IgG4-related sclerosing cholangitis and primary sclerosing cholangitis

Abstract

Sclerosing cholangitis (SC) is defined as a condition with progressive stenosis and destruction of the bile ducts due to diffuse inflammation and fibrosis and currently includes three categories: primary sclerosing cholangitis (PSC), secondary cholangitis, and IgG4-related sclerosing cholangitis (IgG4-SC). SC categories share similar clinical features, such as cho-lestasis. Patients with SC present with cholestatic symptoms, including jaundice and pruritus, and blood tests reveal elevation of cholestatic enzymes. Cholangiography, endoscopic or magnetic, is inevitably required for making a diagnosis. Although the presentation of IgG4-SC and PSC are similar, the comorbidities, treatment response, and outcomes differ significantly, and therefore, it is strongly advisable to be familiar with these two diseases to make a correct diagnosis. Differentiation of cholangiocarcinoma from IgG4-SC and PSC is also extremely important. In this review, the clinical characteristics, comorbidities, treatment and outcomes of IgG4-SC and PSC will be outlined based on experience mainly from Japan.