Asian diagnostic criteria for autoimmune pancreatitis: consensus of the Japan-Korea Symposium on Autoimmune Pancreatitis

Abstract

In 2002, the Japan Pancreas Society (JPS) was the first in the world to propose diagnostic criteria for autoimmune pancreatitis (AIP). Since the concept of AIP has changed with the accumulation of AIP cases, the Research Committee of Intractable Pancreatic Diseases (RCIPD) provided by the Ministry of Health, Labour and Welfare of Japan and the JPS issued revised clinical diagnostic criteria of AIP in 2006. The Asan Medical Center of Korea also proposed diagnostic criteria for AIP in 2006. However, there are subtle but clinically challenging differences between the Japanese and Korean criteria. This inconsistency makes it difficult to compare data in studies from different centers and elucidate the characteristics of AIP. To reach a consensus on AIP, the RCIPD and the Korean Society of Pancreatobiliary Diseases established the following Asian criteria for the diagnosis of AIP: I-1. Imaging studies of pancreatic parenchyma show a diffuse/segmental/focally enlarged gland, occasionally with a mass and/or a hypoattenuation rim. I-2. Imaging studies of pancreaticobiliary ducts show diffuse/segmental/focal pancreatic ductal narrowing, often with stenosis of the bile duct. (Both I-1 and I-2 are required for diagnosis). II. Elevated level of serum IgG or IgG4, and detection of autoantibodies. III. Common lymphoplasmacytic infiltration and fibrosis, with abundant IgG4-positive cell infiltration. AIP should be diagnosed when criterion I and one of the other two criteria are satisfied, or when histology shows the presence of lymphoplasmacytic sclerosing pancreatitis in the resected pancreas. A diagnostic trial of steroid therapy can be applied carefully by expert pancreatologists only in patients fulfilling criterion I alone with negative diagnostic work-up results for pancreatobiliary cancer.

Amendment of the Japanese Consensus Guidelines for Autoimmune Pancreatitis, 2013 I. Concept and diagnosis of autoimmune pancreatitis

“…The Japanese diagnostic criteria were designed to be as simple as possible, to be easy for general physicians as well as pancreatologists to use. After a decade of international discussion about diagnostic criteria [94][95][96], the ICDC enabled the diagnosis of two distinctive subtypes of AIP, type 1 and type2 AIP [9]. However, the ICDC is somewhat complicated for general use.…”

“…This decision is based on the following reasons: (1) autoimmune hepatitis is the only autoimmune disease that uses the effect of steroid treatment as a diagnostic criteria; (2) the clinical significance is different for the case of autoimmune hepatitis requiring differentiation from chronic hepatitis of other pathogenesis and the case of AIP requiring differentiation from pancreatic or bile duct cancer; (3) no evidence exists to show that the use of steroids does not affect the success of an operation or the long-term prognosis; (4) there is a danger that therapeutic diagnosis by steroid administration may be used as an easy solution to differentiate AIP from malignant tumors such as pancreatic cancer; (5) the standards were established for not only pancreas specialists but also general gastrointestinal internists and general practitioners; (6) in Japan, the objective of the diagnostic criteria is not so much to find AIP but rather to eliminate the misdiagnosis of diseases with malignant tumors as often as possible; and (7) there have been reports of AIP associated with pancreatic cancer [3][4][5]. The ICDC [9] include response to steroid treatment following the Korean [95], and Asian criteria [96] in the criteria proposed jointly by Japan and South Korea in 2008. The JPS-2011 [10,11] states that if the possibility of pancreatic cancer is excluded by a reliable exclusivediagnosis using EUS-FNA or a similar test, the effect of steroid treatment may be used as diagnostic criteria.…”

Mechanisms of Lower Bile Duct Stricture in Autoimmune Pancreatitis

“…Diagnosis of AIP was based on the Asian diagnostic criteria for AIP. 17 Image analysis ERCP findings of lower bile duct stricture and pancreatic duct narrowing in the head region were assessed by three expert endoscopists. Subsequently, IDUS was performed using a 20 MHz probe (2.0 mm diameter, UM-G20-29R, Olympus Optical Co, Tokyo, 8 Japan).…”

Autoimmune Pancreatitis - A Case Report

“…Chari et al, proposed the Mayo Clinic ( HISORt) criteria in 2006 which took into account the histology, imaging, serology, other organ involvement and response to therapy to reach a diagnosis of AIP [7]. Asian Diagnostic Criteria was proposed in 2008 [8]. Also known as lymphoplasmacytic sclerosing pancreatitis, chronic sclerosing pancreatitis, non alchololic duct destructive pancreatitis, granulocytic epithelial lesion (GEL) positive pancreatitis AIP is a widely accepted terminology because the clinical, serological, histological and immunohistochemical findings point towards an autoimmune etiology.…”