Idiopathic acute pancreatitis in patients with inflammatory bowel disease: A multicenter cohort study

Background: Idiopathic acute pancreatitis (LAP) in patients with inflammatory bowel disease (IBD) is not well characterized. Our purpose was to better understand this condition and its natural history. Methods: Retrospective cohort study conducted at nine Spanish IBD referral centers. Patients with IBD and a first episode of acute pancreatitis (AP) between 1998 and 2018 were included. Patients with a previous episode of AP or a diagnosis of chronic pancreatitis were excluded. LAP and non-LAP were compared by multivariate logistic regression and survival analysis. Results: We identified 185 patients with IBD (68.7% Crohn's disease) and a first episode of AP. Thirty-eight of those 185 (20.6%) fulfilled criteria for LAP. There were no severe cases of LAP. On multivariate analysis, AP before IBD diagnosis (21.1% vs. 3.4%, p = 0.04) and ulcerative colitis (52.6% vs. 23.1%, p = 0.002) were significantly more common in LAP. Further work-up was performed in 16/38 (42%) LAP patients, and a cause was identified in 6/16 (37.5%). Median time from AP to the end of follow-up was 6.3 years (3.1-10). Five-year risk of AP recurrence was significantly higher in LAP group (28% vs. 5.1%, log-rank p = 0.001), with a median time to first recurrence of 4.4 months (2.9-12.2). Conclusions: LAP represents the second cause of AP in patients with IBD. It is more frequent in ulcerative colitis, and presents a high risk of recurrence. Additional imaging work-up after a first episode of LAP in IBD patients is highly advisable, as it identifies a cause in more than one-third of cases. (C) 2020 LAP and EPC. Published by Elsevier B.V. All rights reserved.