[Circulating anticoagulants, antiphospholipids and thrombosis]

Antiphospholipids are auto-antibodies which can be detected both by immunological assays and by prolongation of coagulation test times. The latter has lead them to be called "lupus anticoagulant". They act preferentially on anionic phospholipids. Their presence increases the risk of thrombosis, especially in LED. They can appear at all ages, spontaneously, in autoimmune, infectious, or neoplastic pathologies, or after the intake of certain drugs. When these antibodies are associated with thrombosis or repeated fetal loss, the "antiphospholipid syndrome" is evoked. No causal relationship between the presence of these antibodies and thrombosis has yet been demonstrated. Standardization of laboratory diagnosis is not easy, particularly for weak positive samples. Because of their heterogeneity, an association of several tests is required for detection.