Evaluation of histological staging systems for primary biliary cirrhosis: correlation with clinical and biochemical factors and significance of pathological parameters in prognostication

Aims: A new Japanese histological staging system for primary biliary cirrhosis (PBC) has been proposed. We aimed to evaluate the efficacies of the Scheuer, Ludwig and Japanese staging systems, with emphasis on their clinical and biochemical correlations and prognostic significances. Methods and results: We conducted a retrospective review of a cohort of 58 Chinese PBC patients, with follow-up of up to 16.9 years. All three systems correlated well with prognostically significant parameters, namely serum bilirubin, Mayo scores and model for end-stage liver disease (MELD) score. Only the Japanese staging system was associated with Child-Pugh score, which was the single independent prognostic factor for liver-related events (log-rank P < 0.001; Cox proportional hazard ratio (HR) 6.723, P < 0.001). The Japanese system (log-rank P = 0.007; Cox proportional HR 10.400, P = 0.025) predicted liver-related events, while Scheuer (log-rank P = 0.112) and Ludwig (log-rank P = 0.147) systems did not. The copper-associated protein (CAP) deposition score, a component of the Japanese system, was the most powerful histological prognostic parameter (log-rank P < 0.001; Cox proportional HR 99.534, P = 0.049) and provided extra prognostic values in additional to serum albumin, serum bilirubin, Child-Pugh score, Mayo scores and MELD score. Conclusion: The Japanese staging system is more effective than classical systems. The degree of CAP deposition is an essential prognostic histological parameter.