Effects of Age and Sex of on Response to Ursodeoxycholic Acid and Transplant-free Survival in Patients with Primary Biliary Cholangitis

Background & Aims Primary biliary cholangitis (PBC) predominantly affects middle-aged women; there are few data on disease phenotypes and outcomes of PBC in men and younger patients. We investigated whether differences in sex and/or age at the start of ursodeoxycholic acid (UDCA) treatment are associated with response to therapy, based on biochemical markers, or differences in transplant-free survival. Methods We performed a longitudinal retrospective study of 4355 adults in the Global PBC Study cohort, collected from 17 centers across Europe and North America. Patients received a diagnosis of PBC from 1961 through 2014. We evaluated the effects of sex and age on response to UDCA treatment (based on GLOBE score) and transplant-free survival using logistic regression and Cox regression analyses, respectively. Results Male patients were older at the start of treatment (58.3±12.1 years vs 54.3±11.6 years for women; P<.0001) and had higher levels of bilirubin and lower circulating platelet counts (P<.0001). Younger patients (45 years or younger) had increased serum levels of transaminase than older patients (older than 45 years). Patients older than 45 years at time of treatment initiation had increased odds of a biochemical response to UDCA therapy, based on GLOBE score, compared to younger patients. The greatest odds of response to UDCA were observed in patients older than 65 years (odds ratio compared to younger patients 45 years or younger, 5.48; 95% CI, 3.92–7.67; P<.0001). Risk of liver transplant or death (compared to a general population matched for age, sex, and birth year) decreased significantly with advancing age: hazard ratio for patients 35 years or younger, 14.59 (95% CI, 9.66–22.02) vs hazard ratio for patients older than 65 years, 1.39 (95% CI, 1.23–1.57) (P<.0001). On multivariable analysis, sex was not independently associated with response or transplant-free survival. Conclusion In longitudinal analysis of 4355 adults in the Global PBC Study, we associated patient age, but not sex, with response to UDCA treatment and transplant-free survival. Younger age at time of PBC diagnosis is associated with increased risk of treatment failure, liver transplant, and death.