Acute Pancreatitis in Inflammatory Bowel Disease: Results from the European Pandora Study

Background and aims: An increased risk of acute pancreatitis (AP) has been reported in patients with inflammatory bowel disease (IBD), but data on its prevalence, etiology, and outcomes are limited. Materials and Methods: A two-step retrospective analysis spanning 10 years (2011-2020) was conducted across 34 European centers. The first step surveyed the prevalence of AP in patients with IBD, while the second gathered data on disease characteristics, etiology, and outcomes. Results: The survey found an expected AP prevalence of 1.13% (780/68,989), though only 0.58% (n = 398) met the inclusion criteria. The mean age was 33.6 ± 14.3; 52% were female, and 56.5% had Crohn's disease (CD). AP was clinically mild in most cases (86.9%). Among 347 patients with available imaging, no alterations were observed in 81 (23.3%), whereas edematous AP was observed in 218 (62.8%). Drugs (mainly azathioprine) were the leading cause (55.3%), followed by biliary (14.8%) and autoimmune (7.8%) causes. In 13.5% of patients, AP was considered idiopathic. During a median follow-up of 67 months [IQR 34-96] from the index episode, recurrence was observed in 13% of patients, and 1.5% developed chronic pancreatitis. CD patients exhibited distinct risk profiles, including ileal involvement and smoking, whereas ulcerative colitis (UC) patients showed more frequent autoimmune and idiopathic etiologies. Conclusions: The PANDORA study established a 0.58% prevalence of AP in IBD patients, which was lower than expected. AP is usually mild both clinically and radiologically. An ileal location in CD and extensive colitis in UC are usually reported, and azathioprine seems to be the most common cause of AP in this setting, especially a few weeks after its introduction.