Abstract
Primary sclerosing cholangitis (PSC) is a chronic progressive inflammatory disease with fibrous obliteration of intra- and extrahepatic bile ducts. Although immunological abnormalities are considered to cause PSC, precise pathogenesis of PSC is unknown. According to national surveys, PSC patients in Japan have revealed to have two peaks in the age distribution; Typical PSC patients complicated with inflammatory bowel disease (IBD) are included in the younger peak, whereas the elder peak includes patients with sclerosing cholangitis with autoimmune pancreatitis (AIP), which are nowadays considered to be different from typical PSC. Recently, the presence of patients with sclerosing cholangitis similar to AIP without apparent pancreatic lesions has been identified. The actual situation of such patients, which is also called as IgG4-related sclerosing cholangitis, should be clarified in near future.
