Serological detection of antiphospholipid antibodies

Antiphospholipid antibodies are heterogeneous. A subset of these antibodies is associated with arterial and venous thrombosis and recurrent pregnancy loss. This subset is best diagnosed by the lupus anticoagulant and solid-phase anticardiolipin tests. Solid-phase anticardiolipin tests use an enzyme-linked immunosorbent assay employing cardiolipin or other negatively charged phospholipids as the antigen. Patients with antiphospholipid antibodies who have experienced thrombotic disorders often have an IgG isotype, persistent at high levels for prolonged periods. The anticardiolipin test has been standardized so that antibody isotype and level can be determined reproducibly. Standardized serological tests to measure antiphospholipid antibodies will enable uniform identification of patients at risk for thrombosis and will help elucidate the origin and mechanisms of action of these antibodies.