Clinical profiles and outcomes in idiopathic duct-centric chronic pancreatitis (type 2 autoimmune pancreatitis): the Mayo Clinic experience

• Published in: Gut Vol. 65; no. 10; pp. 1702 - 1709
• Main Authors: Hart, Phil A, Levy, Michael J, Smyrk, Thomas C, Takahashi, Naoki, Abu Dayyeh, Barham K, Clain, Jonathan E, Gleeson, Ferga C, Pearson, Randall K, Petersen, Bret T, Topazian, Mark D, Vege, Santhi S, Zhang, Lizhi, Chari, Suresh T
• Format: Journal Article
• Language: English
• Published: England 01.10.2016
• Subjects: Adult; Age Factors; Autoimmune Diseases; Demography; Disease-Free Survival; Female; Glucocorticoids - therapeutic use; Humans; Inflammatory Bowel Diseases - complications; Inflammatory Bowel Diseases - diagnosis; Inflammatory Bowel Diseases - therapy; Kaplan-Meier Estimate; Male; Middle Aged; Pancreatic Ducts - immunology; Pancreatic Ducts - pathology; Pancreatitis, Chronic - complications; Pancreatitis, Chronic - diagnosis; Pancreatitis, Chronic - immunology; Pancreatitis, Chronic - therapy; Recurrence; Retrospective Studies; Surgical Procedures, Operative - statistics & numerical data; Symptom Assessment - methods; United States; CHRONIC PANCREATITIS; ACUTE PANCREATITIS
• ISSN: 0017-5749; 1468-3288
• DOI: 10.1136/gutjnl-2015-309275

Idiopathic duct-centric chronic pancreatitis (IDCP), also known as type 2 autoimmune pancreatitis (AIP), is an uncommon subtype of AIP. International Consensus Diagnostic Criteria for IDCP propose that the diagnosis requires pancreatic histology and/or concurrent IBD. We examined our experience with IDCP (type 2 AIP) to assess the appropriateness of these criteria, and identify unique characteristics in patients presenting with acute pancreatitis. We reviewed the Mayo Clinic AIP database through May 2014 to identify subjects with either definitive (n=31) or probable (n=12) IDCP. We compared demographic and clinical factors based on strength of diagnostic confidence (definitive versus probable), presence of IBD, and acute pancreatitis as the presenting manifestation. Relapse-free survival was determined using the Kaplan-Meier method. The clinical profiles were similar irrespective of the diagnostic criteria fulfilled. Common clinical presentations included acute pancreatitis (n=25, 58.1%, 12 of whom (27.9%) had recurrent pancreatitis) and pancreatic mass/obstructive jaundice (n=15, 34.9%). The cumulative relapse rate was 10.6% at 3 years (median follow-up 2.9 years). Relapse-free survival was similar for the different diagnostic categories, but was decreased in those initially presenting with acute pancreatitis (p=0.047) or treated with steroids (vs surgery, p=0.049). The current diagnostic classification of probable IDCP and the inclusion of IBD as a supportive criterion appear valid, because patients have similar clinical profiles and disease-related outcomes to those with definitive IDCP. Concurrent IBD, especially in young patients, may suggest when IDCP is the underlying cause of recurrent acute pancreatitis, but additional studies are needed for validation.