lupus anticoagulant


lu·pus an·ti·co·ag·u·lant (LA),

antiphospholipid antibody causing elevation in partial thromboplastin time; associated with venous and arterial thrombosis.

lupus anticoagulant

Lupus inhibitor Lab Medicine Any IgG or IgM class antibody that arise spontaneously in Pts with SLE; while LAs produce in vitro interference with phospholipid-dependent coagulation–eg, activated partial thromboplastin time–aPTT and kaolin clotting time assays in specimens from Pts with LE, they do not produce in vivo coagulopathy without other platelet or coagulation defects or drug-induced antibodies; LAs also occur in Pts with HIV, DVT, and other conditions Lab ↑ aPTT; LAs interfere with derivative assays for factors VIII, IX, XI, and XII. See Systemic lupus erythematosus. Cf Anticardiolipin antibodies.

lu·pus an·ti·co·ag·u·lant

(lū'pŭs an'tē-kō-ag'yŭ-lănt) Antiphospholipid antibody causing elevation in partial thromboplastin time; associated with venous and arterial thrombosis.

lupus anticoagulant

An antibody, or groups of antibodies, to negatively-charged phospholipids liable to be associated, paradoxically, with a tendency for blood to clot within the blood vessels. This may lead to deep vein thrombosis, arterial thrombosis with strokes and heart attacks and, in pregnant women, a strong tendency to fetal death and abortion. Some patients with LUPUS ERYTHEMATOSUS are known to have a positive result in tests for syphilis while not suffering from the disease. This effect is caused by the lupus anticoagulant. See also HUGHES' SYNDROME.