Rate of non-response to ursodeoxycholic acid in a large real-world cohort of primary biliary cholangitis patients in Italy.

Background and aim: Response to ursodeoxycholic acid (UDCA) is crucial for the prediction of primary biliary cholangitis (PBC) prognosis, and different response criteria were validated and proposed by reference centers for PBC. To date, rates of non-response to UDCA from real-world series are lacking. Methods: Hepatology/Gastroenterology centers belonging to 'Club Epatologi Ospedalieri' (CLEO) and 'Associazione Italiana Gastroenterologi Ospedalieri' (AIGO) were invited to participate in the study, and asked to extract all patients followed for PBC, without any selection or exclusion, and fill in the database provided. Results: Thirty-four centers were enrolled throughout Italy, for a total of 713 patients. None of these centers, except one, had a hepatology outpatient clinic devoted to the care of patients with autoimmune liver diseases. After excluding 79 cases of PBC/autoimmune hepatitis overlaps, 634 patients were analyzed: mean age, 64.4 +/- 12.0 years; 91.2% females; F/M 10.3/1. For patients with at least 1 year of UDCA treatment (583), rates of non-response to UDCA were evaluated according to the Paris-I/-II, Toronto and GLOBE criteria, and compared with those in the original cohorts: 27% vs 39% in Paris-I cohort; 39.6% vs 52% in Paris-II; 20.1% vs 43.5% in Toronto; 15.7% vs 30% in GLOBE (age-specific cutoffs). Mean alkaline phosphatase levels on UDCA treatment, and the age-adjusted prevalence of F3/F4 fibrosis, appeared lower in this PBC population than in reference cohorts. Conclusions: A mean similar to 15% better response to UDCA is observed in a real-world PBC population, probably due to migration of some of most severe/advanced cases to PBC referral centers.