Prevalence of inflammatory bowel disease in alcoholic, non-alcoholic and autoimmune pancreatitis.

Objectives: Patients with inflammatory bowel disease (IBD) frequently reveal features of pancreatic inflammation. However, the prevalence of IBD in patients with alcoholic pancreatitis (AP) and nonalcoholic pancreatitis (NAP) has not yet been determined, and the prevalence of IBD in patients with autoimmune pancreatitis (AiP) from Germany is unknown.

Aims: Thus, we aimed, first, to determine the prevalence of IBD in AP, NAP, and AiP from a tertiary center in Germany and, second, to characterize patients with AiP and IBD.

Methods: We performed a retrospective cross-sectional study to determine the prevalence of IBD in patients with different forms of pancreatitis presenting to our clinic.

Results: Compared to the general population and to a control group with viral hepatitis from our clinic, we observed the most significant increase of IBD in patients with AiP (n = 3/28; p < 0.0001 vs. general population, binomial proportion test; p = 0.0112 vs. hepatitis group, Fisher's exact test), followed by a significant increase in subjects with NAP (n = 11/278; p < 0.0001 vs. general population, binomial proportion test; p = 0.0338 vs. hepatitis group, Fisher's exact test). A review of previous studies on the prevalence of IBD among patients with AiP revealed a combined prevalence of 12 % (n = 43/355). Type 2 AiP is significantly more often associated with IBD than type 1 AiP (n = 28/48, 58 % vs. n = 7/129, 5 %; combined patient cohort, p < 10E - 12; Fisher's exact test).

Conclusions: Immune-mediated mechanisms related to IBD may participate in the development of AiP, especially AiP type 2, and may also increase the risk for the development of other forms of pancreatic inflammation.