Recent advances in IgG4-related disease, autoimmune pancreatitis and sclerosing cholangitis.

Recently, a novel concept of IgG4-related disease (IgG4-RD), which shows increased serum IgG4/IgE levels, abundant infiltration of IgG4+plasmacytes and lymphocytes, fibrosis, and steroid responsiveness, has been worldwide accepted. The international consensus diagnostic criteria suggested the existence of two subtypes of autoimmune pancreatitis (AIP) : type 1 related with IgG4, and type 2 related with a granulocytic epithelial lesion. Before the IgG4-era, most of IgG4-SC cases were misdiagnosed as primary sclerosing cholangitis (PSC). Now, type 1 AIP and IgG4-sclerosing cholangitis (IgG4-SC) are defined as pancreatic and biliary manifestations of IgG4-RD, individually. Inflammatory bowel disease is often associated with type 2 AIP and PSC, but not Iwith type 1 or IgG4-SC. Steroid treatment is effective for IgG4-RD, but the long-term outcome still remains unclear.