IgM response is a prognostic biomarker of primary biliary cholangitis treated with ursodeoxycholic acid and bezafibrate

Abstract

Background and aim: Primary biliary cholangitis (PBC) patients who are refractory to ursodeoxycholic acid (UDCA) are at risk for progression to cirrhosis and liver failure. Bezafibrate could be an alternative second-line therapeutic option in these patients. This study aimed to evaluate the long-term outcome(s) of combined UDCA and bezafibrate therapy in UDCA-refractory PBC patients and identify prognostic factors.

Methods: Among 445 patients treated with UDCA, 150 patients inadequately responded to UDCA monotherapy and received long-term UDCA plus bezafibrate (median, 15 years). Data from these patients were used for this retrospective analysis.

Results: Combination therapy resulted in significant improvements in serum biochemistry and liver transplantation risk estimated using the UK-PBC-risk and the GLOBE scores. The cumulative normalization rates of alkaline phosphatase, gamma-glutamyltransferase, and immunoglobulin M (IgM) were significantly higher in patients without cirrhosis-related symptoms or liver-related events than in those with them. Overall, IgM constantly emerged as a significant factor associated with cirrhosis-related symptoms and liver-related events at all time points. Cumulative survival rates were significantly lower in patients with IgM ≥ 240 mg/dL than in patients with IgM < 240 mg/dL. Thus, normalization of IgM levels was a good surrogate predictor of long-term prognosis. None of the patients discontinued combination therapy due to any adverse events during the follow-up period.

Conclusions: Our findings point to the beneficial effects of long-term UDCA plus bezafibrate combination therapy for UDCA-refractory PBC patients, and IgM response can be a useful predictive biomarker of long-term clinical outcomes.

Keywords: IgM; bezafibrate; primary biliary cholangitis; refractory; ursodeoxycholic acid.