Long-term risk of inflammatory bowel disease in autoimmune hepatitis: Over a 20-year population-based study

Autoimmune hepatitis (AIH) is a chronic immune-mediated liver disease with a recognized, but incompletely defined, association with inflammatory bowel disease (IBD). The long-term risk of developing IBD in AIH patients and its influence on hepatic outcomes remain unclear.

To determine the incidence and risk factors for IBD in a large AIH cohort over a 20-year follow-up and to assess its impact on liver-related complications.

We performed a retrospective, population-based study using data from Clalit Health Services in Israel, including 1284 adult patients diagnosed with AIH between 2000 and 2024. Patients with pre-existing cirrhosis, other chronic liver diseases, or IBD prior to AIH diagnosis were excluded. Demographic, clinical, and outcome data were analyzed.

Over a median follow-up of 4.8 years, 9.81 % of AIH patients developed IBD, most commonly Crohn's disease. The cumulative incidence of IBD increased with longer follow-up. Smoking was identified as an independent risk factor for IBD development. Patients with both AIH and IBD had a higher prevalence of cirrhosis compared with those with AIH alone, but rates of other major hepatic complications were similar between groups.

In this nationwide cohort, the incidence of IBD among AIH patients increased progressively over time, with smoking emerging as a modifiable risk factor. While IBD was associated with a greater prevalence of cirrhosis, it did not increase the risk of other liver-related complications.