Extrahepatic biliary atresia: a disease or a phenotype?

Considerable differences in management of cytomegalovirus infection in patients with biliary atresia

Objectives

Patients with biliary atresia (BA) and ongoing cytomegalovirus (CMV) infection may have poorer outcomes after Kasai portoenterostomy than uninfected patients. Still, there is no consensus on the usefulness of viral testing and antiviral treatment (AVT). This study aims to explore the need for future research on AVT for CMV infection by assessing how CMV infection in BA patients is managed in different centers.

Methods

An online questionnaire with 10 questions was offered to participants at an international congress on BA, organized in collaboration with the European Reference Network for rare liver diseases in 2022. Answers to questions were either dichotomic or multiple choices of different numeric intervals. Ongoing CMV infection was defined by detecting cytomegalovirus-immunoglobulin M (CMV-IgM) in serum or cytomegalovirus-deoxyribonucleic acid (CMV-DNA) by polymerase chain reaction in blood or urine.

Results

There were 43 respondents from 36 centers in 26 countries. The total number of BA patients per year was between 208 and 380 from centers with 0-5 to >20 BA patients yearly (median 6-10). CMV infection was tested in 27 centers (75%), of which 18 (67%) use AVT. The rate of CMV infection varied between 0%-5% and 40%-50% (median 5%-10%). Willingness to treat the infection did not differ between centers with low and high rates of CMV infection.

Conclusions

Most centers test for CMV infection, and a considerable proportion use AVT despite the lack of evidence of its benefits. A future randomized study on treating CMV infection in BA patients is necessary and feasible.

Role of indocyanine green-guided near-infrared fluorescence imaging in identification of the cause of neonatal cholestasis

To evaluate the efficacy and safety of indocyanine green (ICG)-guided near-infrared fluorescence (NIRF) imaging during surgery to diagnose the cause of neonatal cholestasis (NC). Data on NC patients who underwent both NIRF with ICG and conventional laparoscopic bile duct exploration (the gold standard) at our institute from January 2022 to December 2022 were retrospectively analyzed. The patients' baseline characteristics and liver function outcomes were collected and analyzed, and the diagnostic consistency was compared between the 2 methods. In total, 16 NC patients were included in the study, comprising 8 (50%) male and 8 (50%) female patients, ranging in age from 42 to 93 days, with a median age of 54.4 ± 21 days. During surgery, all the patients underwent NIRF with ICG, followed by conventional laparoscopic bile duct exploration. Finally, 15 of the patients were diagnosed with biliary atresia (BA) (1 with type-I BA, and 14 with type-II BA). The other patient was diagnosed with cholestasis. The diagnostic results from fluorescence imaging with ICG were consistent with those from conventional laparoscopic bile duct exploration. ICG-guided NIRF is associated with an easy operation, less trauma, and good safety. Also, its diagnostic accuracy is similar to conventional laparoscopic bile duct exploration.

Diagnostic accuracy of serum matrix metalloproteinase-7 as a biomarker of biliary atresia in a large North American cohort

BACKGROUND AND AIMS

High levels of serum matrix metalloproteinase-7 (MMP-7) have been linked to biliary atresia (BA), with wide variation in concentration cutoffs. We investigated the accuracy of serum MMP-7 as a diagnostic biomarker in a large North American cohort.

APPROACH AND RESULTS

MMP-7 was measured in serum samples of 399 infants with cholestasis in the Prospective Database of Infants with Cholestasis study of the Childhood Liver Disease Research Network, 201 infants with BA and 198 with non-BA cholestasis (age median: 64 and 59 days, p = 0.94). MMP-7 was assayed on antibody-bead fluorescence (single-plex) and time resolved fluorescence energy transfer assays. The discriminative performance of MMP-7 was compared with other clinical markers. On the single-plex assay, MMP-7 generated an AUROC of 0.90 (CI: 0.87-0.94). At cutoff 52.8 ng/mL, it produced sensitivity = 94.03%, specificity = 77.78%, positive predictive value = 64.46%, and negative predictive value = 96.82% for BA. AUROC for gamma-glutamyl transferase = 0.81 (CI: 0.77-0.86), stool color = 0.68 (CI: 0.63-0.73), and pathology = 0.84 (CI: 0.76-0.91). Logistic regression models of MMP-7 with other clinical variables individually or combined showed an increase for MMP-7+gamma-glutamyl transferase AUROC to 0.91 (CI: 0.88-0.95). Serum concentrations produced by time resolved fluorescence energy transfer differed from single-plex, with an optimal cutoff of 18.2 ng/mL. Results were consistent within each assay technology and generated similar AUROCs.

CONCLUSIONS

Serum MMP-7 has high discriminative properties to differentiate BA from other forms of neonatal cholestasis. MMP-7 cutoff values vary according to assay technology. Using MMP-7 in the evaluation of infants with cholestasis may simplify diagnostic algorithms and shorten the time to hepatoportoenterostomy.

Left-Sided Heart Defects and Laterality Disturbance in Hypoplastic Left Heart Syndrome

Hypoplastic left heart syndrome (HLHS) is a complex congenital heart disease characterized by hypoplasia of left-sided heart structures. The developmental basis for restriction of defects to the left side of the heart in HLHS remains unexplained. The observed clinical co-occurrence of rare organ situs defects such as biliary atresia, gut malrotation, or heterotaxy with HLHS would suggest possible laterality disturbance. Consistent with this, pathogenic variants in genes regulating left-right patterning have been observed in HLHS patients. Additionally, Ohia HLHS mutant mice show splenic defects, a phenotype associated with heterotaxy, and HLHS in Ohia mice arises in part from mutation in Sap130, a component of the Sin3A chromatin complex known to regulate Lefty1 and Snai1, genes essential for left-right patterning. Together, these findings point to laterality disturbance mediating the left-sided heart defects associated with HLHS. As laterality disturbance is also observed for other CHD, this suggests that heart development integration with left-right patterning may help to establish the left-right asymmetry of the cardiovascular system essential for efficient blood oxygenation.

Incidence and antiviral treatment of cytomegalovirus infection in infants with biliary atresia

PURPOSE

Patients with biliary atresia (BA) and cytomegalovirus (CMV) infection may have poorer outcomes after Kasai portoenterostomy (KPE) than uninfected patients, suggesting a rationale for antiviral treatment (AVT). We aimed to describe the incidence of CMV infection and of AVT in BA patients, and to detect any differences between infected and uninfected patients to conclude if AVT is of use.

METHODS

Data on BA patients who underwent KPE 2004-2020 were retrospectively collected, and the outcome was analyzed with regard to CMV status.

RESULTS

Fifteen out of forty-six (33%) BA patients had signs of ongoing CMV infection. They did not differ significantly from the CMV-negative patients regarding rate of prematurity, birth weight, or biochemical markers but were slightly older at KPE. All patients received steroids postoperatively and all patients with ongoing CMV infection received AVT with very good effect on viremia and without major side effects. The AVT consisted of oral valganciclovir (10-40 (- 58) mg/kg/d) or intravenous ganciclovir (5.3-11 mg/kg/d).

CONCLUSION

Ongoing CMV infection is common in this group of patients. The viremia can effectively be treated with AVT without any major side effects. Larger, randomized studies are needed to clarify the possible effect on clinical outcome.

The Impact of a CMV Infection on the Expression of Selected Immunological Parameters in Liver Tissue in Children with Biliary Atresia

The pathogenesis of biliary atresia (BA) is still not clear. The aim of this study was to evaluate the expression of selected immunological parameters in liver tissue in BA children based on CMV/EBV infection status. Eight of thirty-one children with newly diagnosed BA were included in this prospective study and assigned to two groups (I with active infection, II without active or past infection). All studies were performed on surgical liver biopsies. To visualize CD8+ T cells and CD56 expression, immunohistochemical staining was performed. The viral genetic material in the studied groups was not found, but CMV infection significantly affected the number of CD8+ lymphocytes in both the portal area and the bile ducts. The average number of CD8+ cells per mm² of portal area in Groups I and II was 335 and 200 (p = 0.002). The average number of these cellsthat infiltrated the epithelium of the bile duct per mm² in Group I and II was 0.73 and 0.37 (p = 0.0003), respectively. Expression of CD56 in the bile ducts corresponded to the intensity of the inflammatory infiltrate of CD8+ cells. Our results suggest that active CMV infection induces an increased infiltration of CD8+ lymphocytes, which could play a role in BA immunopathogenesis. Increased CD56 expression can be a sign of a newly formed bile structure often without lumen, suggesting inhibition of the maturation process in BA.

Differentiating Biliary Atresia From Idiopathic Neonatal Hepatitis: A Novel Keratin 7 Based Mathematical Approach on Liver Biopsies

BACKGROUND AND AIMS

Differentiating biliary atresia (BA) from idiopathic neonatal hepatitis (INH) is vital in routine pediatric practice. However, on liver biopsy, few cases offer a diagnostic challenge to discriminate these entities with certainty. Bile ductular reaction (DR), intermediate hepatobiliary cells (IHBC) and extra-portal ductules (EPD) indicate progenitor cell activation, as a response to various hepatic insults. The present study aims to quantify DR, IHBC and EPD by Keratin 7 (CK7) immunohistochemistry (IHC) in BA and INH and to devise a mathematical approach to better differentiate the two, especially in histologically equivocal cases.

METHODS

A total of 98 cases were categorized on biopsy as BA, INH or equivocal histology, favoring BA or INH. CK7 DR mean, IHBC mean and EPD mean values were compared between BA and INH. A formula was derived to help distinguish these two entities, the cut-off value, sensitivity and specificity of which were determined by receiver operating characteristic (ROC) curve. This formula was applied and validated on histologically equivocal cases.

RESULTS

Univariate logistic regression revealed significant difference between BA and INH with respect to CK7 DR and CK7 EPD mean (p < 0.001 in both); however, CK7 IHBC mean was not significant (p = 0.08). On multivariate logistic regression, only CK7 DR had significant impact on diagnosis (p < 0.001). A formula: (CK7 DR)² + (CK7 EPD)/(CK7 IHBC) was derived to help distinguish BA from INH. Cut off value of 10.5 and above, determined by ROC curve, favored a diagnosis of BA (sensitivity= 93.4%, specificity= 94.6%). Histologically equivocal and discrepant cases could be correctly categorized using this formula.

CONCLUSIONS

Formula using CK7 IHC parameters may aid pathologists better distinguish BA from INH, especially in histologically equivocal cases.

Diffusion-Weighted Imaging for Differentiation of Biliary Atresia and Grading of Hepatic Fibrosis in Infants with Cholestasis

Objective

To determine whether the values of hepatic apparent diffusion coefficient (ADC) can differentiate biliary atresia (BA) from non-BA or be correlated with the grade of hepatic fibrosis in infants with cholestasis.

Materials and Methods

This retrospective cohort study included infants who received liver MRI examinations to evaluate cholestasis from July 2009 to October 2017. Liver ADC, ADC ratio of liver/spleen, aspartate aminotransferase to platelet ratio index (APRI), and spleen size were compared between the BA and non-BA groups. The diagnostic performances of all parameters for significant fibrosis (F3–4) were obtained by receiver-operating characteristics (ROCs) curve analysis.

Results

Altogether, 227 infants (98 males and 129 females, mean age = 57.2 ± 36.3 days) including 125 BA patients were analyzed. The absolute ADC difference between two reviewers was 0.10 mm²/s for both liver and spleen. Liver ADC value was specific (80.4%) and ADC ratio was sensitive (88.0%) for the diagnosis of BA with comparable performance. There were 33 patients with F0, 15 with F1, 71 with F2, 35 with F3, and 11 with F4. All four parameters of APRI (τ = 0.296), spleen size (τ = 0.312), liver ADC (τ = −0.206), and ADC ratio (τ = −0.288) showed significant correlation with fibrosis grade (all, p < 0.001). The cutoff values for significant fibrosis (F3–4) were 0.783 for APRI (area under the ROC curve [AUC], 0.721), 5.9 cm for spleen size (AUC, 0.719), 1.044 × 10⁻³ mm²/s for liver ADC (AUC, 0.673), and 1.22 for ADC ratio (AUC, 0.651).

Conclusion

Liver ADC values and ADC ratio of liver/spleen showed limited additional diagnostic performance for differentiating BA from non-BA and predicting significant hepatic fibrosis in infants with cholestasis.

Improved Outcomes for Liver Transplantation in Patients with Biliary Atresia Since Pediatric End-Stage Liver Disease Implementation: Analysis of the Society of Pediatric Liver Transplantation Registry

OBJECTIVE

To identify changes in demographics, outcomes, and risk factors for patient and graft loss in patients with biliary atresia undergoing liver transplantation since Pediatric End-Stage Liver Disease implementation (2002).

STUDY DESIGN

Demographics and outcomes were compared between patients enrolled in the Society of Pediatric Liver Transplantation registry before (n = 547) and after (n = 1477) 2002. Kruskal-and χ² Wallis tests identified significant differences between eras. Risk factors for patient and graft loss after 2002 were determined by Cox regression model analysis of time to event data.

RESULTS

Significant patient differences after 2002 support increasing disease severity including more status 1 patients and those with a derived Model for End-Stage Liver Disease/Pediatric End-Stage Liver Disease score of greater than 30 awaiting transplant. Both patient and graft survival improved after 2002 from 90% to 97% and 81% to 90%, respectively (primary transplant; P < .0001). Significant differences in complications within 30 days included reduced relisting for transplant, rejection, culture-positive infection, repeat operation, hepatic artery thrombosis, portal vein thrombosis, and death/transplant before discharge. Multivariable analysis identified deceased technical variant vs whole graft and retransplantation predictive for patient death, hazard ratios of 4.041 and 8.308, respectively. Deceased technical variant vs whole graft (hazard ratio, 1.963) and donor age 0-5 months vs 1-17 years (hazard ratio, 5.525) were risk factors for graft loss.

CONCLUSIONS

The overall outcomes of patients receiving liver transplantation for patients with biliary atresia have improved since 2002 despite evidence of increased disease severity at the time of transplant. Risk factors impacting post-transplant morbidity and mortality in patients with biliary atresia are now mainly surgical including donor variables.

[Staging of liver fibrosis in biliary atresia : Comparison of Chevallier and Ishak score as well as automated evaluation]

BACKGROUND

Biliary atresia (BA) is a rare disease of the newborn, resulting in liver cirrhosis due to obliterative cholangiopathy. Liver biopsies are commonly performed in order to confirm the diagnosis and in order to stage fibrosis.

OBJECTIVES

The present study intended to analyze two established scores for evaluating liver fibrosis focusing on the interobserver variability as well as the prognostic reliability towards the time of liver transplantation.

MATERIALS AND METHODS

Liver biopsies of BA patients between 2012 and 2015 were evaluated retrospectively by two pathologists at the Hannover Medical School (MHH) and the RWTH Aachen University Hospital. Fibrosis was measured using Ishak and Chevallier scores. Furthermore, a computerized automatically algorithm-based analyzation (ABAA) was performed. Results were evaluated towards the time point of liver transplantation and hepatoportoenterostomy (HPE).

RESULTS

Overall, 34 liver biopsies were analyzed. The Ishak score showed a remarkable interobserver variability (Κ_W = 0.68) while the Chevallier score was proven to have a poor interobserver variability (Fleiss' Κappa = -0.01). However, both scores were correlated positively, as was the ABAA (p < 0.001). Regarding prognostic reliability, ROC analyses of the Ishak score revealed the best validity towards an early liver transplantation within 12 months (AUC 0.813, p = 0.011). In addition, an increased Ishak score ≥4 reduced the survival time with the native liver (hazard ratio 6.6 [95% CI 1.9-23.3]).

CONCLUSIONS

The Ishak score was revealed to have the best interobserver variability as well as prognostic validity towards an early liver transplantation in BA patients. Due to its easy applicability, the Ishak score was proven superior in comparison to the Chevallier score and ABAA. Therefore, use of the Ishak score is recommended in daily clinical routine for analyzing liver biopsies in BA patients.

Divergent expression of liver transforming growth factor superfamily cytokines after successful portoenterostomy in biliary atresia

BACKGROUND

Pathogenesis of progressive liver fibrosis in biliary atresia after successful portoenterostomy remains unclear. We related hepatic expression of transforming growth factor beta (TGF-β) superfamily cytokines to histologic liver injury after successful portoenterostomy.

METHODS

Enrolled in our study were 28 patients with biliary atresia who had liver biopsies obtained during and after successful portoenterostomy, which normalized serum bilirubin (<20 µmol/l). Biopsies were evaluated for cholestasis, inflammation, ductal reaction, and fibrosis and were stained immunohistochemically for transforming growth factor beta 1, transforming growth factor beta 2, connective tissue growth factor, and decorin. Respective gene expression (TGFB1, TGFB2, TGFB3, CTGF, DCN) was analyzed at follow-up using quantitative reverse transcription polymerase chain reaction (qRT-PCR). Results were compared with fibrotic and healthy control livers.

RESULTS

After median follow-up of 3.0 years, histologic cholestasis resolved, whereas fibrosis had progressed only in isolated biliary atresia. Liver protein expression of transforming growth factor beta 1 and connective tissue growth factor (P < .001 for both), but not that of transforming growth factor beta 2 or decorin, decreased after successful portoenterostomy, although expression of all four cytokines remained elevated. In accordance with postportoenterostomy changes in protein expression, follow-up ribonucleic acid expression of TGFB2 and DCN, but not that of TGFB1 and CTGF, was upregulated when compared with the controls. Both protein and gene expression of transforming growth factor beta 1 and protein expression of transforming growth factor beta 2, connective tissue growth factor and decorin correlated with METAVIR fibrosis stage. Syndromic patients (n = 12) showed milder fibrosis and lower transforming growth factor beta 1 expression than patients with isolated biliary atresia.

CONCLUSION

These findings support a central role of transforming growth factor beta superfamily in mediating continuing liver fibrogenesis after successful portoenterostomy. Transforming growth factor beta pathway cytokines responded divergently to clearance of jaundice, which was reflected by differential progression of fibrosis between syndromic and isolated patients.

Factors Associated with Timing and Adverse Outcomes in Patients with Biliary Atresia Undergoing Kasai Hepatoportoenterostomy

OBJECTIVE

To assess factors associated with timing of hepatoportoenterostomy (HPE) and adverse perioperative outcomes in patients with biliary atresia in the US.

STUDY DESIGN

We examined hospitalizations in infants aged <1 year using the National Inpatient Sample database for 2000-2011. We identified cases using the International Classification of Diseases, Ninth Revision, Clinical Modification codes for biliary atresia and HPE. Multivariable logistic regression models were used to examine association between select factors and age at HPE, as well as adverse perioperative outcomes.

RESULTS

Our analysis of 1243 biliary atresia hospitalizations showed that only 37.7% of patients had HPE in the first 60 days of life. Patients who underwent HPE after 60 days of age were uninsured, were more likely to be black (aOR, 4.22; 95% CI, 1.49-11.95), less likely to be admitted at a teaching hospital (aOR, 0.27; 95% CI 0.10-0.79), and less likely to have a concomitant congenital malformation (aOR, 0.49; 95% CI 0.25-0.98). Patients with delayed age at HPE incurred significantly higher hospital costs ($57 914 vs $34 074; P = .026). Delayed age at HPE and weekend admission were independently associated with increased odds of adverse perioperative outcome (aOR, 1.09; 95% CI, 1.01-3.02 and 3.98; 95% CI, 1.67-9.46, respectively).

CONCLUSION

Current outcomes in patients with biliary atresia in the United States are suboptimal and result in higher costs. The specific factors associated with delayed care are further evidence that universal health care and screening are needed for all infants, along with systematic referral of potential patients with biliary atresia to specialized health centers.

Role of viruses in biliary atresia: news from mice and men

Biliary atresia (BA) is still an enigmatic disease of unknown etiology and cryptic pathomechanism. Despite the fact that BA is rated among rare diseases, it represents the most frequent indication for pediatric liver transplantation. Although every effort is made to elucidate the origin of the ongoing deterioration of liver function, no breakthrough has so far been achieved, which switches the surgical but symptomatic therapy to a cause-oriented approach. The nowadays leading hypothesis focuses on hepatotropic virus as a triggering agent for an autoimmunological self-limiting inflammatory process along the entire biliary tree. The present review highlights the current state of research on the factor "viruses in biliary atresia" in both patients undergoing the Kasai procedure and the virus-induced BA mouse model.

Three-dimensional structural analysis reveals a Cdk5-mediated kinase cascade regulating hepatic biliary network branching in zebrafish

The intrahepatic biliary network is a highly branched three-dimensional network lined by biliary epithelial cells, but how its branching patterns are precisely established is not clear. We designed a new computer-based algorithm that quantitatively computes the structural differences of the three-dimensional networks. Utilizing the algorithm, we showed that inhibition of Cyclin-dependent kinase 5 (Cdk5) led to reduced branching in the intrahepatic biliary network in zebrafish. Further, we identified a previously unappreciated downstream kinase cascade regulated by Cdk5. Pharmacological manipulations of this downstream kinase cascade produced a crowded branching defect in the intrahepatic biliary network and influenced actin dynamics in biliary epithelial cells. We generated larvae carrying a mutation in cdk5 regulatory subunit 1a (cdk5r1a), an essential activator of Cdk5. cdk5r1a mutant larvae show similar branching defects as those observed in Cdk5 inhibitor-treated larvae. A small-molecule compound that interferes with the downstream kinase cascade rescued the mutant phenotype. These results provide new insights into branching morphogenesis of the intrahepatic biliary network.

Molecular signature of active fibrogenesis prevails in biliary atresia after successful portoenterostomy

BACKGROUND

In biliary atresia mechanisms of progressive liver injury leading to need of liver transplantation after successful portoenterostomy remain unknown. A better understanding is a prerequisite for development of novel therapies to extend native liver survival, and we aimed to unravel molecular characteristics of liver injury after successful portoenterostomy.

METHODS

Liver biopsies obtained from 28 biliary atresia children during successful portoenterostomy and at median age 3.0 years were studied. Biopsies were analyzed for histology and immunohistochemical expression of collagen 1, myofibroblast marker α-smooth muscle actin, and cytokeratin-7 positive ductal reactions. Hepatic ribonucleic acid (RNA) expression of growth factors and inflammatory cytokines was evaluated. Intestinal failure patients with comparable liver fibrosis and nonfibrotic gallstone patients and donor livers were controls.

RESULTS

After successful portoenterostomy, histologic cholestasis resolved and portal inflammation reduced, while fibrosis along with ductal reactions and overexpression of collagen and α-smooth muscle actin persisted. At follow-up, liver RNA expression of collagen and platelet-derived growth factor was increased, whereas RNA expression of various inflammatory cytokines remained low. Disappearance of periductal α-smooth muscle actin expression after successful portoenterostomy (36% of patients) associated with contracted ductal reactions and reduced progression of fibrosis, collagen accumulation, platelet-derived growth factor RNA expression, and serum levels of bile acids and bilirubin. Fibrosis progressed less rapidly in syndromic than in isolated biliary atresia patients.

CONCLUSION

These findings suggest that instead of inflammation, molecular signature of active fibrogenesis in association with ductal reactions prevails in long-term native liver survivors with biliary atresia. Patients should be stratified for isolated and syndromic disease forms in interventional studies.

Patient complexity and genotype-phenotype correlations in biliary atresia: a cross-sectional analysis

Background

Biliary Atresia (BA) is rare and genetically complex, and the pathogenesis is elusive. The disease course is variable and can represent heterogeneity, which hinders effective disease management. Deciphering the BA phenotypic variance is a priority in clinics and can be achieved by the integrative analysis of genotype and phenotype. We aim to explore the BA phenotypic features and to delineate the source of its variance.

Methods

The study is a cross-sectional observational study collating with case/control association analysis. One-hundred-and-eighty-one type III non-syndromic BA patients and 431 controls were included for case–control association tests, including 89 patients (47.19% males, born June 15th, 1981 to September 17th, 2007) have detailed clinical records with follow-up of the disease course (median ~17.2 years). BA-association genes from the genome-wide gene-based association test on common genetic variants (CV) and rare copy-number-variants (CNVs) from the genome-wide survey, the later comprise only CNVs > 100 kb and found in the BA patients but not in the local population (N = 1,381) or the database (N = 11,943). Hereby comorbidity is defined as a chronic disease that affects the BA patients but has no known relationship with BA or with the BA treatment. We examined genotype-phenotype correlations of CNVs, connectivity of these novel variants with BA-associated CVs, and their role in the BA candidate gene network.

Results

Of the 89 patients, 41.57% have comorbidities, including autoimmune-allergic disorders (22.47%). They carried 29 BA-private CNVs, including 3 CNVs underpinning the carriers’ immunity comorbidity and one JAG1 micro-deletion. The BA-CNV-intersected genes (N = 102) and the CV-tagged genes (N = 103) were both enriched with immune-inflammatory pathway genes (FDR q < 0.20), and the two gene sets were interconnected (permutation p = 0.039). The molecular network representing CVs and rare-CNV association genes fit into a core/periphery structure, the immune genes and their related modules are found at the coherence core of all connections, suggesting its dominant role in the BA pathogenesis pathway.

Conclusions

The study highlights a patient-complexity phenomenon as a novel BA phenotypic feature, which is underpinned by rare-CNVs that biologically converge with CVs into the immune-inflammatory pathway and drives the BA occurrence and the likely BA association with immune diseases in clinics.

Electronic supplementary material

The online version of this article (doi:10.1186/s12920-017-0259-0) contains supplementary material, which is available to authorized users.

Epidemiology of Biliary Atresia in Korea

Biliary atresia (BA) is the major cause of cholestasis and the leading indication for liver transplantation (LT). However, the incidence of BA in Korea has not been reported. The aim of this study was to investigate the incidence and clinical outcomes of BA in Korea. We used the Korean universal health insurance database and extracted data regarding BA patients younger than 18 years of age admitted between 2011 and 2015. The incidence of BA was calculated by dividing the number of BA patients by the number of live births. Two hundred forty infants were newly diagnosed with BA. A total of 963 BA patients younger than 18 years of age were followed up for 5 years. The overall incidence of BA was 1.06 cases per 10,000 live births. The incidence of BA was 1.4 times higher for female patients than for male patients. Additionally, significant seasonal variation was observed; in particular, the incidence of BA was 2 times higher from June through August than from December through February. Congenital anomalies were found in 38 of 240 patients (15.8%). Congenital heart diseases were major associated congenital anomalies (6.3%). Several complications developed during the study period, including cholangitis (24.0%), varix (6.2%), and gastrointestinal bleeding (4.4%). Three hundred and one of the 963 BA patients under 18 years of age (31.3%) received LT for BA. The incidence of BA is higher in Korea than that in Western countries. We also report significant gender-associated differences and seasonal variation with respect to the incidence of BA.

Incidence of biliary atresia associated congenital malformations: A retrospective multicenter study in China

BACKGROUND

Some patients with biliary atresia (BA) have associated anomalies. Our study aimed to investigate the incidence of BA-associated malformations in mainland China, and compare the results with those reported in the Western literature.

METHODS

Clinical data were collected retrospectively from five medical centers in mainland China. BA patients were diagnosed and confirmed by laparotomy with intraoperative cholangiography and liver biopsy. Cases were divided into isolated type BA and BA with associated anomalies, including polysplenia, situs inversus, intestinal malrotation, and cardiovascular anomalies.

RESULTS

A total of 851 BA patients were recruited from Tianjin, Beijing, Wuhan, Guangzhou, and Shenzhen. Patients were grouped as follows: Type I, 13 cases (1.5%); Type II, five cases (0.6%); Type III, 833 cases (97.9%). Forty-two (4.94%) patients had 54 associated congenital abnormalities. The intra-abdominal anomalies included polysplenia (n = 4, 1 fusion between liver and spleen), situs inversus (n = 2), and intestinal malrotation (n = 3). The cardiovascular anomalies included atrial septal defect and ventricular septal defect (n = 29), patent foramen ovale (n = 1), patent ductus arteriosus (n = 4), and other cardiac malformations (n = 3, including coronary sinus dilation, left superior vena cava, Tetralogy of Fallot).

CONCLUSION

Our data showed that spleen anomaly is not as common as reported in the Western literature. The difference may suggests different genetic and environmental risk factors for BA.

Diagnostic and Prognostic Significance of Various Histopathological Features in Extrahepatic Biliary Atresia

INTRODUCTION

Extrahepatic biliary atresia is a progressive disorder characterised by fibroinflammatory obliteration or stenosis of the extrahepatic biliary tree leading to obstruction of bile flow and cholestatic jaundice. It is the most common cause for cholestasis in newborn. Histopathological criteria for diagnosing biliary atresia from liver biopsy have not been clearly defined.

AIM

This study was undertaken to analyse the significance of the various histopathological features in diagnosis and prognosis of extrahepatic biliary atresia from liver biopsy specimens.

MATERIALS AND METHODS

This was a retrospective study of 43 cases of extra-hepatic biliary atresia diagnosed and treated at a tertiary care hospital between January 2010 to December 2014. Formalin fixed paraffin embedded liver biopsy tissues were processed by standard technique and the slides were stained with haematoxylin and eosin. All the slides were reviewed and graded by a semi-quantitative scoring system. Features such as increased age at kasai's portoenterostomy, portal fibrosis, bile duct proliferation, cholestasis, portal inflammation and duct plate malformation were studied. Statistical analysis was worked out using SPSS 17.0 (statistical package for the social science software). Chi-square test was used to find association between various parameters with respect to mortality and Kaplan-Meier estimator was used for survival analysis of the population under study.

RESULTS

In this study comprising of 43 cases, only 6 cases (13.95%) were alive at the end of 6 months follow-up. Twenty patients who died and the 17 cases with poor survival had greater degrees of fibrosis, bile duct proliferation and cholestasis. Majority of the cases with duct plate malformation expired inspite of earlier surgical intervention. Thus proving the association of fibrosis, bile duct proliferation, cholestasis and duct plate malformation with the survival and prognosis of biliary atresia cases. Age at surgery did not show any correlation with prognosis as cases operated even at <60 days had poor survival.

CONCLUSION

From this study it can be concluded that in extrahepatic biliary atresia patients, presence of duct plate malformation, greater degrees of fibrosis, bile duct proliferation and cholestasis were strongly associated with poor prognosis.

Genome-wide association studies in biliary atresia

Biliary atresia (BA) is a model complex disease resulting from interactions between multiple susceptibility loci and environmental factors. This perception is based on a heterogeneous phenotype extending beyond an absent extrahepatic bile duct to include gut and cardiovascular anomalies, and the association of BA with viral infections. Refractory jaundice and progression to cirrhosis shortly after birth can be fatal without surgical correction, and further suggests a pathogenesis during liver and bile duct development. Conclusive proof for a developmental origin would require documentation of disease progression in the perinatal or fetal liver, an impossible task for obvious reasons. We review three different sets of genome-wide association studies (GWAS) from three different cohorts of BA patients by three different groups of investigators, which address this knowledge gap. Knockdown of each susceptibility gene identified by GWAS in zebrafish embryos impairs excretion of bile from the liver, duplicating the characteristic diagnostic finding seen in affected children. This finding is associated with impaired intrahepatic biliary network formation in zebrafish morphants. Although distinct, these susceptibility genes share several functions including roles in mechanisms for organogenesis (glypican 1 or GPC1, and adenosine diphosphate ribosylation factor 6, or ARF6) or a greater expression in fetal liver than in adult liver (adducin 3 or ADD3). Together, these studies emphasize the importance of the human evidence, and present opportunities to map novel pathways which explain the phenotypic heterogeneity of BA.

The effect of curcumin on liver fibrosis in the rat model of microsurgical cholestasis

We aimed to determine the effects of curcumin on liver fibrosis and to clarify the role of nuclear factor-κB (NF-κB) and inducible nitric oxide synthase (iNOS) in a model of microsurgical cholestasis in the early stage of extrahepatic biliary atresia.

Polymorphism of ITGB2 gene 3'-UTR+145C/A is associated with biliary atresia

BACKGROUND AND STUDY AIMS

Biliary atresia (BA) is a devastating disease of infants, invariably leading to cirrhosis, end-stage liver disease, and death if untreated. The etiology of BA is unknown, although infectious, immune, and genetic causes have been suggested. This study was designed to investigate whether polymorphism of the ITGB2 (CD18) gene is associated with susceptibility to BA.

METHODS

The ITGB2 gene promoter and 16 exons were genotyped following amplification and sequencing, with associations assessed using Fischer's exact test in 106 patients diagnosed with BA and 108 unrelated healthy controls.

RESULTS

We found one single nucleotide polymorphism (SNP) in the ITGB2 promoter region (-680 C/T) and five SNPs in exons, including: -111 T/C in exon 1, 117 G/A in exon 3, 819 G/A in exon 7, 1101 C/A in exon 10, and 3'-UTR+145C/A in exon 16. There were no significant differences in genotype and allelic frequencies of any of the SNPs between controls and patients with BA in both the promoter and exons 1, 3, 7, and 10. 3'-UTR+145C/A showed a significant increase in the C allele frequency (OR = 2.19, 95% CI: 1.39-3.46, p = 0.0006) and a significant increase in the CC genotype (p = 0.001) in BA patients compared with healthy controls. Using a reporter gene assay, the construct that contained the risk allele (3'-UTR+145 C) showed significantly higher luciferase activity than the nonrisk A allele (p = 0.007).

CONCLUSION

Our study provides the first evidence of a possible role of ITGB2 3'-UTR+145C/A polymorphism in the pathogenesis of BA.

Maternal grafts protect daughter recipients from acute cellular rejection after pediatric living donor liver transplantation for biliary atresia

Some studies have found that gender mismatch between donors and recipients are related to poor graft prognosis after liver transplantation. However, few studies have investigated the impact of gender mismatch on acute cellular rejection (ACR) in pediatric living donor liver transplantation (LDLT). This retrospective study investigated the clinical significance of these factors in ACR after pediatric LDLT. Between November 2001 and February 2012, 114 LDLTs were performed for recipients with biliary atresia (BA) using parental grafts. We performed univariate and multivariate analyses to identify the factors associated with ACR. The donor-recipient classifications included mother donor to daughter recipient (MD; n = 43), mother to son (n = 18), father to daughter (FD; n = 33), and father to son (n = 20) groups. The overall incidence rate of ACR in the recipients was 36.8%. Multivariate analysis showed that gender mismatch alone was an independent risk factor for ACR (P = 0.012). The FD group had a higher incidence of ACR than the MD group (P = 0.002). In LDLT, paternal grafts with gender mismatch were associated with a higher increased incidence of ACR than maternal grafts with gender match. Our findings support the possibility that maternal antigens may have an important clinical impact on graft tolerance in LDLT for patients with BA.

Aetiology of biliary atresia: what is actually known?

Biliary atresia (BA) is a rare disease of unknown etiology and unpredictable outcome, even when there has been timely diagnosis and exemplary surgery. It has been the commonest indication for liver transplantation during childhood for the past 20 years. Hence much clinical and basic research has been directed at elucidating the origin and pathology of BA. This review summarizes the current clinical variations of BA in humans, its occasional appearance in animals and its various manifestations in the laboratory as an experimental model.

Neonatale Cholestase

Die Inzidenz der NC wird auf 1 : 2500 Neugeborene geschätzt. Dies entspricht jährlich ca. 300 Erkrankungsfällen in Deutschland.

Hepatocellular telomere length in biliary atresia measured by Q-FISH

BACKGROUND

Liver transplantation for biliary atresia is indicated whenever a Kasai portoenterostomy is considered unfeasible. However, the timing of liver transplantation in biliary atresia has not been precisely defined. Excessive shortening of hepatocellular telomeres may occur in patients with biliary atresia, and therefore, telomere length could be a predictor of hepatocellular reserve capacity.

METHODS

Hepatic tissues were obtained from 20 patients with biliary atresia who underwent LT and 10 age-matched autopsied individuals (mean age, 1.7 and 1.2 years, respectively). Telomere lengths were measured by Southern blotting and quantitative fluorescence in situ hybridization using the normalized telomere-centromere ratio. The correlation between the normalized telomere-centromere ratio for the hepatocytes in biliary atresia and the pediatric end-stage liver disease score was analyzed.

RESULTS

The median terminal restriction fragment length of the hepatic tissues in biliary atresia was not significantly different from that of the control (p = 0.425), whereas the median normalized telomere-centromere ratio of hepatocytes in biliary atresia was significantly smaller than that of the control (p < 0.001). Regression analysis demonstrated a negative correlation of the normalized telomere-centromere ratio with the pediatric end-stage liver disease score in biliary atresia (p < 0.001).

CONCLUSIONS

Telomere length analysis using quantitative fluorescence in situ hybridization could be an objective indicator of hepatocellular reserve capacity in patients with biliary atresia, and excessive telomere shortening supports the early implementation of liver transplantation.

Biliary atresia: the animal models

Biliary atresia (BA) is a progressive fibrosing process of the neonatal biliary tree and liver, of unknown origin, and an as-yet unexplained pathologic mechanism. The crucial point is to elucidate the origin of this rare disease to change palliative surgery to etiology-related procedures. Patient-based research can only begin at the time of the Kasai procedure and does not allow retracing of the pathology back to its origin. Basic research has focused on similar diseases in the veterinary literature and started to simulate BA in animal models. Unfortunately, even after 50 years of research, no knowledge has been gained from such models, which has led to a single clinical application. This article reviews BA in the context of the animal models available and discusses whether future studies are promising or futile.

Neonatal cholestasis: opportunities to increase early detection

OBJECTIVE

To describe primary care management of early and prolonged jaundice in otherwise-healthy term infants to identify opportunities to increase early diagnosis of cholestasis.

METHODS

Community-based pediatricians in St Louis, Missouri completed a mailed, anonymous, 29-item survey to assess practice demographics, timing of routine newborn office visits, and the management of early and prolonged neonatal jaundice.

RESULTS

A total of 108 of 230 (47%) of eligible physicians responded (mean years in practice, 15.3, SD, 9.4). More respondents were very familiar with national guidelines for management of early (49%) than prolonged (16%) neonatal jaundice. Eighty-six percent reported all newborns were checked with transcutaneous bilirubin before hospital discharge. For transcutaneous bilirubin results at 48 hours of 7, 10, 12 and 15 mg/dL, 1%, 26%, 70%, and 74% of respondents, respectively, would order a fractionated bilirubin. Although the first routine visit usually occurred in the first week after discharge, 25% of physicians reported the 2nd visit was routinely scheduled after 4 weeks of age. Ninety-four percent reported they would obtain a fractionated bilirubin for infants jaundiced beyond 4 weeks of age. If cholestasis was identified at 6 weeks of age, 32% would obtain additional testing without referral to a subspecialist.

CONCLUSIONS

Management of early and prolonged neonatal jaundice is variable. Current practices appear to miss opportunities for early diagnosis of cholestasis and referral that are unlikely to be addressed without redesigning systems of care.

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.

Assessment of liver fibrosis and cirrhosis by aspartate aminotransferase-to-platelet ratio index in children with biliary atresia

BACKGROUND

In patients with biliary atresia (BA), liver fibrosis and cirrhosis commonly occur even after Kasai hepatoportoenterostomy. Although liver biopsy is the gold standard to evaluate liver fibrosis, it is invasive and may result in life-threatening complications. The aspartate aminotransferase-to-platelet ratio index (APRI) is a safe and simple method to assess liver fibrosis in patients with chronic liver diseases. To use APRI as a postoperative follow-up tool, we validated the diagnostic power of APRI for the degree of liver fibrosis in postoperative patients with BA.

PATIENTS AND METHODS

Patients with newly diagnosed BA who underwent the Kasai procedure between March 2006 and May 2009 were analyzed. Several laboratory tests including APRI were performed. Liver wedge biopsy specimens were obtained during the surgical procedure, and histopathologic analyses were performed using the Metavir classification.

RESULTS

Thirty-five patients (12 boys, median age of 1.9 months) were enrolled. Metavir scores were F1 in 0, F2 in 11, F3 in 11, and F4 in 13 patients. The areas under the receiver operating characteristics curves for F > or = 3 and F = 4 were 0.92 and 0.91, respectively. Distinct optimal cutoff values of APRI for F > or = 3 and F = 4 were obtained (1.01 and 1.41, respectively). Clinical outcomes of patients were significantly different between 2 groups (noncirrhosis vs cirrhosis) based on APRI before and 3 months after the Kasai procedure.

CONCLUSION

APRI may be used as a simple and readily available tool for assessing liver fibrosis without additional risks in patients with BA during postoperative follow-up care.

Language and motor skills are impaired in infants with biliary atresia before transplantation

OBJECTIVE

To test the hypothesis that in very young patients with biliary atresia, cognitive deficits are apparent before transplantation.

STUDY DESIGN

With the Mullen Scales of Early Learning (Mullen), we examined 15 infants (mean age, 7.8 months) with biliary atresia, correlating Mullen scores with standard clinical and biochemical parameters.

RESULTS

Overall, participants displayed significant delays in gross motor and language skills, and fine motor and visual reasoning skills were relatively preserved. The international normalized ratio correlated inversely with gross (P < .01) and fine (P < .05) motor skills. Growth parameters correlated positively with expressive language ability, but length of hospitalization and mode of feeding did not. Age at performance of the Kasai procedure was found to correlate with receptive language performance (P < .05).

CONCLUSIONS

Very young children with biliary atresia display a characteristic profile of early developmental deficits before transplantation. These findings suggest that early intervention and aggressive nutritional management should be the standard of care to minimize neurocognitive effects.

Liver fibrosis in biliary atresia

Biliary atresia (BA) is the most common cholestatic liver disorder requiring liver transplantation in children. Hepatic fibrosis is not only a universal and prominent feature of BA, it is also the most important predictor of outcome following portoenterostomy (PE). Without PE, the progression of hepatic fibrosis is quite dramatic, such that liver cirrhosis is established within a few weeks after birth. Etiologies and molecular networks underpinning such an expeditious fibrogenic process have not been well established. However, immune and nonimmune factors implicated in the pathogenesis of BA, and the resultant cholestasis and oxidative stress, appear to be the main triggers of hepatic fibrosis in BA. Owing to a lack of validated noninvasive tools to monitor liver fibrosis, current prognostic models of BA entail clinical and biochemical variables reflecting liver dysfunction rather than hepatic fibrogenesis. Further work is necessary to validate the results of preliminary studies indicating a good relationship between liver fibrosis determined by transient elastography and other clinical and routinely performed biochemical parameters in pediatric patients. Although a prime candidate for a number of antifibrotic therapies on the horizon, owing to poor understanding of molecular mechanisms, a clear framework of antifibrotic targets has not been outlined in BA. Similarly, specific antifibrotic therapies have not yet been incorporated in clinical practice, limiting these measures to prompt diagnosis and PE operation, prevention and treatment of cholangitis and optimal nutritional support including the administration of fat-soluble vitamins.

Serum vascular endothelial growth factor per platelet count in patients with biliary atresia

Background: Biliary atresia (BA) is a progressive, sclerosing, inflammatory process resulting in complete obliteration of the extrahepatic bile ducts. The obstruction of bile flow engenders worsening cholestasis, hepatic fibrosis, and cirrhosis, which lead to portal hypertension and a decline in hepatic synthetic function. Hepatic stellate cells, which play roles in hepatic fibrogenesis, are an important source of various inflammatory mediators including vascular endothelial growth factor (VEGF) in the injured liver. Objectives: Investigate the level of serum VEGF and serum VEGF per platelet count in patients with BA and its relation to clinical characteristics. Methods: Peripheral blood samples were taken from 70 BA patients and 15 healthy control children. Serum VEGF was measured by enzyme-linked immunosorbent assay. We compared serum VEGF and serum VEGF per platelet count in BA patients with the respective results obtained in healthy control children. The relation of serum VEGF per platelet count with clinical variables of BA patients was investigated. Results: Serum VEGF levels and serum VEGF per platelet count in BA patients were not significantly different from those in normal controls (289.64±230.01 pg/mL vs. 312.36±189.05 pg/mL; p=0.72 and 1.72±1.21x106 vs. 1.57±0.97x106; p=0.66). Significant differences were observed among BA patients when VEGF per platelet count was categorized by the presence of esophageal varice (p=0.03). Only in BA patients was the serum level of VEGF correlated with the number of platelets (r=0.53, p<0.001). Conclusion: A high serum VEGF per platelet count is a useful marker for the development of portal hypertension in BA patients, especially for esophageal varice. Serum VEGF per platelet count may be useful for monitoring disease course in BA after hepatic portoenterostomy.

Timing of liver transplantation in biliary atresia-results in 71 children managed by a multidisciplinary team

BACKGROUND

Kasai portoenterostomy (KP) remains the initial surgical therapy for biliary atresia (BA). Liver transplantation (LTx) is offered after a failed KP or if KP is not feasible. The timing of LTx in these children is not well established. We attempted to define factors that may help choose the optimal timing for LTx in children with BA managed by a multidisciplinary team including a pediatric surgeon, hepatologist, and liver transplant surgeon.

METHODS

Records of children who underwent LTx for BA at our institution between January 1998 and December 2006 were reviewed. Clinical data such as pre-LTx pediatric end-stage liver disease (PELD) score, location of KP, and outcome were evaluated.

RESULTS

Seventy one children underwent 77 liver transplants for BA at an average age of 25 months (range, 3-216 months). Sixty-one had a previous KP, 30 at our institution. Ten had LTx without KP. The overall patient survival was 94.4% and overall graft survival was 87% at median follow-up of 58 months (range, 6-111 months). Four patients died, 1 because of vascular thrombosis despite repeat LTx, 1 because of fungal infection after LTx, and 2 because of causes unrelated to LTx. Six children required retransplantation. Living donor liver transplantation was performed in 32 of these children with 91% patient and graft survival. Fifty-three children had a PELD score of 10 or higher with patient and graft survivals of 92% and 86%, respectively. Eighteen children had a PELD score of less than 10 with patient and graft survivals of 100%. For the 30 children who underwent KP at our institution, the median age at LTx was 9 months (range, 3-168 months), and patient and graft survival were both 93%.

CONCLUSIONS

Outcome of LTx for BA is excellent. Children with higher PELD scores (>/=10) at LTx may have worse outcome. Children with a PELD score of less than 10 survived with their original grafts. In children with BA, the PELD score should be monitored and may help stratify patients for eventual LTx. When a child with BA is deemed a candidate for LTx, the PELD score should be determined. A PELD score that approaches 10 should trigger discussion of LTx and living donor liver transplantation with the family.

Congenital bile duct anomalies (biliary atresia) and chromosome 22 aneuploidy

Biliary atresia is a disease of unknown etiology but not usually thought to have a significant genetic predisposition. We report 5 infants with various forms of chromosome 22 aneuploidy as follows: 2 infants who have classical cat-eye syndrome, 2 who have partial duplication of chromosome 22 (supernumerary der(22) syndrome), and 1 who is mosaic for trisomy 22. All of these infants had significant congenital bile duct anomalies (specifically biliary atresia, n = 4)-that was the most important component of their clinical presentation. We consider whether this has possible implications about the genetic contribution to the etiology of biliary atresia.

Biliary atresia: recent progress

Extrahepatic biliary atresia (EHBA), an inflammatory sclerosing cholangiopathy, is the leading indication for liver transplantation in children. The cause is still unknown, although possible infectious, genetic, and immunologic etiologies have received much recent focus. These theories are often dependent on each other for secondary or coexisting mechanisms. Concern for EHBA is raised by a cholestatic infant, but the differential diagnosis is large and the path to diagnosis remains varied. Current treatment is surgical with an overall survival rate of approximately 90%. The goals of this article are to review the important clinical aspects of EHBA and to highlight some of the more recent scientific and clinical developments contributing to our understanding of this condition.

Polymorphisms of the ICAM-1 gene are associated with biliary atresia

Inflammation is an important feature of biliary atresia, and recent studies suggest that its occurs in a genetically susceptible host. The intercellular adhesion molecule-1 (ICAM-1) is of paramount importance for the initiation and propagation of various inflammatory conditions.

AIM

To determine whether the Glu241Arg polymorphism in the ICAM-1 gene, which impairs inflammatory responses, is associated with biliary atresia.

METHODS

Between February 2002 and November 2004, 19 patients (mean age 1 +/- 0.4 years) diagnosed as biliary atresia were included in the study. Thirty-eight children with chronic liver disease and a group of unrelated healthy controls (n = 123) included in this study. After informed consent, blood was collected and genomic DNA was obtained. Genotyping was performed by amplification-refractory mutation system polymerase chain reaction (ARMSPCR). Associations were assessed by using Fischer's exact test.

RESULTS

ICAM G242R A allele frequency was significantly higher in the BA group than in both the CLD and healthy control groups (OR = 4.4, 95 CI% 1.3-15.1, P = 0.03 and OR = 4.8 CI% 1.5-15.6, P = 0.01, respectively). Univariate analysis showed that polymorphism of ICAM G241R polymorphism was significantly related to biliary atresia. There was not significant correlation between PELD score and ICAM-1 genotypes both in BA and CLD groups.

CONCLUSION

These findings provide evidence for the possible role of ICAM-1 241R polymorphism in BA pathogenesis.

Histologic oddities at the porta hepatis in biliary atresia

PURPOSE

Highly unusual histologic findings at the porta hepatis in 3 infants who underwent Kasai portoenterostomy for biliary atresia are reported.

METHODS

Portoenterostomy was performed using a standard operative technique. Serial transverse sections of the excised portal plate were examined by light microscopy along with sections from the distal extrahepatic biliary remnants, gallbladder, and liver biopsy.

RESULTS

Of 61 consecutive infants who underwent Kasai portoenterostomy for biliary atresia, 3 were found to have highly unusual histologic features at the porta hepatis. All had type 3 biliary atresia. Two had hilar biliary ductules lined in part by squamous epithelium, and the third had a focus of mature hyaline cartilage surrounded by perichondrium adjacent to biliary ductules. In each case, these unusual histologic features were localized to the porta hepatis in the region of the transected portal plate.

CONCLUSIONS

The presence of hyaline cartilage at the portal plate is likely to be an expression of defective morphogenesis, thus supporting the concept of disordered embryogenesis in the etiology of biliary atresia. Squamous epithelium within biliary ductules might also reflect a similar mechanism but could alternatively be an unusual metaplastic response to inflammation at this site.

Integrin alphavbeta6 and mediators of extracellular matrix deposition are up-regulated in experimental biliary atresia

INTRODUCTION

Biliary atresia (BA) is a progressive obliteration of the extrahepatic bile ducts resulting in hepatic fibrosis. The underlying mechanisms have not been defined. We used an animal model of BA to evaluate mediators of extracellular matrix (ECM) processing to determine which factors may be involved.

METHODS

Newborn BALB/c mice received an intraperitoneal injection with rhesus rotavirus or saline within 24 h of birth. Livers were harvested on days 7 and 14 for histology and immunohistochemistry (IHC). RNA expression was determined using quantitative real-time PCR. Human liver from patients with BA and those having a resection for nonfibrosing diseases was also evaluated.

RESULTS

In experimental mice, mRNA expression for tissue inhibitor of metalloproteinase (TIMP)-1 and matrix metalloproteinase (MMP)-7 was increased 18-fold and 69-fold, respectively on day 7, with further increases on day 14. On day 14, mRNA expression for plasminogen activator inhibitor (PAI)-1 (38-fold), TIMP-4 (9.5-fold), and MMP-9 (5.5-fold) mRNA was also observed. Furthermore, integrin alpha(v) beta(6) mRNA expression was increased on days 7 (11-fold) and 14 (6-fold). Presence of integrin alpha(v) beta(6) protein was confirmed by IHC in both mouse and human specimens in the proliferating biliary epithelium.

CONCLUSIONS

Our data suggest experimental BA is associated with increased mRNA expression of ECM degradation inhibitors, TIMP-1, PAI-1, and TIMP-4. MMP-7 and MMP-9 expression is also elevated in this model. Furthermore, increased gene expression of integrin alpha(v)beta(6) was demonstrated and IHC confirmed protein expression. Integrin alpha(v)beta(6) or the inhibitors of ECM breakdown may be attractive targets for future treatment strategies.

The effect of recipient-specific surgical issues on outcome of liver transplantation in biliary atresia

Biliary atresia (BA), the most common reason for orthotopic liver transplantation (OLT) in children, is often accompanied by unique and challenging anatomical variations. This study examines the effect of surgical-specific issues related to the presence of complex vascular anatomic variants on the outcome of OLT for BA. The study group comprised 944 patients who were enrolled in the Studies of Pediatric Liver Transplantation (SPLIT) registry and underwent OLT for BA over an 11-year period. 63 (6.7%) patients met the study definition of complex vascular anomalies (CVA). Patient survival, but not graft survival, was significantly lower in the CVA group, (83 vs. 93 % at 1-year post-OLT). The CVA group had a significantly higher incidence of all reoperations, total biliary tract complications, biliary leaks and bowel perforation. The most frequent cause of death was infection, and death from bacterial infection was more common in the CVA group. Pretransplant portal vein thrombosis and a preduodenal portal vein were significant predictors of patient survival but not graft survival. This study demonstrates that surgical and technical factors have an effect on the outcome of BA patients undergoing OLT. However, OLT in these complex patients is technically achievable with an acceptable patient and graft survival.

Prolonged neonatal jaundice and the diagnosis of biliary atresia: a single-center analysis of trends in age at diagnosis and outcomes

Age at diagnosis is a modifiable risk factor in outcomes after hepatoportoenterostomy in biliary atresia; however, distinguishing biliary atresia from other more common causes of prolonged neonatal jaundice can be difficult. To focus attention on diagnosis of biliary atresia, we analyzed secular trends in the age at diagnosis, and other factors that might influence outcome. We performed a retrospective analysis of 55 consecutive infants with biliary atresia presenting to a single academic pediatric center over 15-year period from 1990 to 2004. The median age at diagnosis was 60 days (range: 21-152). In recent era (2000-2004), the median age was 69.0 days, compared with 48.5 days (1990-1994) and 59.5 days (1995-1999), respectively. Consistent with previous studies, the median age at diagnosis of those with poor outcomes (death or liver transplant) exceeded those with good outcomes after the hepatoportoenterostomy (72 vs 52 days, P < .001). The lack of improvement, or a concerning trends toward an increase in the age at diagnosis of biliary atresia, is perhaps attributable to neonatal follow-up practices. Efforts to make an earlier diagnose of this important condition deserve wider application and study.

Maternal microchimerism in underlying pathogenesis of biliary atresia: quantification and phenotypes of maternal cells in the liver

OBJECTIVE

The goal was to examine whether microchimerism plays a crucial role in the pathogenesis of biliary atresia; we analyzed the localization of maternal microchimeric cells and their phenotypes.

METHODS

Liver biopsy specimens from 8 male infants with biliary atresia and 6 control subjects with other liver diseases were investigated for maternal chimeric cells and their phenotypes through double-staining fluorescence in situ hybridization and immunohistochemical analyses.

RESULTS

Significantly larger numbers of maternal XX+ cells were found in the portal area and sinusoids of patients with biliary atresia, in comparison with control patients. In phenotypic analyses of XX+ cells, CD8+ T cells, CD45+ cells, and cytokeratin-positive cells were found, and the numbers and proportions among total CD8+ T cells were significantly higher than those in control patients.

CONCLUSIONS

Significantly more maternal chimeric CD8+ T cells in the livers of patients with biliary atresia suggest that maternal immunologic insults represent the underlying pathogenesis in biliary atresia. The findings support the recently postulated mechanisms of alloautoimmune and/or autoalloimmune responses.

Insignificant seasonal and geographical variation in incidence of biliary atresia in Japan: a regional survey of over 20 years

PURPOSE

Biliary atresia (BA) is the leading cause of obstructive jaundice in the newborn and the major indication for liver transplantation in Japan. Viral infection has been implicated in its etiology because of seasonality and space clustering. However, this has been controversial among whites. The present study investigates space-time clustering of the incidence of BA in Japan.

METHODS

Birth prevalence rates of BA were analyzed in infants born in Hyogo prefecture between 1985 and 2004 to assess time clustering among 3 seasons. The birth prevalence rates were also analyzed for space clustering between the northern (Hokkaido) and the southern islands (Kyushu) (difference of latitude, 10 degrees ) based on the Japanese Biliary Atresia Society Survey 1996-2004. We compared the prevalence rates between these groups using relative risks (RRs) calculated from 2 x 2 contingency tables.

RESULTS

One hundred nineteen infants were born with BA in Hyogo (1.1/10000 live births). Seasonal clustering in April to July did not significantly differ from that of the reference period (RR, 1.45; 95% confidence interval, 0.93-2.27). Based on Japanese registry data, space clustering between the northern and southern islands did not significantly differ (RR, 1.24; 95% confidence interval, 0.83-1.86).

CONCLUSIONS

Neither seasonal nor spatial clustering was statistically proven in Japan.

Growth failure and outcomes in infants with biliary atresia: a report from the Biliary Atresia Research Consortium

Malnutrition is a significant clinical problem in infants with biliary atresia. The natural history of poor growth and its potential association with early transplantation or death in children with biliary atresia was determined. Serial weight- and length-for-age z-scores were computed as part of a retrospective study of 100 infants who underwent hepatoportoenterostomy (HPE) for biliary atresia at 9 U.S. pediatric centers between 1997 and 2000. Poor outcome was defined as transplantation or death by 24 months of age (n = 46) and good outcome was defined as survival with native liver at 24 months of age with total serum bilirubin less than 6 mg/dL (n = 54). Growth velocity was significantly slower in the poor outcome group compared to the good outcome group (P < 0.001 for both weight and length). Mean weight z-scores were significantly lower by 6 months after HPE in the poor outcome group (-2.1 +/- 1.4) compared to the good outcome group (-1.2 +/- 1.4) (P < 0.001). In a subgroup with total bilirubin between 2 and 6 mg/dL at 3 months after HPE (n = 28), the weight z-scores at 3 months after HPE were significantly lower in the poor outcome group (-2.0 +/-1.2) compared to the good outcome group (-1.0 +/- 1.2) (P = 0.04) despite similar bilirubin concentrations.

CONCLUSION

Growth failure after HPE was associated with transplantation or death by 24 months of age. The combination of intermediate bilirubin concentrations and poor mean weight z-scores 3 months after HPE was also associated with poor clinical outcome.