Biopsy Validated Study of Biomarkers for Liver Fibrosis and Transplant Prediction in Inherited Cholestasis

Alagille syndrome (ALGS) and progressive familial intrahepatic cholestasis (PFIC) are inherited cholestatic disorders with risk of developing end‐stage liver disease requiring liver transplantation (LT). We investigated aspartate aminotransferase‐to‐platelet ratio index (APRI), Fibrosis‐4 score (FIB‐4), and conjugated bilirubin as biomarkers to assess fibrosis severity and risk for LT among children with ALGS and PFIC. This multicenter, cross‐sectional study included 64 children with ALGS or PFIC (per genetics or strict clinical criteria) with APRI, FIB‐4, and conjugated bilirubin levels collected within ±90 days of their most recent liver biopsy. A single, blinded pathologist staged all biopsies (metavir; F0‐F2: nonsevere, F3‐F4: severe). Logistic regression and area under the receiver operating characteristic curve analysis (AUC) were used to assess biomarker associations with fibrosis severity and risk for LT. In ALGS, only APRI distinguished F3‐F4 (AUC 0.72, P = 0.012), with a cutoff greater than 2.97 demonstrating a sensitivity of 61.5% (95% confidence interval 0.32, 0.86) and specificity of 81.5% (0.62, 0.94). In ALGS, a 50% increase of APRI increased the odds of F3‐F4 by 1.31‐fold (1.04, 1.65; P = 0.023). In ALGS, APRI (AUC 0.87; P < 0.001) and FIB‐4 (AUC 0.84; P < 0.001) were able to predict risk for LT. In PFIC, only APRI distinguished F3‐4 (AUC 0.74, P = 0.039), with a cutoff greater than 0.99 demonstrating a sensitivity of 80% (0.44, 0.98) and specificity of 64.3% (0.35, 0.87). In PFIC, only FIB‐4 was able predict risk for LT (AUC 0.80; P = 0.002). In ALGS or PFIC, conjugated bilirubin could not distinguish F3‐F4 or predict risk for LT. Conclusion: This liver biopsy–validated study suggests that APRI is able to distinguish F3‐F4 from F0‐F2 in ALGS and PFIC. APRI and FIB‐4 may also serve as predictors of risk for LT in ALGS (APRI and FIB‐4) and PFIC (FIB‐4).