Immunoglobulin G4 (IgG4)‐related autoimmune hepatitis and IgG4‐hepatopathy: A histopathological and clinical perspective

Immunoglobulin G4 (IgG4)‐related disease (IgG4‐RD) is a chronic inflammatory disease that simultaneously or consecutively involves multiple organs of the body. It is characterized by elevated serum IgG4 levels and massive infiltration of IgG4 + plasma cells in the damaged tissues. IgG4‐related autoimmune hepatitis (IgG4‐AIH) and IgG4‐hepatopathy are relatively new entities that have been proposed as a phenotype of IgG4‐RD in the liver....