ANTIBODIES: The term antiphospholipid antibodies (APLA) regroups a family antibodies that recognise anionic and neutral phospholipids, which are the components of plasmatic cell membranes. These antibodies expose the patients to risk of venous and/or arterials thromboembolic accidents and obstetrical complications such as repeated early miscarriage or, more rarely foetal loss. A SYNDROME: The presence of such antibodies associated with this type of clinical events defines the antiphospholipid antibody syndrome (APS) that can be isolated and defined as primary or associated with systemic lupus erythematosus. The APS represents one of the most frequent thrombophilic states. The two APLA used in the diagnosis of APS are the circulating lupus anticoagulant and anticardiolipid antibodies. Indeed, these are the only APS for which research techniques have been standardised. PERSONALISED TREATMENT: Treatment relies on anticoagulants. Steroids are unnecessary except when APS is associated with lupus during the catastrophic syndrome of APS, characterised by multiorgan failure related to thrombotic microangiopathy lesions. The modalities of use of anticoagulants (indications, dose and duration) remain debated and underline the great risk of recurrent thrombosis on withdrawal of treatment.