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BACKGROUND: Although rotavirus is the most common cause of gastroenteritis worldwide, data regarding nosocomial rotavirus gastroenteritis (NRVGE) are limited. Our objectives were to study the rates, seasonality, epidemiology, and clinical features of NRVGE. METHODS: This was a 4-year prospective study. RESULTS: NRVGE occurred in 1% of all admissions (356/35,833), 0.8% of all hospitalization days (1164/145,595) and 0.24 cases per 100 hospitalization days. Rates of NRVGE were age-dependent, occurring in 1.8%, 1.5%, 0.3%, and 0.1% of the admissions of children age < or = 1, > 1 to 2, > 2 to 5, and > 5 years, respectively (P < .001). Of the children age > 5 years, 90% received immunosuppressive treatment or had significant underlying diseases. The number of NRVGE cases was highest in winter months, but it occurred throughout the year, and its percentage of all hospitalizations for rotavirus gastroenteritis was highest in the summer months. NRVGE occurred after a median hospitalization of 6 days, required a median hospital stay of 3 days, and warranted treatment with intravenous fluids in 67% of cases. CONCLUSION: NRVGE is a significant health burden, especially in children age < or = 2 years, although it also can affect children age > 5 years with significant underlying disturbances. Vaccine prevention of rotavirus gastroenteritis also could reduce NRVGE and should be considered in cost-effectiveness analyses. [ABSTRACT FROM AUTHOR]

Aim: This retrospective study aimed to assess the efficacy of prophylactic antibiotics in preventing ascending cholangitis following Kasai portoenterostomy (KPE). Data from 72 patients treated across four tertiary centres in Israel from 2008 to 2018 were analysed., Methods: Clinical and laboratory data were collected from biliary atresia (BA) diagnosis until liver transplantation (LT) or study completion., Results: Median age at KPE was 58.5 days. Successful KPE was achieved in 23 (32%) patients. Ascending cholangitis occurred in 6/23 (26%) successful KPE cases and 15/45 (33%) unsuccessful cases. Primary antibiotic prophylaxis (49% of patients) was associated with earlier onset of cholangitis (median 77 vs 239 days, p = 0.016). During follow-up, 39% underwent LT, with a 5-year survival with native liver (SNL) of 54%., Conclusion: Prophylactic antibiotics did not reduce cholangitis rates post-KPE in our cohort. Further research is essential to optimise management strategies for infants with BA., (© 2024 The Author(s). Acta Paediatrica published by John Wiley & Sons Ltd on behalf of Foundation Acta Paediatrica.)

Cholangiopathies are poorly understood disorders with no effective therapy. The extrahepatic biliary tree phenotype is less studied compared to the intrahepatic biliary injury in both human disease and Mdr2 -/- mice, the established cholestatic mouse model. This study aimed to characterize the extra hepatic biliary tree of Mdr2 -/- mice at various ages and to determine if injury can be repaired with the antioxidant and glutathione precursor N-acetyl-L-Cysteine treatment (NAC). We characterized extra hepatic bile ducts (EHBD)s at various ages from 2 to 40 weeks old FVB/N and Mdr2 -/- mice. We examined the therapeutic potential of local NAC ex vivo using EHBD explants at early and late stages of injury; and systematic therapy by in vivo oral administration for 3 weeks. EHBD and liver sections were assessed by histology and immunofluorescent stains. Serum liver enzyme activities were analyzed, and liver spatial protein expression analysis was performed. Mdr2 -/- mice developed progressive EHBD injury, similar to extrahepatic PSC. NAC treatment of ex vivo EHBD explants led to improved duct morphology. In vivo, oral administration of NAC improved liver fibrosis, and decreased liver enzyme activities. Spatial protein analysis revealed cell-type specific differential response to NAC, collectively indicating a transition from pro-apoptotic into proliferative state. NAC treatment should be further investigated as a potential therapeutic option for human cholangiopathies., (© 2024. The Author(s).)

Background: Survival after pediatric liver transplantation has increased dramatically over the years, revealing extra-hepatic complications including impaired kidney function. We conducted a large single-center retrospective study to evaluate kidney outcomes after pediatric liver transplantation., Methods: From electronic charts of 121 children who underwent liver transplantation during 2007-2020, we collected pre- and post-transplant data. We investigated the presence of post-transplant permanent kidney injury, including proteinuria, hypertension, and decreased estimated glomerular filtration rate (eGFR). We excluded children who died, underwent liver-kidney transplantation, or had less than 1 year of follow-up., Results: During a median follow-up of 5.1 (interquartile range 2.9-7.3) years, eGFR decreased, mostly in the first year post-transplant. In addition, 41% of the children presented with acute kidney injury. At their last follow-up, 35% showed permanent kidney injury (hypertension 13%, proteinuria 36%, and eGFR < 90 mL/min per 1.73 m 2 7%). Kidney ultrasounds were abnormal for 44% of the children at the last visit, compared to 11% before transplant (p < 0.001). In multivariate analysis, abnormal kidney ultrasound before transplant (odds ratio = 4.53, 95% CI 1.1-18.7) and liver disease with potential risk of primary kidney involvement (odds ratio = 4.77, 95% CI 1.58-14.4) were predictors for hypertension or decreased eGFR at the last follow-up., Conclusions: The high prevalence of kidney injury after pediatric liver transplantation and the pretransplant predictors for kidney injury highlight the importance of a thorough kidney pretransplant evaluation and follow-up., (© 2024. The Author(s), under exclusive licence to International Pediatric Nephrology Association.)

Background: Mechanisms underlying bile duct injury in biliary atresia (BA) remain unclear and mechanisms of bile duct repair are unknown. This study aimed to explore the roles of microtubule instability and Wnt and Hippo signaling pathways in a biliatresone-induced BA model., Methods: Using primary murine neonatal cholangiocytes in both 2D and 3D cultures, and ex-vivo extra hepatic bile ducts (EHBD) which also has peri-cholangiocyte area, we analyzed injury and recovery processes. Injury was induced by the toxin biliatresone and recovery was induced by toxin wash-out., Results: Microtubule stabilizer paclitaxel prevented biliatresone-induced injury, both to cholangiocytes as well as reduced periductal αSMA stain, this process is mediated by decreased glutathione levels. RhoU and Wnt11 (Wnt signaling) and Pard6g and Amotl1 (Hippo signaling) are involved in both injury and recovery processes, with the latter acting upstream to Wnt signaling., Conclusions: Early stages of biliatresone-induced EHBD injury in cholangiocytes and periductal structures are reversible. Wnt and Hippo signaling pathways play crucial roles in injury and recovery, providing insights into BA injury mechanisms and potential recovery avenues., Impact: Microtubule stabilization prevents cholangiocyte injury and lumen obstruction in a toxic model of biliary atresia (biliatresone induced). Early stages of biliatresone-induced injury, affecting both cholangiocytes and periductal structures, are reversible. Both Wnt and Hippo signaling pathways play a crucial role in bile duct injury and recovery, with a noted interplay between the two. Understanding mechanisms of cholangiocyte recovery is imperative to unveil potential therapeutic avenues., (© 2024. The Author(s).)

Background and Aims: Alagille syndrome (ALGS) is characterized by chronic cholestasis with associated pruritus and extrahepatic anomalies. Maralixibat, an ileal bile acid transporter inhibitor, is an approved pharmacologic therapy for cholestatic pruritus in ALGS. Since long-term placebo-controlled studies are not feasible or ethical in children with rare diseases, a novel approach was taken comparing 6-year outcomes from maralixibat trials with an aligned and harmonized natural history cohort from the G lobal AL agille A lliance (GALA) study., Approach and Results: Maralixibat trials comprise 84 patients with ALGS with up to 6 years of treatment. GALA contains retrospective data from 1438 participants. GALA was filtered to align with key maralixibat eligibility criteria, yielding 469 participants. Serum bile acids could not be included in the GALA filtering criteria as these are not routinely performed in clinical practice. Index time was determined through maximum likelihood estimation in an effort to align the disease severity between the two cohorts with the initiation of maralixibat. Event-free survival, defined as the time to first event of manifestations of portal hypertension (variceal bleeding, ascites requiring therapy), surgical biliary diversion, liver transplant, or death, was analyzed by Cox proportional hazards methods. Sensitivity analyses and adjustments for covariates were applied. Age, total bilirubin, gamma-glutamyl transferase, and alanine aminotransferase were balanced between groups with no statistical differences. Event-free survival in the maralixibat cohort was significantly better than the GALA cohort (HR, 0.305; 95% CI, 0.189-0.491; p <0.0001). Multiple sensitivity and subgroup analyses (including serum bile acid availability) showed similar findings., Conclusions: This study demonstrates a novel application of a robust statistical method to evaluate outcomes in long-term intervention studies where placebo comparisons are not feasible, providing wide application for rare diseases. This comparison with real-world natural history data suggests that maralixibat improves event-free survival in patients with ALGS., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc.)

Background and Aims: An increase in the number of cases of acute hepatitis of unknown origin (HUO) in children was observed in 2021. Adenovirus and adeno-associated virus 2 (AAV2) infections have been suggested as possible triggers. However, the potential etiology is still unclear. We aimed to characterize a cohort of children with HUO in Israel in view of the COVID-19 pandemic., Method: Demographics, clinical data, and laboratory results on the children compatible with the CDC criteria for HUO were collected by the established registry of the Ministry of Health. Available specimens were sent to the Central Virology Laboratory., Results: A total of 39 children were included in the registry. A total of 20 were enrolled prospectively, in which human herpes virus 6 (HHV6) infection or reactivation was identified in 11/19, adenovirus was found in 4/19 of the cases, and AAV2 was detected in 2/16. Past COVID-19 exposure was recorded for 24/39 of the children. A total of 10 children underwent liver biopsy, and 8 were successfully treated with steroids and 2 underwent liver transplantation., Conclusions: The COVID-19 pandemic and the related containment measures combined with reactivation or active infection with other viruses could have been a trigger for the HUO outbreak. In our cohort, HHV6 was the most abundant finding.

Background: Biliary strictures are a significant cause of morbidity and graft loss in pediatric liver transplant recipients. Risk factors for the development of biliary strictures are not fully established. We aimed to evaluate the incidence of biliary strictures and treatment modalities outcomes and to identify potential risk factors for occurrence., Methods: Pediatric patients who underwent liver transplantation in the single tertiary pediatric liver transplant center in Israel were evaluated. We compared demographics, presentation, laboratory results, imaging, treatment, and outcomes between patients with and without biliary stricture. Multivariate regression analyses were used to identify risk factors for biliary strictures., Results: Among 121 pediatric liver transplant patients, 65 (53.7%) were males; the median age at the time of liver transplantation was 43 (3-215) months. Fifteen patients (12.4%) had biliary strictures following transplantation. One (7%) patient with biliary stricture was treated via endoscopic retrograde cholangiopancreatography, and 12 patients (80%) underwent interventions via a percutaneous transhepatic approach. Nine of the 12 patients were treated successfully, requiring one or multiple procedures, while the remaining had surgery or laser therapy. Risk factors for the development of biliary strictures were biliary leak, acute cellular rejection, and the presence of two biliary anastomoses., Conclusions: In our cohort, the presence of two biliary anastomoses and post-transplant complications including acute cellular rejection and early biliary leaks were associated with biliary strictures in pediatric liver transplantation recipients. Percutaneous transhepatic interventions result in good outcomes in most patients., (© 2024 The Authors. Pediatric Transplantation published by Wiley Periodicals LLC.)

Celiac disease (CeD) is likely to be associated with growth impairment and poor weight gain. However, long-term growth patterns following diagnosis are poorly characterized. We evaluated long-term anthropometric changes in a large cohort of pediatric patients with CeD. A retrospective chart review of patients diagnosed with CeD between 1999 and 2018 was conducted. Demographic and clinical data were collected, and anthropometrics were analyzed from diagnosis and throughout follow-up. The study included 500 patients (59.8% females, median (IQR) age at diagnosis 5.7 (3.7-8.9) years), with a mean follow-up of 5.5 (range 1.5-16.2) years. Weight, height, and BMI Z-score-for-age (WAZ, HAZ, and BMIZ) increased significantly from a mean (± SD) of - 0.82 (± 1.21), - 0.73 (± 1.16), and - 0.32 (± 1.11) at diagnosis to - 0.41 (± 1.23), - 0.45(± 1.16), and - 0.17 (± 1.14) at last follow-up, respectively (p < 0.001 for WAZ and HAZ and p = 0.002 for BMIZ). The largest improvements were observed in patients diagnosed before 3 years of age (p < 0.01). Patients for whom the final adult height was available (n = 86) improved from HAZ mean (± SD) - 0.89 ± 1.37 at diagnosis to - 0.51 ± 1.28 at adulthood measurement, p < 0.05. Wasting was present in 19.7% and stunting in 16.4% of the cohort at diagnosis and normalized in 77.3% and 64.8%, respectively, within a median (IQR) time of 0.79 (0.42-4.24) and 2.3 (0.72-6.02) years, respectively. Gluten-free diet adherence and frequency of visits were not associated with normalization of wasting or stunting in all age groups.  Conclusion: Over a long-term follow-up, pediatric patients with CeD demonstrate significant increases in weight, height, and BMI-for-age. Younger age at diagnosis is associated with greater improvement in weight and linear growth, emphasizing the importance of early diagnosis of CeD. What is Known: • Celiac disease (СeD) is likely to be associated with growth impairment and poor weight gain. • Long-term changes in anthropometric indices after diagnosis of CeD are not well characterized. What is New: • Over a long-term follow-up, pediatric patients with CeD demonstrate significant increases in weight, height, and BMI-for-age. • Young age at diagnosis is associated with larger improvement in weight and linear growth., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Biliary atresia is a neonatal disease characterized by damage, inflammation, and fibrosis of the liver and bile ducts and by abnormal bile metabolism. It likely results from a prenatal environmental exposure that spares the mother and affects the fetus. Our aim was to develop a model of fetal injury by exposing pregnant mice to low-dose biliatresone, a plant toxin implicated in biliary atresia in livestock, and then to determine whether there was a hepatobiliary phenotype in their pups. Pregnant mice were treated orally with 15 mg/kg/d biliatresone for 2 days. Histology of the liver and bile ducts, serum bile acids, and liver immune cells of pups from treated mothers were analyzed at P5 and P21. Pups had no evidence of histological liver or bile duct injury or fibrosis at either timepoint. In addition, growth was normal. However, serum levels of glycocholic acid were elevated at P5, suggesting altered bile metabolism, and the serum bile acid profile became increasingly abnormal through P21, with enhanced glycine conjugation of bile acids. There was also immune cell activation observed in the liver at P21. These results suggest that prenatal exposure to low doses of an environmental toxin can cause subclinical disease including liver inflammation and aberrant bile metabolism even in the absence of histological changes. This finding suggests a wide potential spectrum of disease after fetal biliary injury., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Gupta et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Objectives: Patients with moderate-severe Crohn's disease (CD) who are treated with antitumor necrosis factor alpha (TNF-α) agents may be subjected to primary nonresponse or partial response. We aimed to identify tissue markers that may predict response to these agents., Methods: Pediatric patients (6-18 years) with either ileal or ileo-colonic CD who were treated with anti-TNF-α were stratified into three different groups based on their overall response to therapy at the end of induction including clinical and laboratory parameters (group 1-full responders [FR], group 2-partial responders [PR], group 3-nonresponders [NR]). Seven tissue markers (fibronectin, interleukin [IL]-23R, IL-23, TNF-α, collagen-III, IL-13R, and hypoxia-inducible factors [HIF]-1α) were evaluated. Immunofluorescence (IF) analyses were performed on biopsies from the terminal ileum, which were retrieved up to 6 months before treatment initiation., Results: Twenty-six CD patients (16 [61.5%] males; age 13.9 ± 2.9 years), including 8 (30.8%) with ileal disease and 18 (69.2%) with ileo-colonic disease, were enrolled. Terminal ileum biopsies from nine patients from group 1, nine from group 2, and eight from group 3 were evaluated. Three antibodies were found to be significantly different between NR and FR groups; Collagen III and fibronectin stains were significantly more prominent in NR patients, while TNF-α stain was significantly more pronounced in FR, p < 0.05 for each. PR could not have been predicted with neither of markers., Conclusions: Decreased tissue IF intensity of fibronectin and collagen III and increased intensity of TNF-α may predict response to anti-TNF-α treatment., (© 2024 European Society for Pediatric Gastroenterology, Hepatology, and Nutrition and North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition.)

Background: Solid organ transplantation has evolved in recent decades, resulting in a rise in patient and graft survival. Frequent hospitalizations affect graft function, patients' health, and quality of life. This study characterizes the frequency and causes of post-transplant hospitalizations among pediatric recipients., Methods: This is a retrospective observational study evaluating pediatric kidney transplant recipients (KTR) and liver transplant recipients (LTR) aged 0-21 years, followed at a tertiary pediatric center in Israel from 2012 to 2017. Data were collected starting at 60 days post-transplantation. Diagnoses of admissions were based on clinical, laboratory, and radiographic findings., Results: Forty-nine KTR experienced 199 all-cause re-hospitalizations (median number of re-hospitalizations per patient - 3 (IQR [interquartile range] 1-5.5), while 351 re-hospitalizations were recorded in 56 LTR (median - 5 [IQR 2-8.8]). Median follow-up time was 2.2 years for KTR (IQR 1-3.9) and 3 years for LTR (IQR 2.1-4.1). The most common cause for hospitalization for both cohorts was infection (50.8% and 62%, respectively). Gram-negative bacteria were the most common pathogens identified in KTR, while viral pathogens were more common in LTR (51% and 57% of pathogen-identified cases, respectively)., Conclusions: This is the largest study to describe rehospitalizations for pediatric solid organ recipients. The hospital admission rate was higher in LTR in comparison to KTR. Infections were the most common cause of hospitalization throughout the whole study period in both populations. Frequent hospitalizations impose a heavy burden on patients and their families; better understanding of hospitalization causes may help to minimize their frequency., (© 2023 Wiley Periodicals LLC.)

Exploring the pathogenesis of and developing therapies for cholestatic liver diseases such as primary sclerosing cholangitis (PSC) remains challenging, partly due to a paucity of in vitro models that capture the complex environments contributing to disease progression and partly due to difficulty in obtaining cholangiocytes. Here we report the development of a human vascularized bile duct-on-a-chip (VBDOC) that uses cholangiocyte organoids derived from normal bile duct tissue and human vascular endothelial cells to model bile ducts and blood vessels structurally and functionally in three dimensions. Cholangiocytes in the duct polarized, formed mature tight junctions and had permeability properties comparable to those measured in ex vivo systems. The flow of blood and bile was modeled by perfusion of the cell-lined channels, and cholangiocytes and endothelial cells displayed differential responses to flow. We also showed that the device can be constructed with biliary organoids from cells isolated from both bile duct tissue and the bile of PSC patients. Cholangiocytes in the duct became more inflammatory under the stimulation of IL-17A, which induced peripheral blood mononuclear cells and differentiated Th17 cells to transmigrate across the vascular channel. In sum, this human VBDOC recapitulated the vascular-biliary interface structurally and functionally and represents a novel multicellular platform to study inflammatory and fibrotic cholestatic liver diseases., (Creative Commons Attribution license.)

Objective: There is no gold standard to assess adherence to gluten-free diet (GFD) among patients with celiac disease (CeD). Gluten immunogenic peptides (GIPs) in urine and stool were suggested as novel markers for evaluating adherence to GFD. Our aim was to assess the presence of GIP in pediatric patients with CeD, and to compare the results with alternative methods for evaluating GFD adherence., Methods: Pediatric patients diagnosed with CeD, who were on GFD for at least 1 year, were enrolled and followed prospectively between November 2018 and January 2021. Study visits included clinical assessment, a dietitian interview, Biagi score, food questionnaires, anthropometric and laboratory measurements, and urine and stool samples obtained for laboratory GIP analysis., Results: The study included 74 patients (63.5% females), with median (interquartile range, IQR) age of 9.9 (7.8-11.7) years, and median (IQR) duration on GFD of 2.5 (2-5.5) years. Good GFD adherence, assessed by Biagi score, was reported in 93.1% of cases. GIP was evaluated during 134 visits, with GIP detected in 27 of 134 (20.1%) of the visits (16.3% of stool samples and 5.3% of urine samples). Positive GIP results were significantly more common in males compared to females (30.6% vs 14.1%, respectively, P < 0.05). Detection of positive GIP was not associated with dietary assessment of GFD adherence, celiac serology results, or reported symptoms., Conclusions: Stool and urine GIP can be detected in children with CeD, even when dietary assessment indicate good adherence to GFD. The role of GIP testing in clinical practice should be further explored., Competing Interests: The authors report no conflicts of interest., (Copyright © 2023 by European Society for European Society for Pediatric Gastroenterology, Hepatology, and Nutrition and North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition.)

Background: Post-liver transplant thrombocytopenia is common and associated with worse outcome in adults. In children, however, the prevalence, course, and significance of post-liver transplantation thrombocytopenia are not described. Therefore, we aimed to assess this phenomenon in children., Methods: A retrospective chart review of children who underwent liver transplantation at a single tertiary center between 2004 and 2021., Results: Overall, 130 pediatric liver transplantations were reviewed. During the first 28 POD, thrombocytopenia was evident in 116 (89%, 95% CI 83%-94%). The median nadir platelet count was 54 K/μl (IQR: 37-99). Nadir platelet count was reached in half the patients by the third POD (IQR: 1-6). In multivariate analysis, preoperative platelet count (p = .024), volume of intraoperative packed cell transfusion (p = .045), and hypersplenism (p = .007) were associated with lower postoperative platelet counts. Patients with platelet count lower than the 50th centile on the first POD suffered from a more complicated course leading to a longer PICU admission (p = .039)., Conclusions: Early post-liver transplant thrombocytopenia appears to be common in children and associated with preoperative thrombocytopenia, hypersplenism, and higher intraoperative blood transfusion volumes. A low first POD platelet count (<86 K/μl) was found to be independently associated with a more complicated postoperative course, suggesting the need for heightened surveillance., (© 2022 Wiley Periodicals LLC.)

Objectives: Severe acute respiratory syndrome coronavirus 2, the novel coronavirus responsible for coronavirus disease (COVID-19), has been a major cause of morbidity and mortality worldwide. Gastrointestinal and hepatic manifestations during acute disease have been reported extensively in the literature. Post-COVID-19 cholangiopathy has been increasingly reported in adults. In children, data are sparse. Our aim was to describe pediatric patients who recovered from COVID-19 and later presented with liver injury., Methods: This is a retrospective case series study of pediatric patients with post-COVID-19 liver manifestations. We collected data on demographics, medical history, clinical presentation, laboratory results, imaging, histology, treatment, and outcome., Results: We report 5 pediatric patients who recovered from COVID-19 and later presented with liver injury. Two types of clinical presentation were distinguishable. Two infants aged 3 and 5 months, previously healthy, presented with acute liver failure that rapidly progressed to liver transplantation. Their liver explant showed massive necrosis with cholangiolar proliferation and lymphocytic infiltrate. Three children, 2 aged 8 years and 1 aged 13 years, presented with hepatitis with cholestasis. Two children had a liver biopsy significant for lymphocytic portal and parenchyma inflammation, along with bile duct proliferations. All 3 were started on steroid treatment; liver enzymes improved, and they were weaned successfully from treatment. For all 5 patients, extensive etiology workup for infectious and metabolic etiologies was negative., Conclusions: We report 2 distinct patterns of potentially long COVID-19 liver manifestations in children with common clinical, radiological, and histopathological characteristics after a thorough workup excluded other known etiologies., Competing Interests: The authors report no conflicts of interest., (Copyright © 2022 by European Society for European Society for Pediatric Gastroenterology, Hepatology, and Nutrition and North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition.)

Background: The COVID-19 pandemic has affected medical care worldwide. Thus, we aimed to assess the impact of the COVID-19 pandemic on pediatric LT recipients., Methods: A cross-sectional study based on a structured internet or telephone survey was conducted among pediatric LT recipients. Survey results were compared with results of a survey conducted among pediatric patients with IBD., Results: Seventy-six pediatric LT patients participated in the study. Of them, 58 (76.3%) reported fear of severe COVID-19 infection due to LT or LT-associated medications. Half of the patients reported needing emotional support. Most patients (51, 67.1%) reported strictly following official guidance, while more stringent protective measures were taken by 64 (84.2%) patients. None of the patients discontinued their medications due to COVID-19. Compared to pediatric patients with IBD, a higher proportion of pediatric LT recipients reported fears of contracting severe COVID-19 infection due to their illness or medications (45, 59.2% vs. 110, 45.1%)., Conclusion: Among pediatric LT recipients a higher proportion reported fear of severe COVID-19 infection, implemented additional protective measures and expressed a need for emotional support, compared to patients with IBD. Medical teams should provide adequate information and offer a support system for this vulnerable population., (© 2022 The Authors. Pediatric Transplantation published by Wiley Periodicals LLC.)

Purpose: Kasai portoenterostomy (KPE) is the only treatment currently available for biliary atresia (BA). Age at KPE and surgical experience are prognostic factors for a successful KPE. Here, we aimed to assess whether the size of bile ductules at the porta hepatis during KPE correlates with KPE success and transplant-free survival (TFS)., Methods: A retrospective analysis of patients diagnosed with BA during 2000-2019. Porta hepatis biopsies were reviewed for diameters of five representative ducts, and a mean ductal diameter (MDD) was calculated. Laboratory values including pre- and postoperative bilirubin levels were analyzed., Results: The cohort included 77 patients; for 33, ductal plate biopsy was available. KPE was successful in six of eight patients with MDD ≥ 50 µm, and in five of 25 with MDD < 50 µm, p = 0.008, OR = 12.0 (95% CI 1.83-78.3). Ten-year survival with native liver was higher in patients with MDD ≥ 50 µm than in patients with MDD < 50 µm, p < 0.001, HR 0.038 (95% CI 0.007-0.207). Direct bilirubin < 1 mg/dl 3 months post-KPE was associated with improved 2-year post-KPE TFS (27.7% vs. 13.9%, p < 0.0001)., Conclusions: MDD ≥ 50 µm correlates with KPE success and a higher rate of TFS. Direct bilirubin < 1 mg/dl 3 months post-operation may serve as a marker of successful biliary excretion, and a predictor of 2-year TFS., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Content available: Audio Recording., Competing Interests: Nothing to report., (© 2022 American Association for the Study of Liver Diseases.)

Aim: Infants with biliary atresia (BA) generally have chronic malnutrition. However, the best anthropometric measure to assess malnutrition and its correlation with disease severity is unknown. We aimed to assess correlations of various anthropometric measurements, including air displacement plethysmography (ADP), with laboratory parameters and with the pediatric end-stage liver disease (PELD) score in infants with BA., Methods: Infants with BA were followed at a pediatric liver transplantation center during 2014-2018. Follow-up comprised laboratory tests and nutritional assessment by a dietitian including dietary intake, weight, height, mid-upper arm circumference (MUAC), and skin-fold thickness. Fat-free mass (FFM) and fat mass (FM) were measured by ADP., Results: Forty-three nutritional evaluations were performed in 28 infants with BA (13 boys, 44.4%). The median age was 20.7 weeks (IQR: 13-25.9). Based on the various anthropometry modalities, infants with BA were found to be malnourished on most of the visits; 63% had a MUAC-Z score lower than -2 standard deviations. High serum bilirubin level predicted lower weight for age, length for age, and MUAC-Z. Lower MUAC-Z was associated with a higher PELD score. Neither FM mass nor FFM correlated with PELD or with serum bilirubin level. However, FM correlated with skin-fold thickness-Z and was low in most patients., Conclusions: The majority of BA infants suffer from malnutrition as assessed by most anthropometrics modalities; low MUAC correlated best with disease severity and serum bilirubin level. Further studies are warranted to determine the contribution of FM measurement by ADP to the anthropometric assessment of infants with BA., (© 2021 Wiley Periodicals LLC.)

Niemann-Pick disease type C (NPC) is a rare autosomal recessive neuro-visceral lipid storage disease. We describe nine cases of infantile-onset NPC with various genetic mutations in the NPC1 gene, which presented with neonatal cholestasis. Serum alpha-fetoprotein (AFP) levels were obtained as part of their workup during the first four months of life. In eight of nine (89%) patients, serum AFP demonstrated elevated levels. Seven infants displayed marked elevations, ranging from 4 to 300 times the upper limit for age-adjusted norms. In most patients, AFP levels peaked during the initial test and declined over time as cholestasis resolved. We conclude that elevated AFP levels are a common, although non-specific, marker for NPC-associated liver disease. These findings demonstrate the benefit of including AFP levels in the workup of neonatal liver disease, especially if there is accompanied cholestasis and if NPC is suspected.

Introduction: Bile duct integrity is essential for the maintenance of the structure and function of the biliary tree. We previously showed that cholangiocyte injury in a toxic model of biliary atresia leads to increased monolayer permeability. Increased epithelial permeability was also shown in other cholangiopathies. We hypothesized that after initial cholangiocyte injury, leakage of bile acids into the duct submucosa propagates cholangiocyte damage and fibrosis. We thus aimed to determine the impact of bile acid exposure on cholangiocytes and the potential therapeutic effect of a non-toxic bile acid., Materials and Methods: Extrahepatic bile duct explants were isolated from adult and neonatal BALB/c mice. Explants were cultured with or without glycochenodeoxycholic acid and ursodeoxycholic acid. They were then fixed and stained., Results: Explants treated with glycochenodeoxycholic acid demonstrated cholangiocyte injury with monolayer disruption and partial lumen obstruction compared to control ducts. Masson's trichrome stains revealed increased collagen fibers. Myofibroblast marker α-SMA stains were significantly elevated in the periductal region. The addition of ursodeoxycholic acid resulted in decreased cholangiocyte injury and reduced fibrosis., Conclusions: Bile acid leakage into the submucosa after initial cholangiocyte injury may serve as a possible mechanism of disease propagation and progressive fibrosis in cholangiopathies., Competing Interests: The authors have declared that no competing interests exist.

We describe the clinical and laboratory manifestations and outcomes of 25 pediatric solid organ transplant recipients who tested positive for severe acute respiratory coronavirus-2. Twenty-one (84%) developed a mild disease; 22 of 23 (96%) had a positive serologic response. Two patients (8%), both kidney transplant recipients with additional comorbidities, developed a severe disease. The findings emphasize the need for close monitoring of this population., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: Hepatic and biliary tract diseases are common in sickle cell disease (SCD) patients, likely due to sickling, hemosiderosis, viral hepatitis, or cholelithiasis. Literature is lacking on associations between SCD, autoimmune hepatitis (AIH), and/or sclerosing cholangitis (SC)-together, autoimmune liver disease (AILD). We aimed to better understand the relationship of these diseases in pediatric patients., Materials and Methods: A retrospective analysis of patients with SCD and AILD at the Children's Hospital of Philadelphia (January 2008 to August 2015)., Results: Seven patients, ages 8 to 23 years (3 males), were identified. Three had AIH, 2 SC, and 2 AIH/SC overlap, known as autoimmune SC. All patients with AIH treated with azathioprine significantly improved their liver enzymes. One patient with SC and inflammatory bowel disease underwent successful bone marrow transplant. Two SC patients died from SCD complications., Conclusions: In this cohort, there seems to be an association between SCD and AILD; SC in this population was severe. Physicians should be aware of this and evaluate patients with SCD and elevated liver enzymes for AILD., Competing Interests: The authors declare no conflict of interest., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Identifying the etiology of an acute respiratory infection in children is a well-known challenge. In this study, we evaluated the correlation between salivary C-reactive protein (CRP) and its serum counterpart, which is known to be higher in bacterial infections but necessitates a venipuncture. Salivary and serum CRPs were measured in children with an acute respiratory illness, aged 2 months to 18 years. Pearson's correlation coefficients were used to measure correlation. Discrimination of the salivary CRP levels for predicting serum levels above 100 mg/L was calculated and compared to serum CRP levels. Sensitivity and specificity were similarly calculated. Salivary CRP was measured in 104 samples. Levels correlated significantly and positively with serum CRP levels (r = 0.670, p<0.001). Area under the curve for predicting serum CRP levels of 100 mg/L was 0.848. For a salivary CRP concentration above 32,610 ng/L, the sensitivity and specificity were 69% and 93%, respectively, for accurately predicting a serum CRP level ≥100 mg/L.Conclusions: Salivary CRP can be used in the pediatric acute setting due to its high specificity for predicting elevated serum levels without the need for venipuncture. Further studies are required to achieve higher sensitivity rates. What is known: • Salivary C-reactive protein has shown correlation to its serum counterpart, mainly in healthy children, adults, and ill neonates. What is new: • In a large population of children with acute respiratory illness, aged 2 months to 18 years, salivary C-reactive protein showed high specificity for predicting elevated serum levels, thus indicating its potential as a diagnostic tool., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objectives: Severe obesity in the pediatric population has lifelong consequences. Bariatric surgery has been suggested for selected adolescents with severe obesity after careful evaluation. The indications for preoperative esophagogastroduodenoscopy (EGD) in this age group are not clear, despite its established usefulness in adults. We aimed to assess the usefulness of EGD before bariatric surgery in pediatric patients with severe obesity and metabolic comorbidities., Methods: We conducted a retrospective chart review in a single tertiary pediatric medical center of adolescents treated during 2011 to 2018. Data collected from electronic medical records included patient demographics, endoscopic findings, and laboratory parameters., Results: A total of 80 patients (40 boys) underwent evaluation. Macroscopic abnormalities were detected in 54% of the endoscopies, including gastritis, esophagitis, and duodenitis in 46%, 16%, and 13%, respectively. Forty-nine percentage of the biopsies showed histological abnormalities; in 35 (44%) patients, Helicobacter pylori was detected. Thirty-three patients (41%) received medical treatment and 2 (2.5%) required a second EGD. Metabolic comorbidities included hypertriglyceridemia (38% of the patients), low high-density lipoprotein (23%), and prediabetic (16%) or diabetic levels of HbA1C (4%). Fifty-five percentage of the cohort had elevated alanine aminotransferase (ALT), suggestive of nonalcoholic fatty liver disease (NAFLD)., Conclusions: Endoscopies performed before bariatric surgeries suggest a higher prevalence of clinically significant findings, many of which required treatment. These findings support incorporating an EGD into the preoperative evaluation of this patient population., Competing Interests: The authors report no conflicts of interest., (Copyright © 2021 by European Society for Pediatric Gastroenterology, Hepatology, and Nutrition and North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition.)

Objectives: Celiac disease (CD) is a common intestinal autoimmune disorder with diverse presenting features. We aimed to determine age-dependent patterns in CD presentation, diagnosis and management at a large tertiary referral center., Methods: A retrospective review of electronic medical records of pediatric patients diagnosed with CD between January 1999 and December 2018 at Schneider Children's Medical Center of Israel. We compared demographics, clinical and laboratory parameters between four age groups at CD presentation., Results: A cohort of 932 children was divided into four groups by age (in years) at diagnosis: 0-3 (17.9%), 3-6 (31.8%), 6-12 (34.5%), 12-18 (15.8%). The youngest age group presented more frequently with diarrhea, weight loss, abdominal distention, vomiting and lower weight z scores, P < 0.01. Hypoalbuminemia and zinc deficiency were also more frequent in this age group, compared to older patients (P < 0.05, each). Rates of anemia were higher in younger age groups (0-3 and 3-6 years), compared to older age groups, P < 0.05. Patients in the younger age groups (0-3 and 3-6 years) presented more frequently with tissue transglutaminase (TTG) levels above 10 times the upper limit of normal (ULN; P < 0.05), and more often normalized their CD serologies by 24 months of gluten-free diets (GFD) compared to older age groups (P < 0.05)., Conclusion: There is an age-dependent variation in CD presentation during childhood. Younger patients present more often with malabsorptive features, and higher TTG levels, yet normalize TTG while on GFD more rapidly than older patients. Clinicians should be aware of the diversity in CD presentation and course at the various presentation age., Competing Interests: The authors report no conflict of interests., (Copyright © 2021 by European Society for Pediatric Gastroenterology, Hepatology, and Nutrition and North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition.)

Biliary atresia is a neonatal liver disease with extrahepatic bile duct obstruction and progressive liver fibrosis. The etiology and pathogenesis of the disease are unknown. We previously identified a plant toxin, biliatresone, responsible for biliary atresia in naturally-occurring animal models, that causes cholangiocyte destruction in in-vitro models. Decreases in reduced glutathione (GSH) mimic the effects of biliatresone, and agents that replenish cellular GSH ameliorate the effects of the toxin. The goals of this study were to define signaling pathways downstream of biliatresone that lead to cholangiocyte destruction and to determine their relationship to GSH. Using cholangiocyte culture and 3D cholangiocyte spheroid cultures, we found that biliatresone and decreases in GSH upregulated RhoU/Wrch1, a Wnt signaling family member, which then mediated an increase in Hey2 in the NOTCH signaling pathway, causing downregulation of the transcription factor Sox17. When these genes were up- or down-regulated, the biliatresone effect on spheroids was phenocopied, resulting in lumen obstruction. Biopsies of patients with biliary atresia demonstrated increased RhoU/Wrch1 and Hey2 expression in cholangiocytes. We present a novel pathway of cholangiocyte injury in a model of biliary atresia, which is relevant to human BA and may suggest potential future therapeutics.

Background: Celiac disease (CD) is common worldwide with increasing prevalence and changing presentation., Aims: To evaluate changes in the presentation and management of CD over the last two decades., Methods: Retrospective chart review of pediatric patients with CD between 01.1999 to 12.2018 was performed. Comparisons were made between an early (1999 to 2008) and late (2009 to 2018) decade, regarding clinical and laboratory parameters at presentation and follow-up., Results: In a cohort of 932 patients (early decade n = 316, late decade n = 616), patients from the late decade presented with lower rates of weight loss and abdominal distention (24.2% vs 34.7% and 6% vs 11%, respectively p < 0.01), and with higher rates of abdominal pain or asymptomatic presentation (41.4% vs 27.4%, p < 0.01, and 18% vs 13%, p < 0.05, respectively). Good adherence to gluten-free diet was reported more often in the late decade (64% vs 50.6%, p < 0.001), and fewer patients were lost to follow-up. During the late decade, significantly higher rates of celiac serology normalization were achieved during the first two years of follow-up., Conclusion: In recent years, children with CD were diagnosed with milder symptoms, showed better adherence and demonstrated earlier normalization of celiac serology., (Copyright © 2020 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.)

Background & Aims: The extrahepatic bile duct is the primary tissue initially affected by biliary atresia. Biliary atresia is a cholangiopathy which exclusively affects neonates. Current animal models suggest that the developing bile duct is uniquely susceptible to damage. In this study, we aimed to define the anatomical and functional differences between the neonatal and adult mouse extrahepatic bile ducts., Methods: We studied mouse passaged cholangiocytes, mouse BALB/c neonatal and adult primary cholangiocytes, as well as isolated extrahepatic bile ducts, and a collagen reporter mouse. The methods used included transmission electron microscopy, lectin staining, immunostaining, rhodamine uptake assays, bile acid toxicity assays, and in vitro modeling of the matrix., Results: The cholangiocyte monolayer of the neonatal extrahepatic bile duct was immature, lacking the uniform apical glycocalyx and mature cell-cell junctions typical of adult cholangiocytes. Functional studies showed that the glycocalyx protected against bile acid injury and that neonatal cholangiocyte monolayers were more permeable than adult monolayers. In adult ducts, the submucosal space was filled with collagen I, elastin, hyaluronic acid, and proteoglycans. In contrast, the neonatal submucosa had little collagen I and elastin, although both increased rapidly after birth. In vitro modeling of the matrix suggested that the composition of the neonatal submucosa relative to the adult submucosa led to increased diffusion of bile. A Col-GFP reporter mouse showed that cells in the neonatal but not adult submucosa were actively producing collagen., Conclusion: We identified 4 key differences between the neonatal and adult extrahepatic bile duct. We showed that these features may have functional implications, suggesting the neonatal extrahepatic bile ducts are particularly susceptible to injury and fibrosis., Lay Summary: Biliary atresia is a disease that affects newborns and is characterized by extrahepatic bile duct injury and obstruction, resulting in liver injury. We identify 4 key differences between the epithelial and submucosal layers of the neonatal and adult extrahepatic bile duct and show that these may render the neonatal duct particularly susceptible to injury., (Copyright © 2019 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Objectives: Although gluten-free diet (GFD) is the only proven therapy for celiac disease (CD), its effect on cardiovascular disease (CVD) risk factors is still unclear. Our aim was to determine whether adherence to GFD affects CVD risk factors among newly diagnosed pediatric CD subjects., Methods: We prospectively enrolled pediatric subjects undergoing upper gastrointestinal endoscopy for suspected CD. We collected anthropometric and laboratory parameters related to CVD risk factors at the time of CD diagnosis and 1 year after initiation of a GFD and evaluated changes in CVD risk factors. Paired t tests or Wilcoxon nonparametric tests were used, each when appropriate., Results: One hundred ten newly diagnosed CD pediatric subjects were included in the analysis. There were 64 (58.2%) girls and the mean age at diagnosis was 6.8 ± 3.4 years. Median body mass index z scores (P = 0.84), rates of underweight or overweight (P = 0.32), and rates of elevated blood pressure (P = 0.78) remained unchanged. Although median fasting insulin levels increased (1.9 vs 5.4 μU/mL, P < 0.001), insulin resistance as measured by homeostatic model assessment did not increase after 1 year of GFD (P = 0.16). Although rates of dyslipidemia remained unchanged, median high-density lipoprotein levels increased on GFD (47 vs 51 mg/dL, P < 0.001)., Conclusions: In this pediatric CD cohort, GFD for 1 year was not associated with increased CVD risk factors. The long-term significance of these mild changes is yet to be determined.

Current guidelines recommend steroids for induction of remission in all children diagnosed with autoimmune hepatitis regardless of the clinical presentation. In this report, we describe our experience in treating selected asymptomatic children with autoimmune hepatitis using a steroid-free regimen; this treatment strategy was safe and effective in inducing remission., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Biliary atresia (BA) is a neonatal liver disease characterized by progressive obstruction and fibrosis of the extrahepatic biliary tree as well as fibrosis and inflammation of the liver parenchyma. Recent studies found that infants who will go on to develop BA have elevated direct bilirubin levels in the first few days of life, suggesting that the disease starts in utero . The etiology and pathogenesis of BA, however, remain unknown. Here, we discuss recent studies examining potential pathogenetic mechanisms of BA, including genetic susceptibility, involvement of the immune system, and environmental insults such as viruses and toxins, although it is possible that there is not a single etiological agent but rather a large group of injurious insults that result in a final common pathway of extrahepatic bile duct obstruction and liver fibrosis. The management and diagnosis of BA have not advanced significantly in the past decade, but given recent advances in understanding the timing and potential pathogenesis of BA, we are hopeful that the next decade will bring early diagnostics and novel therapeutics., Competing Interests: No competing interests were disclosed.No competing interests were disclosed.No competing interests were disclosed.No competing interests were disclosed.

Various perinatal factors have been implicated in association with the risk of developing celiac disease (CD) in genetically susceptible individuals. Our aim was to investigate the association of month and season of birth with the development of CD later in life in a large National cohort in Israel. Data were retrieved from a National database of more than 2 million Israeli Jewish adolescents born between 1971 and 1998. Overall, 10,566 CD cases out of 2,001,353 subjects (0.53%) were identified and analyzed. CD risk was significantly higher for subjects born in May (odds ratio [OR] 1.07, P = 0.04) and June (OR 1.09, P = 0.008). Birth during the winter season (December to February) showed a marginal significance toward reduced risk (OR 0.97, P = 0.05). In conclusion, children born in May and June are at increased risk for CD. This increased risk provides further evidence that perinatal environmental factors increase the risk of developing CD.

Biliary atresia (BA) is a rare pediatric cholangiopathy characterized by fibrosclerosing obliteration of the extrahepatic bile ducts, leading to cholestasis, fibrosis, cirrhosis, and eventual liver failure. The etiology of BA remains unknown, although environmental, inflammatory, infectious, and genetic risk factors have been proposed. We performed a genome-wide association study (GWAS) in a European-American cohort of 343 isolated BA patients and 1716 controls to identify genetic loci associated with BA. A second GWAS was performed in an independent European-American cohort of 156 patients with BA and other extrahepatic anomalies and 212 controls to confirm the identified candidate BA-associated SNPs. Meta-analysis revealed three genome-wide significant BA-associated SNPs on 2p16.1 (rs10865291, rs6761893, and rs727878; P < 5 ×10-8), located within the fifth intron of the EFEMP1 gene, which encodes a secreted extracellular protein implicated in extracellular matrix remodeling, cell proliferation, and organogenesis. RNA expression analysis showed an increase in EFEMP1 transcripts from human liver specimens isolated from patients with either BA or other cholestatic diseases when compared to normal control liver samples. Immunohistochemistry demonstrated that EFEMP1 is expressed in cholangiocytes and vascular smooth muscle cells in liver specimens from patients with BA and other cholestatic diseases, but it is absent from cholangiocytes in normal control liver samples. Efemp1 transcripts had higher expression in cholangiocytes and portal fibroblasts as compared with other cell types in normal rat liver. The identification of a novel BA-associated locus, and implication of EFEMP1 as a new BA candidate susceptibility gene, could provide new insights to understanding the mechanisms underlying this severe pediatric disorder., Competing Interests: The authors have declared that no competing interests exist.

Introduction: Massive splenomegaly from portal hypertension (PHTN) in children raises the specter of splenic rupture; however, the incidence, etiology, and risk of rupture have not been studied, nor have existing practices to reduce risk. We therefore performed an international survey to describe the splenic rupture cases in PHTN and to describe the existing empirical practice among hepatologists., Methods: A questionnaire was constructed to elicit cases of splenic rupture and collect hepatologists' common practices for prevention of splenic rupture. Pediatric hepatologists working in selected tertiary academic centers in the United States, Canada, and the United Kingdom were contacted., Results: Hepatologists from 30 of 35 centers who met the inclusion criteria replied to the survey. Thirteen cases of splenic rupture were described of which 11 resulted from trauma. In the opinion of the practitioners, high-risk activities were football, hockey, and wrestling. Sixty-one percent recommended total restriction from high-risk activities. Seventy-four percent stated that platelet count had no effect on this decision and 61% advised a spleen guard for certain activities., Conclusions: Splenic rupture in patients with PHTN and splenomegaly seems to be rare. The reported splenic rupture cases were mostly related to falling (and not to participation in sports). There was general agreement among hepatologists about restricting high impact sports. There was variation in recommendations regarding the use of a spleen guard. The authors recommend use of spleen guards in children with splenomegaly from PHTN for physical activities with risk of fall or blunt abdominal trauma.

Progressive Familial Intrahepatic Cholestasis type 2 (PFIC2) is a rare cholestatic disorder diagnosed in infancy or childhood that can lead to severe hepatic fibrosis and liver failure. Mutations in the ABCB11 gene result in a deficiency of the bile salt export protein (BSEP) and accumulation of bile inside the hepatocytes. Hepatocellular carcinoma is another condition associated with severe forms of deletion mutations in the ABCB11 gene. Treatment options including ursodeoxycholic acid biliary diversion have mixed outcomes and some patients require liver transplantation. Here, we describe two siblings with an extremely mild form of PFIC2 inherited from heterozygous parents. The elder sibling had acute liver failure at the age of six months and both siblings had pruritus, cholestasis, coagulopathy and fat-soluble-vitamin deficiencies in infancy but have been asymptomatic past infancy. Genetic testing of the siblings revealed that each were compound heterozygotes for two missense mutations of the ABCB11 gene: p.C68Y and p.R832H. Medical treatment typical for PFIC2 has not been necessary for either patient. This is the first report of these variants following a mild course in two affected patients.

Unlabelled: Biliatresone is an electrophilic isoflavone isolated from Dysphania species plants that has been causatively linked to naturally occurring outbreaks of a biliary atresia (BA)-like disease in livestock. Biliatresone has selective toxicity for extrahepatic cholangiocytes (EHCs) in zebrafish larvae. To better understand its mechanism of toxicity, we performed transcriptional profiling of liver cells isolated from zebrafish larvae at the earliest stage of biliatresone-mediated biliary injury, with subsequent comparison of biliary and hepatocyte gene expression profiles. Transcripts encoded by genes involved in redox stress response, particularly those involved in glutathione (GSH) metabolism, were among the most prominently up-regulated in both cholangiocytes and hepatocytes of biliatresone-treated larvae. Consistent with these findings, hepatic GSH was depleted at the onset of biliary injury, and in situ mapping of the hepatic GSH redox potential using a redox-sensitive green fluorescent protein biosensor showed that it was significantly more oxidized in EHCs both before and after treatment with biliatresone. Pharmacological and genetic manipulation of GSH redox homeostasis confirmed the importance of GSH in modulating biliatresone-induced injury given that GSH depletion sensitized both EHCs and the otherwise resistant intrahepatic cholangiocytes to the toxin, whereas replenishing GSH level by N-acetylcysteine administration or activation of nuclear factor erythroid 2-like 2 (Nrf2), a transcriptional regulator of GSH synthesis, inhibited EHC injury., Conclusion: These findings strongly support redox stress as a critical contributing factor in biliatresone-induced cholangiocyte injury, and suggest that variations in intrinsic stress responses underlie the susceptibility profile. Insufficient antioxidant capacity of EHCs may be critical to early pathogenesis of human BA. (Hepatology 2016;64:894-907)., (© 2016 by the American Association for the Study of Liver Diseases.)