Protein biomarkers GDF15 and FGF21 to differentiate mitochondrial hepatopathies from other pediatric liver diseases.

BACKGROUND: Mitochondrial hepatopathies (MHs) are primary mitochondrial genetic disorders that can present as childhood liver disease. No recognized biomarkers discriminate MH from other childhood liver diseases. The protein biomarkers growth differentiation factor 15 (GDF15) and fibroblast growth factor 21 (FGF21) differentiate mitochondrial myopathies from other myopathies. We evaluated these biomarkers to determine if they discriminate MH from other liver diseases in children. METHODS: Serum biomarkers were measured in 36 children with MH (17 had a genetic diagnosis); 38 each with biliary atresia, α1-antitrypsin deficiency, and Alagille syndrome; 20 with NASH; and 186 controls. RESULTS: GDF15 levels compared to controls were mildly elevated in patients with α1-antitrypsin deficiency, Alagille syndrome, and biliary atresia-young subgroup, but markedly elevated in MH (p<0.001). FGF21 levels were mildly elevated in NASH and markedly elevated in MH (p<0.001). Both biomarkers were higher in patients with MH with a known genetic cause but were similar in acute and chronic presentations. Both markers had a strong performance to identify MH with a molecular diagnosis with the AUC for GDF15 0.93±0.04 and for FGF21 0.90±0.06. Simultaneous elevation of both markers >98th percentile of controls identified genetically confirmed MH with a sensitivity of 88% and specificity of 96%. In MH, independent predictors of survival without requiring liver transplantation were international normalized ratio and either GDF15 or FGF21 levels, with levels <2000 ng/L predicting survival without liver transplantation (p<0.01). CONCLUSIONS: GDF15 and FGF21 are significantly higher in children with MH compared to other childhood liver diseases and controls and, when combined, were predictive of MH and had prognostic implications.

Characteristics of infections and their risk factors in children with biliary atresia.

BACKGROUND: Children with biliary atresia (BA) may experience various infections (e.g., cholangitis, bacteremia, and viral respiratory infections (VRI)) throughout their disease course. This study aimed to identify and describe these infections and their risk factors for development in children with BA. METHODS: This retrospective observational study identified infections in children with BA using predefined criteria, including VRI, bacteremia with and without central line (CL), bacterial peritonitis, positive stool pathogens, urinary tract infections, and cholangitis. Infections were identified until liver transplant, death or last follow-up with native liver. Infection-free survival was estimated by Kaplan-Meier analysis. Logistic regression was used to estimate odds of infection per clinical characteristics. Cluster analysis was performed to identify patterns of infection development. RESULTS: 48 of 65 (73.8%) children had ≥1 infection during their disease course (mean length of follow up: 40.2 months). Cholangitis (n = 30) and VRI (n = 21) were most common. Nearly half (45%) of all infections developed within 3-months of Kasai hepatoportoenterostomy. Kasai performed ≥45 days of life was associated with 3.5-fold increased risk of any infection (95% CI 1.2-11.4). Risk of VRI was inversely related to platelet count at 1-month post-Kasai (OR 0.5, 0.19-0.99). Cluster analysis of infectious patterns identified three unique cohorts of patients based on their infection history: no/few infections (n = 18), mostly cholangitis (n = 20) or mixed infections (n = 27). CONCLUSION: Variability of infection risk exists amongst children with BA. Age at Kasai and platelet count are risk factors for future infections, suggesting that patients with more severe disease are at greater risk. Cirrhosis associated immune deficiency may exist in chronic pediatric liver disease and should be the subject of future investigations in order to optimize outcomes.

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

OBJECTIVE: To identify key epidemiologic factors relevant to fetal development that are associated with biliary atresia. STUDY DESIGN: This population-based registry study examined infants born in Texas between 1999 and 2014. Epidemiologic data relevant to fetal development were compared between cases of biliary atresia identified in the Texas Birth Defects Registry (n = 305) vs all live births (n = 4 689 920), and Poisson regression was used to calculate prevalence ratios (PRs) and 95% CIs. RESULTS: The prevalence of biliary atresia over the study period was 0.65 per 10 000 live births. Biliary atresia was positively associated with female sex (adjusted PR, 1.68; 95% CI, 1.33-2.12), delivery before 32-37 weeks of gestation (adjusted PR, 1.64; 95% CI, 1.18-2.29), delivery before 32 weeks of gestation (adjusted PR, 3.85; 95% CI, 2.38-6.22), and non-Hispanic Black vs non-Hispanic White maternal race/ethnicity (adjusted PR, 1.54, 95% CI, 1.06-2.24), while biliary atresia was inversely associated with season of conception in the fall relative to spring (adjusted PR, 0.62; 95% CI, 0.45-0.86). In addition, biliary atresia was associated with maternal diabetes (adjusted PR, 2.34; 95% CI, 1.57-3.48), with a stronger association with pregestational diabetes compared with gestational diabetes. In subgroup analyses, these associations were present in isolated biliary atresia cases that do not have any additional birth defects. CONCLUSIONS: Biliary atresia is associated with multiple factors related to fetal development, including pregestational maternal diabetes, female sex, and preterm birth. These associations also were observed in isolated cases of biliary atresia without other malformations or laterality defects. Our results are consistent with early life events influencing the pathogenesis of biliary atresia, and support further studies investigating in utero events to better understand etiology and time of onset.

Operational Definitions for Chronic Liver Disease Manifestations and Recurring Clinical Events in Biliary Atresia.

BACKGROUND: The disease course of biliary atresia (BA) may be complicated by development of chronic liver disease (CLD) manifestations (eg, ascites) and recurring clinical events (eg, cholangitis). Most pediatric CLD-manifestations/events lack standardized operational definitions, leading to inconsistent identification in clinical research. This study aimed to develop operational research definitions of CLD-manifestations/events in BA for application in retrospective analysis. METHODS: Operational definitions of CLD-manifestations/events were developed by literature review and revised by a panel of experienced pediatric hepatologists. Definitions were applied to a single-center review of infants with BA post-Kasai. Manifestations/events were captured until last clinical visit with native liver (SNL), liver transplantation (LT), or death. Native liver survival and event-free survival were estimated by Kaplan-Meier method. Cluster analysis was performed to identify similar patterns of manifestation/event development. RESULTS: Of 65 infants with BA post-Kasai (2006-18; median Kasai 56.8 days; 65% girls), 29 underwent LT (median 12.9 months) and 4 died without LT (median 6.9 months). Seventy-six percent of CLD-manifestations/events presented within the first year. Presence of definite clinically evident portal hypertension, thrombocytopenia, and dCE ascites were associated with poor transplant-free survival (P < 0.01). Similar pattern developments of CLD-manifestations/events identified 3 outcome groups: poor outcomes (87.8% LT/death), SNL with manifestations/events, and SNL with few/no events. CONCLUSIONS: Operational definitions can provide a timely description of the disease course progression in infants with BA. Research definitions may provide better consistency in future pediatric CLD studies. Furthermore, definitions may serve as endpoints in therapeutic trials or used as variables for disease pattern identification in potential multicenter studies.

Nonfasted Liver Stiffness Correlates with Liver Disease Parameters and Portal Hypertension in Pediatric Cholestatic Liver Disease.

Elastographic measurement of liver stiffness is of growing importance in the assessment of liver disease. Pediatric experiences with this technique are primarily single center and limited in scope. The Childhood Liver Disease Research Network provided a unique opportunity to assess elastography in a well-characterized multi-institutional cohort. Children with biliary atresia (BA), alpha-1 antitrypsin deficiency (A1ATD), or Alagille syndrome (ALGS) followed in a prospective longitudinal network study were eligible for enrollment in a prospective investigation of transient elastography (FibroScan). Studies were performed in participants who were nonfasted and nonsedated. Liver stiffness measurements (LSMs) were correlated with standard clinical and biochemical parameters of liver disease along with a research definition of clinically evident portal hypertension (CEPH) graded as absent, possible, or definite. Between November 2016 and August 2019, 550 participants with a mean age of 8.8 years were enrolled, 458 of whom had valid LSMs (BA, n = 254; A1ATD, n = 104; ALGS, n = 100). Invalid scans were more common in participants <2 years old. There was a positive correlation between LSM and total bilirubin, international normalized ratio (INR), aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transpeptidase (GGT), GGT to platelet ratio (GPR), pediatric end-stage liver disease score, AST to platelet ratio index, and spleen size, and a negative correlation with albumin and platelet count in BA, with similar correlations for A1ATD (except AST, ALT, and albumin) and ALGS (except for INR, GGT, GPR, and ALT). Possible or definite CEPH was more common in BA compared to ALGS and A1ATD. LSM was greater in definite versus absent CEPH in all three diseases. Disease-specific clinical and biochemical characteristics of the different CEPH grades were observed. Conclusion: It is feasible to obtain LSMs in children, especially over the age of 2 years. LSM correlates with liver parameters and portal hypertension, although disease-specific patterns exist.

The Fecal Microbiome in Infants With Biliary Atresia Associates With Bile Flow After Kasai Portoenterostomy.

BACKGROUND: Biliary atresia's (BA) response to surgical Kasai portoenterostomy (KP) is uneven and dependent upon bile flow; 50% of infants require a liver transplant by 24 months. We hypothesized that the microbiome may identify and associate with outcomes in BA. METHODS: Stool samples were collected from infants with cholestasis (n = 15), 8 of which with BA were followed longitudinally.16S sequencing was performed on all samples (n = 45). Whole Genome Sequencing (WGS) was performed on BA pre-KP samples (n = 8). Infants with BA, other forms of cholestasis, BA infants with very good bile flow (VGBF) and not (nVGBF) (VGBF dichotomized by TSBA <40 µmol/L by 6 months) were compared. RESULTS: Of the 8 infants with BA, 4 infants had VGBF. Microbial richness was inversely proportional to degree of cholestasis (P = 0.046). Increased Bifidobacterium abundance associated with VGBF (P = 0.03) and decreased cholestasis (P < 0.01) at 1 month post-KP. Pre-KP, community structure differed in infants with BA versus other cholestasis. Interestingly, infants who subsequently achieved VGBF had increased diversity (P = 0.03) and different community structure at the pre-KP time point. WGS corroborated Bifidobacterium's pre-KP importance. CONCLUSIONS: The microbiome differs between infants with BA and other cholestasis. It additionally differs between infants with BA who have good and poor bile flow, and thus outcomes, post-KP. These differences are seen even before KP. These data suggest that bile influences the development of the infant microbiome and that there may be possible influences of the pre- and post-KP microbiome on bile flow after KP. Further larger studies are needed to confirm these findings.

Neurodevelopmental Outcomes in Preschool and School Aged Children With Biliary Atresia and Their Native Liver.

OBJECTIVES: The aim of the study was to assess neurodevelopmental outcomes among children with biliary atresia (BA) surviving with their native liver at ages 3 to 12 years and evaluate variables that associate with neurodevelopment. METHODS: Participants (ages 3-12 years) in a prospective, longitudinal, multicenter study underwent neurodevelopmental testing with Weschler Preschool and Primary Scale of Intelligence, 3rd edition (WPPSI-III, ages 3-5 years) and Weschler Intelligence Scale for Children, 4th edition (WISC-IV, ages 6-12 years). Continuous scores were analyzed using Kolmogorov-Smironov tests compared with a normal distribution (mean = 100 ±â€Š15). Effect of covariates on Full-Scale Intelligence Quotient (FSIQ) was analyzed using linear regression. RESULTS: Ninety-three participants completed 164 WPPSI-III (mean age 3.9) and 51 WISC-IV (mean age 6.9) tests. WPPSI-III FSIQ (104 ±â€Š14, P < 0.02), Verbal IQ (106 ±â€Š14, P < 0.001), and General Language Composite (107 ±â€Š16, P < 0.001) distributions were shifted higher compared with test norms. WISC-IV FSIQ (105 ±â€Š12, P < 0.01), Perceptual Reasoning Index (107 ±â€Š12, P < 0.01), and Processing Speed Index (105 ±â€Š10, P < 0.02) also shifted upwards. In univariate and multivariable analysis, parent education (P < 0.01) was a significant predictor of FSIQ on WPPSI-III and positively associated with WISC-IV FSIQ. Male sex and higher total bilirubin and gamma glutamyl transferase (GGT) predicted lower WPPSI-III FSIQ. Portal hypertension was predictive of lower WISC-IV FSIQ. CONCLUSIONS: This cohort of children with BA and native liver did not demonstrate higher prevalence of neurodevelopmental delays. Markers of advanced liver disease (higher total bilirubin and GGT for age ≤5 years; portal hypertension for age ≥6) correlate with lower FSIQ and may identify a vulnerable subset of patients who would benefit from intervention.