Elevated Serum Bile Acids Predict Poor Liver Outcomes in Children With Alagille Syndrome: Results From the GALA Study Group

Background and Aim: Alagille syndrome (ALGS) is a rare disorder characterised by cholestasis and extrahepatic manifestations. Given the current era of ileal bile acid transporter (IBAT) inhibitor therapies that reduce serum bile acid (SBA) levels, we evaluated whether SBA predicts liver disease outcomes in ALGS. Methods: Patients were ascertained from the Global ALagille Alliance (GALA) cohort. A prognostic threshold of SBA 102 μmol/L was assessed as a time-dependent covariate in Cox regression analyses for native liver survival (NLS) and event-free survival (EFS), while adjusting for total bilirubin (TB) levels. Results: 570 GALA patients were included (348 [61%] male). There was a moderate positive correlation between SBA and TB (Pearson correlation = 0.47, p < 0.001). SBA below 102 μmol/L was a significant predictor of outcomes (NLS: HR = 3.78, 95% CI 2.39–5.99, p < 0.001; EFS: HR = 3.44, 95% CI 2.35–5.04, p < 0.001). SBA remained a significant predictor for improved EFS after adjusting for TB clearance at 1 year (TB < 2 mg/dL; HR = 2.00, 95% CI 1.10–3.65, p = 0.02). Median SBA in the first year of life above 102 μmol/L, predicted lower NLS (67.2% vs. 83.5% at 7 years p = 0.05) and EFS (63.4% vs. 80.9% at 7 years, p = 0.02). Conclusion: Lower SBA in children with ALGS liver disease predicts improved NLS and EFS. SBA is also associated with NLS in children with ALGS who clear their bilirubin, that is, those with anicteric cholestasis. Although the patients studied here did not receive IBAT inhibition, these data suggest that lowering SBA may improve important clinical outcomes.