[Antiphospholipid antibody syndrome].

An Antiphospholipid syndrome (APS) was diagnosed in a patient who had massive pulmonary embolisation from a right atrial thrombus. The (APS) is an autoimmune disease defined by the presence in the serum of at least one type of autoantibody known as antiphospholipid antibody (aPL) and the occurrence of at least one clinical feature from a list of potential disease manifestations, the most common of which are venous or arterial thrombosis, recurrent fetal loss and thrombocytopenia. The prevalence of APS in a series of patients from internal medicine is 2 percent. The mean age at diagnosis is 42 years. The pathogenesis of APS associated with clinical manifestations seems to result from a variety of effects of aPL on coagulation pathways,but the exact mechanism of action of aPL on these pathways is not completely understood. The APS can be primary or secondary to a disease. Thrombosis is the most frequent clinical manifestation of APS. It involves many organs, resulting on multiorgan failure: this is the catastrophic APS. The treatment is the same whether the APS is primary or secondary. It is mainly symptomatic and consists in the prevention of thrombosis at short and long-term by using aspirin and/or anticoagulants. Immunomodulating treatment can be offered but its efficiency at long-term is unproven. The mortality varies according to the etiology and the clinical manifestations. The mortality rate is 50 percent in catastrophic APS, despite treatment.