Anti-DNA antibodies and the problem of autoimmunity.

Several different classes of autoreactive antibodies are known to exist: those that are stimulated by bacterial infection (e.g., streptococci/rheumatic fever), those that react with tissue-specific antigens (e.g., thyrotropin receptor/Graves' disease), and those that bind to ubiquitous autoantigens (e.g., DNA/systematic lupus). The origin of the last kind of autoantibody is unknown, but it now seems that their production is an inherent property of the normal immune system. Indeed, it would appear that autoantibodies of the lupus variety actually have a physiological role in normal immunity. The development of the autoimmune disease may occur when there is an "escape" from the normal function of lupus autoantibodies.