Guideline for the Evaluation of Cholestatic Jaundice in Infants: Joint Recommendations of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition and the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition

Biliary fibrosis is an important but neglected pathological feature in hepatobiliary disorders: from molecular mechanisms to clinical implications

Fibrosis resulting from pathological repair secondary to recurrent or persistent tissue damage often leads to organ failure and mortality. Biliary fibrosis is a crucial but easily neglected pathological feature in hepatobiliary disorders, which may promote the development and progression of benign and malignant biliary diseases through pathological healing mechanisms secondary to biliary tract injuries. Elucidating the etiology and pathogenesis of biliary fibrosis is beneficial to the prevention and treatment of biliary diseases. In this review, we emphasized the importance of biliary fibrosis in cholangiopathies and summarized the clinical manifestations, epidemiology, and aberrant cellular composition involving the biliary ductules, cholangiocytes, immune system, fibroblasts, and the microbiome. We also focused on pivotal signaling pathways and offered insights into ongoing clinical trials and proposing a strategic approach for managing biliary fibrosis-related cholangiopathies. This review will offer a comprehensive perspective on biliary fibrosis and provide an important reference for future mechanism research and innovative therapy to prevent or reverse fibrosis.

Bowel function in a prospective cohort of 1052 healthy term infants up to 4 months of age

The purpose of this study is to describe the defecation pattern of healthy infants up to 17 weeks of age. We included 1052 healthy term infants from the prospective HELMi cohort (NCT03996304). Parents filled in recurring online questionnaires on feeding, gastrointestinal function, and crying weekly for the first 17 weeks of life. Defecation frequency was highest at the age of 3 weeks (a median of 4 times/day, interquartile range (IQR) 2.9-5). At each time point, the median defecation frequency of breastfed infants was higher than that of infants receiving formula (e.g., at week 17 a median of 2 times/day, IQR 0.9-3.6, and a median of 1.1, IQR 0.6-1.4, respectively). The dominant color of the stool was most often yellow or light brown. Nearly black stools were reported in the first week of life in 3.4%. Nearly half (47.4%) of the infants had green stool color dominating for at least 1 week, with comparable frequency among breastfed (47.7%) and formula-fed (45.2%) infants. Green stools were associated with a higher defecation frequency (linear mixed-effect model p < 0.0001). Occasional blood in stool was reported in 9.3% and recurrent blood in 5.2% of the infants with no difference in stool consistency. Hard stools were rare (≤ 1%).     Conclusion: This study enlightens the spectrum of defecation patterns in healthy term infants during the first 17 weeks of life. A better understanding of bowel function helps healthcare professionals distinguish normal from abnormal when addressing defecation, the color of stools, and the type of feeding. What is Known: • Breastfed infants have more frequent and more yellow-colored stools than formula-fed infants. • Stools with green color are often suggested by the parents or even by medical professionals to indicate disease or discomfort in early life. What is New: • Nearly half of the healthy term infants had green stool dominating for at least one week during the first 17 weeks and occasional blood was reported in almost 10% of the infants during this period. • Data on normal variation in bowel function and stool may serve primary health care professionals when educating the families and caretakers of infants.

Effectiveness of oral methylprednisolone as adjuvant therapy for clinical improvement, biochemical markers, and inflammation in infants with cholestasis

Aims

This study analyzed the effectiveness of methylprednisolone in improving jaundice, bilirubin levels, liver function tests, and inflammatory biomarkers in infants with cholestasis.

Methods

The randomized, actively controlled, parallel-group trial (ISRCTN45080388 registry) was conducted from November 2022 to May 2023 in Dr. Soetomo General Academic Hospital, Surabaya, Indonesia, on infants with cholestasis. The ethics committee of Dr. Soetomo General Academic Hospital, Surabaya approved the study protocol. Infants 14 days to 3 months old, with cholestasis followed by acholic stool, dark urine, and hepatomegaly were included in the trial. Participants were randomly assigned to methylprednisolone 2 mg/kg/day twice daily or to placebo twice daily for two weeks. Ursodeoxycholic acid (10 mg/kg) was administered to all patients thrice daily. Clinical examination and laboratory measurements (direct and total bilirubin, Aspartate aminotransferase (AST), Alanine transaminase (ALT), Gamma-glutamyl transferase (GGT), and inflammatory biomarker) were performed at baseline and after 2-week treatment. Measurement of inflammatory biomarkers (IL-2, IL-4, IL-6, IL-10, IFN-γ, TGF-β, and ANCA) was performed using enzyme-linked immunoassays. Data distribution was checked for normality. Analysis was carried out using SPSS ver. 21 with p significant <0.05.

Results

In total, 40 participants were randomized to methylprednisolone (n = 20; mean age 8.39 ± 3.11 weeks) and placebo (n = 18; 2 drop out; mean age 8.98 ± 2.80 weeks) groups. At baseline, the methylprednisolone treatment and placebo groups significantly differed in gender (p = 0.02) but not in clinical, laboratory examination, or inflammatory biomarker levels. The methylprednisolone group had direct bilirubin 8.36 ± 4.84 mg/dL; total bilirubin 10.40 (2.70-33.25) mg/dL; AST 187.05 (42.00-911.00) U/L; ALT 170.43 ± 134.43 U/L; IL-2 171.29 (73.70-378.57) ng/L; IL-4 119.57 ± 59.69 ng/L; IL-6 71.74 ± 29.83 ng/L; IL-10 138.15 ± 70.62 ng/L; IFN-γ 42.54 ± 12.17 ng/L; TGF-β 316.58 (163.68-606.16) ng/L; ANCA 1.70 (0.66-3.25) ng/L. After two weeks of treatment, direct bilirubin, total bilirubin, AST, IL-10, and IFN-γ levels were significantly lower in the methylprednisolone group (p < 0.05) than those in the placebo group. No serious adverse events were reported.

Conclusion

Methylprednisolone was efficacious in reducing 2-week bilirubin levels. These results support the hypothesis that the immunological process is involved in cholestasis. Further studies with larger sample sizes are needed to confirm the bile duct anti-inflammatory effect of methylprednisolone in cholestasis as an opportunity for new therapies to prevent the immunopathological process of cholestasis to biliary atresia.

Porta hepatis lymphnode mimicking biliary atresia: A case report

INTRODUCTION

Cholestasis is the impairment of normal bile flow causing accumulation of bile salts, lipids, and bilirubin in blood which presents as Jaundice. Jaundice beyond 2 weeks of age is rare in infancy with worldwide incidence of 1 in 2500 live births. Biliary atresia is the most common extra hepatic cause of cholestasis in late neonatal and infancy period. Cholestasis and hyperbilirubinemia cause irreversible brain and liver damage if not diagnosed and treated early.

CASE PRESENTATION

A 3-week-old neonate presenting with progressive yellowish discoloration of eyes and skin. Explorative laparotomy found anatomically normal liver and biliary tree, but a lymph node obstructing the common bile duct.

DISCUSSION

This case was particularly unique as history of illness and initial investigations were suggestive of biliary atresia. However, the patient had lymph nodes with no history of any triggers to lymphadenopathy. It is a rare case of obstruction of biliary flow in this age group.

CONCLUSION

Despite biliary atresia being the commonest cause of obstructive jaundice in infancy, it is important to rule out other causes like lymph nodes obstructing the biliary tree.

Biliary atresia in a 3-month-old infant (case report)

Biliary atresia (BA) is a congenital disease that occurs when extrahepatic bile ducts are either absent or deficient, resulting in liver fibrosis, portal hypertension, and eventually cirrhosis. It is the most common cause of persistent obstructive jaundice in newborns lasting more than two weeks is this condition. Abdominal ultrasound (US) is the primary imaging technique used to diagnose BA, while computed tomography (CT) is reserved for more complex cases. The gold standard for diagnosing BA is still intraoperative cholangiogram with liver biopsy. Treatment for BA usually involves Kasai hepatoportoenterostomy, but some patients still require liver transplantation due to diagnostic delays and advanced disease. In this study, the authors present the case of a 3-month-old infant with biliary atresia and its ultrasound characteristics, who underwent liver transplantation due to advanced disease. The primary objective of imaging is to provide a prompt diagnosis, given the crucial significance of timely surgical intervention.

Biliary atresia

Biliary atresia (BA) is a progressive inflammatory fibrosclerosing disease of the biliary system and a major cause of neonatal cholestasis. It affects 1:5,000-20,000 live births, with the highest incidence in Asia. The pathogenesis is still unknown, but emerging research suggests a role for ciliary dysfunction, redox stress and hypoxia. The study of the underlying mechanisms can be conceptualized along the likely prenatal timing of an initial insult and the distinction between the injury and prenatal and postnatal responses to injury. Although still speculative, these emerging concepts, new diagnostic tools and early diagnosis might enable neoadjuvant therapy (possibly aimed at oxidative stress) before a Kasai portoenterostomy (KPE). This is particularly important, as timely KPE restores bile flow in only 50-75% of patients of whom many subsequently develop cholangitis, portal hypertension and progressive fibrosis; 60-75% of patients require liver transplantation by the age of 18 years. Early diagnosis, multidisciplinary management, centralization of surgery and optimized interventions for complications after KPE lead to better survival. Postoperative corticosteroid use has shown benefits, whereas the role of other adjuvant therapies remains to be evaluated. Continued research to better understand disease mechanisms is necessary to develop innovative treatments, including adjuvant therapies targeting the immune response, regenerative medicine approaches and new clinical tests to improve patient outcomes.

A Pilot Study for Biliary Atresia Diagnosis: Fluorescent Imaging of Indocyanine Green in Stool

BACKGROUND

Biliary atresia is the most common cause of obstructive jaundice in infants and conventional cholangiography is the current diagnostic gold standard. Fluorescent cholangiography with indocyanine green can enhance biliary tree visualization during surgery because it is exclusively excreted into the bile ducts and eventually into the intestine. Therefore, we hypothesized that indocyanine green presence in stool could confirm bile duct patency in infants.

METHODS

A prospective single center cohort study was performed on infants (age ≤ 12 months) with and without jaundice after obtaining IRB approval. Indocyanine green was administered intravenously (0.1 mg/kg). Soiled diapers collected post-injection were imaged for fluorescence.

RESULTS

After indocyanine green administration, fluorescence was detected in soiled diapers for control patients (n = 4, x = 14 h22 m post-injection) and jaundiced patients without biliary atresia (n = 11, x = 13 h28 m post-injection). For biliary atresia patients (n = 7), post-injection soiled diapers before and after Kasai portoenterostomy were collected. Fluorescence was not detected in stool from 6 of 7 biliary atresia patients. As a test, indocyanine green detection in stool was 97% accurate for assessing biliary patency.

CONCLUSION

Fluorescent Imaging for Indocyanine Green (FIInd Green) in stool is a fast and accurate approach to assess biliary patency non-invasively in infants.

LEVEL OF EVIDENCE

Level III.

Enteral nutritional strategy during therapeutic hypothermia: who? when? what?

Background

There are no guidelines regarding enteral feeding (EF) of infants with hypoxic-ischemic encephalopathy (HIE) during and shortly after therapeutic hypothermia; consequently, clinical practice is, to date, still variable. The objective of this study is to assess whether a minimal EF strategy during therapeutic hypothermia may be associated with a shorter time to full EF of infants with HIE and to identify the clinical variables that independently affect the time to full EF.

Methods

A retrospective study, covering the period from 1 January 2015 to 30 June 2022 was performed at the Neonatal Intensive Care Unit of the Fondazione Policlinico Universitario "Agostino Gemelli" IRCCS, Rome, which compared infants with HIE who received minimal EF during therapeutic hypothermia with those who did not.

Results

Seventy-eight infants received minimal EF during therapeutic hypothermia, while 75 did not. Infants who were fed reached full EF significantly faster than those who were not. Moreover, they received parenteral nutrition and maintained central venous lines for a shorter time. A multivariate analysis, taking into account the variable of clinical severity, confirmed that minimal EF is an independent beneficial factor for reaching full EF in a shorter time and mechanical ventilation and seizures are independent factors for a longer time to full EF.

Conclusions

Minimal EF during therapeutic hypothermia is associated with a shorter time to full EF in stable infants with HIE. Further prospective studies are needed to better define the enteral nutrition strategy for infants during therapeutic hypothermia, regardless of the severity of clinical conditions.

Porta hepatis lymph nodes on US: not only identify biliary atresia but also predict outcomes after Kasai portoenterostomy surgery

OBJECTIVES

To evaluate the usefulness of porta hepatis lymph nodes (PHLNs) on ultrasonography (US) scans in diagnosing biliary atresia (BA) and predicting the outcomes after Kasai portoenterostomy (KPE) surgery.

METHODS

A total of 668 patients from one hospital were enrolled in the study (542 non-BA and 126 BA). The independent and combined diagnostic efficacy of PHLNs, triangular cord (TC) thickness, and gallbladder morphology were assessed by drawing the receiver operating characteristic (ROC) curves and counting the area under the ROC curve (AUC), sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). The US features, histopathological findings of PHLNs, and serum total bilirubin (TBIL) levels 3 months post-KPE were correlated.

RESULTS

The AUC, sensitivity, specificity, PPV, and NPV of PHLNs with hyperechogenicity and a maximum length larger than 8.4 mm were 0.898, 81.8%, 97.8%, 89.6%, and 95.8%, respectively. The combination of PHLNs, TC thickness, and gallbladder morphology achieved the best overall diagnostic efficacy among all indicators with an AUC of 0.927 and a sensitivity of 99.2%. The germinal center number and bile particle number of PHLNs were positively correlated with pathological size and US echogenicity intensity of PHLNs, respectively (r = 0.591, 0.377, p = 0.001, 0.004). The pathological size of PHLNs in BA patients was negatively correlated with jaundice clearance status 3 months after KPE surgery (r = -0.385, p = 0.047).

CONCLUSION

PHLNs with hyperechogenicity and a maximum length > 8.4 mm are useful US indicators for BA diagnosis. Additionally, the enlargement of PHLNs might play a role in predicting outcomes of KPE surgery.

CRITICAL RELEVANCE STATEMENT

The article proposed for the first time that PHLNs with hyperechogenicity and a maximum length > 8.4 mm are a useful US indicator for diagnosing BA.

KEY POINTS

PHLNs may be helpful in diagnosing BA and predicting outcomes after surgery. Enlarged hyperechoic PHLNs are a useful diagnostic indicator for BA, and play a role in predicting surgical outcomes. These findings can assist clinicians in more accurately diagnosing BA, enabling more timely treatments.

What's new in pediatric genetic cholestatic liver disease: advances in etiology, diagnostics and therapeutic approaches

PURPOSE OF REVIEW

To highlight recent advances in pediatric cholestatic liver disease, including promising novel prognostic markers and new therapies.

FINDINGS

Identification of additional genetic variants associated with progressive familial intrahepatic cholestasis (PFIC) phenotype and new genetic cholangiopathies, with an emerging role of ciliopathy genes. Genotype severity predicts outcomes in bile salt export pump (BSEP) deficiency, and post-biliary diversion serum bile acid levels significantly affect native liver survival in BSEP and progressive familial intrahepatic cholestasis type 1 (FIC1 deficiency) patients. Heterozygous variants in the MDR3 gene have been associated with various cholestatic liver disease phenotypes in adults. Ileal bile acid transporter (IBAT) inhibitors, approved for pruritus in PFIC and Alagille Syndrome (ALGS), have been associated with improved long-term quality of life and event-free survival.

SUMMARY

Next-generation sequencing (NGS) technologies have revolutionized diagnostic approaches, while discovery of new intracellular signaling pathways show promise in identifying therapeutic targets and personalized strategies. Bile acids may play a significant role in hepatic damage progression, suggesting their monitoring could guide cholestatic liver disease management. IBAT inhibitors should be incorporated early into routine management algorithms for pruritus. Data are emerging as to whether IBAT inhibitors are impacting disease biology and modifying the natural history of the cholestasis.

Analysis of gut microecological characteristics and differences between children with biliary atresia and non-biliary atresia in infantile cholestasis

Introduction

In infants with cholestasis, variations in the enterohepatic circulation of bile acids and the gut microbiota (GM) characteristics differ between those with biliary atresia (BA) and non-BA, prompting a differential analysis of their respective GM profiles.

Methods

Using 16S rDNA gene sequencing to analyse the variance in GM composition among three groups: infants with BA (BA group, n=26), non-BA cholestasis (IC group, n=37), and healthy infants (control group, n=50). Additionally, correlation analysis was conducted between GM and liver function-related indicators.

Results

Principal component analysis using Bray-Curtis distance measurement revealed a significant distinction between microbial samples in the IC group compared to the two other groups. IC-accumulated co-abundance groups exhibited positive correlations with aspartate aminotransferase, alanine aminotransferase, total bilirubin, direct bilirubin, and total bile acid serum levels. These correlations were notably reinforced upon the exclusion of microbial samples from children with BA.

Conclusion

The varying "enterohepatic circulation" status of bile acids in children with BA and non-BA cholestasis contributes to distinct GM structures and functions. This divergence underscores the potential for targeted GM interventions tailored to the specific aetiologies of cholestasis.

Awareness, referral and age at Kasai surgery for biliary atresia in Europe: A survey of the Quality-of-Care Task Force of ESPGHAN

OBJECTIVES

To identify infants with biliary atresia (BA), European Society of Paediatric Gastroenteroloy and Nutrition (ESPGHAN)/North American Society of Pediatric Gastroenteroloy and Nutrition (NASPGHAN) guidelines recommend measurement of conjugated/direct bilirubin in infants with prolonged jaundice and using a stool colour card (SCC). The 'Quality of Care' Task Force of ESPGHAN performed two surveys to assess current case finding for BA and age at Kasai portoenterostomy (KPE).

METHODS

The first survey approached 26 European hepatology centres to report age at referral and age at KPE of all infants diagnosed with BA from 2015 to 2019. The second survey targeted paediatricians in France to assess awareness and compliance with the recently introduced SCC.

RESULTS

Data from 785 patients with BA from 18 centres in 15 countries revealed a mean age at referral to tertiary centre of 55 days (median 53, IQR 48-60) (n = 636). The mean age at KPE was 61 days (median 60; IQR 54-67) (n = 772). For 6% of patients, cirrhosis was too advanced for surgery. Of 392 paediatricians answering the second survey, 53% felt familiar with the target diseases, 80% correctly identified cholestasis and 59% always inquired about the infant's stool colour. If abnormal, 93% would order blood tests and 85% call for advice. The SCC screening was considered helpful for case finding and improving knowledge of cholestatic diseases by 62% and 45% paediatricians, respectively.

CONCLUSIONS

Referral of infants for KPE remains late, indicating low adherence to search for cholestasis in icteric infants by age 2-3 weeks. Knowledge and structures need improvement to allow earlier guideline conform case finding, diagnosis and therapy.

Comparison for the diagnostic performance of early diagnostic methods for biliary atresia: a systematic review and network meta-analysis

BACKGROUND

Biliary atresia (BA), a progressive condition affecting canalicular-bile duct function/anatomy, requires prompt surgical intervention for favorable outcomes. Therefore, we conducted a network meta-analysis of common diagnostic methods to assess their performance and provide evidence-based support for clinical decision-making.

METHODS

We reviewed literature in PubMed, EMBASE, and Cochrane for BA diagnostics. The search included gamma-glutamyl transferase (GGT), direct/combined bilirubin, matrix metalloproteinase 7 (MMP-7), ultrasonic triangular cord sign (TCS), hepatic scintigraphy (HS), and percutaneous cholangiocholangiography/percutaneous transhepatic cholecysto-cholangiography (PCC/PTCC). QUADAS-2 assessed study quality. Heterogeneity and threshold effect were evaluated using I2 and Spearman's correlation. We combined effect estimates, constructed SROC models, and conducted a network meta-analysis based on the ANOVA model, along with meta-regression and subgroup analysis, to obtain precise diagnostic performance assessments for BA.

RESULTS

A total of 40 studies were included in our analysis. GGT demonstrated high diagnostic accuracy for BA with a sensitivity of 81.5% (95% CI 0.792-0.836) and specificity of 72.1% (95% CI 0.693-0.748). Direct bilirubin/conjugated bilirubin showed a sensitivity of 87.6% (95% CI 0.833-0.911) but lower specificity of 59.4% (95% CI 0.549-0.638). MMP-7 exhibited a total sensitivity of 91.5% (95% CI 0.893-0.934) and a specificity of 84.3% (95% CI 0.820-0.863). TCS exhibited a sensitivity of 58.1% (95% CI 0.549-0.613) and high specificity of 92.9% (95% CI 0.911-0.944). HS had a high sensitivity of 98.4% (95% CI 0.968-0.994) and moderate specificity of 79.0% (95% CI 0.762-0.816). PCC/PTCC exhibited excellent diagnostic performance with a sensitivity of 100% (95% CI 0.900-1.000) and specificity of 87.0% (95% CI 0.767-0.939). Based on the ANOVA model, the network meta-analysis revealed that MMP-7 ranked second overall, with PCC/PTCC ranking first, both exhibiting superior diagnostic accuracy compared to other techniques. Our analysis showed no significant bias in most methodologies, but MMP-7 and hepatobiliary scintigraphy exhibited biases, with p values of 0.023 and 0.002, respectively.

CONCLUSION

MMP-7 and ultrasound-guided PCC/PTCC show diagnostic potential in the early diagnosis of BA, but their clinical application is restricted due to practical limitations. Currently, the cutoff value of MMP-7 is unclear, and further evidence-based medical research is needed to firmly establish its diagnostic value. Until more evidence is available, MMP-7 is not suitable for widespread diagnostic use. Therefore, considering cost and operational simplicity, liver function tests combined with ultrasound remain the most clinically valuable non-invasive diagnostic methods for BA.

Incidence and Risk Factors of Cholestasis in Newborns with Hemolytic Disease-A Case-Control Study

Background/Objectives: One of the rare causes of cholestasis may be hemolytic disease of the fetus and newborn (HDFN). Methods: We retrospectively analyzed 88 medical records of HDFN newborns with cholestasis and 186 records of children with HDFN without cholestasis and conducted an observational, case-control, retrospective study. Results: Factors influencing the risk of cholestasis were lower gestational age at birth (36.83 ± 1.9 vs. 37.57 ± 1.8, p = 0.002), Rh or Kidd HDFN (80.7% vs. 53.2%), and the need for intrauterine transfusion (27.3 vs. 11.8%). The subjects had lower hemoglobin concentrations at birth (14.01 ± 3.8 vs. 16.39 ± 2.8 g/dL) and during whole hospital stay, higher cord blood total bilirubin concentration (4.26 ± 1.8 vs. 2.39 ± 1.4 mg/dL), higher maximum bilirubin concentration (15.27 ± 5.8 vs. 10.24 ± 3.4 mg/dL), and more frequent liver ultrasound abnormalities (19.9 vs. 6.3%). They also required more extended hospitalization due to higher rates of postnatal blood transfusion (33 vs. 3.8%), more frequent need for exchange transfusion (8.8% vs. 2.2%), more extended time and higher risk of phototherapy (94.3 vs. 59.1%), and higher usage of immunoglobulins (55.7 vs. 8.1%), parenteral nutrition (45.5 vs. 12.9%), and antibiotics (14.8 vs. 4.8%). Conclusions: The risk factors for cholestasis in children with HDFN are lower gestational age at delivery, Rh and Kidd serological type of HDFN, and the need for intrauterine transfusions.

Booster administration of Tc-99m PMT for delayed static imaging in patients with biliary atresia

OBJECTIVE

Tc-99m N-pyridoxyl-5-methyl-tryptophan (PMT) hepatobiliary scintigraphy has high diagnostic performance for biliary atresia. Our hospital implements standard Tc-99m PMT administration followed by a 6 h static imaging review; booster doses are given in cases requiring 24 h delayed scans. This study aimed to evaluate the diagnostic performance of this method.

METHODS

A total of 37 pediatric patients who underwent Tc-99m PMT biliary scintigraphy were classified into the surgically-diagnosed biliary atresia or non-biliary atresia groups. The absence of tracer accumulation in the small bowel was considered a hepatobiliary scintigraphic diagnosis of biliary atresia. The Clopper-Pearson method was used to calculate the 95% confidence intervals (CIs) for determining the diagnostic accuracy, negative predictive value, positive predictive value, sensitivity, and specificity of Tc-99m PMT biliary scintigraphy.

RESULTS

Among the 37 patients, 12 were classified into the diagnosis of biliary atresia group. Regarding biliary scintigraphy findings, 16 of 37 patients demonstrated tracer accumulation in the small bowel within 6 h of testing. These cases were diagnosed as non-biliary atresia, requiring no further testing or booster administration. In contrast, 21 patients underwent delayed testing requiring booster administration, which revealed 13 without tracer excretion and 11 who were diagnosed with biliary atresia. Among the eight patients with tracer accumulation, only one was diagnosed with biliary atresia. Furthermore, two cases without tracer excretion and seven cases with tracer excretion were clinically diagnosed as non-biliary atresia. The diagnostic performance of our examination was as follows: a diagnostic accuracy of 91.9% (34/37; 95% CIs 78.0-98.3%), sensitivity of 91.6% (11/12; 95% CIs 61.5-99.8%), specificity of 92.0% (23/25; 95% CIs 74.0-99.0%), a positive predictive value of 84.6% (11/13; 95% CIs 54.6-98.0%), and a negative predictive value of 95.8% (23/24; 95% CIs 78.9-99.9%).

CONCLUSIONS

Our protocol for Tc-99m PMT biliary scintigraphy using tracer booster administration demonstrated reliable diagnostic performance for biliary atresia. Notably, 43% of cases did not require booster administration, indicating that lesser radiation exposure may still yield comparable diagnostic accuracy.

Proteomics Defines Plasma Biomarkers for the Early Diagnosis of Biliary Atresia

Early diagnosis of biliary atresia (BA) is crucial for improving the chances of survival and preserving the liver function of pediatric patients with BA. Herein, we performed proteomics analysis using data-independent acquisition (DIA) and parallel reaction monitoring (PRM) to explore potential biomarkers for the early diagnosis of BA compared to other non-BA jaundice cases. Consequently, we detected and validated differential protein expression in the plasma of patients with BA compared to the plasma of patients with intrahepatic cholestasis. Bioinformatics analysis revealed the enriched biological processes characteristic of BA by identifying the differential expression of specific proteins. Signaling pathway analysis revealed changes in the expression levels of proteins associated with an alteration in immunoglobulin levels, which is indicative of immune dysfunction in BA. The combination of polymeric immunoglobulin receptor expression and immunoglobulin lambda variable chain (IGL c2225_light_IGLV1-47_IGLJ2), as revealed via machine learning, provided a useful early diagnostic model for BA, with a sensitivity of 0.8, specificity of 1, accuracy of 0.89, and area under the curve value of 0.944. Thus, our study identified a possible effective plasma biomarker for the early diagnosis of BA and could help elucidate the underlying mechanisms of BA.

Predictive modeling for early detection of biliary atresia in infants with cholestasis: Insights from a machine learning study

Cholestasis, characterized by the obstruction of bile flow, poses a significant concern in neonates and infants. It can result in jaundice, inadequate weight gain, and liver dysfunction. However, distinguishing between biliary atresia (BA) and non-biliary atresia in these young patients presenting with cholestasis poses a formidable challenge, given the similarity in their clinical manifestations. To this end, our study endeavors to construct a screening model aimed at prognosticating outcomes in cases of BA. Within this study, we introduce a wrapper feature selection model denoted as bWFMVO-SVM-FS, which amalgamates the water flow-based multi-verse optimizer (WFMVO) and support vector machine (SVM) technology. Initially, WFMVO is benchmarked against eleven state-of-the-art algorithms, with its efficiency in searching for optimized feature subsets within the model validated on IEEE CEC 2017 and IEEE CEC 2022 benchmark functions. Subsequently, the developed bWFMVO-SVM-FS model is employed to analyze a cohort of 870 consecutively registered cases of neonates and infants with cholestasis (diagnosed as either BA or non-BA) from Xinhua Hospital and Shanghai Children's Hospital, both affiliated with Shanghai Jiao Tong University. The results underscore the remarkable predictive capacity of the model, achieving an accuracy of 92.639 % and specificity of 88.865 %. Gamma-glutamyl transferase, triangular cord sign, weight, abnormal gallbladder, and stool color emerge as highly correlated with early symptoms in BA infants. Furthermore, leveraging these five significant features enhances the interpretability of the machine learning model's performance outcomes for medical professionals, thereby facilitating more effective clinical decision-making.

Diagnostic algorithm for neonatal intrahepatic cholestasis integrating single-gene testing and next-generation sequencing in East Asia

BACKGROUND AND AIM

Advances in molecular genetics have uncovered causative genes responsible for neonatal cholestasis. Panel-based next-generation sequencing has been used clinically in infants with neonatal cholestasis. We aimed to evaluate the clinical application of single-gene testing and next-generation sequencing and to develop a diagnostic algorithm for neonatal intrahepatic cholestasis.

METHODS

From January 2010 to July 2021, patients suspected of having neonatal intrahepatic cholestasis were tested at the Seoul National University Hospital. If there was a clinically suspected disease, single-gene testing was performed. Alternatively, if it was clinically difficult to differentiate, a neonatal cholestasis gene panel test containing 34 genes was performed.

RESULTS

Of the total 148 patients examined, 49 (33.1%) were received a confirmed genetic diagnosis, including 14 with Alagille syndrome, 14 with neonatal intrahepatic cholestasis caused by citrin deficiency, 7 with Dubin-Johnson syndrome, 5 with arthrogryposis-renal dysfunction-cholestasis syndrome, 5 with progressive familial intrahepatic cholestasis type II, 1 with Rotor syndrome, 1 with Niemann-Pick disease type C, 1 with Kabuki syndrome, and 1 with Phenylalanyl-tRNA synthetase subunit alpha mutation. Sixteen novel pathogenic or likely pathogenic variants of neonatal cholestasis were observed in this study. Based on the clinical characteristics and laboratory findings, we developed a diagnostic algorithm for neonatal intrahepatic cholestasis by integrating single-gene testing and next-generation sequencing.

CONCLUSIONS

Alagille syndrome and neonatal intrahepatic cholestasis caused by citrin deficiency were the most common diseases associated with genetic neonatal cholestasis. Single-gene testing and next-generation sequencing are important and complementary tools for the diagnosis of genetic neonatal cholestasis.

Distinct effects of racial and socioeconomic disparities on biliary atresia diagnosis and outcome

OBJECTIVES

To identify and distinguish between racial and socioeconomic disparities in age at hepatology care, diagnosis, access to surgical therapy, and liver transplant-free survival in patients with biliary atresia (BA).

METHODS

Single-center retrospective cohort study of 69 BA patients from 2010 to 2021. Patients were grouped into White and non-White cohorts. The socioeconomic milieu was analyzed utilizing neighborhood deprivation index, a census tract-based calculation of six socioeconomic variables. The primary outcomes of this study were timing of the first hepatology encounter, surgical treatment with hepatic portoenterostomy (HPE), and survival with native liver (SNL) at 2 years.

RESULTS

Patients were 55% male and 72% White. White patients were referred at a median of 34 days (interquartile range [IQR]: 17-65) vs. 67 days (IQR: 42-133; p = 0.001) in non-White patients. White infants were more likely to undergo HPE (42/50 patients; 84%) compared to non-White (10/19; 53%), odds ratio (OR) 4.73 (95% confidence interval: 1.46-15.31; p = 0.01). Independent of race, patients exposed to increased neighborhood-level deprivation were less likely to receive HPE (OR: 0.49, p = 0.04) and achieve SNL (OR: 0.54, p = 0.02).

CONCLUSIONS

Racial and socioeconomic disparities are independently associated with timely BA diagnosis, access to surgical treatment, and transplant-free survival. Public health approaches to improve screening for pathologic jaundice in infants of diverse racial backgrounds and to test and implement interventions for socioeconomically at-risk families are needed.

The timing of minimally invasive surgery for prenatally diagnosed choledochal cysts

OBJECTIVE

There are no clear evidence-based recommendations concerning when patients with prenatally diagnosed choledochal cysts (CCs) should undergo surgery. This study was primarily designed to explore the proper timing of minimally invasive surgery for prenatally diagnosed CC patients.

METHODS

Seventy-three patients with prenatally diagnosed CC were enrolled in this study and divided into 4 subgroups according to age at surgery (15 patients in the < 1 month group, 27 in the 1-2 months group, 14 in the 2-3 months group and 17 in the > 3 months group). Eighty-five healthy infants were recruited and divided into 4 age groups (29 in the < 1 month group, 20 in the 1-2 month group, 19 in the 2-3 month group and 17 in the > 3 month group). Preoperative data were collected and compared between CC patients and healthy controls in 4 age groups. Additionally, 73 patients were divided into laparoscopic and open groups to compare postoperative recovery indices and the occurrence of complications to determine the safety and feasibility of laparoscopic CC application in neonates and young infants.

RESULTS

Twenty-one of 73 (28.8%) patients who were prenatally diagnosed with CCs experienced various clinical symptoms, and 15 of 21 (71.4%) patients experienced clinical symptoms less than 2 months after birth. No differences were found in alanine transaminase (ALT), aspartate transaminase (AST) or aspartate transaminase (APRI) levels between CC patients and controls at ≤ 1 month or 1-2 months of age (all p > 0.05), while higher levels were found in CC patients at 2-3 months or > 3 months of age (all p < 0.05). ALT, AST and DBIL levels 1 week after surgery were significantly lower than those before surgery in CC patients who underwent laparoscopic CC excision at > 2 months of age, while DBIL levels 1 week after surgery were also significantly lower than those before surgery in patients who underwent CC excision at ≤ 2 months of age. The initial oral feeding time in the laparoscopic surgery group was significantly earlier than that in the open surgery group for both CC patients who underwent CC excision at ≤ 2 months of age and those > 2 months of age (all p < 0.05). No differences were found in the rates of anastomotic leakage or stricture formation between the laparoscopic and open surgery groups at ≤ 2 months or > 2 months of age.

CONCLUSION

Most clinical symptoms attributed to CC occur less than 2 months after birth, while liver function and liver fibrosis may deteriorate after 2 months of age in patients with prenatally diagnosed CC. Laparoscopic surgery for CC in newborns and young infants (either less than or more than 2 months old) is safe and feasible and can shorten the initial oral feeding time without increasing complications such as postoperative anastomotic leakage or stricture. Thus, performing laparoscopic CC excisions within 2 months after birth in patients with prenatally diagnosed CC may be appropriate.

Diagnostic yield and novel candidate genes by next generation sequencing in 166 children with intrahepatic cholestasis

BACKGROUND AND AIMS

Cholestatic liver disease is a leading referral to pediatric liver transplant centers. Inherited disorders are the second most frequent cause of cholestasis in the first month of life.

METHODS

We retrospectively characterized the genotype and phenotype of 166 participants with intrahepatic cholestasis, and re-analyzed phenotype and whole-exome sequencing (WES) data from patients with previously undetermined genetic etiology for newly published genes and novel candidates. Functional validations of selected variants were conducted in cultured cells.

RESULTS

Overall, we identified disease-causing variants in 31% (52/166) of our study participants. Of the 52 individuals, 18 (35%) had metabolic liver diseases, 9 (17%) had syndromic cholestasis, 9 (17%) had progressive familial intrahepatic cholestasis, 3 (6%) had bile acid synthesis defects, 3(6%) had infantile liver failure and 10 (19%) had a phenocopy of intrahepatic cholestasis. By reverse phenotyping, we identified a de novo variant c.1883G > A in FAM111B of a case with high glutamyl transpeptidase (GGT) cholestasis. By re-analyzing WES data, two patients were newly solved, who had compound heterozygous variants in recently published genes KIF12 and USP53, respectively. Our additional search for novel candidates in unsolved WES families revealed four potential novel candidate genes (NCOA6, CCDC88B, USP24 and ATP11C), among which the patients with variants in NCOA6 and ATP11C recapitulate the cholestasis phenotype in mice models.

CONCLUSIONS

In a single-center pediatric cohort, we identified monogenic variants in 22 known human intrahepatic cholestasis or phenocopy genes, explaining up to 31% of the intrahepatic cholestasis patients. Our findings suggest that re-evaluating existing WES data from well-phenotyped patients on a regular basis can increase the diagnostic yield for cholestatic liver disease in children.

Progress in Biomarkers Related to Biliary Atresia

Biliary atresia (BA) is a congenital cholestatic disease that can seriously damage children's liver function. It is one of the main reasons for liver transplantation in children. Early diagnosis of BA is crucial to the prognosis of patients, but there is still a lack of reliable non-invasive diagnostic methods. Additionally, as some children are in urgent need of liver transplantation, evaluating the stage of liver fibrosis and postoperative native liver survival in children with BA using a straightforward, efficient, and less traumatic method is a major focus of doctors. In recent years, an increasing number of BA-related biomarkers have been identified and have shown great potential in the following three aspects of clinical practice: diagnosis, evaluation of the stage of liver fibrosis, and prediction of native liver survival. This review focuses on the pathophysiological function and clinical application of three novel BA-related biomarkers, namely MMP-7, FGF-19, and M2BPGi. Furthermore, progress in well-known biomarkers of BA such as gamma-glutamyltransferase, circulating cytokines, and other potential biomarkers is discussed, aiming to provide a reference for clinical practice.

Diseases of bile duct in children

Several diseases originate from bile duct pathology. Despite studies on these diseases, certain etiologies of some of them still cannot be concluded. The most common disease of the bile duct in newborns is biliary atresia, whose prognosis varies according to the age of surgical correction. Other diseases such as Alagille syndrome, inspissated bile duct syndrome, and choledochal cysts are also time-sensitive because they can cause severe liver damage due to obstruction. The majority of these diseases present with cholestatic jaundice in the newborn or infant period, which is quite difficult to differentiate regarding clinical acumen and initial investigations. Intraoperative cholangiography is potentially necessary to make an accurate diagnosis, and further treatment will be performed synchronously or planned as findings suggest. This article provides a concise review of bile duct diseases, with interesting cases.

The epidemiological characteristics of liver disease in hospitalized children: a 10-year single-center retrospective study

Background

This investigation aimed to examine the epidemiological characteristics of children with liver disease hospitalized for the first time between June 2012 and May 2022 in a tertiary hospital.

Methods

The study retrospectively recruited children aged between 29 days and 18 years who had been hospitalized for liver disease. Clinical characteristics were categorized by age and etiology, and time trends were assessed using linear regression analysis.

Results

A total of 4,313 children were recruited, with a median age of 0.7 (0.2-4.5) years, and 54.5% of the cases were in the 0-1 years age group. Infection was the primary cause of liver disease (30.0%), followed by undiagnosed cases (25.8%), biliary obstructive disease (15.9%), inherited metabolic liver disease (13.9%), and non-alcoholic fatty liver disease (NAFLD) (3.2%). Genetic diagnoses were established in 43.9% (478/1,088) of patients. The percentage of NAFLD demonstrated an upward trend from 1.2% in 2012 to 12.6% in 2022 (p = 0.006). In contrast, the percentage of cytomegalovirus hepatitis decreased from 13.3% in 2012 to 3.4% in 2022 (p = 0.002).

Conclusions

Liver disease in infancy makes up the largest group in pediatric liver disease. Infection remains the leading cause of pediatric liver disease. Hospital admissions for NAFLD in children have increased rapidly over the past decade, while cytomegalovirus hepatitis has declined markedly.

Genotype correlates with clinical course and outcome of children with tight junction protein 2 (TJP2) deficiency-related cholestasis

BACKGROUND AND AIMS

The study aimed to describe the clinical course and outcomes, and analyze the genotype-phenotype correlation in patients with tight junction protein 2 (TJP2) deficiency.

APPROACH AND RESULTS

Data from all children with chronic cholestasis and either homozygous or compound heterozygous mutations in TJP2 were extracted and analyzed. The patients were categorized into 3 genotypes: TJP2-A (missense mutations on both alleles), TJP2-B (missense mutation on one allele and a predicted protein-truncating mutation [PPTM] on the other), and TJP2-C (PPTMs on both alleles). A total of 278 cases of genetic intrahepatic cholestasis were studied, with TJP2 deficiency accounting for 44 cases (15.8%). Of these, 29 were homozygous and 15 were compound heterozygous variants of TJP2 . TJP2-A genotype was identified in 21 (47.7%), TJP2-B in 7 cases (15.9%), and TJP2-C in 16 cases (36.4%), respectively. Patients with the TJP2-C genotype were more likely to experience early infantile cholestasis (87.5% vs. 53.5%, p =0.033), less likely to clear jaundice (12.5% vs. 52.2%, p =0.037), more likely to develop ascites, and had higher serum bile acids. Patients with the TJP2-C genotype were more likely to die or require liver transplantation (native liver survival: 12.5% vs. 78.6%, p <0.001), with a median age at death/liver transplantation of 2.5 years. Cox regression analysis revealed that TJP2-C mutations ( p =0.003) and failure to resolve jaundice ( p =0.049) were independent predictors of poor outcomes.

CONCLUSIONS

Patients with the TJP2-C genotype carrying PPTMs in both alleles had a rapidly progressive course, leading to early decompensation and death if they did not receive timely liver transplantation.

Clinical and laboratory features of biliary atresia and patterns of management practices: Saudi national study (2000-2018)

BACKGROUND

We utilized the data from the Saudi national biliary atresia (BA) study (2000-2018) to describe the clinical, biochemical, imaging, and histopathological features of BA and the perioperative clinical practices among local pediatric gastroenterologists.

METHODS

This is a retrospective, multicenter, nationwide study that included 10 tertiary care governmental hospitals including the four liver transplant (LT) centers in different regions across Saudi Arabia.

RESULTS

BA was diagnosed in 204 infants (106 females; 10% preterm). The median age at referral was 65 days. Congenital anomalies were present in 68 patients (33%); 22 were splenic malformation (10.8%). The medians of laboratory investigations were total bilirubin (189 μmol/l), direct bilirubin (139 μmol/l), ALT (164 u/l), and GGT (472 u/l). The level of serum GGT was normal in 26 cases (12.7%). The ultrasound findings included hypoplastic or atrophic gall bladder (GB) (65%), normal GB (30%), and cord sign (5%). A HIDA scan was performed in 99 cases (48.52%). Magnetic resonance cholangiopancreatography (MRCP) was performed in 27 cases (13%). A total of 179 liver biopsies (88%) were obtained. The most common histopathologic findings were bile duct proliferation (92%), canalicular cholestasis (96%), bile plugs (84%), and portal fibrosis (95%). Cholangiography was performed in 139 cases (68%): operative in 122 (60%) and percutaneous in 17 (8%). A total of 143 children (70%) underwent Kasai portoenterostomy (KPE) at a median age of 70 days. After KPE, steroid was used in 37% of the cases and 100 cases (70%) were prescribed prophylactic antibiotics for variable duration (ranging between 3 and 12 months).

CONCLUSION

Our data show marked variation in the diagnostic evaluation and perioperative management of BA cases among the different tertiary centers. There is a need to establish a national BA registry in Saudi Arabia aiming to standardize pre- and postoperative clinical practices. Additionally, normal serum GGT level, normal GB size on ultrasound, and being a premature baby should not preclude the diagnostic workup for BA.

Biliary Disorders, Anomalies, and Malignancies in Children

Biliary abnormalities in children are uncommon, and the spectrum of biliary disorders is broader than in adult patients. Unlike in adults, biliary disorders in children are rarely neoplastic and are more commonly rhabdomyosarcoma rather than cholangiocarcinoma. Pediatric biliary disorders may be embryologic or congenital, such as anatomic gallbladder anomalies, anomalous pancreaticobiliary tracts, various cholestatic processes, congenital cystic lesions, or genetic conditions. They may also be benign, such as biliary filling anomalies, biliary motility disorders, and biliary inflammatory and infectious disorders. Distinguishing these entities with a single imaging modality is challenging. US is the primary imaging modality for initial evaluation of biliary abnormalities in children, due to its wide availability, lack of ionizing radiation, and low cost and because it requires no sedation. Other examinations such as MRI, CT, and nuclear medicine examinations may provide anatomic and functional information to narrow the diagnosis further. Hepatobiliary-specific contrast material with MRI can provide better assessment of biliary anatomy on delayed images than can traditional MRI contrast material. MR cholangiopancreatography (MRCP) allows visualization of the intra- and extrahepatic biliary ducts, which may not be possible with endoscopic retrograde cholangiopancreatography (ERCP). Suspected biliary atresia requires multiple modalities for diagnosis and timely treatment. Determining the type of choledochal cyst calls for a combination of initial US and MRCP. Many benign and malignant biliary masses require biopsy for definitive diagnosis. Knowledge of the imaging appearances of different pediatric biliary abnormalities is necessary for appropriate imaging workup, providing a diagnosis or differential diagnosis, and guiding appropriate management. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

An Approach to Investigations of Chronic Liver Disease

Chronic liver disease (CLD) in children is more diverse compared to adults with respect to the etiology, progression and response to therapy. After history and clinical examination, the first step is to confirm the presence of CLD with basic blood investigations and ultrasonography. Markers of portal hypertension are splenomegaly, increased portal vein diameter, thrombocytopenia and presence of varices on endoscopy. The next step is to evaluate the etiology of CLD which will depend on the age of the child and needs targeted investigations as metabolic and inherited causes predominate in early childhood. CLD progression ought to be monitored regularly and several non-invasive markers are available but they have to be evaluated further in children. Since CLD progresses, complications have to be detected early not only to initiate appropriate treatment but also to prognosticate.

Biliary atresia in preterm infants: a single center experience and review of literature

Introduction

The diagnosis of biliary atresia (BA) remains challenging, and there is still uncertainty regarding the optimal time to perform a Kasai portoenterostomy (KPE). Little is known about the difficulties in the diagnosis and outcomes of BA in preterm infants (PBA). This study, which represents the first Italian report of preterm infants with BA, aims to describe a single-center experience of BA in preterm newborns.

Methods

We retrospectively reviewed all infants consecutively diagnosed with BA who underwent a Kasai procedure at the Bambino Gesù Children's Hospital between January 1998 and December 2021. Prematurity was defined as a gestational age (GA) of <37 weeks. Demographic, laboratory, and histology data were recorded, and the main outcomes considered were clearance of jaundice (COJ), native liver survival, and mortality.

Results

A total of 21 PBA were compared with 117 term BA controls (TBA). The median GA of PBA was 35.1 (32-36.1) weeks, with a mean birth weight of 2,100 (1,897-2,800) g. Age at first presentation was significantly lower in PBA patients: 46 (22-68) vs. 61 (44-72) days; p = 0.02. The median age at KPE was similar between the two groups: 70 days (33 corrected) for PBA vs. 67 in TBA; p = 0.8. At the time of surgery, median serum bilirubin was lower in the PBA group (7.7 vs. 8.6 mg/dl, p = 0.04). Similarly, the median APRi at the time of KPE was lower but not significant in the PBA group: 1.09 vs. 1.16; p = 0.8. No differences were found in terms of COJ between the PBA and TBA groups: n = 9 (43%) vs. 34 (35%); p = 0.2. Overall native liver survival was similar between the two groups: 8.6 (4.8-12.2) for the PBA group vs. 7.6 (5.6-9.5) years for the TBA group with no significant differences; p = 0.45. Post-KPE native liver survival was similar between the two groups: 38% vs. 52% at 5 years for the TBA and PBA groups, respectively;   p = 0.54.

Conclusion

The PBA and TBA groups appear to have similar outcomes in terms of COJ, overall native liver survival, and 5-year liver survival. Considering the corrected GA, early KPE is related to lower cholestatic damage. Further multicenter studies are required.

Severe Cholestasis in Neonates with Hemolytic Disease of the Fetus and Newborn-A Case Report

Hemolytic disease of the fetus and newborn (HDFN) may cause severe cholestasis with direct bilirubin concentrations reaching up to 50 times the upper limit of normal. This case report describes twins whose highest direct bilirubin concentrations were 32.2 mg/dL and 50.2 mg/dL, with no significant signs of hepatic impairment. The index pregnancy was complicated by Rhesus factor immunization with anti-D antibodies present in maternal serum, which caused fetal anemia requiring intrauterine blood transfusions. Complementary tests demonstrated Rhesus D alloimmunization as the sole cause of cholestasis. To the best of our knowledge, this is the first study to describe such elevated direct bilirubin concentrations caused by HDFN.

Multisystemic Disease in a Child and Successful Recovery With Antiviral Treatment

Cytomegalovirus (CMV), a member of the Herpesviridae family, typically causes asymptomatic infections or mild mononucleosis-like syndromes in immunocompetent individuals. However, severe manifestations are well-documented in immunocompromised populations. This case report presents a previously healthy seven-year-old girl with a rare and complex presentation of primary CMV infection leading to severe multiorgan involvement, hepatosplenomegaly, cholestasis, bicytopenia, and a prolonged disease course. The patient's condition prompted an exhaustive diagnostic investigation, ruling out other potential causes. The diagnosis was confirmed by positive CMV IgM and IgG antibodies and a significantly elevated CMV DNA viral load. Treatment with intravenous ganciclovir resulted in a remarkable recovery. The case underscores the importance of considering CMV as a potential etiology of hepatitis, even in immunocompetent children, and the challenges of diagnosing complicated CMV infections. While guidelines for treating CMV in immunocompetent individuals are lacking, this report suggests that antiviral therapy may be beneficial in severe cases. Further research is needed to establish clear treatment protocols for such instances. This report contributes to the limited body of literature on severe CMV-induced hepatitis in immunocompetent children, emphasizing the need for heightened clinical awareness and timely interventions to prevent progression to acute liver failure.

Ketamine restriction correlates with reduced cholestatic liver injury and improved outcomes in critically ill patients with burn injury

Background & Aims

Ketamine-associated cholestatic liver injury is reported in patients with severe burn injury, but its association with patient outcome is unclear. We investigated the relationship between ketamine exposure, cholestatic liver injury, and outcome of critically ill patients with burn injury.

Methods

In a retrospective study, patients with severe burn injury were analysed across two periods: unrestricted ketamine prescription (ketamine-liberal) and capped ketamine dosage (ketamine-restricted). The primary endpoint was cholestatic liver injury, and the secondary endpoint was 3-month mortality. Binary logistic regression models and the revised electronic causality assessment method were used to measure the strength of associations and causality assessment, respectively.

Results

Of 279 patients (median age 51 [IQR 31-67] years; 63.1% men; burned surface area 28.5%, IQR 20-45%), 155 (56%) were in the ketamine-liberal group, and 124 (44%) were in the ketamine-restricted group, with comparable clinical characteristics, except for ketamine exposure (median doses 265.0 [IQR 0-8,021] mg and 20 [IQR 0-105] mg, respectively; p <0.001). A dose- and time-dependent relationship was observed between ketamine exposure and cholestatic liver injury. Ketamine restriction was associated with a reduced risk of cholestatic liver injury (adjusted odds ratio 0.16, 95% CI 0.04-0.50; p = 0.003) and with a higher probability of 3-month survival (p = 0.035). The revised electronic causality assessment method indicated that ketamine was probably and possibly the cause of cholestatic liver injury for 14 and 10 patients, respectively. Cholangitis was not observed in the ketamine-restricted group. In propensity-matched patients, the risk of 3-month mortality was higher (adjusted odds ratio 9.92, 95% CI 2.76-39.05; p = 0.001) in patients with cholestatic liver injury and ketamine exposure ≥10,000 mg. Other sedative drugs were not associated with liver and patient outcome.

Conclusions

In this cohort, ketamine restriction was associated with less cholestatic liver injury and reduced 3-month mortality.

Impact and implications

In a cohort of 279 critically ill patients with burn injury, ketamine was associated with a risk of liver bile duct toxicity. The risk was found to be dependent on both the dosage and duration of ketamine use. A restriction policy of ketamine prescription was associated with a risk reduction of liver injury and 3-month mortality. These findings have implications for the analgesia and sedation of critically ill patients with ketamine, with higher doses raising safety concerns.

Pediatric Cholestatic Diseases: Common and Unique Pathogenic Mechanisms

Cholestasis is the predominate feature of many pediatric hepatobiliary diseases. The physiologic flow of bile requires multiple complex processes working in concert. Bile acid (BA) synthesis and excretion, the formation and flow of bile, and the enterohepatic reuptake of BAs all function to maintain the circulation of BAs, a key molecule in lipid digestion, metabolic and cellular signaling, and, as discussed in the review, a crucial mediator in the pathogenesis of cholestasis. Disruption of one or several of these steps can result in the accumulation of toxic BAs in bile ducts and hepatocytes leading to inflammation, fibrosis, and, over time, biliary and hepatic cirrhosis. Biliary atresia, progressive familial intrahepatic cholestasis, primary sclerosing cholangitis, and Alagille syndrome are four of the most common pediatric cholestatic conditions. Through understanding the commonalities and differences in these diseases, the important cellular mechanistic underpinnings of cholestasis can be greater appreciated.

The effects of gestational age on neonatal cholestasis: A retrospective cohort study

BACKGROUND

Reference guidelines for neonatal conjugated hyperbilirubinemia (cholestasis) management use a uniform approach regardless of gestational age (GA). We hypothesize that the clinical pattern of neonatal cholestasis is tightly related to GA. The aim of this study was to describe the effects of GA on neonatal cholestasis.

METHODS

A retrospective 4-year cohort study in a 70-bed neonatal care unit. Neonates with conjugated bilirubin≥34.2μmol/L (2 mg/dL) were identified. The incidence, clinical characteristics, etiology, treatment, and prognosis were compared between infants <32 and≥32 weeks GA.

RESULTS

Overall incidence of cholestasis was 4% (125/3402). It was >5 times higher and the mean duration was >1.5 times longer in neonates <32 weeks GA (10% versus 1.8%, p <0.01 and 49 versus 31 days, p <0.01, respectively). The onset of cholestasis was later in neonates <32 weeks (22 versus 10 days of life, p <0.001). This later onset of cholestasis was associated with parenteral nutrition, whereas the earlier onset was associated with other causes. Treatment using fish oil lipids was more frequently administrated to infants <32 weeks GA, whereas Ursodeoxycholic acid was administrated more frequently in≥32 weeks GA. Cholestasis resolved during hospitalization in 73% of <32 versus 38% in≥32 weeks GA infants (p <0.01).

CONCLUSIONS

The incidence, clinical presentation, etiology, treatment, and clinical evolution of neonatal cholestasis were all significantly affected by GA. Our results support the use of a GA-oriented approach for the management of neonatal cholestasis.

Opinion paper on the diagnosis and treatment of progressive familial intrahepatic cholestasis

Background & Aims

Progressive familial intrahepatic cholestasis (PFIC) relates to a group of rare, debilitating, liver disorders which typically present in early childhood, but have also been reported in adults. Without early detection and effective treatment, PFIC can result in end-stage liver disease. The aim of the paper was to put forward recommendations that promote standardisation of the management of PFIC in clinical practice.

Methods

A committee of six specialists came together to discuss the challenges faced by physicians in the management of PFIC. The committee agreed on two key areas where expert guidance is required to optimise care: (1) how to diagnose and treat patients with a clinical presentation of PFIC in the absence of clear genetic test results/whilst awaiting results, and (2) how to monitor disease progression and response to treatment. A systematic literature review was undertaken to contextualise and inform the recommendations.

Results

An algorithm was developed for the diagnosis and treatment of children with suspected PFIC. The algorithm recommends the use of licensed inhibitors of ileal bile acid transporters as the first-line treatment for patients with PFIC and suggests that genetic testing be used to confirm genotype whilst treatment is initiated in patients in whom PFIC is suspected. The authors recommend referring patients to an experienced centre, and ensuring that monitoring includes measurements of pruritus, serum bile acid levels, growth, and quality of life following diagnosis and during treatment.

Conclusions

The algorithm presented within this paper offers guidance to optimise the management of paediatric PFIC. The authors hope that these recommendations will help to standardise the management of PFIC in the absence of clear clinical guidelines.

Impact and implications

This opinion paper outlines a consistent approach to the contemporaneous diagnosis, monitoring, referral and management of children with progressive familial intrahepatic cholestasis. This should assist physicians given the recent developments in genetic diagnosis and the availability of effective drug therapy. This manuscript will also help to raise awareness of current developments and educate health planners on the place for new drug therapies in progressive familial intrahepatic cholestasis.

Pathologic approach to Neonatal cholestasis with a simple scoring system for biliary atresia

A liver biopsy is essential for the diagnostic workup of persistent neonatal cholestasis (NC). The differential diagnosis of NC is broad, including obstructive and non-obstructive causes. In addition, histologic features of certain disorders may be non-specific in the early course of the disease. To evaluate liver biopsies using a practical histopathologic approach for NC and to define a simple scoring system for biliary atresia (BA) for routine clinical practice. From June 2006 to December 2021, liver biopsy specimens from infants with persistent NC were examined by two independent pathologists. The cases diagnosed as BA were correlated with clinical, radiologic, and laboratory data to calculate the final score. Four hundred and fifty-nine cases were enrolled in the study. They had a mean age of 63.94 ± 20.62 days and were followed for a median time of 58 (1-191) months. They included 162 (35.3%) cases of BA. On multivariate analysis, portal edema, ductular proliferation, cholangiolitis, and bile duct/ductular plugs were the histopathologic predictors of BA. A liver biopsy did perform well with a 95.1% sensitivity, 91.6% specificity, 86% PPV, and 97.1% NPV. At a cutoff of 5 of the scoring system, diagnosis of BA could be done with a sensitivity of 95.1% and a specificity of 100%. We have shown detailed histopathologic features of BA with more depth to infants aged ≤ 6 weeks. We have developed a simple scoring system using a combination of liver biopsy with non-invasive methods to increase the diagnostic accuracy of BA.

Liver Dysfunction with Severe Cholestasis and Coagulation Disorders in the Course of Hemolytic Disease of the Newborn Requiring Chelation Therapy-A Case Report and Review of the Literature

Severe hemolytic disease of the fetus and newborn (HDFN) requiring intrauterine transfusions (IUTs) may cause iron accumulation, resulting in liver damage, which may lead to cholestasis and coagulation disorders. In this article, we reported a case of a female neonate who underwent chelation therapy with a positive outcome, and we reviewed the English and Polish literature on chelation therapy in HDFN available in PubMed. The patient with maximum ferritin concentration above 33,511.2 ng/mL developed liver dysfunction with coagulation disorders requiring multiple transfusions of fresh frozen plasma (FFP), Octaplex® and cryoprecipitate, and hypoalbuminemia treated with numerous albumin infusions. Furthermore, severe cholestasis was observed with direct bilirubin levels up to 33.14 mg/dL. Additionally, the child developed transient myelosuppression with neutropenia, thrombocytopenia, and low reticulocyte count due to several blood transfusions. The differential diagnosis tests were conducted to rule out any causes of hepatic failure other than hemolytic disease of the newborn. This case proves that adequate treatment of severe HDFN with anemia requiring IUT and hepatic failure can lead to positive outcomes with no long-term consequences.

Expedited Laparoscopic Cholangiogram and Liver Biopsy in the Workup of Biliary Atresia

PURPOSE

Recent studies demonstrate the success of Kasai portoenterostomy for biliary atresia (BA) is linearly related to infant age at time of Kasai. We sought to review the feasibility and safety of laparoscopic needle micropuncture cholangiogram with concurrent core liver biopsy (if needed) for expedited exclusion of BA in patients with direct conjugated hyperbilirubinemia.

METHODS

Expedited laparoscopic cholangiogram and liver biopsy were instituted at our facility for infants with direct hyperbilirubinemia for whom clinical exam and laboratory workup failed to diagnose. A retrospective chart review was performed in infants <1 year with hyperbilirubinemia from 2016 to 2021. Demographics, preoperative evaluation, procedure details, and complications were reviewed.

RESULTS

Two hundred ninety-seven infants with unspecified jaundice were identified, of which, 86 (29%) required liver biopsy. Forty-seven percutaneous liver biopsies were obtained including 8 (17%) in whom BA could not be excluded. Laparoscopic cholangiogram was attempted in 47 infants following basic workup; BA was diagnosed in 22 infants (47%) of which 3 were <18 days old. Biliary patency was demonstrated laparoscopically in 22 of 25 (88%); 3 (12%) required conversion to open cholangiogram. Infants with percutaneous liver biopsy had an average delay of 3 days (range: 2-36) to cholangiogram. Preoperative studies and liver biopsy alone did not reliably exclude the diagnosis of BA.

CONCLUSION

Laparoscopic cholangiogram with liver biopsy is a safe procedure resulting in the confirmation or exclusion of BA in infants. Forty-seven percent of infants who underwent laparoscopic cholangiogram were found to have BA; those who were surgical candidates underwent Kasai during the same operation.

Improved Kasai Hepatoportoenterostomy Outcomes After Implementation of a Dedicated Biliary Atresia Team

It can be difficult or impractical to refer all biliary atresia (BA) patients to high-volume centers. Our hypothesis was that a low volume center could improve outcomes with implementation of a dedicated multidisciplinary BA team. We conducted a retrospective study of patients with BA who underwent hepatic portoenterostomy at our institution from 2003 to 2020, before and after the development of a dedicated BA team. Ten consecutive patients with BA were identified following the establishment of a dedicated BA team. Since the establishment of the BA team, total bilirubin (TB) clearance (TB < 2 mg/dL) achieved by 3 and 6 months has been 60% and 60%, respectively, and survival of the native liver (SNL) at 1 and 2 years post HPE at 90% and 86%, respectively. Outcomes were markedly improved after the team was established. A dedicated BA team prioritizing communication and expeditious workup can improve outcomes at a low volume center.

Infant liver biochemistry is different than current laboratory accepted norms

The purpose is to study liver biochemistry in a well-defined cohort of term infants. The methods include healthy term infants (n = 619) provided blood samples at 3 and 6 months of age when participating to the DIABIMMUNE study. The infants were followed up at clinical study visits 3, 6, 12, 18, 24, and 36 months the participation rate being 88.6% at the end of follow-up, while none disclosed any signs of a liver disease. The serum levels of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), total bilirubin (BIL), and conjugated bilirubin (BIL-conj) were determined using Siemens Atellica CH 930 analyzers. The results are at 3 months of age, the upper 90% CI for ALT, AST, ALP, GGT, BIL, and BIL-conj were higher than the current upper reference limits in our accredited hospital laboratory. At 6 months, the upper 90% CIs for ALT had declined but was still higher than the cut-offs for a raised value. The upper 90% CI for AST remained as high as at 3 months, whereas ALP, BIL-conj, and GGT had decreased close to the current cut-offs. The type of feeding was associated with the levels of liver biochemistry. Exclusively or partially breastfed infants showed higher ALT, AST, BIL, and BIL-conj values at 3 months than formula-fed. Breastfed infants had higher AST, Bil, and Bil-conj values also at 6 months.  Conclusion: We encourage setting appropriate reference ranges for liver biochemistry for the first year of life and to note the type of feeding. What is Known: • Healthy infants may show higher values of liver biochemistry during their first year of life than in later life. • It has been speculated that type of feeding may play a role in liver biochemistry levels among infants. What is New: • In a cohort of healthy infants, several analytes of liver biochemistry were higher than the currently used upper reference limits at 3 and 6 months of age, and exclusively or partially breastfed infants showed higher values than formula-fed. • The findings address the importance of setting appropriate reference ranges for liver biochemistry for the first year of life.

Severity assessment to guide empiric antibiotic therapy for cholangitis in children after Kasai portoenterostomy: a multicenter prospective randomized control trial in China

BACKGROUND

Cholangitis is common in patients with biliary atresia following Kasai portoenterostomy (KPE). The prompt use of empiric antibiotics is essential due to the lack of identified microorganisms. The authors aimed to validate a severity grading system to guide empiric antibiotic therapy in the management of post-KPE cholangitis.

MATERIALS AND METHODS

This multicenter, prospective, randomized, open-label study recruited patients with post-KPE cholangitis and was conducted from January 2018 to December 2019. On admission, patients were categorized into mild, moderate, and severe cholangitis according to the severity grading system. Patients in the mild cholangitis group were randomized to receive cefoperazone sodium tazobactam sodium (CSTS) or meropenem (MEPM). Patients with severe cholangitis were randomized to treatment with MEPM or a combination of MEPM plus immunoglobulin (MEPM+IVIG). Patients with moderate cholangitis received MEPM.

RESULTS

The primary endpoint was duration of fever (DOF). Secondary outcomes included blood culture, length of hospital stay, incidence of recurrent cholangitis, jaundice clearance rate, and native liver survival (NLS). For mild cholangitis, DOF, and length of hospital stay were similar between those treated with CSTS or MEPM (all P >0.05). In addition, no significant difference in recurrence rate, jaundice clearance rate, and NLS was observed between patients treated with CSTS and MEPM at 1-month, 3-month, and 6-month follow-up. In patients with moderate cholangitis, the DOF was 36.00 (interquartile range: 24.00-48.00) h. In severe cholangitis, compared with MEPM, MEPM+IVIG decreased DOF and improved liver function by reducing alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, and direct bilirubin at 1-month follow-up. However, recurrence rate, jaundice clearance rate, and NLS did not differ significantly between MEPM+IVIG and MEPM at 1-month, 3-month, and 6-month follow-up.

CONCLUSIONS

In patients with post-KPE cholangitis, MEPM is not superior to CSTS for the treatment of mild cholangitis. However, MEPM+IVIG treatment was associated with better short-term clinical outcomes in patients with severe cholangitis.

Alterations in gut microbiota and metabolite profiles in patients with infantile cholestasis

BACKGROUND

Infantile cholestasis (IC) is the most common hepatobiliary disease in infants, resulting in elevated direct bilirubin levels. Indeed, hepatointestinal circulation impacts bile acid and bilirubin metabolism. This study evaluates changes in the gut microbiota composition in children with IC and identifies abnormal metabolite profiles associated with microbial alterations.

RESULTS

The gut microbiota in the IC group exhibits the higher abundance of Veillonella, Streptococcus and Clostridium spp. (P < 0.05), compared to healthy infants (CON) group. Moreover, the abundance of Ruminococcus, Vibrio butyricum, Eubacterium coprostanogenes group, Intestinibacter, and Faecalibacterium were lower (P < 0.05). In terms of microbiota-derived metabolites, the levels of fatty acids (palmitoleic, α-linolenic, arachidonic, and linoleic) (P < 0.05) increased and the levels of amino acids decreased in IC group. Furthermore, the abundances of Ruminococcus, Eubacterium coprostanoligenes group, Intestinibacter and Butyrivibrio are positively correlated with proline, asparagine and aspartic acid, but negatively correlated with the α-linolenic acid, linoleic acid, palmitoleic acid and arachidonic acid. For analysis of the relationship between the microbiota and clinical index, it was found that the abundance of Veillonella and Streptococcus was positively correlated with serum bile acid content (P < 0.05), while APTT, PT and INR were negatively correlated with Faecalibalum and Ruminococcus (P < 0.05).

CONCLUSION

Microbiota dysbiosis happened in IC children, which also can lead to the abnormal metabolism, thus obstructing the absorption of enteral nutrition and aggravating liver cell damage. Veillonella, Ruminococcus and Butyrivibrio may be important microbiome related with IC and need further research.

Treatment of Cholestasis in Infants and Young Children

PURPOSE OF REVIEW

Cholestasis is characterized by a conjugated hyperbilirubinemia secondary to impaired bile synthesis, transport, or excretion from the liver. It is always pathologic and can be indicative of an underlying hepatobiliary, genetic, or metabolic disorder, several of which require timely diagnosis to ensure proper management and optimal outcomes. This review provides an overview of the evaluation of cholestasis with a focus on current and emerging treatment strategies.

RECENT FINDINGS

Increased accessibility of next generation sequencing (NGS) allows for utilization of genetic testing early in the diagnostic process. This may alter the clinical algorithm for diagnosis of cholestatic disorders. An enhanced understanding of the underlying pathophysiology may help guide future development of targeted therapies, such as ileal bile acid transporter (IBAT) inhibitors. These were recently approved for treatment of cholestatic pruritus in patients with Alagille syndrome and Progressive Familial Intrahepatic Cholestasis. Current management of cholestasis is aimed at the biochemical consequences of impaired bile flow, including malnutrition, pruritus, and progressive fibrosis. NGS has led to an enhanced understanding of biliary pathology and may guide development of future treatment modalities based on specific gene mutations. Rapid discernment of the underlying etiology is essential as new treatment modalities emerge.

Intrahepatic portosystemic shunts, from prenatal diagnosis to postnatal outcome: a retrospective study

OBJECTIVE

Congenital intrahepatic portosystemic shunts (IHPSS) are rare vascular malformations resulting in blood bypassing the liver to the systemic circulation. Previous studies included symptomatic patients diagnosed postnatally, but the outcome of IHPSS diagnosed prenatally is rarely reported. We present a cohort of children prenatally diagnosed with IHPSS and report their natural course and outcome.

METHODS AND DESIGN

This was a retrospective study of all fetal cases diagnosed by ultrasound with IHPSS between 2006 and 2019 at a single tertiary centre which were prospectively followed up at the paediatric gastroenterology unit. The postnatal outcome was compared between patients with a single versus multiple intrahepatic shunts.

RESULTS

Twenty-six patients (70.3% boys) were included in the study, of them, eight (30.8%) patients had multiple intrahepatic shunts. The median gestational age at diagnosis was 29.5 weeks. Growth restriction affected 77% of the cohort. Postnatally, spontaneous shunt closure occurred in 96% of patients at a median age of 7.5 months (IQR 2.2-20 months). Failure to thrive (FTT) and mild developmental delay were observed in eight (30.8%) and seven (26.9%) patients, respectively. FTT was significantly more prevalent in patients with multiple shunts compared with patients with a single shunt (62.5% vs 16.7%, p=0.02); however, the rate of shunt closure and age at time of closure were similar between these groups. All patients survived with limited to no sequelae.

CONCLUSIONS

IHPSS usually close spontaneously by 2 years of age. Children with prenatally detected IHPSS may develop FTT and mild developmental delay. Close surveillance at a paediatric gastroenterology unit may be beneficial.

Reverse Mirizzi Syndrome

A man in his 40s presented to our Hospital with abdominal pain, jaundice, and pruritus. He had a history of Alagille Syndrome treated with cholecystojejunostomy in the neonatal period because of initial misdiagnosis of biliary atresia. Laboratory investigations showed hyperbilirubinemia (total bilirubin 1.76 mg/dL [<1.2 mg/dL]; conjugated 1.06 mg/dL [<0.3 mg/dL]) and cholestasis (GGT 78 U/L [<50 U/L]; ALP 200 U/L [<50 U/L]). Transabdominal ultrasound was limited by aerobilia due to the cholecystojejuno-anastomosis. Subsequent basal CT scan revealed an impacted stone within the patient's native common bile duct (CBD). Aerobilia in intrahepatic bile ducts and gallbladder was reported. Magnetic Resonance cholangiopancreatography confirmed the gallstone in the CBD compressing cystic duct and common hepatic duct, with dilation of the upstream bile ducts. Furthermore, the native CBD was obstructed by other gallstones. In Mirizzi syndrome, gallstones impacted in gallbladder's Hartmann's pouch or cystic duct extrinsically compress CBD. We suggest naming the present condition "Reverse Mirizzi Syndrome" (Renzulli Matteo Syndrome, RMS) because it is the exact opposite of Mirizzi syndrome.

Evaluation of Newborn Direct Bilirubin As Screening for Cholestatic Liver Disease

Background

Biliary atresia (BA) remains the most common indication for pediatric liver transplantation. Early diagnosis is essential for a favorable long-term prognosis for patients with BA. Preliminary data suggests that measurement of direct bilirubin (DB) in newborns may be an effective screening tool for neonatal cholestasis, particularly BA, allowing for early referral and diagnosis. The objective of our study was to establish a cutoff DB value to predict diagnosis of cholestatic liver disease (CLD) with high sensitivity and specificity, as well as, to evaluate whether newborns with elevated DB received appropriate follow-up in our health system.

Methods

Baseline data were collected on infants born between 2016 and 2019 who had serum total bilirubin and DB drawn in the nursery, and who continued to follow in our health system. Sensitivity, specificity, and positive and negative predictive values were examined using cutoff values of 0.5, 0.6, and 0.7 mg/dL for identifying infants at risk for CLD. Patients' charts were reviewed to note whether they had follow-up levels drawn by their pediatrician or by the hepatology team within 2 months of age and whether they were diagnosed with CLD.

Results

Serum total bilirubin and DB levels were drawn from 11 965 infants during their hospitalizations. Three infants from this cohort were diagnosed with CLD: 2 with BA and 1 with Alagille syndrome. DB cutoff values of 0.5, 0.6, and 0.7 mg/dL had sensitivity of 100% and specificity of 96.83% (95% confidence interval [CI], 96.69%-97.53%), 99.08% (95% CI, 98.81%-99.30%), and 99.63% (95% CI, 99.4%-99.7%), respectively. Given that a DB of 0.6 mg/dL had a sensitivity of 100% and specificity of 99%, this value was chosen as the cutoff value to monitor for DB follow-up and diagnosis of CLD. Out of 60 infants who met criteria for DB ≥0.6 mg/dL, only 15 (25%) had a repeat level drawn after nursery discharge; 3 (5%) were eventually diagnosed with CLD.

Conclusions

A DB cutoff value of 0.6 mg/dL yielded high sensitivity and specificity for identifying patients with CLD. All 3 patients diagnosed with CLD had elevated DB at hospital discharge. The data revealed that the majority (75%) of eligible newborns did not receive follow-up for their elevated DB in the outpatient setting.

Plasticity between type 2 innate lymphoid cell subsets and amphiregulin expression regulates epithelial repair in biliary atresia

BACKGROUND AND AIMS

Although a dysregulated type 1 immune response is integral to the pathogenesis of biliary atresia, studies in both humans and mice have uncovered a type 2 response, primarily driven by type 2 innate lymphoid cells. In nonhepatic tissues, natural type 2 innate lymphoid cell (nILC2s) regulate epithelial proliferation and tissue repair, whereas inflammatory ILC2s (iIlC2s) drive tissue inflammation and injury. The aim of this study is to determine the mechanisms used by type 2 innate lymphoid cell (ILC2) subpopulations to regulate biliary epithelial response to an injury.

APPROACH AND RESULTS

Using Spearman correlation analysis, nILC2 transcripts, but not those of iILC2s, are positively associated with cholangiocyte abundance in biliary atresia patients at the time of diagnosis. nILC2s are identified in the mouse liver through flow cytometry. They undergo expansion and increase amphiregulin production after IL-33 administration. This drives epithelial proliferation dependent on the IL-13/IL-4Rα/STAT6 pathway as determined by decreased nILC2s and reduced epithelial proliferation in knockout strains. The addition of IL-2 promotes inter-lineage plasticity towards a nILC2 phenotype. In experimental biliary atresia induced by rotavirus, this pathway promotes epithelial repair and tissue regeneration. The genetic loss or molecular inhibition of any part of this circuit switches nILC2s to inflammatory type 2 innate lymphoid cell-like, resulting in decreased amphiregulin production, decreased epithelial proliferation, and the full phenotype of experimental biliary atresia.

CONCLUSIONS

These findings identify a key function of the IL-13/IL-4Rα/STAT6 pathway in ILC2 plasticity and an alternate circuit driven by IL-2 to promote nILC2 stability and amphiregulin expression. This pathway induces epithelial homeostasis and repair in experimental biliary atresia.