapy
 
Biochemical progression–free survival and metastasis-free survival
On univariate analysis, a post-SRT nadir PSA ≥0.1 ng/mL, positive ECE, and bPFS ≤12 months were significantly associated with a shorter MFS (all P<0.001; Fig 2). Similarly, a post-SRT nadir PSA ≥0.1 ng/mL (P<0.001), positive ECE (P<0.001), negative SM (P=0.045), pathological Gleason score ≥8 (P=0.002), and time from surgery to SRT ≤24 months (P=0.008) were significant predictors of a shorter bPFS (Fig 3). The pre-SRT PSA level, age, and SRT dose were not associated with either MFS or bPFS in this cohort on univariate analysis. On multivariate analysis using the Cox regression method, negative SM (hazard ratio [HR]=2.7; 95% confidence interval [CI], 1.1-6.6), positive ECE (HR=4.6; 95% CI, 1.8-11.7), post-SRT nadir PSA ≥0.1 ng/mL (HR=17.3; 95% CI, 5.3-57.0), and time from surgery to SRT ≤24 months (HR=7.4; 95% CI, 2.2-24.0) retained significant association with a shorter bPFS (Table 2). There was no variable significantly associated with MFS after multivariate analysis.
 

Figure 2. Metastasis-free survival by (a) nadir PSA; (b) bPFS; and (c) ECE (all P<0.001)
 

Figure 3. Biochemical progression–free survival by (a) nadir PSA; (b) GS; (c) SM; (d) ECE; and (e) time from RP to SRT
 

Table 2. Predictive factors of shorter bPFS on multivariate analysis
 
Discussion
Most patients who develop biochemical recurrence after RP for localised PCa remain asymptomatic for many years.14 However, patients with increasing PSA level are at high risk of developing DM. Salvage radiotherapy is effective in terms of biochemical control when it is administered at low PSA level. Stephenson et al12 reported a 6-year progression-free probability of 32% after SRT. In their multi-institutional retrospective cohort of 1603 consecutive patients from 17 North American tertiary referral centres who received SRT after RP for PSA recurrence between 1987 and 2005, the median dose was only 64.8 Gy (interquartile range, 63-66 Gy) delivered using older techniques. The 5-year bPFS of 62.7% in the present study is similar or better than those reported in western countries.12 15 16 This might be due to better selection of patients (most patients started SRT when their PSA level was ≤0.5 ng/mL), or the higher dose of SRT to the prostatic fossa (median 70 Gy). In our cohort, all patients but one were treated using IMRT/VMAT. Intensity-modulated radiotherapy was introduced in the 1990s and it has since enabled radiation oncologists to deliver higher doses of radiation to treat patients with PCa—including patients with residual disease at the prostatic fossa—without causing excessive radiation damage to healthy tissue.17 18 19 Volumetric modulated arc radiotherapy has recently attracted much interest because it can dynamically deliver a radiation dose during rotation of the gantry; this is also superior to IMRT in terms of its plan qualities and efficiency in the treatment of PCa.20 21
 
Pisansky et al22 reported that SRT doses of ≥66.0 Gy were associated with reduced cumulative incidence of biochemical progression. A systemic review by King23 provides level 2a evidence for escalated SRT dose of at least 70 Gy. A 2% improvement in relapse-free survival can be achieved for each additional Gy from 60 Gy to 70 Gy.23 However, higher SRT dose was not shown to be associated with better bPFS/MFS in our 84 patients by univariate analysis, because most (79%) had been treated with an SRT dose of ≥70 Gy, and the follow-up time may still be too short to demonstrate any further dose-response relationship. We postulated that such high-dose SRT can be delivered safely with modern techniques using VMAT, therefore our current usual prescribed dose is 70 Gy to the prostatic fossa, unless limited by dose constraints of the organ at risk. We have previously shown the efficiency and low toxicities using VMAT for SRT to the prostatic fossa.24 Longer follow-up is necessary to ensure that late complications are within safety limits.
 
Despite the success of SRT in biochemical control, some patients may develop further biochemical progression. In our present study, patients whose surgical pathology revealed negative margin and positive ECE had a shorter bPFS (HRs of 2.7 and 4.6, respectively). Patients who start SRT within 2 years of RP may also have a shorter PSA doubling time, leading to earlier detection of recurrence. These patients have a greater than 7-fold higher risk of biochemical regression after SRT than those with later recurrence. Salvage radiotherapy to the prostatic fossa alone cannot eradicate cancer that has spread outside the surgical bed after RP. In fact, negative SM, positive ECE, and shorter PSA doubling time are three of the many adverse factors which predict a shorter bPFS after SRT, using the nomogram proposed by Stephenson et al.25 However, we cannot demonstrate the importance of pre-SRT PSA level in our patient cohort because more than 65% of the patients had started SRT when their PSA level was ≤0.5 ng/mL.
 
Overall, the role of SRT in improving MFS and overall survival is less certain, because the disease can be indolent and mortality due to causes other than PCa is more likely in older patients. Patients also have other complications related to disease progression, such as painful bone metastasis. Efforts have been made to identify surrogate endpoints that can predict further disease progression, metastasis, and even cancer-related death after SRT. In a single institution review, Johnson et al26 reported approximately 50% of men experience further biochemical progression after SRT. Those who have a short interval to biochemical progression of ≤18 months after SRT are most likely to experience DM, PCa-specific mortality, and overall mortality. Bartkowiak et al27 reported on the long-term outcomes of patients with a median follow-up of 7 years (maximum, 14 years) after SRT. They found that a post-SRT nadir PSA <0.1 ng/mL was associated with improved bPFS and overall survival. The results of our univariate analysis support the abovementioned findings27 (Fig 2a, b). On multivariate analysis, we found that undetectable nadir PSA (<0.1 ng/mL) is the most important factor for predicting longer bPFS (Table 2). In the present study, of the 47 patients who achieved biochemical complete response after SRT, none developed DM. In contrast, among the 25 patients who had biochemical progression, nine whose disease progressed within 1 year after SRT eventually developed DM. Although our result of a 5-year MFS of nearly 90% is encouraging, with the median follow-up of only 4 years, we can hypothesise only that better biochemical control is correlated with improvements in other clinical outcomes. For patients whose PSA level does not become undetectable and rapidly rises within 1 year after SRT (bPFS ≤12 months), close monitoring for DM may be needed.
 
The improvement in overall survival and MFS of adjuvant ADT with SRT has been demonstrated by Shipley et al28 in a phase III study. However, ADT is not routinely recommended to our patients because of the known metabolic and cardiovascular toxicities and the negative impact on patients’ quality of life. In addition, most of our patients have fewer adverse features than those reported by Shipley et al.28 For patients with biochemical regression alone after SRT, we suggest monitoring for any site of disease recurrence such that further SRT could still be feasible. Nonetheless, we applied positron emission tomography with 68 Ga-labelled prostate-specific membrane antigen (PET-PSMA) to identify the site of recurrence in four of our patients when their PSA levels increased to ≥2.2 ng/mL (Table 3). All four patients were found to have DM which was not amenable to further local treatment and ADT had become their only option. It remains unclear whether PET-PSMA or other imaging studies at lower PSA levels are sensitive or useful enough to alter the management decision.29 Further research to study the use of novel radiological examinations in this situation is needed.
 

Table 3. Pattern of disease progression
 
Conclusions
This is the first report to demonstrate the therapeutic effects in terms of bPFS and MFS of SRT in Chinese patients in a Hong Kong centre. Salvage radiotherapy is an effective local treatment that can prevent DM and avoid the need for ADT in most patients who have PSA failure after RP in Chinese patients. Our results appear to be better than those of some studies in western countries, in which older radiotherapy techniques and lower radiation doses were used. The limitations of our study include the retrospective design with lack of evaluation of patients’ reported outcome, small sample size, and short duration of follow-up. A multi-institutional study is recommended to collect more local data and experiences.
 
Author contributions
Concept or design: EKC Lee, Y Tung.
Acquisition of data: EKC Lee, AW Chan.
Analysis or interpretation of data: EKC Lee.
Drafting of the article: EKC Lee, WH Mui, FCS Wong.
Critical revision for important intellectual content: EKC Lee, WH Mui, FCS Wong.
 
Funding/support
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
Declaration
All authors have no conflicts of interest to disclose. All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity. An earlier version of this paper was presented as poster presentation at the 9th European Multidisciplinary Meeting on Urological Cancers, 16-19 November 2017, Barcelona, Spain.
 
Ethical approval
The study was conducted with approval from the New Territories West Cluster Clinical and Research Ethics Committee.
 
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7. Valicenti RK, Thompson I Jr, Albertsen P, et al. Adjuvant and salvage radiation therapy after prostatectomy: American Society for Radiation Oncology/American Urological Association guidelines. Int J Radiat Oncol Biol Phys 2013;86:822-8. Crossref
8. Wiegel T, Lohm G, Bottke D, et al. Achieving an undetectable PSA after radiotherapy for biochemical progression after radical prostatectomy is an independent predictor of biochemical outcome—results of a retrospective study. Int J Radiat Oncol Biol Phys 2009;73:1009-16. Crossref
9. Michalski JM, Lawton C, El Naqa I, et al. Development of RTOG consensus guidelines for the definition of the clinical target volume for postoperative conformal radiation therapy for prostate cancer. Int J Radiat Oncol Biol Phys 2010;76:361-8. Crossref
10. Poortmans P, Bossi A, Vandeputte K, et al. Guidelines for target volume definition in post-operative radiotherapy for prostate cancer, on behalf of the EORTC Radiation Oncology Group. Radiother Oncol 2007;84:121-7. Crossref
11. Sidhom MA, Kneebone AB, Lehman M, et al. Post-prostatectomy radiation therapy: consensus guidelines of the Australian and New Zealand Radiation Oncology Genito-Urinary Group. Radiother Oncol 2008;88:10-9. Crossref
12. Stephenson AJ, Scardion PT, Kattan MW, et al. Predicting the outcome of salvage radiation therapy for recurrent prostate cancer after radical prostatectomy. J Clin Oncol 2007;25:2035-41. Crossref
13. Cole TJ. Too many digits: the presentation of numerical data. Arch Dis Child 2015;100:608-9. Crossref
14. Pound CR, Partin AW, Eisenberger MA, Chan DW, Pearson JD, Walsh PC. Natural history of progression after PSA elevation following radical prostatectomy. JAMA 1999;281:1591-7. Crossref
15. Geinitz H, Riegel MG, Thamm R, et al. Outcome after conformal salvage radiotherapy in patients with rising prostate-specific antigen levels after radical prostatectomy. Int J Radiat Biol Oncol Phys 2012;82:1930-7. Crossref
16. Fossati N, Karnes RJ, Boorjian SA, et al. Long-term impact of adjuvant versus early salvage radiation therapy in pT3N0 prostate cancer patients treated with radical prostatectomy: results from a multi-institutional series. Eur Urol 2017;71:886-93. Crossref
17. Goldin GH, Sheets NC, Meyer A, et al. Patterns of intensity modulated radiation therapy (IMRT) use for the definitive and postoperative treatments of prostate cancer: a SEER-medicare analysis. Int J Radiat Oncol Biol Phys 2011;81(2 Suppl):S408. Crossref
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Hypospadias surgery in children: improved service model of enhanced recovery pathway and dedicated surgical team

Hong Kong Med J 2018 Jun;24(3):238–44 | Epub 21 May 2018
DOI: 10.12809/hkmj177039
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
ORIGINAL ARTICLE
Hypospadias surgery in children: improved service model of enhanced recovery pathway and dedicated surgical team
YS Wong, FHKAM (Surgery); Kristine KY Pang, FHKAM (Surgery); YH Tam, FHKAM (Surgery)
Division of Paediatric Surgery and Paediatric Urology, Department of Surgery, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong
 
Corresponding author: Dr YH Tam (pyhtam@surgery.cuhk.edu.hk)
 
 Full paper in PDF
 
Abstract
Introduction: Children in Hong Kong are generally hospitalised for 1 to 2 weeks after hypospadias repairs. In July 2013, we introduced a new service model that featured an enhanced recovery pathway and a dedicated surgical team responsible for all perioperative services. In this study, we investigated the outcomes of hypospadias repair after the introduction of the new service model.
 
Methods: We conducted a retrospective study on consecutive children who underwent primary hypospadias repair from January 2006 to August 2016, comparing patients under the old service with those under the new service. Outcome measures included early morbidity, operative success, and completion of enhanced recovery pathway.
 
Results: The old service and new service cohorts comprised 176 and 126 cases, respectively. There was no difference between the two cohorts in types of hypospadias and surgical procedures performed. The median hospital stay was 2 days in the new service cohort compared with 10 days in the old service cohort (P<0.001). Patients experienced less early morbidity (5.6% vs 15.9%; P=0.006) and had a lower operative failure rate (20.2% vs 44.2%; P<0.001) under the new service than the old service. Multivariable analysis revealed that the new service significantly reduced the odds of early morbidity (odds ratio=0.35, 95% confidence interval=0.15-0.85; P=0.02) and operative failure (odds ratio=0.32, 95% confidence interval=0.17-0.59; P<0.001) in comparison with the old service. Of the new service cohort, 111(88.1%) patients successfully completed the enhanced recovery pathway.
 
Conclusions: The enhanced recovery pathway can be implemented safely and effectively to primary hypospadias repair. A dedicated surgical team may play an important role in successful implementation of the enhanced recovery pathway and optimisation of surgical outcomes.
 
 
New knowledge added by this study
  • Children can be discharged early from hospital after primary hypospadias repairs, regardless of the severity of the hypospadias and the surgical techniques used.
  • Improved operative success of hypospadias repair may be achieved by dedicated hypospadias surgeons.
Implications for clinical practice or policy
  • Primary hypospadias repair in children can be considered as short-stay surgery.
  • Tertiary centres for hypospadias may consider concentration of hypospadias repairs among a few dedicated surgeons.
 
 
Introduction
Hypospadias is a congenital abnormality of the external genitalia in boys, and is defined as an arrest in the embryological development of the urethra, foreskin, and ventral aspect of the penis.1 Hypospadias is characterised by abnormal foreskin with a dorsal hood and an ectopic urethral meatus, which can be located anywhere from the ventral aspect of the glans penis, along the penile shaft, within the scrotum, to the perineum (Fig 1). Hypospadias can be classified broadly into distal, mid-shaft, or proximal types, with the proximal type being the most severe form. In general, more severe forms of hypospadias are associated with a higher incidence and severity of penile ventral curvature (chordee).1
 

Figure 1. Distal hypospadias (left) and proximal hypospadias (right)
Ectopic urethral meatus are indicated by arrows
 
Hypospadias repair is generally recommended in early childhood for improved function and cosmesis.2 Although advances in surgical techniques have resulted in favourable outcomes with high success rates for distal hypospadias repair,3 proximal hypospadias repair remains challenging, and complication rates have been reported to be as high as over 50%.4 Postoperatively, the urethral catheter is usually left in place for free drainage for 5 to 7 days in distal repair5 and from 10 to 14 days in proximal repair.6 In many parts of the world, including North America, patients generally have a very short stay in hospital and are discharged home with urethral catheters in situ.7 In contrast, conventional practice in Hong Kong has been to provide in-patient care after hypospadias surgery until removal of the urethral catheter.
 
The Division of Paediatric Surgery and Paediatric Urology at the Prince of Wales Hospital has been a tertiary referral centre for hypospadias surgery for over two decades. We introduced a new service (NS) model in July 2013, which featured the establishment of a dedicated surgical team and the implementation of an enhanced recovery pathway (ERP). The present study aimed to compare the outcomes of the NS model with those of the old service (OS) model. We hypothesised that ERP implementation by a dedicated surgical team would reduce the risk of early morbidity and increase the operative success of hypospadias repair.
 
Methods
Patients
A historical cohort study was conducted on consecutive patients younger than 18 years who underwent primary repair of hypospadias in our centre from January 2006 to August 2016. The patients were identified using both the ICD-10 (International Classification of Diseases, 10th revision) code related to hypospadias surgery and the registry of operative procedures entry in operating theatres. We used ICD-10 code 752.61, which covered the diagnosis of various types of hypospadias, as well as codes 58.45 and 58.46, which covered various techniques of hypospadias repairs. The patients underwent either one-stage tubularised incised plate (TIP) repair5 8 (Fig 2), or two-stage preputial flap repair9 (Fig 3), as these two techniques had been our standard practice for primary repair of hypospadias from distal to proximal types during the study period. We excluded reoperative hypospadias repairs and repairs with buccal mucosal graft (BMG). Reoperative hypospadias surgery is highly variable in complexity, involves multiple surgical techniques, and is usually investigated separately from primary hypospadias surgery in literature. Children who undergo BMG harvest are generally not considered suitable for early hospital discharge. Moreover, BMG is used rarely in hypospadias surgery, and only under special circumstances. We also excluded minor hypospadias repairs by meatal advancement with glansplasty or meatoplasty alone, as such procedures did not require prolonged urethral catheterisation.
 

Figure 2. Before (left) and after (right) one-stage tubularised incised plate repair
Ectopic urethral meatus are indicated by arrows
 

Figure 3. Before (left) and after (right) two-stage preputial flap repair
Ectopic urethral meatus are indicated by arrows
 
New service model versus old service model
In this study, we assigned patients to two cohorts. The OS cohort was the control cohort comprising patients on whom we operated from January 2006 to June 2013. All the patients in this cohort remained as in-patients until removal of the urethral catheter and received intravenous antibiotics and regular wound care by medical staff in the postoperative period. Six specialist paediatric surgeons were involved in performing the repairs in the OS cohort. The NS cohort comprised patients who underwent surgery in July 2013 or thereafter. Patients in the NS cohort were routinely discharged on postoperative day 2 or, rarely, on postoperative day 3, with their urethral catheters in situ. The dedicated surgical team comprising three (initially only two) specialist paediatric surgeons who subspecialised in paediatric urology provided all perioperative services, including handling of the consent process, surgical repairs, postoperative demonstration of wound care, and explanation of the discharge plan. Parents or main caregivers were instructed to perform saline irrigation to the penile wound at home 3 to 4 times per day. Patients received oral antibiotics and were scheduled to return in a day visit for removal of urethral catheters by a member of the dedicated team. Parents were instructed to call the ward to arrange an unplanned consultation visit if necessary. After urethral catheter removal, patients were followed up at 2 to 4 weeks, 3 months, 6 to 9 months, and then yearly thereafter.
 
Outcome measures
Medical records were retrospectively reviewed and data were collected by the authors, who were not blinded to the type of service model. Data collected were age at time of surgery, type of hypospadias, type of surgical repair, early morbidity, length of hospital stay (LOS), unplanned hospital visits, and follow-up evaluation for long-term complications. Data on the types of hypospadias and surgical techniques were based on the operative findings and surgical procedures documented in the operative records. The presence of any early morbidity was based on investigation results (including urine/wound swab culture) and/or documentations of urethral catheter dislodgement, wound bleeding, or wound gaping in the early postoperative period when the urethral catheter was in situ. The presence of any long-term complications was based on the findings in the latest follow-up visit, or any reintervention/reoperation records subsequent to the primary surgery. When collecting data, we tried to minimise potential bias regarding long-term complications by defining such complications as meatal stenosis, neourethra dehiscence, urethral fistula, urethral stricture or diverticulum, and significant recurrent chordee. All of these long-term complications required re-intervention/reoperation and were documented if present.
 
Primary outcomes of interest were early morbidity and operative failure. Early morbidity was defined by the presence of one or more of the following conditions when the urethral catheter was still in situ: urinary tract infection, catheter dislodgement, and wound-related events (bleeding/infection/gaping). In the OS cohort, early morbidity was detected during the hospitalisation period after hypospadias repair. In the NS cohort, early morbidity was detected at the time of urethral catheter removal or during unplanned hospital visits before the scheduled date of urethral catheter removal.
 
Successful or failed repair was determined during follow-up in those who had undergone TIP repair or had completed both stages of the two-stage repair. Operative failure was defined as the development of one or more of the long-term complications that required reoperation or reintervention. The secondary outcome measure was the successful completion rate of ERP. Failure of ERP was defined as any unplanned hospital visit earlier than the scheduled date for urethral catheter removal. Failure was further subdivided into day visit or overnight stay.
 
Statistical analysis
Discrete variables were expressed as percentage frequency, whereas continuous variables were reported as mean with standard deviation or median with interquartile range (IQR). The two cohorts were compared using Chi squared, Fisher’s exact, Student’s t, and Mann-Whitney U tests, as appropriate. Using the outcomes of early morbidity and operative failure, multivariable analysis was performed using a logistic regression model by the enter method, which estimated the odds ratios (ORs) and 95% confidence intervals (95% CIs) of potential associated factors, including age at the time of surgery, type of hypospadias, type of surgical repair, and the service model. Statistical analysis was performed with SPSS (Windows version 23; IBM Corp, Armonk [NY], United States). A two-tailed P value of <0.05 was considered to be statistically significant. Based on type I error of 0.05 and power of 0.8, 82 to 152 cases in each cohort would be required to show any two-tailed significant difference in the operative failure rates with a difference of 15% to 20% between the two cohorts.
 
Results
There were 302 major primary hypospadias repairs (OS cohort=176; NS cohort=126) eligible for inclusion in the study. We identified 107 cases of reoperative hypospadias repairs and one case of BMG during the study period; these were excluded from this study. No patients were lost to the first follow-up examination after urethral catheter removal. The median follow-up durations of the OS and NS cohorts were 32 (IQR, 20-58) and 20 (IQR, 14-30) months, respectively (P<0.001).
 
Of the NS cohort, 111 (88.1%) patients successfully completed the ERP. Of the 15 patients who failed to complete ERP, 11 (8.7% of total) returned earlier in an unplanned day visit for wound assessment; these patients only required reassurance without any intervention. Four patients (3.2% of total) required additional overnight hospital stay. Reasons for additional overnight stay were minor wound bleeding (n=1), dislodgement of urethral catheter (n=2), and social reasons (n=1). The patient who failed ERP for social reasons was an orphan, and staff at the orphanage found it difficult to perform wound care at their institution.
 
Table 1 summarises the findings comparing patient characteristics and early morbidity between the two cohorts. The median age at the time of surgery was older in the OS than the NS cohort (P<0.001). There was no difference between the two groups in type of hypospadias, type of surgical procedures, and time interval between surgery and urethral catheter removal. The median LOS was 2 days in the NS cohort versus 10 days in the OS cohort (P<0.001). Patients in the NS cohort experienced less early morbidity than those in the OS cohort (5.6% vs 15.9%; P=0.006).
 

Table 1. Results of univariable analysis comparing baseline characteristics and early morbidity of the two cohorts
 
Excluding patients who had received only the first stage of a two-stage repair, 138 and 109 patients of the OS and NS cohort were eligible for assessment of operative success, respectively. Patients in the NS cohort had a lower operative failure rate than those in the OS cohort (20.2% vs 44.2%; P<0.001). Specifically, patients in the NS cohort had a lower incidence of urethral fistula and dehiscence than patients in the OS cohort (P=0.002 and 0.001); there were no differences in the other complications (Table 2).
 

Table 2. Results of univariable analysis comparing operative failure rates of the two cohorts
 
In the multivariable analysis, the NS model was the only factor that was independently associated with reduced odds of early morbidity (OR=0.35, 95% CI=0.15-0.85; P=0.02). The NS model was also associated with reduced odds of operative failure (OR=0.32, 95% CI=0.17-0.59; P<0.001) compared with the OS model. Compared with proximal hypospadias, distal hypospadias had reduced odds for operative failure (OR=0.14, 95% CI, 0.06-0.37; P<0.001). Age at the time of surgery and surgical techniques were not associated with any difference in operative success (Table 3).
 

Table 3. Results of multivariable analysis of independent predictors for early morbidity and operative failure
 
Discussion
The conventional practice of keeping patients in hospital until urethral catheter removal after hypospadias surgery is well reflected from the first annual Surgical Outcome Monitoring and Improvement Programme Report in 2008/09 to the fifth report in 2012/13 issued by the Hong Kong Hospital Authority.10 11 12 13 14 The median LOS after hypospadias surgery performed in Hospital Authority hospitals ranged from 9 to 11 days from 2008 to 2013.10 11 12 13 14 It was a traditionally held belief that Hong Kong parents would not be sufficiently competent to provide proper wound care at home, and that surgical outcomes would be adversely affected if patients were discharged from hospital with the urethral catheter in situ. There was also concern that Hong Kong parents would not welcome the offer of early hospital discharge, given the reality that the actual costs billed to parents for in-patient service in Hospital Authority hospitals are relatively insignificant, compared with other parts of the world where medical insurance covers only very short in-patient care after hypospadias surgery. The present study was the first in Hong Kong to investigate the outcomes of hypospadias surgery after the introduction of an ERP. It is important to note that our findings do not reflect purely the effect of ERP but the effect of an NS model that features ERP implementation by a dedicated surgical team.
 
Our findings demonstrate that ERP can be applied effectively and safely to all children who undergo primary hypospadias repair, regardless of the severity and type of hypospadias. Since its introduction, we have offered ERP to 126 consecutive patients and none of the parents or caregivers have declined the offer. Only one patient discontinued ERP for social reasons, as that child was an institutionalised orphan. Penile wound care does not require special skills and involves only wound irrigation with normal saline or clean water a few times daily. Patients can also be bathed with the urethral catheters in situ. Adequate preoperative counselling and postoperative wound care demonstration by the same surgeons who performed the surgery is the key to promoting the acceptance of ERP among parents.
 
Almost 90% of our patients completed ERP successfully. Among those who failed to complete ERP, none had major adverse events that required surgical intervention and, overall, only 3.2% of patients required additional overnight stay. The median hospital stay of 2 days under the NS model was significantly shorter than the median of 10 days in our OS control cohort. In-patient services are precious resources in our health care system. A much shorter LOS after hypospadias surgery allows for better allocation of health care resources to other service areas in which in-patient care is more indicated.
 
More importantly, our findings suggest that ERP does not increase early morbidity after primary hypospadias repair. On the contrary, the NS model was the only factor that was found to independently predict a reduced risk of early morbidity. Our finding of an early morbidity rate of 5.6% in the NS model is in agreement with the 4.9% reported by a previous study in the United States.15 Our finding that most of the early morbidity in the OS model was wound-related and our observation that, in some of these patients, the wound swab grew Pseudomonas and extended spectrum beta-lactamase Escherichia coli raised the concern of possible hospital-acquired infection. While more evidence is needed to attribute the high early morbidity rate under the OS model solely to the prolonged hospital stay, it follows logically that avoiding unnecessary hospital stay is an effective way to prevent hospital-acquired infection if in-patient care does not give any additional benefits.
 
We found a better outcome after primary hypospadias repair under the NS versus OS model in both univariable and multivariable analyses. This study not only provides evidence that the implementation of ERP did not reduce operative success, but also demonstrates how our centre has responded to the international trend of concentrating hypospadias repairs among dedicated hypospadias surgeons.2 16 17 In recent years, there has been an international call to stop the practice of hypospadias repair by occasional surgeons. Proponents of this view hold that surgeons who perform hypospadias repair should be proficient in using various techniques to correct the full spectrum of hypospadias defects, from distal hypospadias to the most complex proximal type.17 18 The preoperative impression of the ectopic meatal position is not a reliable reflection of the severity of hypospadias, and many cases are found to be more complicated intra-operatively.19 Under the NS model, we abandoned our policy of allowing all paediatric surgical specialists to perform hypospadias surgery; instead, all hypospadias repairs were concentrated among the three specialists who subspecialised in paediatric urology.
 
We believe the improved operative success under the NS model is attributable to the establishment of the dedicated team, which has also introduced some technical modifications in the existing techniques.20 Our overall failure rate of 20.2% of patients requiring reoperation or re-intervention in the NS cohort is in agreement with the 18.1% reported by a national population-based study in the United Kingdom21 and the 24.1% reported by a regional tertiary centre in Europe.22 Both studies included primary repairs of all types of hypospadias performed by multiple techniques, such as those used in the present study.21 22 Previous studies have shown that centres that operate on more than 20 cases per year have a better operative success than those that operate less frequently,21 and surgeons who perform 20 primary repairs annually have reduced odds of failure compared with those who perform 10 per year.23 Although the minimum number of hypospadias repairs per year a surgeon must perform to be considered competent remains debatable, it is recommended that hypospadias repairs be performed by surgeons who perform a high volume of repairs and are intellectually interested in this subject, with continuous review of their own results.17 The current three-member team in our institution strikes a balance between surgical outcomes and other practical issues, such as stable staffing, expertise, training, and succession.
 
Proximal hypospadias has been known to be associated with a higher failure rate in primary repair and a higher reoperation rate than distal hypospadias.24 25 The most recent studies from major centres have unanimously suggested that the failure rate of primary repair of proximal hypospadias has actually been underreported in the literature.6 26 27 Our finding of increased odds of failure in primary repair of proximal hypospadias when compared with the distal type is in agreement with the current evidence. We did not find age at the time of surgery and surgical techniques to be independent predictors of repair failure, and our finding is in agreement with other studies.22
 
We acknowledge the limitations of the retrospective nature of our study and the lack of randomisation. Data are lacking on anatomical variations such as quality of urethral plate and glans size, which may have affected the surgical outcomes. Patients were not randomised by the type of recovery programme and the study participants were assigned to the two cohorts according to the service model at the time. Our results could have been confounded by the effect of accumulating experience in hypospadias surgery throughout the study period. Data were collected by investigators who were not blinded to the types of service models; therefore, there was potential bias in the data collection process, but inter-rater reliability was not examined. As the ERP was implemented at the same time as the establishment of the dedicated team, these two factors could not be analysed separately. Being the more recent cohort, the patients under the NS model had shorter follow-up duration than those under the OS model. However, our median follow-up duration of 20 months in the NS cohort compares favourably to that of many published studies.25
 
Despite these limitations, our findings demonstrate the safety and effectiveness of implementing ERP to primary hypospadias repair for the full spectrum of hypospadias severity. A dedicated surgical team may play an important role in the successful implementation of ERP and optimisation of surgical outcomes.
 
Author contributions
All authors have made substantial contributions to the concept of this study; acquisition of data; analysis or interpretation of data; drafting of the article; and critical revision for important intellectual content.
 
Funding/support
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
Declaration
All authors have no conflicts of interest to disclose. All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.
 
Ethical approval
The study protocol was approved by the Joint Chinese University of Hong Kong–New Territories East Cluster Clinical Research Ethics Committee. The requirement for patient consent was waived by the ethics board.
 
References
1. Baskin LS, Ebbers MB. Hypospadias: anatomy, etiology, and technique. J Pediatr Surg 2006;41:463-72. Crossref
2. Steven L, Cherian A, Yankovic F, Mathur A, Kulkarni M, Cuckow P. Current practice in paediatric hypospadias surgery; a specialist survey. J Pediatr Urol 2013;9(6 Pt B):1126-30. Crossref
3. Wilkinson DJ, Farrelly P, Kenny SE. Outcomes in distal hypospadias: a systematic review of the Mathieu and tubularized incised plate repairs. J Pediatr Urol 2012;8:307-12. Crossref
4. Long CJ, Canning DA. Hypospadias: are we as good as we think when we correct proximal hypospadias. J Pediatr Urol 2016;12:196.e1-5. Crossref
5. Snodgrass WT, Bush N, Cost N. Tubularized incised plate hypospadias repair for distal hypospadias. J Pediatr Urol 2010;6:408-13. Crossref
6. Pippi Salle JL, Sayed S, Salle A, et al. Proximal hypospadias: a persistent challenge. Single institution outcome analysis of three surgical techniques over a 10-year period. J Pediatr Urol 2016;12:28.e1-7. Crossref
7. Pohl HG, Joyce GF, Wise M, Cilento BJ Jr. Cryptorchidism and hypospadias. J Urol 2007;177:1646-51. Crossref
8. Snodgrass W, Bush N. Tubularized incised plate proximal hypospadias repair: continued evolution and extended applications. J Pediatr Urol 2011;7:2-9. Crossref
9. McNamara ER, Schaeffer AJ, Logvinenko T, et al. Management of proximal hypospadias with 2-stage repair: 20-year experience. J Urol 2015;194:1080-5. Crossref
10. Surgical Outcomes Monitoring & Improvement Program (SOMIP) report. Volume One: July 2008-June 2009. Hospital Authority, Hong Kong SAR Government; 2010.
11. Surgical Outcomes Monitoring & Improvement Program (SOMIP) report. Volume Two: July 2009-June 2010. Hospital Authority, Hong Kong SAR Government; 2011.
12. Surgical Outcomes Monitoring & Improvement Program (SOMIP) report. Volume Three: July 2010-June 2011. Hospital Authority, Hong Kong SAR Government; 2012.
13. Surgical Outcomes Monitoring & Improvement Program (SOMIP) report. Volume Four: July 2011-June 2012. Hospital Authority, Hong Kong SAR Government; 2013.
14. Surgical Outcomes Monitoring & Improvement Program (SOMIP) report. Volume Five: July 2012-June 2013. Hospital Authority, Hong Kong SAR Government; 2014.
15. Meyer C, Sukumar S, Sood A, et al. Inpatient hypospadias care: trends and outcomes from the American nationwide inpatient sample. Korean J Urol 2015;56:594-600. Crossref
16. Springer A, Krois W, Horcher E. Trends in hypospadias surgery: results of a worldwide survey. Eur Urol 2011;60:1184-9. Crossref
17. Snodgrass W, Macedo A, Hoebeke P, Mouriquand PD. Hypospadias dilemmas: a round table. J Pediatr Urol 2011;7:145-57. Crossref
18. Malone P. Commentary to “A standardized classification of hypospadias”. J Pediatr Urol 2012;8:415. Crossref
19. Orkiszewski M. A standardized classification of hypospadias. J Pediatr Urol 2012;8:410-4. Crossref
20. Tam YH, Pang KK, Wong YS, et al. Improved outcomes after technical modifications in tubularized incised plate urethroplasty for mid-shaft and proximal hypospadias. Pediatr Surg Int 2016;32:1087-92. Crossref
21. Wilkinson DJ, Green PA, Beglinger S, et al. Hypospadias surgery in England: higher volume centres have lower complication rates. J Pediatr Urol 2017;13:481.e1-6. Crossref
22. Spinoit AF, Poelaert F, Van Praet C, Groen LA, Van Laecke E, Hoebeke P. Grade of hypospadias is the only factor predicting for re-intervention after primary hypospadias repair: a multivariate analysis from a cohort of 474 patients. J Pediatr Urol 2015;11:70.e1-6. Crossref
23. Lee OT, Durbin-Johnson B, Kurzrock EA. Predictors of secondary surgery after hypospadias repair: a population based analysis of 5,000 patients. J Urol 2013;190:251-5. Crossref
24. Castagnetti M, El-Ghoneimi A. Surgical management of primary severe hypospadias in children: systematic 20-year review. J Urol 2010;184:1469-74. Crossref
25. Pfistermuller KL, McArdle AJ, Cuckow PM. Meta-analysis of complication rates of the tubularized incised plate (TIP) repair. J Pediatr Urol 2015;11:54-9. Crossref
26. Stanasel I, Le HK, Bilgutay A, et al. Complications following staged hypospadias repair using transposed preputial skin flaps. J Urol 2015;194:512-6. Crossref
27. Long CJ, Chu DI, Tenney RW, et al. Intermediate-term followup of proximal hypospadias repair reveals high complication rate. J Urol 2017;197(3 Pt 2):852-8. Crossref

Outcomes of a pharmacist-led medication review programme for hospitalised elderly patients

Hong Kong Med J 2018 Apr;24(2):98–106 | Epub 9 Feb 2018
DOI: 10.12809/hkmj176871
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
ORIGINAL ARTICLE
Outcomes of a pharmacist-led medication review programme for hospitalised elderly patients
Patrick KC Chiu, FRCP (Glasg), FHKAM (Medicine)1; Angela WK Lee, MPharm, RPharmS (Great Britain)2; Tammy YW See, MClinPharm, RPharmS (Great Britain)2; Felix HW Chan, FRCP (Edin, Glasg, Irel), FHKAM (Medicine)1
1 Geriatric Medical Unit, Grantham Hospital, Wong Chuk Hang, Hong Kong
2 Pharmacy, Grantham Hospital, Wong Chuk Hang, Hong Kong
 
Corresponding author: Dr Patrick KC Chiu (chiukc@ha.org.hk)
 
 Full paper in PDF
 
Abstract
Introduction: Elderly patients are at risk of drug-related problems. This study aimed to determine whether a pharmacist-led medication review programme could reduce inappropriate medications and hospital readmissions among geriatric in-patients in Hong Kong.
 
Methods: This prospective controlled study was conducted in a geriatric unit of a regional hospital in Hong Kong. The study period was from December 2013 to September 2014. Two hundred and twelve patients were allocated to receive either routine care (104) or pharmacist intervention (108) that included medication reconciliation, medication review, and medication counselling. Medication appropriateness was assessed by a pharmacist using the Medication Appropriateness Index. Recommendations made by the pharmacist were communicated to physicians.
 
Results: At hospital admission, 51.9% of intervention and 58.7% of control patients had at least one inappropriate medication (P=0.319). Unintended discrepancy applied in 19.4% of intervention patients of which 90.7% were due to omissions. Following pharmacist recommendations, 60 of 93 medication reviews and 32 of 41 medication reconciliations (68.7%) were accepted by physicians and implemented. After the program and at discharge, the proportion of subjects with inappropriate medications in the intervention group was significantly lower than that in the control group (28.0% vs 56.4%; P<0.001). The unplanned hospital readmission rate 1 month after discharge was significantly lower in the intervention group than that in the control group (13.2% vs 29.1%; P=0.005). Overall, 98.0% of intervention subjects were satisfied with the programme. There were no differences in the length of hospital stay, number of emergency department visits, or mortality rate between the intervention and control groups.
 
Conclusions: A pharmacist-led medication review programme that was supported by geriatricians significantly reduced the number of inappropriate medications and unplanned hospital readmissions among geriatric in-patients.
 
 
New knowledge added by this study
  • This is the first prospective controlled study of the effect of a pharmacist-led medication review programme on medication use and health services utilisation among hospitalised Chinese elderly patients in Hong Kong.
  • The medication review programme led by a clinical pharmacist resulted in a substantial reduction in the use of inappropriate medications among hospitalised elderly patients and all-cause unscheduled readmissions at 1 month after hospital discharge.
Implications for clinical practice or policy
  • A pharmacist-led medication review programme is an important strategy that can enhance the safety and quality of prescription among elderly patients in hospital.
  • It is strongly recommended that these programmes be standardised and implemented in all medical and geriatric wards in Hong Kong.
 
 
Introduction
Elderly patients have multiple co-morbidities and they are consequently prone to multiple medication use. Inappropriate medication use is common among hospitalised older adults. The number of drugs taken is one of the important determinants of risk for receiving an inappropriate medication.1 There is a high prevalence of unnecessary drug use in frail older people. In one hospital study, 44% of patients were prescribed at least one unnecessary drug, with the most common reason being lack of indication.2 The most commonly prescribed unnecessary drug classes were gastrointestinal, central nervous system, and therapeutic nutrients/minerals.2 Appropriate use of drugs is particularly important in the frail older people who are especially at risk of adverse drug reactions.3 It has been shown that implementation of a clinical pharmacist service has a positive effect on medication use and health care service utilisation among hospitalised patients.4 5 A local study in a geriatric hospital demonstrated the effectiveness of a drug rationalisation programme with involvement of a clinical pharmacist in reducing the incidence of polypharmacy and inappropriate medications.6 Interacting with the health care team on patient rounds, interviewing patients, reconciling medications, and providing patient discharge counselling and follow-up all resulted in improved outcomes.7 It is for this reason that patient safety strategies encourage the use of medication reconciliation and clinical pharmacists in health care systems to reduce adverse drug events.8 9 10
 
There is not much information about the effectiveness of a medical review programme among hospitalised elderly patients in Hong Kong. Two recent local reports that examined the effects of a clinical pharmacist–led medication review on hospital readmissions showed conflicting results and did not specifically address elderly patients.11 12 We therefore conducted a prospective controlled study to investigate the effectiveness of a comprehensive pharmacist intervention on medication use and hospital readmission among a group of geriatric in-patients in Hong Kong.
 
Methods
This prospective controlled study was conducted in the geriatric unit of a regional hospital in Hong Kong. The unit has 38 in-patient beds and admits older people aged 65 years or above who are transferred from an acute hospital after initial stabilisation of medical and/or geriatric problems. The unit admits more than 1000 patients per year and provides medical treatment, rehabilitation, and discharge planning services by a multidisciplinary team composed of a geriatrician, residents, nurses, physiotherapists, occupational therapists, and medical social workers. All patients admitted to the unit during December 2013 to September 2014 were included. Patients were excluded if they refused to participate, were terminally ill with a life expectancy of less than 3 months, or if they had already received pharmacist intervention in another hospital prior to this admission. Eligible subjects were assigned to an intervention or control group according to the admission day of the week. Those who were admitted on Monday through Thursday were assigned to the intervention group, and those admitted on Friday through Sunday to the control group. This arrangement was to ensure that pharmacist intervention could be initiated promptly within 48 hours of patient admission. Demographic data, functional status, co-morbidities, and number of drugs on admission were collected at admission.
 
The intervention was conducted by a pharmacist who was present in the unit from Monday to Saturday. The pharmacist provided pharmaceutical care from admission to discharge. Interventions performed by the pharmacist consisted of the following:
 
(1) Medication reconciliation on admission to identify unintended discrepancies between medications prescribed on admission and the usual medications prior to admission—sources to assist medication reconciliation included: electronic patient record; patient’s ward case notes; interview with patient and/or patient carer. The number and type of unidentified discrepancies were recorded.
 
(2) Medication review to check for medication appropriateness on admission and also at discharge—medication appropriateness was assessed by the Medication Appropriateness Index (MAI).13 There are 10 criteria to assess for appropriateness, namely indication, effectiveness, dosage, correct direction, practical direction, drug-drug interaction, drug-disease interaction, duplication, duration, and expense. For a drug item coded as ‘inappropriate’, relative weights for each criterion would apply. A sum of MAI scores could then be calculated to give a score ranging from 0 to 18. The higher the score, the more inappropriate the drug. Recommendations from the pharmacist after the reconciliation and medication review in the intervention group were then communicated to the in-charge doctor via a written note in the medical records. Recommendations were reinforced verbally if deemed appropriate by the pharmacist.
 
(3) Pharmacist counselling on admission and also at discharge was provided to improve patients’ drug knowledge to ensure proper use of drugs and compliance after discharge. A discharge counselling service was provided for all patients who returned home. The counselling included any changes to drug regimen; an explanation of each drug’s indication; any untoward effects that might occur and when to seek medical advice; and drug storage and administration instructions. To ensure patient understanding, written information such as patient information leaflets were given to patients and their carers to remind them of the correct drug regimen. If the patient was illiterate, a simple diagram was drawn on drug labels to demonstrate the time of day and number of tablets to be taken. If necessary, individualised pictorial schedules with drug images and administration instructions could be produced for patients and their carers. The assistance of a family member or external care services such as a community nurse was enlisted if the patient was found to have compliance issues.
 
The control group received routine clinical services. Records of the control group were retrospectively reviewed by the pharmacist after patient discharge to check for medication appropriateness on admission and also at discharge. The primary outcome measure was the appropriateness of prescription as measured by the MAI. Secondary outcomes included the acceptance rate by physicians, number of subjects with unintended discrepancies, patient satisfaction with the programme (for those home-living only), and unplanned hospitalisations 1 and 3 months after discharge.
 
A sample size of 98 patients per group was required to have 85% power to detect an effect size of 0.9 on the MAI. Our sample size was finally set at 210 patients to account for loss of participants due to dropout or death. This sample size was comparable with a study by Spinewine et al14 in which MAI was used as one of the tools to assess appropriateness of prescribing in an acute geriatric care unit and 203 patients were recruited. Our study included 212 patients and was expected to have adequate statistical power to detect differences between groups. Descriptive analyses were performed and included the number and types of unintended discrepancies, MAI score upon admission and at discharge, types of drug-related problems, number of interventions made by pharmacists, and number of recommendations accepted by doctors and implemented. Outcomes for the two groups before and after the programme were compared using the t test and Chi squared test. The Statistical Package for the Social Sciences (Windows version 17.0; SPSS Inc, Chicago [IL], United States) was used and a P value of <0.05 was regarded as statistically significant. The study was approved by the Cluster Research Ethics Committee of the Hospital Authority Hong Kong West Cluster. Written consent was obtained from the patient or their caregiver. The absence of pharmacist intervention in the control group was considered acceptable because a pharmacy service was not a part of routine care at the institution.
 
Results
Figure 1 summarises the patient flow from recruitment to hospital discharge, the components of the medication review programme, and the planned outcome measures. A total of 212 patients were recruited. There were 108 subjects in the intervention group and 104 in the control group (Fig 2). There were no statistical differences in the baseline characteristics of patients (Table 1).
 

Figure 1. Patient flow of the medication review programme from patient recruitment to patient discharge
 

Figure 2. Patient flow diagram
 

Table 1. Baseline demographics and characteristics of the intervention and control groups
 
Appropriateness of prescription
On admission, 51.9% (56/108) of the intervention group and 58.7% (61/104) of the control group had at least one drug classified as inappropriate (P=0.319). Overall, 1996 drug items were reviewed by a pharmacist on admission of which 1020 were from the intervention group and 976 from the control group. Among them, 9.3% and 11.1% of the drugs, respectively, were classified as inappropriate (P=0.282). In the intervention group, 93 recommendations were made by the pharmacist of which 60 (64.5%) were accepted by the physicians and implemented. The mean (standard deviation) MAI score per patient was 2.19 (3.03) in the intervention group and 2.28 (3.09) in the control group (P=0.841). The mean MAI score per drug was 0.23 (0.30) in the intervention group and 0.25 (0.31) in the control group (P=0.628) [Table 2].
 
After the program and at discharge, the proportion of subjects with inappropriate medications in the intervention group was significantly lower than that in the control group (28.0% vs 56.4%; P<0.001). Among the 1999 drug items reviewed by the pharmacist on patient discharge, 3.5% (37 of 1048) of the intervention group and 9.7% (92 of 951) of the control group were classified as inappropriate (P<0.001). The intervention group also had a significantly lower MAI score per patient (0.95 (2.02) vs 2.02 (2.53); P<0.001) and MAI score per drug (0.09 (0.17) vs 0.24 (0.30); P<0.001) implying a significant reduction in medication inappropriateness after the pharmacist medication review (Table 2).
 

Table 2. A comparison of the number of subjects with inappropriate medications and the MAI scores between the intervention and control groups on admission and at discharge
 
Types of inappropriateness according to the MAI in the two groups are illustrated in Figure 3. In both the intervention and control groups, the common causes were indication, effectiveness, dosage, practical direction, duration, and expense. After the programme, there was a significant reduction in the number of these drug-related problems in the intervention group.
 

Figure 3. Comparison of the types of inappropriate medication use between the intervention and control groups on admission and at discharge (paired t test)
 
Unintended discrepancy of medications
Among the 108 subjects in the intervention group, 19.4% had at least one unintended discrepancy in medications, involving a total of 43 drug factors. The majority (90.7%) of these factors were omission of drugs, and 4.6% were due to inappropriate dosages. Of all the drug factors involved, 69.8% involved prescribed drugs from hospitals, 25.6% were from a private clinic, and 4.6% were over-the-counter drugs. Overall, 41 recommendations were made, of which 32 (78.0%) were accepted by physicians and implemented.
 
Patient satisfaction
Contact was made with 50 of the 90 non-institutionalised subjects 1 month after discharge to assess satisfaction with the programme. Of those contacted, 98.0% were satisfied with the programme and only one (2.0%) patient expressed a neutral opinion.
 
Impact on health care services utilisation and mortality
There were no statistical differences in the length of hospital stay, in-patient mortality, or mortality at 1 month or 3 months after discharge. There was also no statistical difference in the number of attendances at the accident and emergency department 1 month or 3 months after discharge or in the unplanned hospital readmission rate at 3 months after discharge. The unplanned hospital readmission rate 1 month after discharge, however, was significantly lower in the intervention group than that in the control group (13.2% vs 29.1%; P=0.005) [Table 3].
 

Table 3. Comparison of the impact on health services utilisation and mortality between the intervention and control groups
 
Discussion
To the best of our knowledge, this is the first local prospective controlled study to investigate the effectiveness of a pharmacist-led medication review programme on medication appropriateness and clinical outcomes among geriatric in-patients in Hong Kong. This study has demonstrated superior outcomes that favour a pharmacist-led intervention. There was a substantial reduction in the use of inappropriate medications and all-cause unscheduled readmissions 1 month after hospital discharge. Nonetheless, analysis of length of hospital stay, number of all-cause emergency department visits, and mortality rate favoured neither the intervention nor the usual pharmacist care.
 
This study showed that one in five geriatric in-patients had an unintended medication discrepancy on admission. This figure was slightly higher than that found in a group of 3317 hospitalised medical patients (13%) over 1 year in an acute hospital in Hong Kong by Kwok et al.15 Subjects in our study were all elderly patients, whereas those in Kwok et al’s study were adults of all ages. Elderly subjects tend to have polypharmacy and thus are more vulnerable to unintended medication discrepancy when they move in and out of hospital or are transferred to another health care unit for further care. Unjustifiable medication discrepancies account for more than half of the medication errors that occur during transition of care and up to one third have the potential to cause harm.16 17 This does not bode well for our elderly patients with multiple co-morbidities.
 
Up to 30% of the discrepancies in our study involved medications that had been prescribed by private practitioners or purchased over-the-counter. Unlike medications prescribed from the Hospital Authority, these medications might be overlooked unless the admitting doctor specifically asks for a detailed drug history from the patient. Knowing the medication history and hence resuming these medications are important if new health problems are to be prevented. Pharmacist-led medication reconciliation is therefore a critical process that can enhance patient medication safety by compiling a complete and accurate medication list for patients in hospital.
 
This study revealed that more than half of the subjects (55.2%) received inappropriate medications. The majority of reasons for inappropriateness related to effectiveness, dosage, practical directions, and expense as reflected by the MAI. The inappropriate dosage and the questionable effectiveness might lead to not only failed pharmacological effects, but also potentially an untoward adverse drug reaction, especially in elderly individuals with pre-existing organ dysfunction.18 When a medication is not used according to the practical directions, it may lead to patient non-compliance. Optimising outcomes while reducing costs are the keys for medication management in today’s health care environment.19 Often there are several choices of drugs available to treat a disease or health condition and some are more expensive than others. The involvement of a ward-based pharmacist to review medication can enhance the use of appropriate medications in hospitalised patients and potentially reduce medication costs.
 
Following the medication review (60/93) and medication reconciliation (32/41), there were 92 recommendations that were accepted by the physician. The overall acceptance rate by physicians and the implementation of pharmacist recommendations in our study was 68.7% (92/134). This figure ranged from 39% to 100% in a previous systematic review of 32 studies.4 Our study did not specifically record recommendations accepted by physicians but not implemented. Hence the acceptance rate in our study may be underestimated. Nevertheless, the clinical pharmacist is encouraged to discuss the medication-related problems in person with the physician as well as contacting the patient in order to enhance the implementation rate.4
 
Pharmacy departments within the public hospital system in Hong Kong have strived to implement the aforementioned patient safety strategies in different specialties. Nonetheless, this is not a standard practice simply because of insufficient pharmacist staffing resources. In some hospitals, a pharmacist service is provided in wards, but this does not apply in all cases and is not standardised. Experience of a pharmacist-led medication reconciliation service from an acute teaching hospital in Hong Kong showed promising results over a 1-year trial run with high acceptance and recognition by other health care professionals.16 It is hoped that the clinical role of clinical pharmacists in patient medication management in hospitals can be encouraged. Another local study has demonstrated a positive impact on medication safety in patients with diabetes by pharmacists’ intervention in collaboration with a multidisciplinary team.20 The feasibility of incorporating a pharmacist as part of a multidisciplinary team of health care professionals must be explored in geriatric wards in Hong Kong. With increasing life expectancy, the expanding elderly population will equate to an increase in morbidity and mortality owing to drug-related problems where the need for trained health care professionals to perform medication reviews will be in even greater demand. To enhance safe drug use with limited resources, a systematic approach must be adopted to cover all aspects that affect drug therapy.
 
In terms of the impact on health care services utilisation, a recent systematic review and meta-analysis of the effectiveness of a pharmacist-led medication reconciliation programme revealed a substantial reduction in the rate of all-cause readmissions (19%), all-cause emergency department visits (28%), and adverse drug event–related hospital visits (67%).21 Our study revealed a significant reduction in unplanned hospital admissions (all-cause admission) at 1 month but not at 3 months. This implication might be due to an inadequate sample size to show the difference at 3 months. Alternatively, it might also imply that pharmacist intervention needs to be continued after patient discharge in order to have a sustained effect. This is supported by a study by Schnipper et al22 in which pharmacist intervention after patient discharge was associated with a lower rate of preventable adverse drug events 30 days after hospital discharge.
 
During the pharmacist review, cost-effectiveness of drug use was assessed through MAI. Alternative options such as less-expensive formulations or drugs but of the same quality would be recommended to the doctor in-charge. This was a means of encouraging cost-effective use of drugs in a hospital. Furthermore, the reduction in unscheduled hospital readmissions in the intervention group implies a potential saving in hospital costs. Although a detailed analysis was not performed in this study, a rough estimation is that nearly HK$2 million may be saved annually as a result of lower drug costs and reduced hospital admissions, even after considering the cost of employing a pharmacist. The estimation was based on the following calculations. The estimated drug saving as a result of a switch to a more cost-effective alternative was HK$7500 among the 108 patients in the intervention group. This can be projected to a saving of about HK$69 500 in a unit that admits 1000 patients annually. In the current study, there were 16 fewer readmissions in the intervention group compared with the control group. Assuming a daily cost of an acute hospital bed is HK$4680 and the mean length of hospital stay is 3 days, this equates to a potential saving of about HK$2 080 000 per year in a unit that admits 1000 patients annually. If it is assumed that a pharmacist spends 30 minutes for each patient at an hourly salary of HK$433, the projected cost of an additional pharmacist to run the intervention would be HK$216 500 per year. The net annual saving of this programme to serve 1000 patients in this unit would thus still be close to HK$2 million.
 
This study had several limitations. First, a substantial proportion (35%) of all the admitted patients were not screened by a pharmacist on admission. This was due to a temporary pause in subject recruitment when patients were admitted on public holidays, when the pharmacist was on holiday or when she had to relieve another pharmacist in the hospital. Moreover, a substantial proportion (44%) of eligible subjects were not included owing to no consent or refusal. These factors might have resulted in selection or self-selection bias. Second, subject recruitment was not randomised, but done according to the day of admission. This might be a source of bias. Nevertheless, this would have minimal influence on the outcomes, as the baseline characteristics of the intervention and control groups were comparable. Third, the pharmacist who carried out the review and data extraction was not blinded to the study hypothesis and the group status of the subjects. This could potentially lead to information bias, although this might be partially offset by the fact that the majority of the information or data on the outcome measures were taken with reference to a well-established and validated tool. Fourth, this study was performed in a single unit, so generalisation to other settings is not possible. Fifth, MAI is an implicit tool that is subjective. A single pharmacist as the rater might limit the reliability of the assessment results. Nevertheless, the more explicit tools of STOPP/START criteria23 had also been referred to in addition to the MAI during the review process. Sixth, this study only addressed appropriateness of drug use, whereas underuse of drugs was not investigated. Finally, this study could not conclude a causal relationship between the reduction in inappropriate medications and the reduction in unscheduled hospital readmissions because there were several components in the intervention that included a medication review, medication reconciliation, and discharge counselling. It is difficult to be certain which of these components alone or in combination gave rise to the positive outcome of this study.
 
On the other hand, there were several strengths in this study. This was the first prospective controlled study of the effect of a pharmacist-led medication review programme on medication use and health services utilisation involving over 200 Chinese elderly patients in Hong Kong. Second, a well-validated tool was used to assess medication appropriateness. The use of the MAI tool focused on the patient and the entire medication regimen. Third, there was a comprehensive review of outcomes including quality of prescribing, health services utilisation, mortality, length of hospital stay, and patient satisfaction.
 
Conclusions
This study supported the role of a hospital-based clinical pharmacist to enhance appropriate medication use among elderly Chinese in-patients. A systematic medication review programme in a geriatric unit resulted in a reduced number of drug omissions and fewer inappropriate medications. The service provided by the clinical pharmacist and supported by geriatricians was welcomed by patients and their carers. Together with the potential to reduce hospital readmissions and their associated cost, it is hoped that an in-hospital pharmacist-led medication review programme can be recognised as one of the important strategies to enhance the safety and quality of prescription among elderly patients in hospitals. It is strongly recommended that these programmes be standardised and implemented in all medical and geriatric wards in Hong Kong. Future studies should recruit a larger sample size in a randomised controlled design in other geriatric hospital settings to reiterate our findings. Furthermore, these studies might consider including adverse drug event–related hospital visits as one of the outcome measures.
 
Declaration
All authors have disclosed no conflicts of interest.
 
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