Increase in age at diagnosis of Primary Biliary Cholangitis over the last 40 years

Background and Aims: In recent decades, primary biliary cholangitis (PBC) patients tend to present at an earlier disease stage. However, calendar time trends in age at diagnosis, biochemical response to ursodeoxycholic (UDCA) and clinical outcomes have not been fully characterized. The current study aims to describe calendar time trends in a large international cohort of PBC patients and provide important information on the evolution of PBC over the years. Methods: Patient data was retrieved from the Global PBC Study group database, comprising of PBC patients from 16 centers across Europe and North America. Patients were subdivided into 10-year cohorts according to their year of diagnosis: 1970-1980(n=144), 1980-1990(n=868), 1990-2000(n=1858), 2000-2010(n=1966), >=2010(n=255). Calendar time trends in age at diagnosis, biochemical response to UDCA, biochemical and histological disease stage, and clinical outcomes (death or liver transplantation) were assessed in each 10-year cohort. Results: A total of 5091 PBC patients were included, 4507(90.7%) were AMA positive and median follow-up time was 7.2 years (IQR 3.6-11.5). The proportion of male patients increased from 8.3% in the 1970’s to 13.3% in 2010. Age at diagnosis increased incrementally from the 1970’s (mean 46.9, SD 10.1) to 2010 (mean 57.3, SD 12.1, p<0.001), irrespective of biochemical disease stage (Figure 1). Additionally, there was an increase in the number of patients presenting with an earlier disease stage, both biochemically and histologically, p<0.001. The proportion of patients with an early biochemical disease stage in the 1970’s and after 2010 was 41% and 69.9%, respectively. In accordance, patients were more likely to respond to UDCA according to the Paris-I criteria, 51.7% vs. 71% (p<0.001). An increase in response may account for the improved 10-year transplant-free survival between patients from the 1970’s and 2010, 48.1% and 79.7%, respectively (p=0.004). Conclusions: Patient and disease characteristics of PBC at diagnosis have changed over the years, most notably by an increase in age at diagnosis and increased proportion of males. Furthermore, patients tend to present with milder biochemical disease stage regardless of age and gender.