What is IgG4-related sclerosing disease

IgG4-related sclerosing disease , also known as IgG4–related systemic disease (IgG4-RSD), hyper-IgG4 disease and IgG4-related disease is an autoimmune disease in which inflammatory cells cause fibrosis, the deposition of connective tissue, in one or more organs. The disease is so named because the antibody subtype IgG4 can be detected on tissue samples and often at elevated levels in the bloodstream. The association with IgG4 is a relatively recent finding, and the condition has been described under numerous other names in the past.

IgG4-related disease is an immune-mediated condition that can affect multiple organ systems.[1][2][3][4] Common features include IgG4-related autoimmune pancreatitis, swelling of or within an organ system (an inflammatory pseudotumor), salivary gland disease (which can lead to enlargement of the salivary glands), swollen lymph nodes (lymphadenopathy), skin manifestations, and symptoms consistent with allergies or asthma. The cause of IgG4-related disease is unknown. Some researchers believe that it may be an autoimmune or allergic disorder.[1][2] IgG4-related disease is usually treated with systemic steroids like prednisone. Immunosuppressive medications (azathioprine or mycophenolate mofetil) and biologics (rituximab or bortezomib) may be used in those who don’t respond to steroids or for longer-term management. In severe cases, organ replacement therapy may be needed.[1][2][3][4]

This information is provided by the National Institutes of Health (NIH) Genetic and Rare Diseases Information Center (GARD).
https://rarediseases.info.nih.gov/diseases/12521/igg4-related-disease