any of a class of proteins, present in the blood plasma, identified by their characteristic rate of movement in an electric field (see electrophoresis). Almost all gammaglobulins are immunoglobulin. Injection of gammaglobulin provides temporary protection against hepatitis A and has recently been shown to reduce the incidence of coronary artery involvement in Kawasaki disease. Infusions of gammaglobulin are used to treat immunodeficiencies or immune-mediated disorders, such as autoimmune haemolytic anaemia or idiopathic thrombocytopenic purpura. See also globulin.
Medical dictionary. 2011.