The use of laboratory methods in differential diagnosis and treatment of SLE and antiphospholipid syndrome.

The detection of autoantibodies has become an important component in the diagnosis and management of systemic lupus erythematosus (SLE) and antiphospholipid syndrome. Their importance lies in the fact that they are not only markers of the disease and used as part of a diagnostic panel, but many of them also show correlation with disease activity. All antibody testing should be interpreted in the context of the clinical features. The antinuclear antibodies test is an effective screening assay in patients with clinical features of SLE. The combination of antinuclear antibodies test, dsDNA and ENA (Ro, La, Sm, RNP) antibodies help to establish the diagnosis of most patients with SLE. New antibodies, such as antinucleosomes and anti-C1q, appear to be useful for SLE diagnosis, monitoring disease activity and predicting renal flares, particularly in dsDNA-negative patients. Anticardiolipin antibodies and lupus anticoagulant are the tests most commonly used in the diagnosis of antiphospholipid syndrome. However, the use of anti-beta(2)-glycoprotein I as a routine diagnostic test remains controversial.