Diagnostic Trends in Laboratory Evaluation of Antiphospholipid Syndrome
Antiphospholipid syndrome (APS) is an autoimmune disease characterized by vascular thrombosis and/or pregnancy-related morbidity accompanied by persistently positive antiphospholipid (aPL) antibodies. Current recommended laboratory tests include immunoassays for detecting IgG and IgM antibodies to cardiolipin (aCL), and beta-2 glycoprotein I (anti-β2GPI) as well as coagulation-based assays for lupus anticoagulant activities. It is increasingly recognized that a subset of patients with classical features of APS do test negative for the recommended criteria aPL tests. While APS experts acknowledge that such patients may have clinical features that are not of an autoimmune etiology, ‘seronegativity’ for criteria autoantibodies may also be due in part to the absence of harmonization and/or standardization of current aPL antibody assays. Alternatively, patients ‘seronegative’ for the recommended tests may have aPL antibodies that target other antigens involved in the pathogenesis of APS with possible relevance for risk assessment and treatment. This presentation will focus on current and emerging aPL antibodies and the evolving concepts for their use in the evaluation and management of APS.
