Predictive scores in primary biliary cirrhosis: a retrospective single center analysis of 204 patients

The aim of this study was to assess the long-term outcome of primary biliary cirrhosis (PBC) patients and to test the clinical value of various outcome models, such as the Mayo Risk Score (MRS), in a large single-center cohort in Germany.

PBC is a chronic autoimmune liver disease with a female gender predominance and a peak incidence in the fifth decade of life. PBC is characterized by portal inflammation and immune-mediated destruction of intrahepatic bile ducts in liver histology and the presence of antimitochondrial antibodies in the serum of nearly 95% of patients. In 5% to 20% of patients an overlap syndrome with autoimmune hepatitis (AIH) is diagnosed. Ursodeoxycholic acid is widely accepted as the standard medical treatment.

A total of 204 patients with PBC or PBC/AIH were retrospectively analyzed with regard to their clinical, biochemical, serological, and histologic features. PBC was diagnosed on the basis of the American Association for the Study of Liver Diseases criteria. Specific PBC scores, such as the MRS, the European and the Yale model, as well as nonspecific scores such as the Child-Pugh, the Model for End-stage Liver Disease, and Aspartate Aminotransferase to Platelet Ratio Index score were analyzed for their utility to predict the clinical outcome of patients.

One hundred eighty-four patients with PBC alone and 20 with primary biliary cirrhosis/autoimmune hepatitis overlap were followed up for an average of 7.0 (range, 0.5 to 33.2) years. Importantly, baseline values of serum bilirubin, alkaline phosphatase, immunoglobulin M (IgM) and IgG, as well as antimitochondrial antibodies titers did not allow in properly predicting patient's outcome. The MRS proved clinical applicability. Patients with an R-value <6 did not develop liver-related complications. The Aspartate Aminotransferase to Platelet Ratio Index score had a significant correlation with the histologic degree of liver fibrosis, with limited value of scores between 1.0 and 1.5. Patients with a Model for End-stage Liver Disease score ≥8 (n=17) had a significantly higher risk to undergo liver transplantation or liver-related death. Outcome was less favorable than predicted by the European model. All scores showed low positive predictive values, limiting their applicability in clinical practice.

Herein, we demonstrate that clinical risk scores in PBC should be interpreted with care. The MRS proved to be helpful to predict a favorable outcome. Novel approaches to predict outcome are needed to identify patients who may benefit from alternative, intensified treatment regimens.