Antiphospholipid antibodies (APLA) represent a heterogenous group of antibodieswhichmayaffect different coagulation cascade pathways by analogy with involvement of phospholipid surfaces in various steps of blood coagulation. The result of this process leads usually to some degree of thrombophilia. The most frequently detected APLA are represented by lupus anticoagulant (LA) and anticardiolipin antibodies (aCL). Protein cofactors of antigen determinantswhich are involved inAPLAgeneration are β2-GPI, prothrombin, proteinC, protein S, annexinV, high andlow molecular mass kininogen, factor XII, thrombomodulin and tissue plasminogen activator. A majority of these factors participate in the initial phase of coagulation cascade or in additional mechanisms of checking on the cascade. It is possible that antibodies against these proteins can affect coagulation balance. The syndrome represented by positive LA and aCL antibodies has been called antiphospholipid syndrome. The basic concept of this syndrome is characterized by thrombophilic syndrome. The main spectrum of clinical manifestations of APS includes arterial and venous thromboses, spontaneous fetal losses and thrombocytopenia.

        Key words: lupus anticoagulant, antiphospholipid syndrome