Biliary Atresia in Children: Update on Disease Mechanism, Therapies, and Patient Outcomes

Gut Bifidobacterium longum is associated with better native liver survival in patients with biliary atresia

Background & Aims

The gut microbiome plays an important role in liver diseases, but its specific impact on biliary atresia (BA) remains to be explored. We aimed to investigate the microbial signature in the early life of patients with BA and to analyze its influence on long-term outcomes.

Methods

Fecal samples (n = 42) were collected from infants with BA before and after Kasai portoenterostomy (KPE). The stool microbiota was analyzed using 16S rRNA next-generation sequencing and compared with that of age-matched healthy controls (HCs). Shotgun metagenomic sequencing analysis was employed to confirm the bacterial composition in 10 fecal samples before KPE. The correlation of the microbiome signature with liver function and long-term outcomes was assessed.

Results

In the 16S rRNA next-generation sequencing analysis of fecal microbiota, the alpha and beta diversity analyses revealed significant differences between HCs and patients with BA before and after KPE. The difference in microbial composition analyzed by linear discriminant analysis and random forest classification revealed that the abundance of Bifidobacterium longum (B. longum) was significantly lower in patients before and after KPE than in HCs. The abundance of B. longum was negatively correlated with the gamma-glutamyltransferase level after KPE (p <0.05). Patients with early detectable B. longum had significantly lower total and direct bilirubin 3 months after KPE (p <0.005) and had a significantly lower liver transplantation rate (hazard ratio: 0.16, 95% CI 0.03-0.83, p = 0.029). Shotgun metagenomic sequencing also revealed that patients with BA and detectable B. longum had reduced total and direct bilirubin after KPE.

Conclusion

The gut microbiome of patients with BA differed from that of HCs, with a notable abundance of B. longum in early infancy correlating with better long-term outcomes.

Impact and implications

Bifidobacterium longum (B. longum) is a beneficial bacterium commonly found in the human gut. It has been studied for its potential impacts on various health conditions. In patients with biliary atresia, we found that a greater abundance of B. longum in the fecal microbiome is associated with improved clinical outcomes. This suggests that early colonization and increasing B. longum levels in the gut could be a therapeutic strategy to improve the prognosis of patients with biliary atresia.

The systemic immune-inflammation index at kasai portoenterostomy: related to clinical outcomes

BACKGROUND

Systemic Immune-Inflammation Index (SII), known as an easy, economical and useful marker, correlates with the balance of inflammation and immune response. However, the usefulness of SII in biliary atresia (BA) remains unclear. Therefore, we evaluated the relationship of SII level and postoperative clinical outcomes of BA.

METHODS

Retrospective review of 168 patients with BA was conducted with assessments of demographic information, histological findings, laboratory parameters, and clinical outcomes. The LASSO logistic regression analysis was established using the "glmnet" software package to explore the influencing factors related to native liver survival time. Numerical variables were dichotomized based on the receiver operating characteristic (ROC) curve and Youden index yielding the best performance of prediction. R software was used for statistical analysis.

RESULTS

Overall, the 24 month native liver survival rate was 43.5% (73 cases) after Kasai portoenterostomy. LASSO logistic regression analysis show that preoperative malnutrition (OR = 0.032, 95%CI 0.001-0.424), gamma-glutamyltransferase (GGT, OR = 0.994, 95%CI 0.987-0.998), lymphocyte count (LY, OR = 2.426, 95%CI 1.467-4.604), SII (OR = 0.977, 95%CI 0.960-0.989), and liver fibrosis grading (LFG, reference: Grade 1, Grade 3, OR = 0.076, 95%CI 0.007-0.614) were the independent influencing factors for 24 month native liver survival. ROC curve analysis showed that the area under the curve of SII level (0.919) was larger than that of preoperative malnutrition (0.690), LFG (0.759), GGT (0.747), and Ly (0.773). A SII < 140.09 was found to be a significant marker in the prediction of 24-month native liver survival, with 90.41% sensitivity and 93.68% specificity. Furthermore, the rates of 24-month native liver survival (33.1% vs. 72.7%), jaundice clearance (46.8% vs. 75.0%), and good liver function recovery (46.8% vs. 65.9%) were lower in the SII ≥ 140.09 group than that in the SII < 140.09 group (all P < 0.05), but there was no difference in the occurrence of cholangitis (P > 0.05).

CONCLUSION

Preoperative malnutrition, GGT, Ly, SII, and LFG were independent influencing factors for postoperative 24-month native liver survival of BA. The SII level, as a routine haematological marker, has better universality and simplicity and is related to clinical outcomes after Kasai portoenterostomy.

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.

Diseases of bile duct in children

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

Biliary atresia in children (analytical literature review and review of own observation)

OBJECTIVE

Aim: to review information resources and analysis of the own experience on this problem for the provision of modern knowledge in the pathogenesis of the pathology, the latest diagnostic and treatment technologies, with consideration of the need to adhere to a single strategy in the management of patients with BA.

PATIENTS AND METHODS

Materials and Methods: The analysis of the data regarding the results of existing studies evaluating the clinical benefit and safety of diagnostic and treatment methods in Biliary atresia.

CONCLUSION

Conclusions: BA is the leading cause of neonatal cholestasis development. Early diagnostics of BA, based on the complex evaluation of clinical-laboratory, instrumental and morphological signs of the pathology, has a significant meaning. Surgical correction during the first 2 months of life - the Kasai procedure, as well as dynamic post-surgery follow-up significantly prolong the life of children and allow postponing liver transplantation. The highest patient survival both at the first stage of treatment - conduction of the Kasai procedure and the stage of liver transplantation may be achieved by joined work of surgeons and pediatricians, which allows considering the whole row of possible problems.

The association of immune-related genes and the potential role of IL10 with biliary atresia

BACKGROUND

Biliary atresia (BA) is a severe immune-related disease that is characterized by biliary obstruction and cholestasis. The etiology of BA is unclear, our aim was to explore the relationship between biliary tract inflammation and immune-related genes.

METHODS

We selected 14 SNPs in 13 immune-related genes and investigated their associations with BA by using a large case‒control cohort with a total of 503 cases and 1473 controls from southern China.

RESULTS

SNP rs1518111 in interleukin10 (IL10) was identified as associated with BA (P = 5.79E-03; OR: 0.80; 95% CI: 0.68-0.94). The epistatic effects of the following pairwise interactions among these SNPs were associated with BA: signal transducer and activator of transcription 4 (STAT4) and chemokine (C-X-C motif) ligand 3 (CXCL3); STAT4 and damage-regulated autophagy modulator1 (DRAM1); CXCL3 and RAD51 paralog B (RAD51B); and interferon gamma (IFNG) and interleukin26 (IL26). Furthermore, we explored the potential role of IL-10 in the pathogenesis of the neonatal mouse model of BA. IL-10 effectively prevented biliary epithelial cell injury and biliary obstruction in murine BA as well as inhibit the activation of BA-related immune cells.

CONCLUSIONS

In conclusion, this study provided strong evidence implicating IL10 as a susceptibility gene for BA in the southern Chinese population.

IMPACT

This study provided strong evidence implicating IL10 as a susceptibility gene for BA in the southern Chinese population. This study could infer that IL-10 may play a protective role in BA mouse model. We found that four SNPs (rs7574865, rs352038, rs4622329, and rs4902562) have genetic interactions.

Biliary atresia and liver transplantation in the United States: A contemporary analysis

BACKGROUND

Biliary atresia (BA) remains the number one indication for paediatric liver transplantation (LT) worldwide but is an uncommon indication for older LT recipients. The impact of recent donor allocation changes, pervasive organ shortage and evolving LT practices on the BA LT population is unknown.

METHODS

We identified patients who underwent LT between January 2010 and December 2021 using the UNOS database. We compared clinical outcomes between patients with BA and those with non-BA cholestatic liver disease. Groups were stratified by age, <12 years (allocated via PELD system) and ≥12 years (allocated via MELD system). Waitlist outcomes were compared using competing-risk regression analysis, graft survival rates were compared using Kaplan-Meier time-to-event analysis and Cox proportional hazards modelling provided adjusted estimates.

RESULTS

There were 2754 BA LT waitlist additions and 2206 BA LTs (1937 <12 years [younger], 269 ≥12 years [older]). There were no differences in waitlist mortality between BA and non-BA cholestatic patients. Among BA LT recipients, there were 441 (20.0%) living-donor liver transplantations (LDLT) and 611 (27.7%) split deceased-donor LTs. Five-year graft survival was significantly higher among BA versus non-BA cholestatic patients in the older group (88.3% vs. 79.5%, p < .01) but not younger group (89.3% vs. 89.5%). Among BA LT recipients, improved graft outcomes were associated with LDLT (vs. split LT: HR: 2, 95% CI: 1.03-3.91) and higher transplant volume (volume >100 vs. <40 BA LTs: HR: 3.41, 95% CI: 1.87-6.2).

CONCLUSION

Liver transplant outcomes among BA patients are excellent, with LDLT and higher transplant centre volume associated with optimal graft outcomes.

Single-cell sequencing of a novel model of neonatal bile duct ligation in mice identifies macrophage heterogeneity in obstructive cholestasis

Macrophages (MΦ) play a role in neonatal etiologies of obstructive cholestasis, however, the role for precise MΦ subsets remains poorly defined. We developed a neonatal murine model of bile duct ligation (BDL) to characterize etiology-specific differences in neonatal cholestatic MΦ polarization. Neonatal BDL surgery was performed on female BALB/c mice at 10 days of life (DOL) with sham laparotomy as controls. Comparison was made to the Rhesus Rotavirus (RRV)-induced murine model of biliary atresia (BA). Evaluation of changes at day 7 after surgery (BDL and sham groups) and murine BA (DOL14) included laboratory data, histology (H&E, anti-CD45 and anti-CK19 staining), flow cytometry of MΦ subsets by MHCII and Ly6c expression, and single cell RNA-sequencing (scRNA-seq) analysis. Neonatal BDL achieved a 90% survival rate; mice had elevated bile acids, bilirubin, and alanine aminotransferase (ALT) versus controls (p < 0.05 for all). Histology demonstrated hepatocellular injury, CD45+ portal infiltrate, and CK19+ bile duct proliferation in neonatal BDL. Comparison to murine BA showed increased ALT in neonatal BDL despite no difference in histology Ishak score. Neonatal BDL had significantly lower MHCII-Ly6c+ MΦ versus murine BA, however, scRNA-seq identified greater etiology-specific MΦ heterogeneity with increased endocytosis in neonatal BDL MΦ versus cellular killing in murine BA MΦ. We generated an innovative murine model of neonatal obstructive cholestasis with low mortality. This model enabled comparison to murine BA to define etiology-specific cholestatic MΦ function. Further comparisons to human data may enable development of immune modulatory therapies to improve patient outcomes.

Development of liver inflammatory injury in biliary atresia: from basic to clinical research

Biliary atresia (BA) is a severe cholangiopathy in infants. It is characterized by inflammatory fibro-obliteration of the intra- and extrahepatic bile ducts. Although the restoration of bile flow can be successful after Kasai operation, the rapid progression of liver fibrosis can continue, leading to cirrhosis. It is believed that the progression of liver fibrosis in BA is exacerbated by complicated mechanisms other than the consequence of bile duct obstruction. The fibrogenic cascade in BA liver can be divided into three stages, including liver inflammatory injury, myofibroblast activation, and fibrous scar formation. Recent studies have revealed that the activation of an immune response following bile duct injury plays an important role in promoting the inflammatory process, the releasing of inflammatory cytokines, and the development of fibrogenesis in BA liver. In this article, we summarized the evidence regarding liver inflammatory injury and the possible mechanisms that explain the rapid progression of liver fibrosis in BA.

Overdiagnosis of adrenal insufficiency in children with biliary atresia

Serum cortisol mainly binds to the cortisol-binding globulin (CBG). Children with biliary atresia (BA) may have low serum CBG levels; thus, low serum total cortisol (TC) levels and adrenal insufficiency (AI) may be overdiagnosed. This study aimed to assess adrenal function in children with BA. All the patients underwent adrenocorticotropic hormone (ACTH) stimulation tests. Plasma ACTH, serum TC, and CBG levels were measured at baseline, with additional TC measurements at 30 and 60 min during testing. Free cortisol (FC) index (FCI) and calculated FC (cFC) were also calculated. AI was defined as peak TC <500 nmol/L (<18 μg/dL), peak FCI <12 nmol/mg, or peak cFC <33 nmol/L (<1.2 μg/dL). This study enrolled 71 children with BA. The Median (IQR) age of the patients was 5.5 (1.7-11.4) years. Twenty-five (35%) patients were diagnosed with AI based on the peak TC. In the AI group, the median serum CBG level was significantly lower than that in the non-AI group (481 vs. 533 nmol/L, p = 0.03). Only eight patients (11%) met all three AI criteria (six secondary AI and two primary AI). In conclusion, low serum CBG levels contribute to reduced peak TC and, consequently, overdiagnosing AI. Peak FCI and cFC could help reduce the overdiagnosis of AI.

Native liver survivors of portoenterostomy for biliary atresia with excellent outcome: redefining "successful" portoenterostomy

PURPOSE

Native liver survivors (NLS) after portoenterostomy (PE) for biliary atresia (BA) with normal biomarkers defined as total bilirubin (T-Bil), aspartate aminotransferase (AST)/alanine aminotransferase (ALT) for liver function (LF), cholinesterase (ChE), platelet count (PC), and absence of portal hypertension (PHT) were reviewed to redefine "successful" PE.

METHODS

92 post-PE BA patients were classified as NLS-1: normal biomarkers, PHT (-); NLS-2: at least one abnormal biomarker, PHT (-); NLS-3: normal biomarkers, PHT ( +); NLS-4: abnormal biomarkers, PHT ( +) and reviewed for a maximum 32 years.

RESULTS

As of June 2022, 55/92 (59.8%) had received liver transplants and 37/92 (40.2%) were NLS. NLS patients were classified as excellent outcome (EO): NLS-1 (n = 10; 27.0%) or non-EO: NLS-2: (n = 8; 21.6%), NLS-3: (n = 6; 16.2%), and NLS-4: (n = 13; 35.1%). Compared with non-EO, EO had PE earlier (50.5 versus 65 days; not significant; p = 0.08), significantly earlier onset of symptoms (13 days versus 32 days; p = 0.01) and significantly shorter jaundice-clearance (JC; 34.5 days versus 56.0 days; p < 0.001). Durations of follow-up were similar: 13 years in EO, 18.5 years in NLS-2, 20 years in NLS-3, and 15 years in NLS-4.

CONCLUSION

Incidence of "successful" PE or EO is low and correlated with early onset of symptoms and quicker JC.