[Cost-benefit relationship of serologic studies in autoimmune diseases]

Autoimmune disorders are mainly clinically defined disease entities. The diagnosis of many of the systemic autoimmunopathies is based on characteristic combinations of symptoms, some of them overlapping various kinds and being of unspecific nature. Therefore, laboratory parameters such as autoantibodies, components of the complement system, some cytokines and their receptors, etc., are used for the diagnosis, although many of them are of limited specificity and sensitivity. The most important immunoparameters being of value for diagnosis and disease monitoring are discussed, and a stepwise procedure is proposed in order to reduce the costs. Basis are the screening tests for antinuclear antibodies (ANA) and for antibodies against cytoplasmatic components of granulocytes (ANCA). Depending on more specific questions, other tests and test combinations are then applied in second and third priorities.