New concepts in systemic autoimmunity testing.

Diagnosis of systemic autoimmune diseases is highly complex, and it is becoming increasingly difficult to make assumptions about the functional roles and diagnostic significance of autoantibodies. The latter is mainly due to the fact that results from different assay systems are not interchangeable. A laboratory "gold standard" which helps the clinician to differentiate irrelevant autoimmune phenomena from significant autoimmune diseases at an early stage, is clearly missed. To meet this challenge, a rheuma entrance screening (RES) assay toolbox is proposed based on fully-automated enzyme immunoassay (EIA) technology on one system for the clinical and routine laboratory. The RES concept is intended to cover the most important syndromes of systemic rheumatic diseases, i.e. collagenosis, early rheumatoid arthritis, early osteoarthritis, anti-phospholipid syndrome and inflammation. The serological part of diagnosis of these diseases comprises testing for anti-nuclear antibodies (ANA), rheumatoid factor (RF), low levels of C-reactive protein (CRP), and disease-specific anti-phospholipid antibodies, e.g. anti-beta-2 glycoprotein I (anti-beta2 GPI). To eliminate the known problems of varying assay systems in this field, a novel, objective, rapid and reproducible approach to screen for such analytes in patient serum or plasma more efficiently is the application of EIAs on the fully-automated immunoassay analyser COBAS CORE (Roche Diagnostics GmbH, Mannheim, Germany). The combined use of the RES (COBAS CORE HEp2 ANA EIA, COBAS CORE RF EIA Quant, COBAS CORE CRP EIA Quant and COBAS CORE Anti-beta2 GPI EIA) is intended for patients sent to the laboratory with the primary suspicion of harbouring a systemic rheumatic disease.