[Antiphospholipid antibodies]

The term 'antiphospholipids' (APL) refers to heterogeneous auto-antibodies, including anticardiolipins detected by immunological methods and lupus anticoagulants detected by clotting tests. APL are currently of considerable interest, both from a clinical and a biological point of view, since their presence is associated with thromboembolic events. In this review, the authors emphasize the diversity of the clinical settings where APL are diagnosed and investigate the relationship between APL and thrombosis. The heterogeneity of APL and the lack of standard techniques make their laboratory diagnosis difficult and require the use of various types of tests. Several pathogenic mechanisms, all related to a possible effect of APL on the antithrombotic functions of vascular endothelium, have been proposed: decrease in prostacyclin synthesis, induction of procoagulant activity, inhibition of the endothelial anticoagulant functions, and impairment of fibrinolysis. Given the heterogeneity of these antibodies, it is unlikely that a single mechanism can account for their prothrombotic effect.