Association between autoimmune pancreatitis and ulcerative colitis: a report of 12 patients.

Background: pancreatic manifestations in inflammatory bowel disease (IBD) mainly include acute pancreatitis secondary to drugs and, less frequently, autoimmune pancreatitis, in particular type 2 autoimmune pancreatitis.

Methods: retrospective study of patients diagnosed with ulcerative colitis (UC) and autoimmune pancreatitis (AIP) in control at two centers in Santiago, Chile, between 2007 and 2018. Clinical data, laboratory results, images and response to treatment were recorded.

Results: twelve patients were identified with both diseases, the average age was 34 years and 42 % were male. In all cases, a likely diagnosis with type-2 AIP was established based on pancreatic magnetic resonance imaging (MRI), association with IBD and a rapid response to therapy with corticosteroids. Samples for histology were obtained from two patients, which showed inconclusive results. AIP recurrence was reported in only one case. A total of 58 % of patients had extensive UC, 100 % received 5-ASA therapy and 33 % were treated with azathioprine. Only one patient had a serious flare-up, none developed complications and none required biologics or surgery.

Conclusions: an association between UC and type-2 AIP was confirmed in our cases. No increase in IBD severity was observed in this group of patients.