Autoimmune pancreatitis type 2 and its relationship with inflammatory bowel disease: a narrative review

This narrative review provides an update of the literature on autoimmune pancreatitis type 2 (AIP-2) and its relationship with inflammatory bowel disease (IBD) in adults. Due to the rarity of this condition, the literature on the topic is sparse. AIP-2 is a pancreas specific condition in contrast to autoimmune pancreatitis type 1, which is the pancreatic manifestation of immunoglobulin G4-related disease. AIP-2 has a strong association with IBD, especially ulcerative colitis.

To establish this review a systematic search using the PubMed database was carried out for English language articles concerning AIP-2 and IBD in an adult population from inception until November of 2025. Every article was screened for eligibilty and included if found relevant.

AIP-2 should be suspected in IBD patients with signs of acute pancreatitis, painless jaundice or a pancreatic mass without an obvious explanation. A definitive diagnosis requires a representative histological sample obtained preferentially with an endoscopic ultrasound guided needle biopsy. A probable diagnosis can be obtained through radiological findings, coexistence of IBD and clinical response to corticosteroids.

Corticosteroids are the first-line treatment of an acute flare of AIP-2 if it doesn't resolve spontaneously. In patients with relapsing, steroid refractory or steroid dependent AIP-2, maintenance therapy can be considered to prevent flare-ups and progression to chronic pancreatitis. In patients with IBD and AIP-2, it is important to consider a relapse preventative strategy that has effect on both conditions.