Long-term native liver fibrosis in biliary atresia: Development of a novel scoring system using histology and standard liver tests

Background & Aims Although liver fibrosis is an important predictor of outcomes for biliary atresia (BA), postsurgical native liver histology has not been well reported. Here, we retrospectively evaluated postsurgical native liver histology, and developed and assessed a novel scoring system - the BA liver fibrosis (BALF) score for non-invasively predicting liver fibrosis grades. Methods We identified 259 native liver specimens from 91 BA patients. Of these, 180 specimens, obtained from 62 patients aged ≥1 year at examination, were used to develop the BALF scoring system. The BALF score equation was determined according to the prediction of histological fibrosis grades by multivariate ordered logistic regression analysis. The diagnostic powers of the BALF score and several non-invasive markers were assessed by area under the receiver operating characteristic curve (AUROC) analyses. Results Natural logarithms of the serum total bilirubin, γ-glutamyltransferase, and albumin levels, and age were selected as significantly independent variables for the BALF score equation. The BALF score had a good diagnostic power (AUROCs = 0.86-0.94, p <0.001) and good diagnostic accuracy (79.4-93.3%) for each fibrosis grade. The BALF score revealed a strong correlation with fibrosis grade (r = 0.77, p <0.001), and was the preferable non-invasive marker for diagnosing fibrosis grades ≥F2. In a serial liver histology subgroup analysis, 7/15 patients exhibited liver fibrosis improvement with BALF scores being equivalent to histological fibrosis grades of F0-1. Conclusions In postsurgical BA patients aged ≥1 year, the BALF score is a potential non-invasive marker of native liver fibrosis.