In response to an antigen the body produces antibodies which include:

  • IgG is the major antibody of plasma and the most important part of the body's immune response. Most immune diseases are marked by IgG autoantibodies.
  • IgM is initially produced to fight antigens but soon decreases and allows IgG to take over. It plays an important but secondary role in autoimmunity.
  • IgA is the major antibody of external secretions (tears, gastrointestinal tract secretions, and respiratory secretions). It is important in autoimmune diseases.
  • IgE binds to mast cells and mediates allergic reactions.
  • IgD is poorly understood but has a role in helping B cells to recognize antigens.

Hypergammaglobulinemia is an increased level of gamma globulins (most often IgE, IgM, and IgG) in blood. It is seen frequently in chronic infectious diseases, including chronic granulomatous inflammations, chronic bacterial infections, liver disease, drug-induced autoimmune liver disease, multiple myeloma, lymphomas, abnormal protein production or secretion, parasitic infection with Toxocara, type 2 autoimmune pancreatitis, and various other autoimmune diseases.


  1. Daniel J. Wallace. The Lupus Book
  2. Recent Advances in Determining the Pathogenesis of Canine Monocytic Ehrlichiosis Shimon Harrus, Trevor Waner,2 Hylton Bark, Frans Jongejan, and Albert W. C. A. Cornelissen. In:Journal of Clinical Microbiology, September 1999, p. 2745-2749, Vol. 37, No. 9
  3. Concise Medical Encyclopedia. American Medical Association
  4. Neglected Parasitic Infections in the United States: Toxocariasis
  5. Autoimmune pancreatitis: pathogenesis, latest developments and clinical guidance
  6. Drug-induced autoimmune liver disease: A diagnostic dilemma of an increasingly reported disease