Epidemiological and clinical features of primary biliary cholangitis in two Croatian regions: a retrospective study

To assess the measures of disease frequency and determine the clinical features of primary biliary cholangitis (PBC) in two Croatian regions. Databases of two tertiary hospitals, one located in the continental and one in the coastal region of Croatia, were retrospectively searched for PBC patients diagnosed from 2007 to 2018. Epidemiologic data analysis was restricted to patients from each hospital's catchment area. We analyzed factors related to response to therapy and event-free survival (EFS), defined as absence of ascites, variceal bleeding, encephalopathy, hepatocellular carcinoma, liver transplantation (LT), or death. In addition, we determined clinical and demographic data of transplanted PBC patients. Out of 83 PBC patients, 86.7% were female, with a median age at diagnosis of 55 years. Average PBC incidence for the 11-year period was 0.79 and 0.89 per 100000 population, whereas the point prevalence on December 31, 2017 was 11.5 and 12.5 in the continental and coastal region, respectively. Of 76 patients with complete medical records, 21% had an advanced disease stage, 31.6% had an associated autoimmune condition, and all received ursodeoxycholic acid. EFS rate at 5 years was 95.8%. In an age and sex-adjusted multivariate Cox regression model, the only factor significantly associated with inferior EFS was no response to therapy (HR=18.4; P=0.018). Of all Croatian patients who underwent LT, 3.8% had PBC, with the survival rate at 5 years after LT of 93.4%. This study gives pioneer insights into the epidemiological and clinical data on PBC in Croatia, thus complementing the PBC map of Southeast Europe.