Abstract
Autoimmune pancreatitis (AIP) is worldwide accepted as distinct pancreatitis with steroid response. The Japan Pancreas Society (JPS) first proposed the diagnostic criteria of AIP in 2002 (Suizo 2002; 17: 587) and the revised one in 2006 (J Gastroenterology 2006; 40: 626-31). The most important issue in diagnosing AIP is how to distinguish it from pancreatic or biliary cancer. The Japanese clinical criteria have been proposed for the practical use and the minimum consensus features of AIP in order to avoid the misdiagnosis of malignancy as far as possible. Internationally, two subtypes of AIP have been proposed in the International Consensus of Diagnostic Criteria (ICDC) for AIP in 2011 (Pancreas 2011; 40: 352-358): type 1 related with IgG4 (lymphoplasmacytic sclerosing pancreatitis: LPSP), and type 2 with granulocytic epithelial lesions (idiopathic duct-centric pancreatitis: IDCP). As the ICDC are still complicated for the practical use, The Research Committee of Intractable Diseases of the Pancreas supported by the Japanese Ministry of Health, Labor and Welfare and the JPS have proposed the revised diagnostic criteria in 2011. Since type 2 is extremely rare in Japan, the diagnostic criteria described here are intended to cover type 1, commonly seen in Japan, with type 2 noted only as reference.
