Antibodies are produced by B cells in two ways: (i) randomly, and (ii) in response to a foreign protein or substance within the body.
Normally, the immune system is able to recognize and ignore the body's own healthy proteins, cells, and tissues, and to not overreact to non-threatening substances in the environment, such as foods.
Sometimes, the immune system ceases to recognize one or more of the body's normal constituents as "self", leading to production of pathological autoantibodies.
Autoantibodies may also play a nonpathological role; for instance they may help the body to destroy cancers and to eliminate waste products.
It is thought that some autoantibody production is due to a genetic predisposition combined with an environmental trigger, such as a viral illness or a prolonged exposure to certain toxic chemicals.
[1][2] The type of autoimmune disorder or disease that occurs and the amount of destruction done to the body depends on which systems or organs are targeted by the autoantibodies, and how strongly.
Based on the patient's signs and symptoms, the doctor may request one or more diagnostic studies that will help to identify a specific disease.
As a rule, information is required from multiple sources, rather than a single laboratory test to accurately diagnose disorders associated with systemic autoantibodies.