autoimmunity

In medicine, condition in which the body's immune responses are mobilized not against ‘foreign’ matter, such as invading germs, but against the body itself. Diseases considered to be of autoimmune origin include myasthenia gravis, rheumatoid arthritis, and lupus erythematosus.

In autoimmune diseases T-lymphocytes reproduce to excess to home in on a target (properly a foreign disease-causing molecule); however, molecules of the body's own tissue that resemble the target may also be attacked, for example insulin-producing cells, resulting in insulin-dependent diabetes; if certain joint membrane cells are attacked, then rheumatoid arthritis may result; and if myelin, the basic protein of the nervous system, then multiple sclerosis results. In 1990 in Israel a T-cell vaccine was produced that arrests the excessive reproduction of T-lymphocytes attacking healthy target tissues.