IgG4-Related Disease

IgG4-related disease (IgG4-RD) is a novel clinical disease entity characterized by an elevated serum IgG4 concentration and tumefaction or tissue infiltration by IgG4-positive plasma cells. IgG4-RD encompasses a wide variety of diseases, formerly diagnosed as Mikulicz's disease (MD), autoimmune pancreatitis (AIP), hypophysitis, Riedel thyroiditis, tubulointerstitial nephritis, prostatitis, retroperitoneal fibrosis, inflammatory aortic aneurysm and inflammatory pseudotumor. However, like a crow flying on a dark night, IgG4-RD passed through the history of medicine, until the concept of an overarching of these systemic disorders was established in Japan at the beginning of the present century. In addition, most…