Antibody-mediated Mechanisms
In 1951, William Harrington, a haematologist, decided to receive an infusion of plasma from a patient with autoimmunethrombocytopenia.Hesooncollapsedwithaseizure, and developed purpura. A blood test demonstrated a sudden drop in platelet count. This crazy and now impermissible experiment represents the first demonstration that autoantibodies can cause human disease. The possibility of transferring the disease into experimental animals represents one of Witebsky’s criteria for the definition of autoimmune disease (the others being the identification of T-cell- and antibody-mediated pathogenetic mechanism, and the identification of the autoantigen against which the immune response is directed). Owing to the ease with which autoimmune diseases can be transferred by plasma or serum, and because of the earlier developed techniques for the identification of circulating as well as tissue-bound antibodies, antibody-mediated autoimmune diseases were characterized before and in more depth than T-cell-mediated diseases. See also: Autoimmune disease: animal models According to the Coombs and Gell (1975) classification of hypersensitivity reactions, the antibody-mediated tissue
injury involved in autoimmune diseases may be classified into three types (Figure 1) as follows. See also: Hypersensitivity (Immunological)