A249 FREQUENCY AND CLINICAL SIGNIFICANCE OF INFLAMMATORY BOWEL DISEASE IN PATIENTS WITH AUTOIMMUNE HEPATITIS

Background Previous studies suggested that patients with autoimmune hepatitis (AIH) and inflammatory bowel disease (IBD) have poorer outcomes; however, the significance of this association is limited. Aims To describe the phenotype of AIH-associated IBD and assess the impact of IBD on the response to treatment and risk of adverse liver outcomes in patients with AIH. Methods In our retrospective cohorts, we identified patients with concomitant diagnoses of IBD and a definite AIH. The comparison cohort consisted of AIH patients matched by gender, age at diagnosis, ethnicity, and time to follow-up. Chi-square and Mann-Whitney tests were used to assess differences. Univariate analysis was performed using the Cox proportional hazards model. Results We identified a total of 16 patients (9 males, 56.3%) with AIH-associated IBD from a cohort of 6006 IBD patients (0.27%) and 357 AIH patients (4.5%). All patients were Caucasians. Twelve patients (75.0%) had ulcerative colitis with a pancolonic extent; 4 (25.0%) – Crohn’s disease: one patient had ileitis, three – ileocolitis with one having stricturing and fistulising gastroduodenal, ileocolonic and perianal disease. The median age at IBD diagnosis was 26.5 years old and varied from 2 to 53. The age at AIH diagnosis ranged from 7 to 59 years old (median 21.1) and median follow-up time was 11.1 years ranging from 11 days to 35.2 years. The matching cohort of 113 AIH-IBD- patients was comparable to the AIH-IBD+ cohort by gender (44 males, 38.9%; p=0.188), age at diagnosis (median 28.4, IQR 32; p=0.442), ethnicity, and the follow-up time (median 8.7 years, IQR 10.2; p=0.764). There was no difference in AST, ALT and ALP at diagnosis. Complete response rates were similar in AIH-IBD+ and AIH-IBD- groups (50.0% vs. 53.1%; p=0.816). The risk of developing cirrhosis and a median time to its onset did not differ significantly: 28.6% vs. 31.0% (p=0.853) and 11.8 vs. 8.2 years (p=0.359), respectively. In univariate Cox regression, IBD was not a predictor of progression to cirrhosis (HR 0.45; 95% CI 0.13–1.50; p=0.192). The risk of developing decompensation and a median time was also comparable between groups: 21.4% vs. 33.0% (p=0.384) and 18.4 vs. 9.8 years (p=0.053), supported by the Cox regression analysis (HR 0.44; 95% CI 0.13–1.48; p=0.187). The presence of IBD was not associated with higher need in liver transplant (18.8% vs. 30.1%; p=0.348), median time was slightly shorter (1.48 vs. 4.73 years; p=0.542), also evidenced by Cox regression (HR 1.40; 95% CI 0.42–4.65; p=0.578). The risk of liver-related death was also not different among the two groups (6.3% vs. 4.4%; p=0.746), and IBD was not a predictor of it (HR 1.94; 95% CI 0.17–21.69; p=0.589). Conclusions The presence of IBD in patients with AIH is rare and do not identify a subgroup of patients with worse response to treatment or poor clinical outcomes. Funding Agencies AbbVie