Biliary atresia screening: why, when, and how?

Population-based screening strategies for biliary atresia in the newborn: A systematic review and meta-analysis

BACKGROUND

Newborn screening for biliary atresia (BA) may facilitate earlier diagnosis and intervention for improved clinical outcomes.

METHODS

We systematically reviewed the accuracy of population-based screening strategies for BA in the newborn using PRISMA-DTA guidelines. We included cohort or cross-sectional studies. The screening (index) tests included stool color card (SCC) and direct/conjugated bilirubin (DB/CB) and the reference standard was intraoperative cholangiogram. Meta-analysis was performed using random-effects logistic regression models.

RESULTS

We included 15 studies (1,816,722 participants) that assessed 5 different population-based screening strategies. QUADAS-2 assessment revealed high risk of bias for patient selection in one study and uncertain risks for reference standard in multiple studies. High certainty evidence suggests that DB/CB assessed after birth had a summary sensitivity of 100% (95% CI 100,100) and specificity of 98.8% (98.8,98.9) (5 studies, 662141 participants). Moderate certainty evidence suggests that SCC screening at a month of age had summary sensitivity of 79.6% (95% CI 70.6, 86.4) and specificity of 99.9% (95% CI 99.9, 99.9) (7 studies, 996262 participants).

CONCLUSIONS

DB/CB in the first few days of life has the best diagnostic accuracy for population screening for biliary atresia in the newborn. Future research should focus on cost-effectiveness and combinations of screening strategies.

Postnatal outcomes of fetuses with isolated gallbladder anomalies: be aware of biliary atresia

OBJECTIVES

To analyze the normal development of fetal gallbladder (GB) and evaluate the postnatal outcomes of fetuses with isolated GB anomalies without other structural abnormalities by ultrasound.

METHODS

This was a retrospective study. We collected normal cases during 2016 between 15 and 40 gestational weeks and measured the length and width of GB to establish a normal reference range of GB. Using the 10th and 90th percentiles of the normal reference range, isolated cases of enlarged or small GB without other structural anomalies were selected between January 2017 and December 2019. Simultaneously, cases of echogenic material in the GB were included. Fetuses with non-visualization of the fetal gallbladder (NVFGB) were collected between January 2010 and December 2019. Postnatal outcomes of these cases were followed up and analyzed.

RESULTS

There were 670 cases in the normal group and a linear correlation was found between the dimensions of GB and the gestational age, including the length (r = 0.69; p < .05; y = 0.97 + 0.70 × gestational age) and width (r = 0.48; p < .05; y = 1.65 + 0.12 × gestational age). Sixty-two cases with isolated GB anomalies were collected, including nine cases of enlarged GB, four cases of small GB, three cases of echogenic material in the GB, and 46 cases of NVFGB. Sixty fetuses (96.8%, 60/62) had good outcomes, except that two neonates (4%, 2/50) in small GB and NVFGB groups were both born with BA. In the NVFGB group, 97.8% (45/46) were with good outcomes, in which gallbladders were finally visualized in 37 (80.4%, 37/46) cases and GB agenesis was postnatally diagnosed in eight (17.4%, 8/46) patients by ultrasound.

CONCLUSION

The postnatal outcomes of most fetuses (96.8%) with isolated GB anomalies such as enlarged GB, echogenic material in the GB were favorable. When it comes to cases of small GB or NVFGB in prenatal ultrasound diagnosis, we should alert biliary atresia in prenatal counseling.

Increased Serum Levels of Activated Caspases in Murine and Human Biliary Atresia

In biliary atresia (BA), apoptosis is part of the pathomechanism, which results in progressive liver fibrosis. There is increasing evidence suggesting that apoptotic liver injury can be non-invasively detected by measuring the caspase activity in the serum. The purpose of this study was to investigate whether serological detection of caspase activation mirrors apoptotic liver injury in the infective murine BA-model and represents a suitable biomarker for BA in humans. Analysis showed increased caspase-3 activity and apoptosis in the livers of cholestatic BALB/c mice, which correlated significantly with caspase activation in the serum. We then investigated caspase activation and apoptosis in liver tissues and sera from 26 BA patients, 23 age-matched healthy and 11 cholestatic newborns, due to other hepatopathies. Compared to healthy individuals, increased caspase activation in the liver samples of BA patients was present. Moreover, caspase-3 activity was significantly higher in sera from BA infants compared to patients with other cholestatic diseases (sensitivity 85%, specificity 91%). In conclusion, caspase activation and hepatocyte apoptosis play an important role in experimental and human BA. We demonstrated that serological detection of caspase activation represents a reliable non-invasive biomarker for monitoring disease activity in neonatal cholestatic liver diseases including BA.

Inflammation Drives MicroRNAs to Limit Hepatocyte Bile Acid Transport in Murine Biliary Atresia

BACKGROUND

Biliary atresia (BA) is an inflammatory pediatric cholangiopathy with only surgical means for treatment. Many contributors to bile acid synthesis and transport have previously been reported to be downregulated in patients with BA; yet, the driving factors of the abnormal bile acid synthesis and transport in regard to BA have not been previously studied.

MATERIALS AND METHODS

Wild type or Ig-α^-/- mice were injected with salt solution (control) or rotavirus on day of life 0, and analyses were performed on day of life 14. The mRNA levels of bile acid transporters/nuclear receptors and liver microRNAs (miRNAs) were compared between groups. A mouse hepatocyte cell line was used to examine the effects of innate cytokines on miRNA levels and bile acid transporter/nuclear receptor expression and miRNAs on bile acid transporter/nuclear receptor expression.

RESULTS

BA mice had significantly increased mRNA expression of innate cytokines and miRNAs known to bind bile acid transporters/nuclear receptors (miRNAs -22-5p, -34a-5p, and -222-3p) and decreased mRNA expression of bile acid transporters and nuclear receptors. In vitro, TNF-α and IL-1β decreased BSEP and CYP7A1 while increasing miRNA-34a-5p and miRNA 222-3p. LXR, SHP, CYP7A1, NTCP, and MRP2 were decreased by miRNA-34a-5p, whereas miRNA-222-3p decreased NTCP and MRP4. TNF-α and IL-1β increased expression of miRNAs 34a-5p and 222-3p and these miRNAs then decrease expression of multiple bile acid transporters and nuclear receptors.

CONCLUSIONS

Loss of bile acid transporters increases hepatotoxicity via bile acid retention. Therapeutic agents that increase bile acid transport or nuclear receptor functioning should be investigated in BA.

Factors Influencing Time-to-diagnosis of Biliary Atresia

OBJECTIVES

Diagnosing biliary atresia (BA) quickly is critical, because earlier treatment correlates with delayed or reduced need for liver transplantation. However, diagnosing BA quickly is also difficult, with infants usually treated after 60 days of life. In this study, we aim to accelerate BA diagnosis and treatment, by better understanding factors influencing the diagnostic timeline.

METHODS

Infants born between 2007 and 2014 and diagnosed with BA at our institution were included (n = 65). Two periods were examined retrospectively: P1, the time from birth to specialist referral, and P2, the time from specialist referral to treatment. How sociodemographic factors associate with P1 and P2 were analyzed with Kaplan-Meier curves and Cox proportional hazard models. In addition, to better characterize P2, laboratory results and early tissue histology were studied.

RESULTS

P1 associated with race/ethnicity, with shorter times in non-Hispanic white infants compared to non-Hispanic black and Hispanic infants (P = 0.007 and P = 0.004, respectively). P2 associated with referral age, with shorter times in infants referred after 30, 45, or 60 days of life (P < 0.001, P < 0.001, and P = 0.001, respectively). One potential reason for longer P2 in infants referred ≤30 days is that aminotransferase levels were normal or near-normal. However, despite reassuring laboratory values, tissue histology in early cases showed key features of BA.

CONCLUSIONS

Our findings suggest 2 opportunities to accelerate BA diagnosis and treatment. First, to achieve prompt referrals for all races/ethnicities, universal screening strategies should be considered. Second, to ensure efficient evaluations independent of age, algorithms designed to detect early features of BA can be developed.

Value of hepatic subcapsular flow by color Doppler ultrasonography in the diagnosis of biliary atresia

BACKGROUND AND AIM

Diagnosis of biliary atresia (BA), particularly distinguishing it from other causes of neonatal cholestasis (NC), is challenging. Ultrasonography is a helpful investigation when evaluating NC. The aim was to determine the value of color Doppler ultrasound, particularly hepatic subcapsular flow, as a possible tool in early discrimination of BA from other causes of NC.

METHODS

Ultrasonographic and color Doppler findings of 27 BA patients were compared with that in 27 non-BA cholestasis patients and a control group of 22 non-hepatic neonates.

RESULTS

Hepatic artery diameter was significantly higher in BA (2.48 ± 0.55 mm) than that in non-BA group (1.91 ± 0.63 mm) (P = 0.001) and the control group (1.6 ± 0.47 mm) (P < 0.0001), while there were no statistically significant difference between BA and non-BA groups as regards portal vein diameter and flow, hepatic vein flow, and hepatic artery resistance index. The frequency of hepatic subcapsular flow was significantly higher in BA than that in non-BA group (96.3% vs 3.7%; P < 0.0001), while it was not detected in any of the non-hepatic control group. The presence of hepatic subcapsular flow had 96.3% sensitivity and specificity in predicting BA.

CONCLUSIONS

Color Doppler ultrasound findings could help significantly in discriminating BA from other causes of NC, among which hepatic subcapsular flow had the best performance. Considering the young age of BA patients (61.8 ± 15.1 days), hepatic subcapsular flow can help in early diagnosis of BA and prevent the delay in surgical correction.

Recent progress in understanding pathogenesis and liver pathology in biliary atresia

Biliary atresia is an infantile destructive inflammatory cholangiopathy that causes obliteration of both intrahepatic and extrahepatic bile ducts and eventually liver cirrhosis. So far, the exact etiology and pathogenesis of biliary atresia remain unclear, and possible etiologies include congenital and genetic factors, infection, inflammation, immune reaction, maternal factors, and vascular factors. Immunoinflammatory theory has been accepted by most researchers, which is supported by liver pathological changes. This review focuses on the recent progress in understanding pathogenesis and liver pathology in biliary atresia.

The beneficial impact of revision of Kasai portoenterostomy for biliary atresia: an institutional study

OBJECTIVE

To determine whether portoenterostomy (PE) revision in patients afflicted with biliary atresia (BA) is a viable treatment option and, if so, identify which patients may benefit.

BACKGROUND

BA, the most common cause of neonatal liver disease, results in biliary tract obstruction and hepatic fibrosis. Kasai PE is the initial surgical intervention performed and, if successful, restores drainage and preserves the native liver. Portoenterostomy failure warrants liver transplantation, but because of complications related to transplantation, treatment strategies to salvage the native liver may be beneficial. Using uniformly applied criteria, we have revised PEs to delay or avoid transplantation.

METHODS

A retrospective review of medical records of patients diagnosed with BA since 1983 was performed. Patient demographics, symptoms, indications for revision, laboratory values, and outcomes were recorded. A cohort of patients who underwent revision after initial PE was identified. Survival rates were assessed using the Kaplan-Meier method. For patients who required transplantation, operative data from the revised PE cohort were compared with those from the unrevised PE cohort. A Cox proportional hazards model was used to determine covariates predictive of a favorable outcome.

RESULTS

Of 181 children who underwent PE, 24 underwent revision. Adequate biliary drainage, as evidenced by normalized conjugated bilirubin levels, was achieved in 75% of revised patients. Overall survival in patients who underwent revision, regardless of transplantation, was 87%. Among patients who underwent PE revision, 46% have survived with their native liver.

CONCLUSION

Experience at our center suggests that with appropriate patient selection, PE revision may delay the need for liver transplanation yielding encouraging patient outcomes.

Stool color card screening for biliary atresia

INTRODUCTION

Biliary atresia is a major cause of extrahepatic obstructive jaundice in neonates. Early Kasai operation is the gold standard of treatment. In this study, we evaluated the effectiveness of stool color card screening by using claims data from the National Health Insurance Research Database.

METHODS

This was a retrospective cohort study. Data from medical charts of all inpatients who were diagnosed with biliary atresia from 1996 to 2008 were collected from Taiwan's National Health Insurance Research Database. Patients who received a Kasai operation or liver transplant were identified by the Operation code. The patients' gender, age at admission, and type of operation were collected and analyzed.

RESULTS

From 1996 to 2008, the overall incidence of biliary atresia was 1.48 per 10,000 live births. The median age at first admission for patients with suspected biliary atresia decreased after the implementation of stool color card screening (47 vs 43 days). The proportion of very late referral decreased from 9.5% to 4.9%. The median age of Kasai operation advanced from 51 to 48 days. The proportions of Kasai operation within 60 days of age were 68.9% before and 73.6% after screening program.

CONCLUSION

Stool color card screening seemed to increase parents' and physicians' awareness of biliary atresia. It also was associated with a decline in the proportion of late referral. Thus, screening might be especially effective in areas with high a proportion of late referral. Improvements in the speed of workup and the operation room should be the focus of education and training in the future.

Diagnostic value of hepatic intercellular adhesion molecule-1 expression in Egyptian infants with biliary atresia and other forms of neonatal cholestasis

AIM

  The diagnosis of biliary atresia (BA) is challenging as no single preoperative test is 100% accurate, especially for distinguishing it from other causes of neonatal cholestasis (NC). Intercellular adhesion molecule (ICAM) elevation was reported in BA as a part of the immune-mediated inflammatory process. The use of ICAM-1 as a discriminative tool between BA and other causes of NC has never been addressed before. This study was to evaluate the diagnostic potentials of ICAM-1 in BA versus other forms of NC.

METHODS

  For this purpose, serum ICAM-1 (sICAM-1) and ICAM-1 expression, in liver biopsy using immunohistochemistry, were estimated in 30 patients with BA and compared to that in 20 patients with other forms of NC. sICAM-1 levels were compared to that in 20 healthy controls.

RESULTS

  sICAM-1 levels were significantly higher in BA (1055.9 ± 230.2 ng/mL) than that in cholestasis (604.8 ± 194.8 ng/mL) and the control groups (158.9 ± 78.7 ng/mL) (P < 0.0001). A cut-off value of 793.8 ng/mL had 86.7% sensitivity and 95% specificity in discriminating the BA from the cholestasis group. The biliary expression score of ICAM-1 at a cut-off value of 110 could discriminate between BA and other causes of NC with 100% sensitivity and specificity. Neither serum levels nor liver expression of ICAM-1 scores correlated with disease severity or with fibrosis stage.

CONCLUSION

  These results suggest that ICAM-1 has a diagnostic value in patients with BA and would be a promising helpful tool when investigating patients with NC.

Absent gallbladder on fetal ultrasound: prenatal findings and postnatal outcome

OBJECTIVES

Fetal gallbladder non-visualization on prenatal ultrasound in the second trimester is uncommon and in most cases the gallbladder is detected eventually. Associations of gallbladder non-visualization with cystic fibrosis, aneuploidy, agenesis of the gallbladder and biliary atresia have been reported. We present our experience and review the literature.

METHODS

During the study period from January 2004 to June 2009 we collected prospectively cases of non-visualization of the fetal gallbladder in the second trimester. In each case the fetus was evaluated by two examiners on at least two occasions, at least a week apart. Cases with no additional sonographic malformations were designated as isolated. Further evaluation included follow-up scans and a meticulous search for fetal anomalies. All patients were offered genetic consultation. Cystic fibrosis testing, amniocentesis for karyotyping and analysis of fetal digestive enzymes in the amniotic fluid were offered.

RESULTS

We collected 21 cases of non-visualization of the fetal gallbladder, 16 of which were isolated and five of which had additional malformations. In four of these five, the associated anomalies were severe and the pregnancies were terminated for aneuploidy (two cases of trisomy 18 and one triploidy) or for the severity of the associated anomalies. Associated anomalies included left isomerism with complex cardiac anomaly and intrauterine growth restriction with multisystem anomalies. The fifth fetus had interrupted inferior vena cava with azygos continuation without other anomalies and the child was alive and well at the age of 4 years. In 15 of the 16 isolated cases, antenatal and postnatal development were normal at the last follow-up, ranging from 4 months to 2.5 years. One case of cystic fibrosis was diagnosed prenatally and this pregnancy was terminated. There were no diagnoses of abnormal karyotype or biliary atresia among cases of isolated non-visualization of the gallbladder.

CONCLUSIONS

When prenatal non-visualization of the fetal gallbladder is associated with other severe malformation, aneuploidy should be suspected. When it is isolated, if cystic fibrosis is ruled out, the outcome is good.