IgG4-Related Liver and Biliary Disease

IgG4-related disease (IgG4-RD) is a multisystem disorder associated with inflammation and fibrosis in affected organs. Almost any organ may be affected, forming part of the IgG4-RD spectrum. Patients with IgG4-RD may present to hepatologists with symptoms related to focal masses or diffuse swelling of the pancreas, with intrahepatic and/or extrahepatic biliary disease, as inflammatory pseudotumors of the liver and biliary tree, and as a variant of autoimmune hepatitis. IgG4-RD involving the pancreas, bile ducts and/or liver may mimic pancreatic cancer, cholangiocarcinoma, and primary sclerosing cholangitis. Distinguishing IgG4-RD from malignancy is critical, often requiring biopsy and histologic analysis. IgG4-RD may be associated with progressive organ dysfunction, organ failure and malignancy. IgG4-RD is usually treated with oral corticosteroids as first line therapy, but relapse rates are high once steroid treatment is tapered or stopped. Secondline and steroidsparing agents are commonly used, but the optimal use of these is not well defined in head to head clinical studies.