Biliary atresia and other cholestatic childhood diseases: Advances and future challenges

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.

Transition care to adolescent hepatology in a tertiary center for rare adult-child liver disease

AIMS

This study analyzed the results of a transition program in a patient population with a rare liver disease of pediatric onset.

METHOD

Data were collected on the clinical course of an adolescent population with a rare disease of pediatric onset and enrolled in a transition program between 1994 and 2022.

RESULTS

A total of 238 adolescents (including 34 having undergone a liver transplant on enrolling in the program) were included. Eight patients were lost to follow-up before the first transition consultation and 16 families requested follow-up in an adult hepatology department closer to their home. Overall, 214 initial transition consultations were carried out; 29 patients were subsequently lost to follow-up and 13 switched center. Overall, 15.4 % of the patients enrolled in our program were lost to follow-up. Five adult patients underwent a liver transplantation during this 28-year period. Overall mortality was 3.2 %, graft survival was 91.5 %, and posttransplant survival was 92 %. In total, the current active file represents 183 patients with a median age of 24.3 years (18-51) and a median follow-up period of 5.8 years (6 months to 28 years).

CONCLUSION

The implementation of a transition program to adult medicine for adolescents with a rare liver disease should follow the recommendations but must be adapted in line with local practice conditions. This process requires close collaboration between the pediatric and adult medicine teams based on a mutual desire to constantly improve practices and enhance knowledge.

Novel NIR-II fluorescent probes for biliary atresia imaging

Biliary atresia is a rare infant disease that predisposes patients to liver transplantation and death if not treated in time. However, early diagnosis is challenging because the clinical manifestations and laboratory tests of biliary atresia overlap with other cholestatic diseases. Therefore, it is very important to develop a simple, safe and reliable method for the early diagnosis of biliary atresia. Herein, a novel NIR-II fluorescence probe, HZL2, with high quantum yield, excellent biocompatibility, low cytotoxicity and rapid excretion through the liver and gallbladder was developed based on the oil/water partition coefficient and permeability. A simple fecal sample after injection of HZL2 can be used to efficiently identify the success of the mouse model of biliary atresia for the first time, allowing for an early diagnosis of the disease. This study not only developed a simple and safe method for the early diagnosis of biliary atresia with great potential in clinical translation but also provides a research tool for the development of pathogenesis and therapeutic medicines for biliary atresia.

Combi-Elasto Evaluation of the Degree of Liver Fibrosis in Children with Cholestatic Liver Disease

Cholestatic liver disease is a common liver disease in infants and young children. Liver fibrosis is a key factor affecting the prognosis, and liver transplantation is the only treatment option for liver cirrhosis. This study aimed to explore the efficacy of Combi-elasto for diagnosing liver fibrosis in children affected by cholestatic liver disease. A total of 64 children with S1-S4-grade liver fibrosis were enrolled. The general data, routine ultrasound, Combi-elasto, aspartate aminotransferase-to-platelet ratio index (APRI) and Fibrosis-4 (FIB-4) score were compared among children with different grades of liver fibrosis, and the efficacy of the above indexes for evaluating the degree of liver fibrosis was reported. There were remarkable differences in liver size, liver echogenicity, Young's modulus (E), fibrosis index (FI), activity index (AI) and FIB-4 score among the groups (all p < 0.05). E and liver echogenicity were the independent impact factors of liver fibrosis. The areas under the curve of E, APRI, FIB-4 score and the combined model (E+ liver echogenicity) in the evaluation of liver fibrosis were 0.84, 0.61, 0.66 and 0.90, respectively. Ultimately, we concluded that CE is an effective method to evaluate liver fibrosis in children with cholestatic liver disease.

Zebrafish as a Useful Model System for Human Liver Disease

Liver diseases represent a significant global health challenge, thereby necessitating extensive research to understand their intricate complexities and to develop effective treatments. In this context, zebrafish (Danio rerio) have emerged as a valuable model organism for studying various aspects of liver disease. The zebrafish liver has striking similarities to the human liver in terms of structure, function, and regenerative capacity. Researchers have successfully induced liver damage in zebrafish using chemical toxins, genetic manipulation, and other methods, thereby allowing the study of disease mechanisms and the progression of liver disease. Zebrafish embryos or larvae, with their transparency and rapid development, provide a unique opportunity for high-throughput drug screening and the identification of potential therapeutics. This review highlights how research on zebrafish has provided valuable insights into the pathological mechanisms of human liver disease.

Opportunities and considerations for studying liver disease with microphysiological systems on a chip

Advances in microsystem engineering have enabled the development of highly controlled models of the liver that better recapitulate the unique in vivo biological conditions. In just a few short years, substantial progress has been made in creating complex mono- and multi-cellular models that mimic key metabolic, structural, and oxygen gradients crucial for liver function. Here we review: 1) the state-of-the-art in liver-centric microphysiological systems and 2) the array of liver diseases and pressing biological and therapeutic challenges which could be investigated with these systems. The engineering community has unique opportunities to innovate with new liver-on-a-chip devices and partner with biomedical researchers to usher in a new era of understanding of the molecular and cellular contributors to liver diseases and identify and test rational therapeutic modalities.

Comparison of Liver Transplant Outcomes in Biliary Atresia Patients, Considering Whether They Underwent the Kasai Procedure Beforehand: A Single Center Analysis of 72 Patients

BACKGROUND

This study examines the results of liver transplantation (LT) in patients with biliary atresia, considering whether they underwent the Kasai procedure beforehand. LT and determine postoperative and long-term graft outcomes.

METHODS

This single-center, retrospective study included 72 pediatric patients diagnosed with postpartum biliary atresia who underwent LT between 2010 and 2022. We included patients who underwent LT either after or without the Kasai procedure and compared the demographic data of the patients with various factors, such as the Pediatric End-Stage Liver Disease scores and laboratory values.

RESULTS

The study included 72 patients, with 39 of them being female (54.2%) and 33 of them being male (45.8%). Of the 72 patients in the study, 47 (65.3%) had undergone the Kasai procedure, and 25 (34.7%) had not. The preoperative and postoperative month 1 bilirubin values were lower in patients who underwent the Kasai procedure and were higher in postoperative months 3 and 6. Preoperative bilirubin values, postoperative month 3 bilirubin values, and preoperative albumin values were higher in patients who developed mortality (P < .05). Cold ischemia time was longer in patients who developed mortality (P < .05).

CONCLUSIONS

Our study showed a higher mortality rate in patients who underwent the Kasai procedure. The results also showed that LT was more effective in children, as patients with Kasai had higher mean bilirubin values and higher preoperative albumin values than patients without Kasai.

The influence of liver transplantation on the interplay between gut microbiome and bile acid homeostasis in children with biliary atresia

BACKGROUND

Biliary atresia (BA) causes neonatal cholestasis and rapidly progresses into cirrhosis if left untreated. Kasai portoenterostomy may delay cirrhosis. BA remains among the most common indications for liver transplantation (LT) during childhood. Liver function and gut microbiome are interconnected. Disturbed liver function and enterohepatic signaling influence microbial diversity. We, herein, investigate the impact of LT and reestablishment of bile flow on gut microbiome-bile acid homeostasis in children with BA before (pre, n = 10), 3 months (post3m, n = 12), 12 months (post12m, n = 9), and more than 24 months (post24 + m, n = 12) after LT.

METHODS

We analyzed the intestinal microbiome of BA patients before and after LT by 16S-rRNA-sequencing and bioinformatics analyses, and serum primary and secondary bile acid levels.

RESULTS

The gut microbiome in BA patients exhibits a markedly reduced alpha diversity in pre (p = 0.015) and post3m group (p = 0.044), and approximated healthy control groups at later timepoints post12m (p = 1.0) and post24 + m (p = 0.74). Beta diversity analysis showed overall community structure similarities of pre and post3m (p = 0.675), but both differed from the post24 + m (p < 0.001). Longitudinal analysis of the composition of the gut microbiome revealed the Klebsiella genus to show increased abundance in the post24 + m group compared with an age-matched control (p = 0.029). Secondary bile acid production increased 2+ years after LT (p = 0.03). Multivariable associations of microbial communities and clinical metadata reveal several significant associations of microbial genera with tacrolimus and mycophenolate mofetil-based immunosuppressive regimens.

CONCLUSIONS

In children with BA, the gut microbiome shows strongly reduced diversity before and shortly after LT, and approximates healthy controls at later timepoints. Changes in diversity correlate with altered secondary bile acid synthesis at 2+ years and with the selection of different immunosuppressants.

Association analysis and functional follow-up identified common variants of JAG1 accounting for risk to biliary atresia

Background: Biliary atresia (BA) is a destructive, obliterative cholangiopathy characterized by progressive fibro-inflammatory disorder and obliteration of intra- and extrahepatic bile ducts. The Jagged1 (JAG1) gene mutations have been found in some isolated BA cases. We aim to explore the association of common variants in JAG1 with isolated BA risk in the Chinese Han population. Methods: We genotyped 31 tag single nucleotide polymorphisms covering the JAG1 gene region in 333 BA patients and 1,665 healthy controls from the Chinese population, and performed case-control association analysis. The expression patterns of JAG1 homologs were investigated in zebrafish embryos, and the roles of jag1a and jag1b in biliary development were examined by morpholino knockdown in zebrafish. Results: Single nucleotide polymorphisms rs6077861 [P _Allelic = 1.74 × 10^-4, odds ratio = 1.78, 95% confidence interval: 1.31-2.40] and rs3748478 (P _Allelic = 5.77 × 10^-4, odds ratio = 1.39, 95% confidence interval: 1.15-1.67) located in the intron region of JAG1 showed significant associations with BA susceptibility. The JAG1 homologs, jag1a and jag1b genes were expressed in the developing hepatobiliary duct of zebrafish, especially at 72 and 96 h postfertilization. Knockdown of both jag1a and jag1b led to poor biliary secretion, sparse intrahepatic bile duct network and smaller or no gallbladders compared with control embryos in the zebrafish model. Conclusion: Common genetic variants of JAG1 were associated with BA susceptibility. Knockdown of JAG1 homologs led to defective intrahepatic and extrahepatic bile ducts in zebrafish. These results suggest that JAG1 might be implicated in the etiology of BA.

Liver-restricted deletion of the biliary atresia candidate gene Pkd1l1 causes bile duct dysmorphogenesis and ciliopathy

BACKGROUND AND AIMS

A recent multicenter genetic exploration of the biliary atresia splenic malformation syndrome identified mutations in the ciliary gene PKD1L1 as candidate etiologic contributors. We hypothesized that deletion of Pkd1l1 in developing hepatoblasts would lead to cholangiopathy in mice.

APPROACH AND RESULTS

CRISPR-based genome editing inserted loxP sites flanking exon 8 of the murine Pkd1l1 gene. Pkd1l1Fl/Fl cross-bred with alpha-fetoprotein-Cre expressing mice to generate a liver-specific intrahepatic Pkd1l1 -deficient model (LKO). From embryonic day 18 through week 30, control ( Fl/Fl ) and LKO mice were evaluated with standard serum chemistries and liver histology. At select ages, tissues were analyzed using RNA sequencing, immunofluorescence, and electron microscopy with a focus on biliary structures, peribiliary inflammation, and fibrosis. Bile duct ligation for 5 days of Fl/Fl and LKO mice was followed by standard serum and liver analytics. Histological analyses from perinatal ages revealed delayed biliary maturation and reduced primary cilia, with progressive cholangiocyte proliferation, peribiliary fibroinflammation, and arterial hypertrophy evident in 7- to 16-week-old LKO versus Fl/Fl livers. Following bile duct ligation, cholangiocyte proliferation, peribiliary fibroinflammation, and necrosis were increased in LKO compared with Fl/Fl livers.

CONCLUSIONS

Bile duct ligation of the Pkd1l1 -deficient mouse model mirrors several aspects of the intrahepatic pathophysiology of biliary atresia in humans including bile duct dysmorphogenesis, peribiliary fibroinflammation, hepatic arteriopathy, and ciliopathy. This first genetically linked model of biliary atresia, the Pkd1l1 LKO mouse, may allow researchers a means to develop a deeper understanding of the pathophysiology of this serious and perplexing disorder, including the opportunity to identify rational therapeutic targets.

Necroptosis of macrophage is a key pathological feature in biliary atresia via GDCA/S1PR2/ZBP1/p-MLKL axis

Biliary atresia (BA) is a severe inflammatory and fibrosing neonatal cholangiopathy disease characterized by progressive obstruction of extrahepatic bile ducts, resulting in cholestasis and progressive hepatic failure. Cholestasis may play an important role in the inflammatory and fibrotic pathological processes, but its specific mechanism is still unclear. Necroptosis mediated by Z-DNA-binding protein 1 (ZBP1)/phosphorylated-mixed lineage kinase domain-like pseudokinase (p-MLKL) is a prominent pathogenic factor in inflammatory and fibrotic diseases, but its function in BA remains unclear. Here, we aim to determine the effect of macrophage necroptosis in the BA pathology, and to explore the specific molecular mechanism. We found that necroptosis existed in BA livers, which was occurred in liver macrophages. Furthermore, this process was mediated by ZBP1/p-MLKL, and the upregulated expression of ZBP1 in BA livers was correlated with liver fibrosis and prognosis. Similarly, in the bile duct ligation (BDL) induced mouse cholestatic liver injury model, macrophage necroptosis mediated by ZBP1/p-MLKL was also observed. In vitro, conjugated bile acid-glycodeoxycholate (GDCA) upregulated ZBP1 expression in mouse bone marrow-derived monocyte/macrophages (BMDMs) through sphingosine 1-phosphate receptor 2 (S1PR2), and the induction of ZBP1 was a prerequisite for the enhanced necroptosis. Finally, after selectively knocking down of macrophage S1pr2 in vivo, ZBP1/p-MLKL-mediated necroptosis was decreased, and further collagen deposition was markedly attenuated in BDL mice. Furthermore, macrophage Zbp1 or Mlkl specific knockdown also alleviated BDL-induced liver injury/fibrosis. In conclusion, GDCA/S1PR2/ZBP1/p-MLKL mediated macrophage necroptosis plays vital role in the pathogenesis of BA liver fibrosis, and targeting this process may represent a potential therapeutic strategy for BA.

Preliminary exploration of the efficacy of laparoscopic fluorescence cholangiography (LFC) in the diagnosis of biliary atresia compared with intraoperative cholangiography (IOC)

BACKGROUND

Intraoperative cholangiography (IOC) has been the gold standard for diagnosing biliary atresia (BA). Our study attempted to diagnose BA using laparoscopic fluorescein cholangiography (LFC).

METHODS

We retrospectively included 18 patients with preoperative suspected BA as the case group and 4 without extrahepatic biliary obstruction requiring laparoscopic surgery as the control group. All patients received indocyanine green (ICG) intravenously at 0.05 mg/Kg. The first 6 patients in the case group underwent IOC and LFC simultaneously, and the control group completed LFC. The imaging characteristics of LFC were recorded and summarized by the conventional and fluorescence mode of the endoscopic fluorescence imaging system (DPM-ENDOCAM-03). On this basis, 12 patients in the case group were diagnosed as BA according to LFC without IOC, and all 18 patients completed open Kasai surgery to confirm the diagnosis.

RESULTS

Laparoscopic fluorescence mode in BA detected liver fluorescence but no visualization of the extrahepatic bile ducts. However, the extrahepatic bile ducts in the control group were visible. Based on the imaging characteristics summarized from the LFC of the first 6 cases with BA in the case group, the remaining 12 cases who only underwent LFC were also successfully diagnosed with BA. Furthermore, the formation of hepatic hilar fibrous mass was found in all the patients during the open Kasai procedure, which confirmed the BA diagnosis.

CONCLUSIONS

LFC appears as a specific pattern in BA and may be used for intraoperative diagnosis of BA. It has the advantages of simplicity, short time-consuming, and no radiation damage.

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

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

Advances in the Treatment of Neonatal Biliary Disease

This article discusses current standard of care in neonatal biliary disease, particularly management of biliary atresia and choledochal cysts. It highlights surgical considerations, guidelines for adjuvant therapies, and promising therapeutic options that are under investigation.

Metabolic regulation of cholestatic liver injury by D-2-hydroxyglutarate with the modulation of hepatic microenvironment and the mammalian target of rapamycin signaling

Biliary atresia (BA) is a cholestatic liver disease in neonates with devastating obstructive intrahepatic and extrahepatic biliary ducts. Owing to the lack of an early diagnostic marker and limited understanding of its pathogenesis, BA often leads to death within 2 years. Therefore, this study aimed to develop early diagnostic methods and investigate the underlying pathogenesis of liver injury in BA using metabolomics. Metabolomics and organoid combined energy metabolism analysis was used to obtain new insights into BA diagnosis and pathobiology using patient samples, mice liver organoids, and a zebrafish model. Metabolomics revealed that D-2-hydroxyglutarate (D-2-HG) levels were significantly elevated in the plasma and liver of patients with BA and closely correlated with liver injuries and impaired liver regeneration. D-2-HG suppressed the growth and expansion of liver organoids derived from the intrahepatic biliary ducts. The energy metabolism analysis demonstrated that D-2-HG inhibited mitochondrial respiration and ATP synthase; however, it increased aerobic glycolysis in organoids. In addition, D-2-HG exposure caused liver degeneration in zebrafish larvae. Mechanistically, D-2-HG inhibited the activation of protein kinase B and the mammalian target of rapamycin signaling. These findings reveal that D-2-HG may represent a novel noninvasive diagnostic biomarker and a potential therapeutic target for infants with BA.

Surgical and Medical Aspects of the Initial Treatment of Biliary Atresia: Position Paper

Biliary atresia, a fibro-obliterative disease of the newborn, is usually initially treated by Kasai portoenterostomy, although there are many variations in technique and different options for post-operative adjuvant medical therapy. A questionnaire on such topics (e.g., open vs. laparoscopic; the need for liver mobilisation; use of post-operative steroids; use of post-operative anti-viral therapy, etc.) was circulated to delegates (n = 43) of an international webinar (Biliary Atresia and Related Diseases-BARD) held in June 2021. Respondents were mostly European, but included some from North America, and represented 18 different countries overall. The results of this survey are presented here, together with a commentary and review from an expert panel convened for the meeting on current trends in practice.

Rhesus rotavirus receptor-binding site affects high mobility group box 1 release, altering the pathogenesis of experimental biliary atresia

Biliary atresia (BA) is a neonatal inflammatory cholangiopathy that requires surgical intervention by Kasai portoenterostomy to restore biliary drainage. Even with successful portoenterostomy, most patients diagnosed with BA progress to end-stage liver disease, necessitating a liver transplantation for survival. In the murine model of BA, rhesus rotavirus (RRV) infection of neonatal mice induces an inflammatory obstructive cholangiopathy that parallels human BA. The model is triggered by RRV viral protein (VP)4 binding to cholangiocyte cell-surface proteins. High mobility group box 1 (HMGB1) protein is a danger-associated molecular pattern that when released extracellularly moderates innate and adaptive immune response. In this study, we investigated how mutations in three RRV VP4-binding sites, RRVVP4-K187R (sialic acid-binding site), RRVVP4-D308A (integrin α2β1-binding site), and RRVVP4-R446G (heat shock cognate 70 [Hsc70]-binding site), affects infection, HMGB1 release, and the murine model of BA. Newborn pups injected with RRVVP4-K187R and RRVVP4-D308A developed an obstruction within the extrahepatic bile duct similar to wild-type RRV, while those infected with RRVVP4-R446G remained patent. Infection with RRVVP4-R446G induced a lower level of HMGB1 release from cholangiocytes and in the serum of infected pups. RRV infection of HeLa cells lacking Hsc70 resulted in no HMGB1 release, while transfection with wild-type Hsc70 into HeLa Hsc70-deficient cells reestablished HMGB1 release, indicating a mechanistic role for Hsc70 in its release. Conclusion: Binding to Hsc70 contributes to HMGB1 release; therefore, Hsc70 potentially serves as a therapeutic target for BA.

Aetiology and outcomes of prolonged neonatal jaundice in tertiary centres: data from the China Neonatal Genome Project

OBJECTIVE

To investigate the distribution of aetiologies and outcomes in neonates with prolonged neonatal jaundice.

DESIGN

An observational study.

SETTING

Multiple tertiary centres from the China Neonatal Genome Project.

PATIENTS

Term infants with jaundice lasting more than 14 days or preterm infants with jaundice lasting more than 21 days were recruited between 1 June 2016 and 30 June 2020.

MAIN OUTCOME MEASURES

Aetiology and outcomes were recorded from neonates with prolonged unconjugated hyperbilirubinaemia (PUCHB) and prolonged conjugated hyperbilirubinaemia (PCHB).

RESULTS

A total of 939 neonates were enrolled, and known aetiologies were identified in 84.1% of neonates (790 of 939). Among 411 neonates with PCHB, genetic disorders (27.2%, 112 of 411) were the leading aetiologies. There were 8 deceased neonates, 19 neonates with liver failure and 12 with neurodevelopmental delay. Among 528 neonates with PUCHB, a genetic aetiology was identified in 2 of 219 neonates (0.9%) who showed disappearance of jaundice within 4 weeks of age and in 32 of 309 neonates (10.4%) with persistent jaundice after 4 weeks of age. A total of 96 of 181 neonates (53.0%) who received genetic diagnoses had their clinical diagnosis modified as a result of the genetic diagnoses.

CONCLUSION

Known aetiologies were identified in approximately 80% of neonates in our cohort, and their overall outcomes were favourable. Genetic aetiology should be considered a priority in neonates with PCHB or the persistence of jaundice after 4 weeks of age. Moreover, genetic data can modify the clinical diagnosis and guide disease management, potentially improving outcomes.

Exploratory application of indocyanine green quantification in biliary atresia observational study

BACKGROUND

Indocyanine green (ICG) is known to facilitate real-time imaging of the bile outflow during the Kasai procedure. This study explored more possibilities for applying ICG quantification in biliary atresia (BA).

METHODS

We enrolled nine BA patients in this study. All patients received intravenous ICG injections before surgery and underwent Kasai operation. With a fluorescence imaging system (Nanjing Nuoyuan, REAL-IGS FLI-108) to observe the ICG and quantify the ICG fluorescence intensity (ICG-FI) changes of the hepatic portal fibrous tissue and the liver during the operation. As a short-term prognosis assessment, we monitored the postoperative ICG metabolism time in stool and used the jaundice-free (TBIL < 2 mg/dl) at 1-3 months after the operation.

RESULTS

The average age of the patients at the time of surgery was 73 days. There were no adverse reactions after ICG injection. All patients were observed ICG-FI increased after the dissection of hepatic portal fibrous tissue, and the ICG-FI of the liver decreased during the operation. They all received standardized treatment after surgery. Four patients completely metabolized ICG within about two weeks (no fluorescence detected in stool), and the other five were longer than two weeks. Five patients achieved a jaundice-free outcome in the short-term postoperatively, and the other four did not.

CONCLUSIONS

It is feasible to quantify ICG-FI in real-time to evaluate the anatomical degree of hepatic portal fibrous tissue in BA. The variations of ICG-FI in the liver and postoperative ICG metabolism time may be related to prognosis.

Role of Immune Cells in Biliary Repair

The biliary system is comprised of cholangiocytes and plays an important role in maintaining liver function. Under normal conditions, cholangiocytes remain in the stationary phase and maintain a very low turnover rate. However, the robust biliary repair is initiated in disease conditions, and different repair mechanisms can be activated depending on the pathological changes. During biliary disease, immune cells including monocytes, lymphocytes, neutrophils, and mast cells are recruited to the liver. The cellular interactions between cholangiocytes and these recruited immune cells as well as hepatic resident immune cells, including Kupffer cells, determine disease outcomes. However, the role of immune cells in the initiation, regulation, and suspension of biliary repair remains elusive. The cellular processes of cholangiocyte proliferation, progenitor cell differentiation, and hepatocyte-cholangiocyte transdifferentiation during biliary diseases are reviewed to manifest the underlying mechanism of biliary repair. Furthermore, the potential role of immune cells in crucial biliary repair mechanisms is highlighted. The mechanisms of biliary repair in immune-mediated cholangiopathies, inherited cholangiopathies, obstructive cholangiopathies, and cholangiocarcinoma are also summarized. Additionally, novel techniques that could clarify the underlying mechanisms of biliary repair are displayed. Collectively, this review aims to deepen the understanding of the mechanisms of biliary repair and contributes potential novel therapeutic methods for treating biliary diseases.

Variability of Care and Access to Transplantation for Children with Biliary Atresia Who Need a Liver Replacement

Background & Aims: Biliary atresia (BA) is the commonest single etiology indication for liver replacement in children. As timely access to liver transplantation (LT) remains challenging for small BA children (with prolonged waiting time being associated with clinical deterioration leading to both preventable pre- and post-transplant morbidity and mortality), the care pathway of BA children in need of LT was analyzed—from diagnosis to LT—with particular attention to referral patterns, timing of referral, waiting list dynamics and need for medical assistance before LT. Methods: International multicentric retrospective study. Intent-to-transplant study analyzing BA children who had indication for LT early in life (aged < 3 years at the time of assessment), over the last 5 years (2016−2020). Clinical and laboratory data of 219 BA children were collected from 8 transplant centers (6 in Europe and 2 in USA). Results: 39 patients underwent primary transplants. Children who underwent Kasai in a specialist -but not transplant- center were older at time of referral and at transplant. At assessment for LT, the vast majority of children already were experiencing complication of cirrhosis, and the majority of children needed medical assistance (nutritional support, hospitalization, transfusion of albumin or blood) while waiting for transplantation. Severe worsening of the clinical condition led to the need for requesting a priority status (i.e., Peld Score exception or similar) for timely graft allocation for 76 children, overall (35%). Conclusions: As LT currently results in BA patient survival exceeding 95% in many expert LT centers, the paradigm for BA management optimization and survival have currently shifted to the pre-LT management. The creation of networks dedicated to the timely referral to a pediatric transplant center and possibly centralization of care should be considered, in combination with implementing all different graft type surgeries in specialist centers (including split and living donor LTs) to achieve timely LT in this vulnerable population.

Biliary atresia combined Wilson disease identified by whole exome sequencing in Vietnamese patient with severe liver failure

RATIONALE

Hepatobiliary diseases such as biliary atresia (BA), Wilson disease, and progressive familial intrahepatic cholestasis are common causes of morbidity and mortality in young children. Affected patients progress rapidly to end-stage cirrhosis and require liver transplantation or die. Mutations in many genes have been identified to play an important role in the pathogenesis of hepatobiliary diseases.

PATIENT CONCERNS AND DIAGNOSIS

In this study, we identified mutations in an 8-year-old girl who had severe liver failure. The patient was first diagnosed with BA at 2.5 months of age and has undergone Kasai surgery to connect the umbilical cord and jejunum. After that, the patient suddenly had unusual developments with symptoms of jaundice, acute liver failure with hemolysis. She was tested and diagnosed with Wilson disease.

INTERVENTIONS AND OUTCOMES

She was treated according to the regimen for a patient with Wilson disease but had abnormal progress leading to severe liver failure. Genetic analysis was performed by whole exome sequencing and Sanger sequencing methods. The genetic analysis revealed that the patient had a homozygous mutation (p.Gly17Glyfs77∗) in the KRT18 gene, a double heterozygous mutation (p.Ser105∗ and p.Pro992Leu) in the ATP7B gene, and a homozygous variant (p.Val444Ala) in the ABCB11 gene. In silico prediction of mutations indicated that these mutations are the cause of the severe liver failure in the patient.

LESSON

This is a rare clinical case of a BA patient combined with Wilson disease. Our results suggested that whole exome sequencing is an effective diagnostic tool and emphasizes the importance of early diagnosis and appropriate management to save lives and prevent serious complications in the patient.

VEGFA rs3025039 and biliary atresia susceptibility in Chinese population: a systematic review and meta-analysis

Background

Previous studies have suggested an association between vascular endothelial growth factor A (VEGFA) rs3025039 polymorphism and biliary atresia (BA). However, this conclusion is controversial and there is no published pooled evidence of this association.

Methods

This study was conducted and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The protocol was registered with PROSPERO (International Prospective Register of Systematic Reviews). A thorough search was performed on databases including PubMed, Embase, and Chinese Biomedical Database up to August 2020. This study included 846 cases of BA and 2821 controls concerning VEGFA rs3025039 polymorphism. We selected relevant studies based on the following inclusion criteria: (1) the study design was case–control and cohort and (2) the patients carried standard clinical diagnoses of BA, etc. The exclusion criteria were as follows: (1) patients with other related diseases, (2) lack of requisite information and (3) duplicate data. The OR (odd ratio) and the corresponding 95% CI (confidence interval) were calculated to estimate the association.

Results

This study on VEGFA rs3025039 polymorphism in the Chinese population included 846 cases and 2821 controls. The results showed that there was no significant association between rs3025039 and susceptibility to BA under four genetic models. The results of the subgroup analysis were similar to the overall results.

Conclusions

This meta-analysis shows that rs3025039 was not associated with susceptibility to BA in the Chinese population. Further validation may entail additional research.

PROSPERO registration number

CRD42020203812.

Genetic Factors and Their Role in the Pathogenesis of Biliary Atresia

Biliary Atresia, a common basis for neonatal cholestasis and primary indication for Liver Transplantation, accounts for 60% of pediatric Liver Transplantations. While the pathogenesis of Biliary Atresia remains obscure, abnormalities within bile ducts and the liver, inflammation, fibrosis and cilia defects are thought to comprise the pathological basis for this condition. The findings of genetic variants in Biliary Atresia, such as Copy Number Variations and Single Nucleotide Polymorphism, are considered as essential factors in the development of this condition. In this review, we summarize and analyze these Biliary Atresia variants from a perspective of their pathological characteristics. In conclusion, such analyses may offer novel insights into the pathogenesis of Biliary Atresia and provide a foundation for future studies directed toward a better understanding and treatment of Biliary Atresia.

A joint transcriptional regulatory network and protein activity inference analysis identifies clinically associated master regulators for biliary atresia

Biliary atresia (BA) is a devastating cholangiopathy in neonate. Transcription factors (TFs), a type of master regulators in biological processes and diseases, have been implicated in pathogenesis of BA. However, a global view of TFs and how they link to clinical presentations remain explored. Here, we perform a joint transcriptional regulatory network and protein activity inference analysis in order to investigate transcription factor activity in BA. By integration of three independent human BA liver transcriptome datasets, we identify 22 common master regulators, with 14 activated- and 8 repressed TFs. Gene targets of activated TFs are enriched in biological processes of SMAD, NF-kappaB and TGF-beta, while those of repressed TFs are related to lipid metabolism. Mining the clinical association of TFs, we identify inflammation-, fibrosis- and survival associated TFs. In particular, ZNF14 is predictive of poor survival and advanced live fibrosis. Supporting this observation, ZNF14 is positively correlated with T helper cells, cholangiocytes and hepatic stellate cells. In sum, our analysis reveals key clinically associated master regulators for BA.

Adjuvant Therapy with Budesonide Post-Kasai Reduces the Need for Liver Transplantation in Biliary Atresia

Based on the hypothesis that autoimmunological factors coregulate the pathomechanism in biliary atresia (BA), adjuvant therapy with steroids has become routine, although its efficacy has never been proven. In 2010, a study on the advantages of budesonide compared to prednisolone in autoimmune hepatitis gave rise to experimental therapy using budesonide as an adjuvant BA treatment. Ninety-five BA patients prospectively received a budesonide 2 mg/dose rectal foam daily for three months (SG). A case-matched control group (CG: 81) was retrospectively recruited. The outcome measures were survival with native liver (SNL), determined at six months and two years after the Kasai procedure. The follow-up rate was 100%. At six months, SNL was statistically not different but became so after two years (SG: 54%; CG: 32%; p < 0.001). No steroid-related side effects were observed, except for eight patients with finally caught-up growth retardation. This study demonstrates for the first time a significantly longer survival with native liver in patients with BA after adjuvant therapy. However, indication, dosage, and duration of any budesonide application is not given in neonates with BA. Hence, we suggest extending the postoperative use of budesonide in a multicenter observational study with a clearly defined follow-up protocol, particularly in terms of potentially underestimated side effects.

Biliary Atresia/Neonatal Cholestasis: What is in the Horizon?

"Biliary atresia (BA) is a common cause of jaundice in infancy. There is increasing evidence that newborn screening with direct or conjugated bilirubin leads to earlier diagnosis. Although the Kasai portoenterostomy is the primary treatment, there are scientific advances in adjuvant therapies. As pediatric patients transition to adult care, multidisciplinary care is essential, given the complexity of this patient population."

The role of p.Val444Ala variant in the ABCB11 gene and susceptibility to biliary atresia in Vietnamese patients

Biliary atresia (BA) is the most serious type of obstructive cholangiopathy that occurs in infants. BA can be the cause of death in children under 2 years if untreated early. However, the etiology of the disease is not known. BA is considered to be the result of the destruction of the bile duct system including the accumulation of bile acids. The bile salt export pump, a transporter protein encoded by the ABCB11 gene, plays the main role in the exportation and accumulation of bile acids. The p.Val444Ala variant in this gene is known to be associated with many cholestatic diseases. However, to date no study have been performed to evaluate the association of this variant with susceptibility to the risk of BA. In this study, we aimed to identify the frequency of p.Val444Ala variant and the risk of BA in Vietnamese patients.The polymerase chain reaction (PCR)- restriction fragment length polymorphism method was used to determine the frequency of alleles c.1331T>C (p.Val444Ala, rs2287622) in the ABCB11 gene in 266 Vietnamese patients with BA and 150 healthy people. The gene segment containing the variant was amplified by PCR with specific primers, after that the PCR products were cut by HaeIII restriction enzyme and analyzed on agarose gel to determine the genotypes. The frequency of alleles was assessed statistically to determine the association between these alleles and the risk of disease in patients.In our study, the frequency of alleles c.1331T>C (p.Val444Ala, rs2287622) in the ABCB11 gene was investigated the first time in the patients with BA. The results showed that CC and TC genotypes were significantly different between BA patients and healthy people (P < .01), and the C allele was associated with an increased risk of BA (odds ratio = 2.47; 95% confidence interval: 1.84-3.32; P < .01). The initial results of clinical, biochemical, and genetic analysis in our study suggested that the p.Val444Ala variant in the ABCB11 gene may be a susceptibility factor for the disease in Vietnamese patients with BA. These results provided new insights into the role of this ABCB11 variant in the pathogenesis of BA.

Biliary atresia-specific deciduous pulp stem cells feature biliary deficiency

BACKGROUND

Biliary atresia (BA) is a severe hepatobiliary disease in infants that ultimately results in hepatic failure; however, its pathological mechanism is poorly elucidated. Current surgical options, including Kasai hepatoportoenterostomy and orthotopic liver organ transplantations, are palliative; thus, innovation in BA therapy is urgent.

METHODS

To examine whether BA-specific post-natal stem cells are feasible for autologous cell source for BA treatment, we isolated from human exfoliated deciduous teeth, namely BA-SHED, using a standard colony-forming unit fibroblast (CFU-F) method and compared characteristics as mesenchymal stem cells (MSCs) to healthy donor-derived control SHED, Cont-SHED. BA-SHED and Cont-SHED were intrasplenically transplanted into chronic carbon tetrachloride (CCl₄)-induced liver fibrosis model mice, followed by the analysis of bile drainage function and donor integration in vivo. Immunohistochemical assay was examined for the regeneration of intrahepatic bile ducts in the recipient's liver using anti-human specific keratin 19 (KRT19) antibody.

RESULTS

BA-SHED formed CFU-F, expressed MSC surface markers, and exhibited in vitro mesenchymal multipotency similar to Cont-SHED. BA-SHED showed less in vitro hepatogenic potency than Cont-SHED. Cont-SHED represented in vivo bile drainage function and KRT19-positive biliary regeneration in chronic carbon tetrachloride-induced liver fibrosis model mice. BA-SHED failed to show in vivo biliary potency and bile drainage function compared to Cont-SHED.

CONCLUSION

These findings indicate that BA-SHED are not feasible source for BA treatment, because BA-SHED may epigenetically modify the underlying prenatal and perinatal BA environments. In conclusion, these findings suggest that BA-SHED-based studies may provide a platform for understanding the underlying molecular mechanisms of BA development and innovative novel modalities in BA research and treatment.

Secondary Malnutrition and Nutritional Intervention in Cholestatic Liver Diseases in Infants

We aimed to conduct an updated review on the pathophysiology, diagnosis, and nutritional intervention of CCLD and secondary malnutrition in infants. Protein-energy malnutrition, impaired linear growth, fat-soluble vitamin deficiencies, and hepatic osteodystrophy can occur in up to 80% of cases. The proposed pathophysiological mechanisms include insufficient energy intake, lipid- and fat-soluble vitamin malabsorption, increased energy expenditure, altered intermediate metabolism, hormonal dysregulation, and systemic inflammation. The current approach to diagnosis is the identification of the deviation of growth parameters, body composition, and serum concentration of micronutrients, which determines the type and magnitude of malnutrition. Currently, liver transplantation is the best therapeutic alternative for the reversal of nutritional impairment. Early and effective portoenteroanatomosis can extend survival in patients with biliary atresia. Medical and dietary interventions in some storage and metabolic diseases can improve liver damage and thus the nutritional status. A proportion of patients with biliary atresia have fat-soluble vitamin deficiencies despite receiving these vitamins in a water-soluble form. With aggressive enteral nutrition, it may be possible to increase fat stores and preserve muscle mass and growth. The nutritional issues identified in the pre- and post-transplantation stages include muscle mass loss, bone demineralization, growth retardation, and obesity, which seems to correspond to the natural history of CCLD. Due to the implications for the growth and development of infants with CCLD with this complex malnutrition syndrome, innovative projects are required, such as the generation of prediction and risk models, biomarkers of growth and body composition, and effective strategies for nutritional prevention and intervention.

Laparoscopic vs open portoenterostomy in biliary atresia: a systematic review and meta-analysis

Hepatoportoenterostomy remains the cornerstone of treatment for biliary atresia. Current employed techniques include laparoscopy and open surgery. This study aims to determine if either method provides an advantage. Following PRISMA guidelines, a systematic review was conducted. Nineteen studies were included. Mean operative time 34.98 (95% CI 20.10, 49.85; p ≤ 0.00001) was longer in laparoscopic while bleeding volumes - 16.63 (95% CI - 23.39, - 9.86; p ≤ 0.00001) as well as the time to normal diet - 2.42 (95% CI - 4.51, - 0.32; p = 0.02) were lower in the laparoscopic group. No differences were observed in mean length of stay - 0.83. Similar complication, transfusions, postoperative cholangitis 0.97, and transplant free survival rates 1.00 (0.63, 1.60; p = 0.99) were seen between groups. Laparoscopic portoenterostomy provides advantages on operative time and bleeding as well as to normal diet when compared to open procedures. Both procedures showed no differences in length of stay, complications, cholangitis, and importantly, native liver survival. Level of evidence: III.

Effects of odevixibat on pruritus and bile acids in children with cholestatic liver disease: Phase 2 study

PURPOSE

Ileal bile acid transporter inhibition is a novel therapeutic concept for cholestatic pruritus and cholestatic liver disease progression. Odevixibat, a potent, selective, reversible ileal bile acid transporter inhibitor, decreases enteric bile acid reuptake with minimal systemic exposure. Oral odevixibat safety, tolerability, and efficacy in pediatric patients with cholestatic liver disease and pruritus were evaluated.

PATIENTS AND METHODS

In this phase 2, open-label, multicenter study, children received 10‒200 μg/kg oral odevixibat daily for 4 weeks. Changes in serum bile acid levels (primary efficacy endpoint), pruritus, and sleep disturbance were explored.

RESULTS

Twenty patients were enrolled (8 females; 1‒17 years; 4 re-entered at a different dose). Diagnoses included progressive familial intrahepatic cholestasis (n = 13; 3 re-entries), Alagille syndrome (n = 6), biliary atresia (n = 3), and other intrahepatic cholestasis causes (n = 2; 1 re-entry). Mean baseline serum bile acid levels were high (235 µmol/L; range, 26‒564) and were reduced in the majority (-123.1 μmol/L; range, -394 to 14.5, reflecting reductions of up to 98%). Patient-reported diary data documented improved pruritus (3 scales) and sleep. With 100 μg/kg, mean (SEM) decrease was 2.8 (1.1) points for pruritus (visual analogue itch scale 0-10) and 2.9 (0.9) points for sleep disturbance (Patient-Oriented Scoring Atopic Dermatitis scale 0-10). Reduced pruritus correlated significantly with reduced serum bile acids (P ≤ 0.007). Significant correlations were also observed between autotaxin levels and pruritus. All patients completed the study. No serious adverse events were treatment related; most adverse events, including increased transaminases, were transient.

CONCLUSIONS

Orally administered odevixibat was well tolerated, reduced serum bile acids, and improved pruritus and sleep disturbance in children with cholestatic diseases.

What to measure in biliary atresia research: study protocol for developing a core outcome set

AIM

Extrahepatic biliary atresia is a rare disorder. This creates challenges in the quality and quantity of research conducted. This issue is exacerbated by the potential heterogeneity in the reported outcomes in research examining the management of biliary atresia. A core outcome set is required to standardise reporting on the management of biliary atresia in research, facilitate systematic reviews that include outcomes of greatest importance to patients and clinicians, and to evaluate the quality of the existing evidence base on the management of biliary atresia.

METHODS

A list of all potential outcomes will be developed through a systematic review of the literature. This list will be refined through a three-stage Delphi approach, involving key stakeholders in the management of biliary atresia. This will include patients and their parents, clinicians, nurses and allied health professionals. In this way, outcomes will be prioritised into a set of consensus core outcomes.

CONCLUSION

The development of a core outcome set in biliary atresia management is needed to guide future research and assist in evaluating the quality of existing research.

ETHICS AND DISSEMINATION

Ethical approval has been granted by the Children's Health Queensland Hospital and Health Service Human Research Ethics Committee (HREC), Ref: HREC/20/QCHQ/62448. Results of the study will be published in an open access format.

Drug-Induced Vanishing Bile Duct Syndrome: From Pathogenesis to Diagnosis and Therapeutics

The most concerned issue in the context of drug/herb-induced chronic cholestasis is vanishing bile duct syndrome. The progressive destruction of intrahepatic bile ducts leading to ductopenia is usually not dose dependent, and has a delayed onset that should be suspected when abnormal serum cholestasis enzyme levels persist despite drug withdrawal. Immune-mediated cholangiocyte injury, direct cholangiocyte damage by drugs or their metabolites once in bile, and sustained exposure to toxic bile salts when biliary epithelium protective defenses are impaired are the main mechanisms of cholangiolar damage. Current therapeutic alternatives are scarce and have not shown consistent beneficial effects so far. This review will summarize the current literature on the main diagnostic tools of ductopenia and its histological features, and the differential diagnostic with other ductopenic diseases. In addition, pathomechanisms will be addressed, as well as the connection between them and the supportive and curative strategies for ductopenia management.

High Mobility Group Box 1 Release by Cholangiocytes Governs Biliary Atresia Pathogenesis and Correlates With Increases in Afflicted Infants

BACKGROUND AND AIMS

Biliary atresia (BA) is a devastating cholangiopathy of infancy. Upon diagnosis, surgical reconstruction by Kasai hepatoportoenterostomy (HPE) restores biliary drainage in a subset of patients, but most patients develop fibrosis and progress to end-stage liver disease requiring liver transplantation for survival. In the murine model of BA, rhesus rotavirus (RRV) infection of newborn pups results in a cholangiopathy paralleling that of human BA. High-mobility group box 1 (HMGB1) is an important member of the danger-associated molecular patterns capable of mediating inflammation during infection-associated responses. In this study, we investigated the role of HMGB1 in BA pathogenesis.

APPROACH AND RESULTS

In cholangiocytes, RRV induced the expression and release of HMGB1 through the p38 mitogen-activated protein kinase signaling pathway, and inhibition of p38 blocked HMGB1 release. Treatment of cholangiocytes with ethyl pyruvate suppressed the release of HMGB1. Administration of glycyrrhizin in vivo decreased symptoms and increased survival in the murine model of BA. HMGB1 levels were measured in serum obtained from infants with BA enrolled in the PROBE and START studies conducted by the Childhood Liver Disease Research Network. High HMGB1 levels were found in a subset of patients at the time of HPE. These patients had higher bilirubin levels 3 months post-HPE and a lower survival of their native liver at 2 years.

CONCLUSIONS

These results suggest that HMGB1 plays a role in virus induced BA pathogenesis and could be a target for therapeutic interventions in a subset of patients with BA and high HMGB1.

Insight Into Polysaccharides From Panax ginseng C. A. Meyer in Improving Intestinal Inflammation: Modulating Intestinal Microbiota and Autophagy

Polysaccharides from Panax ginseng C. A. Meyer (P. ginseng) are the main active component of P. ginseng and exhibit significant intestinal anti-inflammatory activity. However, the therapeutic mechanism of the ginseng polysaccharide is unclear, and this hinders the application for medicine or functional food. In this study, a polysaccharide was isolated from P. ginseng (GP). The primary structure and morphology of the GP were studied by HPLC, FT-IR spectroscopy, and scanning electron microscopy (SEM). Further, its intestinal anti-inflammatory activity and its mechanism of function were evaluated in experimental systems using DSS-induced rats, fecal microbiota transplantation (FMT), and LPS-stimulated HT-29 cells. Results showed that GP modulated the structure of gut microbiota and restored mTOR-dependent autophagic dysfunction. Consequently, active autophagy suppressed inflammation through the inhibition of NF-κB, oxidative stress, and the release of cytokines. Therefore, our research provides a rationale for future investigations into the relationship between microbiota and autophagy and revealed the therapeutic potential of GP for inflammatory bowel disease.

Common ABCB4 and ABCB11 Genotypes Are Associated with Idiopathic Chronic Cholestasis in Adults

INTRODUCTION

Pathogenic mutations in genes encoding the hepatocanalicular transporters ATP8B1, ABCB11 and ABCB4 are causative for progressive cholestatic liver disease in children. In adults, less severe variants such as the common ABCB4 c.711A>T polymorphism have been associated with intrahepatic cholestasis in pregnancy and elevated liver enzymes. Hence, our aim was to study the role of common polymorphisms in adult patients with chronic unexplained cholestasis.

METHODS

Screening of outpatients of two university hospitals identified a cohort of 94 patients with chronic cholestasis of unknown origin after thorough exclusion of other causes. Genotyping was performed using TaqMan assays, and frequencies for the ABCB4 rs2109505 (c.711A>T), rs1202283 (c.504T>C), ABCB11 rs2287622 (p.A444V) and rs497692 (c.3084A>G) variants of the study cohort were compared to a cohort of 254 healthy controls.

RESULTS

The dominating symptoms of the patients were pruritus and jaundice, though the majority of them did not report symptoms at inclusion. Advanced fibrosis or cirrhosis was present in 11 patients (11.7%) only. Genotyping revealed the presence of the ABCB4 c.711A>T risk variant in 79 patients (84%), a frequency that is significantly (p = 0.037) higher than that in controls (71%). The ABCB11 p.A444V variant was also more frequent in cholestatic patients (p = 0.042).

CONCLUSION

The common ABCB4 c.711A>T and ABCB11 p.A444V polymorphisms are more prevalent in adult patients with idiopathic cholestasis than in healthy controls and may therefore represent risk factors for the development of chronic cholestatic liver disease.

Deleterious Variants in ABCC12 are Detected in Idiopathic Chronic Cholestasis and Cause Intrahepatic Bile Duct Loss in Model Organisms

BACKGROUND & AIMS

The etiology of cholestasis remains unknown in many children. We surveyed the genome of children with chronic cholestasis for variants in genes not previously associated with liver disease and validated their biological relevance in zebrafish and murine models.

METHOD

Whole-exome (n = 4) and candidate gene sequencing (n = 89) was completed on 93 children with cholestasis and normal serum γ-glutamyl transferase (GGT) levels without pathogenic variants in genes known to cause low GGT cholestasis such as ABCB11 or ATP8B1. CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 genome editing was used to induce frameshift pathogenic variants in the candidate gene in zebrafish and mice.

RESULTS

In a 1-year-old female patient with normal GGT cholestasis and bile duct paucity, we identified a homozygous truncating pathogenic variant (c.198delA, p.Gly67Alafs∗6) in the ABCC12 gene (NM_033226). Five additional rare ABCC12 variants, including a pathogenic one, were detected in our cohort. ABCC12 encodes multidrug resistance-associated protein 9 (MRP9) that belongs to the adenosine 5'-triphosphate-binding cassette transporter C family with unknown function and no previous implication in liver disease. Immunohistochemistry and Western blotting revealed conserved MRP9 protein expression in the bile ducts in human, mouse, and zebrafish. Zebrafish abcc12-null mutants were prone to cholangiocyte apoptosis, which caused progressive bile duct loss during the juvenile stage. MRP9-deficient mice had fewer well-formed interlobular bile ducts and higher serum alkaline phosphatase levels compared with wild-type mice. They exhibited aggravated cholangiocyte apoptosis, hyperbilirubinemia, and liver fibrosis upon cholic acid challenge.

CONCLUSIONS

Our work connects MRP9 with bile duct homeostasis and cholestatic liver disease for the first time. It identifies a potential therapeutic target to attenuate bile acid-induced cholangiocyte injury.

Variability in age at Kasai portoenterostomy for biliary atresia across US children's hospitals

BACKGROUND/PURPOSE

The purpose of this study was to assess variability in age at Kasai portoenterostomy (KP) in infants with biliary atresia (BA) across children's hospitals in the United States.

STUDY DESIGN

A multi-institutional retrospective study was performed examining infants with BA undergoing KP within 6 months of birth from 2016-2019, utilizing the Pediatric Health Information System (PHIS). Multivariable negative binomial mixed effects regression was performed for age at KP, and inter-hospital variability was examined.

RESULTS

Across 46 hospitals, 470 infants with BA underwent KP at a median age of 57 days (IQR 42-72), with 212 (45.1%) undergoing KP at ≥60 days of age. There was significant inter-hospital variability in age at KP ranging from 38 days (95% CI: 31d, 47d) to 76 days (95% CI: 63d, 91d) (p<0.0001). Factors associated with later KP were black or African-American race, urgent/emergent admission, and treatment at a hospital in the Pacific-West region. Predictors of earlier KP included later year, history of neonatal comorbidity, and admission to an intensive care service (all p<0.05).

CONCLUSION

There is significant variability in the age at KP in infants with BA across children's hospitals in the United States.

TYPE OF STUDY

Retrospective study.

LEVEL OF EVIDENCE

III.

Bile Acids Impair Vaccine Response in Children With Biliary Atresia

Background

Vaccination is the best way to protect children under 5 years from death or disability. Children with biliary atresia (BA), which is the most common pediatric cholestatic end-stage liver disease (PELD), are more vulnerable to infectious diseases. However, the vaccination coverage and factors modulating vaccine responses in children with BA are largely unknown.

Methods

In this study, 288 children (median age: 7 months) diagnosed with BA before liver transplantation were enrolled for the evaluation of vaccination status and the factors affecting the immune response to the hepatitis B (HBV) vaccine. Moreover, 49 BA children (median age: 4 months) were enrolled for flow cytometric analysis of CD4⁺ T cells and CD19⁺ B cell subsets and correlations with serum bile acid levels.

Results

Generally, these children had very low routine vaccination rates for the meningococcal serogroup AC (Men AC) (41.2%), measles-mumps-rubella (MMR) (31.3%), poliomyelitis (Polio) (25.3%), hepatitis A (HAV) (25.0%), Japanese encephalitis (JE) (15.0%), diphtheria-tetanus-pertussis (DTP) (14.2%), meningococcal serogroup A (Men A) (13.5%) and varicella (VAR) (10.8%) vaccines, but not for the HBV (96.2%) and bacillus Calmette-Guérin (BCG) (84.7%) vaccines. Remarkably, 19.8% (57/288) of the patients had HBV infection. Out of 220 patients vaccinated for HBV, 113 (51.4%), 85 (38.6%) and 22 (10%) had one, two or three doses of the HBV vaccine, respectively. Furthermore, logistic regression analysis revealed that the bile acid level was an independent factor associated with poor HBV vaccine response (p = 0.03; OR = 0.394; 95% CI = 0.170-0.969). Immunophenotyping showed that bile acids were only negatively correlated with the CD19⁺CD27⁺IgG⁺ post-class-switched memory B cell ratio (p = 0.01).

Conclusion

This study reveals the overall vaccination rates of routine vaccines in Chinese BA children are very low and the poor HBV vaccine responses are associated with bile acids, possibly via the inhibition of CD19⁺CD27⁺IgG⁺ post-class-switched memory B cell response.

Clinical Trial Registration

http://www.chictr.org.cn, identifier ChiCTR1800019165.

The usefulness of immunohistochemical staining of bile tracts in biliary atresia

Aim of the study

To assess ductular proliferation (DP) and ductal plate malformation (DPM) in biliary atresia (BA) by means of immunohistochemical staining using cytokeratins CK7 and CK19 and neural cell adhesion molecule (NCAM) antibody CD56.

Material and methods

In 10 cases of BA, liver surgical biopsies obtained at the time of hepatoportoenterostomy were stained with H&E, PAS, Gomori and Azan methods. Immunohistochemical technique was used to outline bile ducts, ductular reaction, reactive bile duct/ductules and DPM by CK7, CK19 and NCAM antibody CD56.

Results

We found fibrosis, bile stasis and mild inflammation in all cases. In the routine staining DP was not seen in 3 cases. The immunohistochemical staining by means of CK19 was helpful in the detection of DP, and allowed it to be demonstrated in all cases. The biliary epithelial cell markers for CD56, CK7, CK19 were used for demonstration of bile duct cell but not hepatocyte alterations in the structure of intrahepatic biliary ducts and different stages of maturation. CD56 as a marker of immature bile ducts was expressed on biliary epithelium of bile ducts and bizarre forms of DPM in 6 cases. The positive expression of CD56 corresponded to the co-localization of CK19 of DPM, but not CK7, to the ductular reaction at the limiting plate of portal tracts. CD7, considered as a marker of DP, also stained ductal hepatocytes and multipotential oval cells, and was a marker of DPM in 3 cases.

Conclusions

Use of CK7, CK19 and CD56 is helpful in BA diagnosis and allows differentiation of the stage of developing bile duct cells according to the expression pattern.

Gut Microbiome: A Potential Modifiable Risk Factor in Biliary Atresia

Biliary atresia (BA) is a fibro-obliterative condition of the biliary tree, presenting in infancy. The bilioenteric conduit formed at Kasai portoenterostomy (KPE), achieves restoration of bile flow in approximately 60% of infants. Even if the operation is successful, cirrhosis and its associated complications are, however, common. BA remains the leading cause for liver transplantation (LT) in children. Antibiotic, choleretic, and steroid therapy post-KPE have not convincingly reduced LT rates. Advances in molecular technology have enabled characterisation of the encoded genes of the gut microbiota (gut microbiome). The gut microbiome plays an important role in host metabolism, nutrition, and immune function, with alterations in its diversity and/or composition, known as dysbiosis, being described in disease states, including liver disease. Liver-gut microbiome exploration in adulthood largely focuses on nonalcoholic liver disease, cirrhosis (mainly alcohol- or viral-based aetiology) and cholestatic liver diseases (eg, primary sclerosing cholangitis), with microbial signatures correlating to disease severity. Investigation of the gut microbiota in BA had been limited to culture-based methodology, but molecular studies are emerging, and although in their infancy, highlight a potential pathogenic role for Enterobacteriaceae and Streptococcus, and a potential beneficial role for Bifidobacteria. Bacterial translocation, and the production of gut microbiome-derived metabolites, are key host-microbiome-mechanistic pathways in liver disease pathogenesis. Microbiome-targeted therapeutics for liver disease are in development, with faecal microbiota transplantation showing promise in cirrhosis. Could the gut microbiome be a novel modifiable risk factor in BA, reducing the need for LT?

Value of the International Classification of Diseases code for identifying children with biliary atresia

BACKGROUND

Although identifying cases in large administrative databases may aid future research studies, previous reports demonstrated that the use of the International Classification of Diseases, Tenth Revision (ICD-10) code alone for diagnosis leads to disease misclassification.

PURPOSE

We aimed to assess the value of the ICD-10 diagnostic code for identifying potential children with biliary atresia.

METHODS

Patients aged <18 years assigned the ICD-10 code of biliary atresia (Q44.2) between January 1996 and December 2016 at a quaternary care teaching hospital were identified. We also reviewed patients with other diagnoses of code-defined cirrhosis to identify more potential cases of biliary atresia. A proposed diagnostic algorithm was used to define ICD-10 code accuracy, sensitivity, and specificity.

RESULTS

We reviewed the medical records of 155 patients with ICD-10 code Q44.2 and 69 patients with other codes for biliary cirrhosis (K74.4, K74.5, K74.6). The accuracy for identifying definite/probable/possible biliary atresia cases was 80%, while the sensitivity was 88% (95% confidence interval [CI], 82%-93%). Three independent predictors were associated with algorithm-defined definite/probable/possible cases of biliary atresia: ICD-10 code Q44.2 (odds ratio [OR], 2.90; 95% CI, 1.09-7.71), history of pale stool (OR, 2.78; 95% CI, 1.18-6.60), and a presumed diagnosis of biliary atresia prior to referral to our hospital (OR, 17.49; 95% CI, 7.01-43.64). A significant interaction was noted between ICD-10 code Q44.2 and a history of pale stool (P<0.05). The area under the curve was 0.87 (95% CI, 0.84-0.89).

CONCLUSION

ICD-10 code Q44.2 has an acceptable value for diagnosing biliary atresia. Incorporating clinical data improves the case identification. The use of this proposed diagnostic algorithm to examine data from administrative databases may facilitate appropriate health care allocation and aid future research investigations.

Two-Dimensional Shear Wave Elastography Predicts Liver Fibrosis in Jaundiced Infants with Suspected Biliary Atresia: A Prospective Study

Objective

This study aimed to evaluate the role of preoperative two-dimensional (2D) shear wave elastography (SWE) in assessing the stages of liver fibrosis in patients with suspected biliary atresia (BA) and compared its diagnostic performance with those of serum fibrosis biomarkers.

Materials and Methods

This study was approved by the ethical committee, and written informed parental consent was obtained. Two hundred and sixteen patients were prospectively enrolled between January 2012 and October 2018. The 2D SWE measurements of 69 patients have been previously reported. 2D SWE measurements, serum fibrosis biomarkers, including fibrotic markers and biochemical test results, and liver histology parameters were obtained. 2D SWE values, serum biomarkers including, aspartate aminotransferase to platelet ratio index (APRi), and other serum fibrotic markers were correlated with the stages of liver fibrosis by METAVIR. Receiver operating characteristic (ROC) curves and area under the ROC (AUROC) curve analyses were used.

Results

The correlation coefficient of 2D SWE value in correlation with the stages of liver fibrosis was 0.789 (p < 0.001). The cut-off values of 2D SWE were calculated as 9.1 kPa for F1, 11.6 kPa for F2, 13.0 kPa for F3, and 15.7 kPa for F4. The AUROCs of 2D SWE in the determination of the stages of liver fibrosis ranged from 0.869 to 0.941. The sensitivity and negative predictive value of 2D SWE in the diagnosis of ≥ F3 was 93.4% and 96.0%, respectively. The diagnostic performance of 2D SWE was superior to that of APRi and other serum fibrotic markers in predicting severe fibrosis and cirrhosis (all p < 0.005) and other serum biomarkers. Multivariate analysis showed that the 2D SWE value was the only statistically significant parameter for predicting liver fibrosis.

Conclusion

2D SWE is a more effective non-invasive tool for predicting the stage of liver fibrosis in patients with suspected BA, compared with serum fibrosis biomarkers.

Recent developments in etiology and disease modeling of biliary atresia: a narrative review

Biliary atresia (BA) is a rare but severe fibroinflammatory disease of the extrahepatic and the intrahepatic bile ducts. Without prompt interventions, BA has fatal outcomes and is the most common indicator for pediatric liver transplantation (LTx). While the mainstay of treatment involves surgically correcting the extrahepatic biliary obstruction via Kasai hepato-portoenterostomy (KHPE), activation of a multitude of biological pathways and yet-to-be-determined etiology in BA continue to foster liver inflammation, cirrhosis and need for LTx. However, important caveats still exist in our understandings of the biliary pathophysiology, the rapidity of liver fibrosis and progression to liver failure, largely due to limited knowledge of the triggers of biliary injury and the inability to accurately model human BA. Although inconclusive, a large body of existing literature points to a potential viral infection in the early peri- or postnatal period as triggers of epithelial injury that perpetuates the downstream biliary disease. Further confounding this issue, are the lack of in-vivo and in-vitro models to efficiently recapitulate the cardinal features of BA, primarily liver fibrosis. To overcome these barriers in BA research, new directions in recent years have enabled (I) identification of additional triggers of biliary injury linked mostly to environmental toxins, (II) development of models to investigate liver fibrogenesis, and (III) translational research using patient-derived organoids. Here, we discuss recent advances that undoubtedly will stimulate future efforts investigating these new and exciting avenues towards mechanistic and drug discovery efforts and disease-preventive measures. The implications of these emerging scientific investigations and disease modeling in severe fibrosing cholangiopathies like BA are enormous and contribute substantially in our understandings of this rare but deadly disease. These findings are also expected to facilitate expeditious identification of translationally targetable pathways and bring us one step closer in treating an infant with BA, a population highly vulnerable to life-long liver related complications.

Case report: progressive familial intrahepatic cholestasis type 3 with compound heterozygous ABCB4 variants diagnosed 15 years after liver transplantation

BACKGROUND

Progressive familial intrahepatic cholestasis (PFIC) type 3 is an autosomal recessive disorder arising from mutations in the ATP-binding cassette subfamily B member 4 (ABCB4) gene. This gene encodes multidrug resistance protein-3 (MDR3) that acts as a hepatocanalicular floppase that transports phosphatidylcholine from the inner to the outer canalicular membrane. In the absence of phosphatidylcholine, the detergent activity of bile salts is amplified and this leads to cholangiopathy, bile duct loss and biliary cirrhosis. Patients usually present in infancy or childhood and often progress to end-stage liver disease before adulthood.

CASE PRESENTATION

We report a 32-year-old female who required cadaveric liver transplantation at the age of 17 for cryptogenic cirrhosis. When the patient developed chronic ductopenia in the allograft 15 years later, we hypothesized that the patient's original disease was due to a deficiency of a biliary transport protein and the ductopenia could be explained by an autoimmune response to neoantigen that was not previously encountered by the immune system. We therefore performed genetic analyses and immunohistochemistry of the native liver, which led to a diagnosis of PFIC3. However, there was no evidence of humoral immune response to the MDR3 and therefore, we assumed that the ductopenia observed in the allograft was likely due to chronic rejection rather than autoimmune disease in the allograft.

CONCLUSIONS

Teenage patients referred for liver transplantation with cryptogenic liver disease should undergo work up for PFIC3. An accurate diagnosis of PFIC 3 is key for optimal management, therapeutic intervention, and avoidance of complications before the onset of end-stage liver disease.

Nasobiliary drainage prior to surgical biliary diversion in progressive familial intrahepatic cholestasis type II

Progressive familial intrahepatic cholestasis (PFIC) can cause intense pruritus that is refractory to medical therapy. Surgical biliary diversion techniques, including partial internal biliary diversion (PIBD), have been developed over the years to relieve pruritus without requiring liver transplantation. No clinical or genetic features can currently predict postoperative pruritus response. We present three PFIC type 2 (PIFC 2) patients who underwent transient endoscopic nasobiliary drainage (NBD) prior to PIBD surgery. Two patients repeatedly responded to NBD and presented with complete pruritus resolution after subsequent PIBD. NBD failed technically in the third patient, and PIBD was partially successful. Mild post-endoscopic biological pancreatitis occurred in 2/6 NBD procedures and resolved spontaneously. The only adverse effect observed within 7 years post-PIBD was very mild transient osmotic diarrhea.Conclusion: Our limited data suggest that NBD is a safe and effective way to predict pruritus response before performing permanent biliary diversion surgery in PFIC patients. What is Known: • Surgical biliary diversion techniques have been developed to relieve intractable pruritus in progressive familial intrahepatic cholestasis (PFIC). • No clinical or genetic features can currently predict pruritus response to surgery. What is New: • Our data suggest that nasobiliary drainage could be a safe and effective tool to predict pruritus response to biliary diversion and avoid unnecessary surgery in PFIC patients.

Comparison of the outcomes of biliary atresia with cystic degeneration and isolated biliary atresia: A matched-pair analysis

BACKGROUND

Patients with biliary atresia (BA) with extrahepatic cystic degeneration (BACD) have a unique pathophysiology; however, clinical outcomes and progression of perinatal degeneration are not well-defined. We aimed to investigate the differences in clinical characteristics and outcomes between BACD and isolated BA (IBA).

METHODS

We performed a retrospective analysis of patients with BA who underwent Kasai portoenterostomy (KPE) from August 1997 to January 2018 and compared the clinical features and outcomes between BACD (n = 21) and IBA (n = 237). Matched-pair analysis for age and sex was performed between BACD and IBA groups to reduce confounding.

RESULTS

Before matched-pair analysis, we found that BACD patients were younger at KPE (45 vs. 64 days, p = 0.008), showed lower total bilirubin at the 3-month follow-up (0.5 vs. 1.4 mg/dL, p = 0.002), and higher 5-year native liver survival rate (95.2% vs. 61.4%, p = 0.006) than IBA patients. After matching, the BACD group showed significantly lower total bilirubin levels at the 3-month follow-up (0.5 vs. 1.5 mg/dL, p = 0.036) and higher 5-year native liver survival rate (95.2% vs. 57.5%, p = 0.006) than the IBA group.

CONCLUSION

BACD demonstrated higher bilirubin clearance and native liver survival rates than IBA.

LEVELS OF EVIDENCE

Treatment Study, Level III.