The Epidemiology of Biliary Atresia: Exploring the Role of Developmental Factors on Birth Prevalence

Experience of post-traumatic growth among parents of children with biliary atresia undergoing living-related liver transplantation: a descriptive phenomenological study

Objectives: To explore the experience of post-traumatic growth among parents of children with biliary atresia undergoing living-related liver transplantation.Methods: Participants were recruited within 2 weeks of their child's transplant surgery using purposive sampling. Transcripts were analyzed using Colaizzi's descriptive analysis framework, with collaborative analysis conducted using NVivo 12 software and a post-traumatic growth model.Results: Five themes were identified: (a) experiencing a devastating blow, (b) cognitive reconstruction under overwhelming pain, (c) an arduous journey of decision-making, (d) rebirth in adversity and (e) post-traumatic growth. Parents undergo significant post-traumatic responses to their child's diagnosis of biliary atresia and liver transplantation, marking two major traumatic events. During the diagnostic stage, parents experience intense post-traumatic reactions characterized by emotional fluctuations and intrusive thoughts. The early treatment phase represents a crucial time for parents to transition from `denial of reality' to `accepting diseases'. The process of liver transplantation is also a significant traumatic event, accompanied by a final hope. Parents in the stable period after liver transplantation feel fortunate, hopeful and grateful, and their post-traumatic growth manifests gradually.Conclusions: Parents' experience of post-traumatic growth involves dynamic changes. Tailored intervention strategies should be developed for different stages to enhance their post-traumatic growth and psychological well-being. During the early treatment stage, mental health professionals could provide cognitive interventions to encourage parents to express their negative emotions and guide them to develop positive cognition toward traumatic events. The coping strategies and increasing personal growth are also important. In the postoperative stage, mental health professionals need to fully evaluate the coping styles of parents, and encourage them to establish effective internal coping strategies, while classic gratitude interventions could be given during the post-traumatic growth stage. Future research could involve a longitudinal qualitative study to explore parents' post-traumatic growth experiences at different stages of their children's transplantation process.

The Outcome of a Centralization Program in Biliary Atresia: Twenty Years and Beyond

OBJECTIVE

Biliary atresia is a rare disease and reported outcomes of surgical management, typically a Kasai portoenterostomy (KPE), vary considerably across the world. Centralization has been proposed to improve this.

BACKGROUND

A national centralization program was started in January 1999, involving 3 English units with colocated liver transplant facilities. As the program has now reached the 20-year point, the main aim was to update outcome statistics and identify trends.

METHODS

Prospective registry and database. The main measures of outcome were (1) time to KPE, (2) clearance of jaundice (CoJ), defined as reaching a bilirubin value of <20 µmol/L (≈1.5 mg/dL), and (3) actuarial native liver survival and overall survival (OS). Data are quoted as median (interquartile range) and nonparametric statistical comparison used with P <0.05 regarded as statistically significant.

RESULTS

A total of 867 infants were born with biliary atresia and managed between January 1999 and December 2019. Death occurred without intervention (n = 10, 1.1%) or were subject to primary transplant (n = 26, 3.0%); leaving 831 (95.9%) infants who underwent KPE at a median age of 51 (interquartile range: 39-64) days. Age at KPE reduced over the period ( P = 0.0001) becoming 48 (35-57) days in the last 5-year era. CoJ was achieved in 505/831 (60.6%), also increasing over the period ( P = 0.002). Forty-two (5.0%) died post-KPE and 384 were transplanted, leaving 405 alive with their native livers at the last follow-up. Of the 412 children transplanted, there were 23 (5.6%) deaths, leaving 387 alive. Five-year and 10-year native liver survivals were 51.3% (95% CI: 54.8-47.8) and 46.5% (95% CI: 50.1-42.9) and OSs were 91.5% (95% CI 93.2-89.4) and 90.5% (95% CI 92.3-88.2%), respectively.

CONCLUSIONS

There have been continued improvements in efficiency over the period of centralization with a significant reduction in time to KPE and improved CoJ after KPE. OS in this disease remains >90%.

Outcomes of Kasai Portoenterostomy in Patients With Congenital Heart Disease: A Silent Comorbidity

INTRODUCTION

Biliary atresia (BA) is the most common cause of end-stage liver disease in children. Around 5 %-15 % of patients with BA have a congenital heart disease (CHD) diagnosis. Despite high prevalence of a CHD diagnosis in patients with BA, outcomes of Kasai portoenterostomy (KPE) in the CHD population remain unexplored.

METHODS

This is a retrospective review of the American College of Surgeons National Surgical Quality Improvement Program-Pediatric (NSQIP-P) database from 2012 to 2022. All patients undergoing KPE were included. Patients with CHD were identified using previously validated ICD9/10 codes.

RESULTS

A total of 854 patients underwent a KPE during the study period. Of this cohort, 502 (59 %) were female, 342 (40 %) White Non-Hispanic, median age of 57.0[IQR: 40.0-72.0] days, and a median weight of 9.4 [IQR: 8.1-10.7] kilograms. A total of 89 (10 %) patients had a diagnosis of CHD. Of those, 63 (7 %) had a simple-CHD diagnosis and 26 (3 %) a complex-CHD diagnosis. A single-ventricle (SV-CHD) diagnosis was present in 7 (1 %) patients. Notably, no in-hospital mortalities were found. When compared to non-CHD, simple-CHD (OR: 2.51; 95 % CI: 1.45-4.36, p = 0.001) and complex-CHD (OR: 3.20; 95 % CI: 1.30-7.87, p = 0.011) had increased risk for any complication. Furthermore, when compared to non-CHD complex-CHD patients had higher odds of undergoing a Kasai related reintervention (OR: 5.01; 95 % CI: 1.76-14.22, p = 0.002. After propensity score matching, when compared to non-CHD a CHD diagnosis was only associated with an increased risk for any complication (OR: 2.50; 95 % CI: 1.30-4.81, p = 0.005).

CONCLUSION

A CHD diagnosis is present in 10 % of children undergoing KPE. KPE appears to be safe in patients with CHD, but associated with increased in-hospital resource utilization. Further studies are needed to understand the impact of a CHD diagnosis on the long-term outcomes after KPE.

TYPE OF STUDY

Retrospective Review.

LEVEL OF EVIDENCE

Level 3.

Comparative Demography of Biliary Atresia and Choledochal Malformation in London

OBJECTIVE

Choledochal malformation (CM) and biliary atresia (BA) are the two most important bile duct pathologies arising in infancy and childhood. The aim was to investigate for evidence of shared demographic features in a common temporo-spatial area.

METHODS

Patients identified prospectively and defined as being born within metropolitan London in the period 1999-2022. Index of Multiple Deprivation (IMD) Rank Index (based on maternal post-code - England 2019) and live-birth data taken from the Office of National Statistics to assess incidence and differences assessed using the Poisson distribution and Chi2 tests. P ≤ 0.05 was regarded as significant.

RESULTS

280 patients (BA n = 202; CM n = 78). The incidence of BA and CM in London was 7.45/100,000 (1 in 13,430) and 2.9/100,000 (i.e. 1 in 34,480) with no change over the period. The incidence of BA in Inner London was significantly higher at 9.42/100,000 (1 in 10,650) (P = 0.006). Marked female predominance evident in the CM group (77 % vs. 54.4 %; P = 0.0006) with more patients of non-white ethnicity in both groups (BA = 52.4 %; CM = 55 %, P = 0.32). No difference in IMDR between BA and CM (11,557 vs. 11,594; P = 0.26), with a marked difference between Inner and Outer boroughs for CM (8976 vs. 16,717; P < 0.001), but less so in BA (10,384 vs. 12,891; P = 0.039). IMDR was higher in those of white ethnicity for BA (11,979 vs. 10,660; P = 0.03).

CONCLUSIONS

Inner London has the highest incidence of BA than anywhere in Europe or North America. The calculated incidence of CM is higher than anticipated and the first to be based on actual observation.

Development of an artificial intelligence-based multimodal diagnostic system for early detection of biliary atresia

BACKGROUND

Early diagnosis of biliary atresia (BA) is crucial for improving patient outcomes, yet remains a significant global challenge. This challenge may be ameliorated through the application of artificial intelligence (AI). Despite the promise of AI in medical diagnostics, its application to multimodal BA data has not yet achieved substantial breakthroughs. This study aims to leverage diverse data sources and formats to develop an intelligent diagnostic system for BA.

METHODS

We constructed the largest known multimodal BA dataset, comprising ultrasound images, clinical data, and laboratory results. Using this dataset, we developed a novel deep learning model and simplified it using easily obtainable data, eliminating the need for blood samples. The models were externally validated in a prospective study. We compared the performance of our model with human experts of varying expertise levels and evaluated the AI system's potential to enhance its diagnostic accuracy.

RESULTS

The retrospective study included 1579 participants. The multimodal model achieved an AUC of 0.9870 on the internal test set, outperforming human experts. The simplified model yielded an AUC of 0.9799. In the prospective study's external test set of 171 cases, the multimodal model achieved an AUC of 0.9740, comparable to that of a radiologist with over 10 years of experience (AUC = 0.9766). For less experienced radiologists, the AI-assisted diagnostic AUC improved from 0.6667 to 0.9006.

CONCLUSIONS

This AI-based screening application effectively facilitates early diagnosis of BA and serves as a valuable reference for addressing common challenges in rare diseases. The model's high accuracy and its ability to enhance the diagnostic performance of human experts underscore its potential for significant clinical impact.

Incidence of biliary atresia in the United States before and during the COVID-19 pandemic

OBJECTIVES

The etiology of biliary atresia (BA) is unclear and potentially involves viral triggers. We aimed to compare the incidence of BA in the United States before and during the coronavirus disease 2019 (COVID-19) pandemic, focusing on potential associations with viral circulation disruptions caused by nonpharmaceutical interventions (NPIs).

METHODS

We queried the Pediatric Health Information System® (PHIS) for all patients discharged with BA between January 1, 2010, and January 31, 2024. Using CDC WONDER, we calculated monthly and overall incidence rates of BA per 1,000,000 live births. We fit a Poisson regression model to assess the association between the widespread implementation of stay-at-home orders (using April 1, 2020, as the cutoff date) and the incidence of BA, accounting for national natality fluctuations.

RESULTS

We identified 3456 newborns with BA from 42 hospitals; 2997 (86.7%) were born before and 459 (13.3%) were born during the pandemic. The mean monthly number of newborns with BA was 24.0 (95% confidence interval, 23.0-25.0) for an overall incidence rate of 74.4 (71.5-77.4) per 1,000,000 live births. We did not identify a statistically significant year-to-year contrast in the incidence of BA before (incidence rate ratio [IRR] = 0.995 [0.983-1.008]; p = 0.49) or after the cutoff date (IRR = 0.999 [0.895-1.116]; p = 0.99). In addition, we did not identify sufficient evidence that trends differed between the two periods (IRR = 1.00 [0.893-1.128]; p = 0.95).

CONCLUSIONS

The NPIs implemented during the COVID-19 pandemic were not significantly associated with changes in the incidence or temporal pattern of BA.

Microcystin-RR is a biliary toxin selective for neonatal extrahepatic cholangiocytes

Background & Aims

Biliary atresia is a fibrosing cholangiopathy affecting neonates that is thought to result from a prenatal environmental insult to the bile duct. Biliatresone, a plant toxin with an α-methylene ketone group, was previously implicated in biliary atresia in Australian livestock, but is found in a limited location and is unlikely to be a significant human toxin. We hypothesized that other unsaturated carbonyl compounds, some with the potential for significant human exposure, might also be biliary toxins.

Methods

We focused on the family of microcystins, cyclic peptide toxins from blue-green algae that are found worldwide, particularly during harmful algal blooms. We used primary extrahepatic cholangiocyte spheroids and extrahepatic bile duct explants from both neonatal [a total of 86 postnatal day (P) 2 mouse pups and 18 P2 rat pups (n = 8-10 per condition for both species)] and adult rodents [a total of 31 P15-18 mice (n = 10 or 11 per condition)] to study the biliary toxicity of microcystins and potential mechanisms involved.

Results

Results showed that 400 nM microcystin (MC)-RR, but not six other microcystins or the related algal toxin nodularin, caused >80% lumen closure in cell spheroids made from extrahepatic cholangiocytes isolated from 2-3-day-old mice (p <0.0001). By contrast, 400 nM MC-RR resulted in less than an average 5% lumen closure in spheroids derived from neonatal intrahepatic cholangiocytes or cells from adult mice (p = 0.4366). In addition, MC-RR caused occlusion of extrahepatic bile duct explants from 2-day-old mice (p <0.0001), but not 18-day-old mice. MC-RR also caused a 2.3-times increase in reactive oxygen species in neonatal cholangiocytes (p <0.0001), and treatment with N-acetyl cysteine partially prevented microcystin-RR-induced lumen closure (p = 0.0004), suggesting a role for redox homeostasis in its mechanism of action.

Conclusions

We identified MC-RR as a selective neonatal extrahepatic cholangiocyte toxin and suggest that it acts by increasing redox stress.

Impact and implications

The plant toxin biliatresone causes a biliary atresia-like disease in livestock and vertebrate animal model systems. We tested the widespread blue-green algal toxin, microcystin-RR, another highly electrophilic unsaturated carbonyl compound that is released during harmful algal blooms, and found that it was also a biliary toxin with specificity for neonatal extrahepatic cholangiocytes. This work should drive further animal studies and, ultimately, studies to determine whether human exposure to microcystin-RR causes biliary atresia.

Epidemiology of Coloboma: Prevalence and Patterns in Texas, 1999-2014

BACKGROUND

Coloboma is a rare congenital malformation in which part of the tissue that makes up the eye is missing and may cause visual impairment or blindness. Little is known about the epidemiology of this condition. Therefore, we obtained data from the Texas Birth Defects Registry on children identified with coloboma for the period 1999-2014.

METHODS

Using information on all live births from the same period, prevalence ratios (PRs) for selected demographic and clinical factors were used to estimate associations using Poisson regression among cases with coloboma. Coloboma cases were divided into subgroups to explore patterns of co-occurring defects and syndromes. All variables significant in unadjusted models (p < 0.05) were included in multivariable models to evaluate adjusted PRs (aPRs).

RESULTS

We identified 1587 cases with coloboma, of whom 934 (58.8%) were nonsyndromic, and 474 (29.9%) were isolated. When considering all identified cases, factors associated with significant differences in prevalence included plurality (multiple vs. singleton aPR = 1.4, 95% CI: 1.1-1.8); maternal education (college or greater vs. less than high school aPR = 0.7, 95% CI: 0.6-0.9); maternal race/ethnicity (Hispanic vs. non-Hispanic White aPR = 0.9, 95% CI: 0.8-1.0); and maternal diabetes (yes vs. no aPR = 1.3, 95% CI: 1.0-1.6). There was a notable increase in the birth prevalence of coloboma during the study period (p-for-trend < 0.001). Effect estimates were similar across the different subgroups.

CONCLUSION

In our large population, we identified several factors associated with the prevalence of coloboma. These findings may help define subgroups of women more likely to have children affected by coloboma, which could inform improved screening efforts.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Heritable Chronic Cholestatic Liver Diseases: A Review

Chronic cholestasis due to heritable causes is usually diagnosed in childhood. However, many cases can present and survive into adulthood. The time course varies considerably depending on the underlying etiology. Laboratory data usually reveal elevated conjugated hyperbilirubinemia, alkaline phosphatase, and gamma-glutamyl transpeptidase. Patients may be asymptomatic; however, when present, the typical symptoms are pruritus, jaundice, fatigue, and alcoholic stools. The diagnostic methods and management required depend on the underlying etiology. The development of genome-wide associated studies has allowed the identification of specific genetic mutations related to the pathophysiology of cholestatic liver diseases. The aim of this review was to highlight the genetics, clinical pathophysiology, presentation, diagnosis, and treatment of heritable etiologies of chronic cholestatic liver disease.

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.

In Utero Extrahepatic Bile Duct Damage and Repair: Implications for Biliary Atresia

Biliary atresia (BA) is a cholangiopathy affecting the extrahepatic bile duct (EHBD) of newborns. The etiology and pathophysiology of BA are not fully understood; however, multiple causes of damage and obstruction of the neonatal EHBD have been identified. Initial damage to the EHBD likely occurs before birth. We discuss how different developmental stages in utero and birth itself could influence the susceptibility of the fetal EHBD to damage and a damaging wound-healing response. We propose that a damage-repair response of the fetal and neonatal EHBD involving redox stress and a program of fetal wound healing could-regardless of the cause of the initial damage-lead to either obstruction and BA or repair of the duct and recovery. This overarching concept should guide future research targeted toward identification of factors that contribute to recovery as opposed to progression of injury and fibrosis. Viewing BA through the lens of an in utero damage-repair response could open up new avenues for research and suggests exciting new therapeutic targets.

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.

Toxins and Biliary Atresia: Is Karenia Brevis (Red Tide) The Culprit?

OBJECTIVE

The study objective was to evaluate the association between Karenia brevis (K. brevis) exposure during pregnancy and the prevalence of biliary atresia (BA) in offspring.

STUDY DESIGN

This was a hospital-based, case-control study in which cases were infants diagnosed with BA at Johns Hopkins All Children's Hospital from October 2001 to December 2019. Cases were matched 1:4 by age to controls who were randomly selected from a pool of healthy infants hospitalized during the study period for common pediatric diagnoses. Infants were excluded if they had congenital anomalies and/or were non-Florida residents. Gestational K. brevis exposure levels (cells/liter) were determined from Florida Fish and Wildlife Conservation Commission exposure data at 10- and 50 mile radii from the mother's zip code of residence. Multivariable conditional logistic regression determined odds of BA in offspring in relation to maternal gestational K. brevis exposure adjusted for infant sex, race/ethnicity, coastal residence, and seasonality.

RESULTS

Of 38 cases and 152 controls, no significant inter-group differences were observed for infant race/ethnicity, season of birth, or coastal residence. Median gestational exposure at the 10 mile radius was 0 cells/liter in both groups. A greater proportion of cases had no gestational K. brevis exposure (63.2 %, n = 24) in comparison to controls (37.5 %, n = 57; p = .04) at a 10 mile radius. At a 50 mile radius, cases had a peak median exposure at 6 months of gestation compared to controls' peak at 9 months. After adjustment for sex, seasonality, race/ethnicity, and coastal residence, there was no significant association between BA and maximum K. brevis exposure per trimester of pregnancy observed at a 10- or 50 mile radius.

CONCLUSION

In this matched case-control study, we observed no association between gestational K. brevis (cells/liter) exposure at a 10- or 50 mile radius from maternal zip code of residence and BA in offspring.

Maternal Prenatal Infections and Biliary Atresia in Offspring

Importance

Investigations into the association of antepartum maternal infections with the pathogenesis of biliary atresia (BA) in human offspring are insufficient.

Objective

To examine the association between prenatal infections in mothers and the development of BA in their offspring.

Design, Setting, and Participants

This population-based case-control study obtained administrative data from the Taiwan National Health Insurance Research Database with linkage to the Taiwan Maternal and Child Health Database, capturing demographic and medical information on nearly all 23 million of the Taiwan population. The cohort comprised 2 905 978 singleton live births among mother-infant dyads between January 1, 2004, and December 31, 2020, in Taiwan. The case group of infants with BA was identified from use of International Classification of Diseases diagnostic codes for BA and subsequent Kasai procedure or liver transplant. The control group was randomly selected from infants without BA, representing approximately 1 in 1000 study population. Data analyses were performed from May 1 to October 31, 2023.

Exposure

Prenatal maternal infections, including intestinal infection, influenza, upper airway infection, pneumonia, soft-tissue infection, and genitourinary tract infection.

Main Outcomes and Measures

The main outcome was exposure to prenatal maternal infections. Inverse probability weighting analysis was performed by building a logistic regression model to estimate the probability of the exposure observed for a particular infant and using the estimated probability as a weight in subsequent analyses. The weighted odds ratio (OR) estimated by logistic regressions was then used to assess the risk of BA in offspring after prenatal maternal infections.

Results

Among the mother-infant dyads included, 447 infants with BA were cases (232 females [51.9%]) and 2912 infants without BA were controls (1514 males [52.0%]). The mean (SD) maternal age at childbirth was 30.7 (4.9) years. Offspring exposed to prenatal intestinal infection (weighted OR, 1.46; 95% CI, 1.17-1.82) and genitourinary tract infection (weighted OR, 1.22; 95% CI, 1.05-1.41) in mothers exhibited a significantly higher risk of BA. Furthermore, maternal intestinal infection (weighted OR, 6.05; 95% CI, 3.80-9.63) and genitourinary tract infection (weighted OR, 1.55; 95% CI, 1.13-2.11) that occurred during the third trimester were associated with an increased risk of BA in offspring.

Conclusions and Relevance

Results of this case-control study indicate an association between prenatal intestinal infection and genitourinary tract infection in mothers and BA occurrence in their offspring. Further studies are warranted to explore the underlying mechanisms of this association.

Microcystin-RR is a biliary toxin selective for neonatal cholangiocytes

BACKGROUND AND AIMS

Biliary atresia is a fibrosing cholangiopathy affecting neonates that is thought to be caused by a prenatal environmental insult to the bile duct. Biliatresone, a plant toxin with an α-methylene ketone group, was previously implicated in toxin-induced biliary atresia in Australian livestock, but is found in a limited location and is highly unlikely to be a significant human toxin. We hypothesized that other molecules with α-methylene ketone groups, some with the potential for significant human exposure, might also be biliary toxins.

APPROACH AND RESULTS

We focused on the family of microcystins, cyclic peptide toxins from blue-green algae that have an α-methylene ketone group and are found worldwide, particularly during harmful algal blooms. We found that microcystin-RR, but not 6 other microcystins, caused damage to cell spheroids made using cholangiocytes isolated from 2-3-day-old mice, but not from adult mice. We also found that microcystin-RR caused occlusion of extrahepatic bile duct explants from 2-day-old mice, but not 18-day-old mice. Microcystin-RR caused elevated reactive oxygen species in neonatal cholangiocytes, and treatment with N-acetyl cysteine partially prevented microcystin-RRinduced lumen closure, suggesting a role for redox homeostasis in its mechanism of action.

CONCLUSIONS

This study highlights the potential for environmental toxins to cause neonatal biliary disease and identifies microcystin-RR acting via increased redox stress as a possible neonatal bile duct toxin.

Genetic alterations and molecular mechanisms underlying hereditary intrahepatic cholestasis

Hereditary cholestatic liver disease caused by a class of autosomal gene mutations results in jaundice, which involves the abnormality of the synthesis, secretion, and other disorders of bile acids metabolism. Due to the existence of a variety of gene mutations, the clinical manifestations of children are also diverse. There is no unified standard for diagnosis and single detection method, which seriously hinders the development of clinical treatment. Therefore, the mutated genes of hereditary intrahepatic cholestasis were systematically described in this review.

Advances in understanding of biliary atresia pathogenesis and progression - a riddle wrapped in a mystery inside an enigma

INTRODUCTION

Biliary atresia is a potentially fatal condition of the bile ducts - both intra- and extrahepatic, for which we have no cure. Though principally a cholestatic condition, much of its pathology stems from its tendency to aggressively induce liver fibrosis and ultimately cirrhosis, only partially restrained by the portoenterostomy.

AREAS COVERED

This review is based on the current literature exploring the heterogeneous nature of biliary atresia. Thus, there are various phenotypes or variants of biliary atresia, each potentially with different etiological backgrounds caused by a number of hypothetical pathological mechanisms thought to be important in the genesis of the condition. Search methodology: the review (Oct. - Nov. 2022) is based on a search of PubMed (NLM) using main keyword 'biliary atresia' with supplementary searches using 'fibrosis'; 'inflammation'; 'BASM'; 'genetics'; 'surgery'; 'experimental'; 'etiology'; 'virology'; 'cases'; and 'syndromes.'

EXPERT OPINION

Future developments will be made on matching clinical variants with a more distinct pathophysiological discrimination and those pathways linking the initial cholestatic phase of biliary atresia to the early stages of fibrosis.

Biliary atresia & choledochal malformation--Embryological and anatomical considerations

The two main biliary pathologies in paediatric practice, biliary atresia and choledochal malformations (CM), have their origins within prenatal life. Nevertheless, the actual mechanisms remain elusive with many unanswered questions. The extrahepatic bile duct develops as a funnel-like structure emerging from the foregut from about 3-4 weeks of gestation into the mesenchyme of the septum transversum. The cranial elements of this contain hepatoblasts - the precursors to the two key cell lines that will become hepatocytes and biliary epithelial cells. The intrahepatic bile ducts develop separately and emerge from a complex process involving the ductal plate surrounding the in-growing portal venous system from about the 7-8^th week of gestation. A developmental defect at some point(s) in this process may be the cause of at least some variants of BA - the Biliary Atresia Splenic Malformation syndrome particularly - though evidence in the more common isolated BA is much more circumstantial. Similarly, some types of choledochal malformation, specifically the cystic type of CM, are invariably present during prenatal life although again an actual aetiological mechanism remains elusive.