Abstract
IgG4-related sclerosing cholangitis (IgG4-SC) is a characteristic type of sclerosing cholangitis with unknown pathogenic mechanism. IgG4-SC patients show increased level of serum IgG4 and dense infiltration of IgG4-positive plasma cells with extensive fibrosis in the bile duct wall. IgG4-SC is frequently associated with autoimmune pancreatitis, and occasionally with IgG4-related symmetrical dacryoadenitis/sialadenitis and IgG4-related retroperitoneal fibrosis. Various cholangiographic features of IgG4-SC are similar to those of primary sclerosing cholangitis, pancreatic cancer, and cholangiocarcinoma. Therefore, it is not easy to discriminate IgG4-SC from these progressive or malignant diseases on the basis of cholangiographic findings alone, and accurate diagnosis of IgG4-SC not associated with autoimmune pancreatitis is particularly difficult. The Research Committee in association with the Ministry of Health, Labor and Welfare Japan, and the Japan Biliary Association established the new clinical diagnostic criteria of IgG4-SC 2012. The criteria are believed to be practically useful for general physicians. Steroid therapy is very effective. Recently, immunosuppressive drugs have been introduced in the treatment of relapsed patients in the United States and Europe. Prognosis is generally good, however IgG4-SC cases showing liver atrophy have been reported.
