Application of international consensus diagnostic criteria to an Italian series of autoimmune pancreatitis

Abstract

BACKGROUND: International consensus diagnostic criteria (ICDC) have been proposed to classify autoimmune pancreatitis (AIP) in type 1, type 2, or not otherwise specified. OBJECTIVE: Aim was to apply the ICDC to an Italian series of patients to evaluate the incidence and clinical profiles among different subtypes of AIP. METHODS: we re-evaluated and classified 92 patients diagnosed by Verona criteria, according to the ICDC. RESULTS: Out of 92 patients, 59 (64%) were diagnosed as type 1, 17 (18%) as type 2, and 15 (16%) as not otherwise specified according to the ICDC. A significant difference between type 1 and type 2 were found for age (54.5 ± 14.5 vs. 34.4 ± 13.9 respectively; p < 0.0001), male sex (76 vs. 47%; p = 0.007), jaundice (66 vs. 18%; p = 0.002) and acute pancreatitis (9 vs. 47%; p < 0.0001), elevated serum IgG4 levels (85 vs. 7%; p < 0.0001), inflammatory bowel disease (8 vs. 82%; < 0.0001), and relapse of the disease (34 vs. 6%; p = 0.058). Imaging and response to steroids in the not-otherwise-specified group were similar to type 1 and 2. CONCLUSIONS: Type 1 has a different clinical profile from type 2 autoimmune pancreatitis. The not-otherwise-specified group has peculiar clinical features which are shared both with type 1 or type 2 groups.