Distinct outcome profile for subtypes of autoimmune pancreatitis : a mid-term study

Background: Few data exist concerning outcome profile of each subtypes of autoimmune pancreatitis (AIP). Aims: To compare clinical, radiological, outcome profile under treatment of the two types of AIP. Patients & methods: 28 AIP patients (M: 19, F : 9, median age : 56.5) have been treated and followed up for an average period of 48 ± 6 months (median : 40) (3 groups: type 1 n 1⁄4 10, type 2 n 1⁄4 11 and undetermined n 1⁄4 7). Results: Male, age and IgG4 cholangitis were significantly higher in type 1 AIP than in type 2 (p < 0.001). Follow up revealed : a significant rate of relapse in the type 1 AIP (60% versus 9% in the type 2, p 1⁄4 0.023), a clinical remission rate increased by more than 3 years in the type 2 AIP (63% versus 11% in the type 1, p 1⁄4 0.03). The relapse rate is related to the absence of normalisation of the pancreatic and/or biliary radiological lesions after corticoid treatment (p 1⁄4 0.008). The duration of remission is significantly longer (p < 0.02) for type 2 AIP and in case of a pseudotumoral type. Conclusion: Both types of AIP have distinct clinical and outcome profiles, with higher relapse rates and shorter remission durations in type 1 AIP patients. The absence of normalisation of radiologic lesions following corticoid has been identified as a predictive factor of relapse. These new data may influence the decision making before the interruption of the corticosteroid treatment in AIP patients. Abstracts / Pancreato