[Antiphospholipid antibodies: cause of thrombosis or an epiphenomenon?]

Antiphospholipid antibodies (aPL) present in systemic lupus erythematosus and the primary antiphospholipid syndrome are a well-known risk factor for thrombosis. Most of them require the presence of a cofactor, beta 2-glycoprotein I for anticardiolipin antibodies, prothrombin for lupus anticoagulant. These aPL are of the "immune" type. APL are also found in various non-immunological conditions, in which repeated endothelial or membranous damages appear to be frequent, but thromboses are rare. Most of these aPL are cofactor-independent, except those induced by chlorpromazine, and might belong to "natural" antibodies.