title: Inflammatory bowel disease in the setting of autoimmune pancreatitis.
abstract: BACKGROUND
  Despite scattered case reports, the prevalence of inflammatory bowel disease (IBD) in patients with autoimmune pancreatitis (AIP) is unknown. We sought to better characterize the putative association between the conditions.
  
  
  METHODS
  Medical records of 71 patients meeting accepted criteria for AIP were reviewed to identify those with endoscopic and histological evidence of IBD. Colon samples in patients with both AIP and IBD were immunostained to identify IgG4-positive cells.
  
  
  RESULTS
  Four patients with AIP (5.6%) had a diagnosis of IBD: 3 had ulcerative colitis (UC) and 1 had Crohn's disease (CD). The diagnosis of IBD preceded or was simultaneous to that of AIP. Two AIP-UC patients treated for AIP with prednisone had a recurrence of AIP, and 1 required 6-mercaptopurine for long-term corticosteroid-sparing treatment. Two AIP-IBD patients underwent Whipple resections, and 1 had recurrent AIP. All 3 patients with UC presented with pancolitis, and 2 required colectomy. Colon samples from 1 patient with UC and 1 patient with CD were available for review. Increased numbers of IgG4-positive cells (10 per high-power field) were noted on the colon sample from the patient with UC.
  
  
  CONCLUSIONS
  Almost 6% of patients with proven AIP had a diagnosis of IBD, compared to a prevalence of approximately 0.4%-0.5% in the general population, potentially implying a 12-15-fold increase in risk. Patients with both AIP and IBD may have increased extent and severity of IBD. The finding of IgG4-positive cells on colon biopsy suggests that IBD may represent an extrapancreatic manifestation of AIP.
authors.affiliation: Department of Internal Medicine, Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: Karthik
authors.initials: K
authors.lastname: Ravi
authors.forename: Suresh T
authors.initials: ST
authors.lastname: Chari
authors.forename: Santhi S
authors.initials: SS
authors.lastname: Vege
authors.forename: William J
authors.initials: WJ
authors.lastname: Sandborn
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Smyrk
authors.forename: Edward V
authors.initials: EV
authors.lastname: Loftus
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001327:Autoimmune Diseases / Q000150:complications* / Q000175:diagnosis; D003093:Colitis, Ulcerative / Q000175:diagnosis / Q000209:etiology*; D003424:Crohn Disease / Q000175:diagnosis / Q000209:etiology*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D008297:Male; D008499:Medical Records; D008875:Middle Aged; D010195:Pancreatitis / Q000150:complications* / Q000175:diagnosis; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate; D055815:Young Adult
chemical_list: D007074:Immunoglobulin G