Serum aspartate aminotransferase to platelet ratio index in relation to liver histopathology of biliary atresia.

OBJECTIVES

To investigate the prognostic significance of aspartate aminotransferase to platelet ratio index (APRI) in relation to histopathological features across the clinical course of biliary atresia (BA).

METHODS

In this observational cohort study, we enrolled 135 BA patients with available APRI values at Kasai portoenterostomy (KPE, n = 116) or at post-KPE follow-up (n = 70; serum samples, n = 139; liver biopsies, n = 139). APRI was matched to manual scorings of liver histology, ductular reaction (DR) analysed using neural network model and fibrosis quantified from Sirius Red-stained sections.

RESULTS

APRI was elevated at both KPE and post-KPE follow-up (0.92 vs. 1.2, p = 0.5), and associated with biochemical markers of cholestasis, and decreased liver function. At KPE, APRI was higher in patients failing to resolve cholestasis postoperatively (0.80 vs. 0.96, p = 0.02) and both at KPE (0.77 vs. 0.94, p = 0.06) and post-KPE (0.7 vs. 2.1, p < 0.001) in those with subsequent need for liver transplant (LT). Across the disease course, APRI moderately predicted LT need (at KPE, HR = 1.4, p = 0.01; post-KPE, HR = 1.2, p < 0.001). APRI correlated with DR (at KPE, R = 0.37, p < 0.001; post-KPE, R = 0.35, p < 0.001), composed of biliary epithelium (R = 0.34, p < 0.001; R = 0.25, p < 0.01) and parenchymal intermediate hepatocytes (R = 0.33, p < 0.001; R = 0.43, p < 0.001) during the entire clinical course. APRI showed no correlation with quantified liver fibrosis at KPE (R = 0.16, p = 0.13), but correlated with quantified fibrosis (R = 0.22, p = 0.02) and Metavir staging (R = 0.46, p < 0.001) after KPE. No association was observed with portal inflammatory cell infiltration or histological cholestasis.

CONCLUSIONS

APRI reflects biliary and portal injury rather than generalised liver fibrosis and associates with poor prognosis in BA.