OP- 4 EPIDEMIOLOGY OF PRIMARY BILIARY CHOLANGITIS IN LATIN AMERICA: PRELIMINARY RESULTS FROM ALLATIN COHORT

No Primary biliary cholangitis (PBC) may present differently depending on various factors such as ethnicity and genetic background. Latin America has a highly admixed population with a unique genetic diversity compared to other regions of the world. However, there is limited information available on the presentation and epidemiology of PBC in this region. This study aims to address the epidemiology of PBC in Latin America. Ongoing retrospective, international, multicentric cohort study sponsored by ALEH that enrolls PBC patients from different countries in Latin America. Data were accrued on 231 patients [Brazil (52%), Argentina (27.4%), Chile (10.8%), Costa Rica (4.5%), Cuba (3.6%), and Mexico (0.9%)], 92.1% female (mean age at diagnosis 50.5 years), 25.6% with cirrhosis at baseline. Overlap with autoimmune hepatitis was reported in 16.0% of cases. Most patients were symptomatic (67.9%) at diagnosis, with fatigue (41.9%) and pruritus (40.5%) being the main symptoms. Anti-mitochondrial antibodies (AMA) were positive in 70.8% and antinuclear antibodies (ANA) in 60.6%. Hashimoto thyroiditis (23.7%) and Sjogren syndrome (9.1%) were the most common extrahepatic autoimmune diseases associated with PBC. Mean baseline alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, and bilirubin levels were 445.9 (± 407), 89.8 (± 137.2), 37.6 (± 8.9) U/L, and 1.6 (± 3.1) mg/dL, respectively. Almost all patients (99.1%) were treated with ursodeoxycholic acid (UDCA). 67.4% achieved adequate response to UDCA according to the Toronto criteria and 32% normalized alkaline phosphatase at 12 months. Only 19.9% received second-line therapy, all with fibrates (89.1% bezafibrate, 8.7% ciprofibrate, 4.3% fenofibrate). Of the patients, 9% died, with 33% of deaths being liver-related, while 6% underwent liver transplantation. Hepatocellular carcinoma was diagnosed in 1.7% of patients. In this unprecedented study, the epidemiology of PBC in Latin America appears similar to that in other parts of the world. However, lower rates of AMA positivity were observed, and most patients were still diagnosed with symptomatic disease. Second-line therapy options were limited to the availability of fibrates only.