Definition: Anitbodies or substances produced by the immune system that attack the body's own tissues.
The antinuclear antibody test (ANA test) is used to screen for these antibodies, which are a marker of autoimmune diseases such as systemic lupus erythematosus). It is not used to diagnose it, however.
The normal titer -- a metric used to measure the presence and amount of antibodies in blood -- of ANA is 1:40. Higher titers in the presence of symptoms are more indicative of an autoimmune disease.
Also Known As: ANA
