Amniotic fluid gamma-glutamyl transferase for prediction of biliary atresia in cases of non-visualisation of the fetal gallbladder: a retrospective study using a validated analytical platform and local reference range.
T Y T Cheung, N K L Wong, D S Sahota, S R Subramaniam, S L Lau, X Zhu, W T Lui, E K W Chan, Y K Y Kwok, K W Choy, T Y Leung, M H M Chan, F C K Wong, Y H Ting
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引用次数: 0
Abstract
Introduction: The level of amniotic fluid gamma-glutamyl transferase (AFGGT) may help identify biliary atresia (BA) in cases of non-visualisation of the fetal gallbladder (NVFGB). This study aimed to validate a serum/plasma matrix-based gamma-glutamyl transferase (GGT) assay for amniotic fluid (AF) samples, establish a local gestational age-specific AFGGT reference range, and evaluate the efficacy of AFGGT for predicting fetal BA in pregnancies with NVFGB using the constructed reference range.
Methods: The analytical performance of a serum/plasma matrix-based GGT assay on AF samples was evaluated using a Cobas c502 analyser. Amniotic fluid gamma-glutamyl transferase levels in confirmed euploid singleton pregnancies (16+0 to 22+6 weeks of gestation) were determined using the same analyser to establish a local gestational age-specific reference range (the 2.5th to 97.5th percentiles). This local reference range was used to determine the positive predictive value (PPV) and negative predictive value (NPV) of AFGGT level <2.5th percentile for identifying fetal BA in euploid pregnancies with NVFGB.
Results: The serum/plasma matrix-based GGT assay was able to reliably and accurately determine GGT levels in AF samples. Using the constructed local gestational age-specific AFGGT reference range, the NPV and PPV of AFGGT level <2.5th percentile for predicting fetal BA in pregnancies with NVFGB were 100% and 25% (95% confidence interval=0, 53), respectively.
Conclusion: In pregnancies with NVFGB, AFGGT level ≥2.5th percentile likely excludes fetal BA. Although AFGGT level <2.5th percentile is not diagnostic of fetal BA, fetuses with AFGGT below this level should be referred for early postnatal investigation.
期刊介绍：
The HKMJ is a Hong Kong-based, peer-reviewed, general medical journal which is circulated to 6000 readers, including all members of the HKMA and Fellows of the HKAM. The HKMJ publishes original research papers, review articles, medical practice papers, case reports, editorials, commentaries, book reviews, and letters to the Editor. Topics of interest include all subjects that relate to clinical practice and research in all branches of medicine. The HKMJ welcomes manuscripts from authors, but usually solicits reviews. Proposals for review papers can be sent to the Managing Editor directly. Please refer to the contact information of the Editorial Office.
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