Antibody specificity and related clinical features in antiphospholipid syndrome

Abstract The concept of antiphospholipid syndrome (APS) has been widely accepted. Antiphospholipid antibodies originally included anticardiolipin antibodies and lupus anticoagulants. However, recent advances have shown that most pathogenic antiphospholipid antibodies are directed to phospholipid binding proteins such as β2-glycoprotein I (β2-GPI) and prothrombin. Other candidates for antigens of so-called antiphospholipid antibodies are protein C, protein S, factor V, factor X, annexin V, high and low molecular weight kininogens, and complex with β2-GPI and oxidized low-density lipoprotein (LDL). These autoantibodies directed to different phospholipid binding proteins are present in the blood stream, and contribute to triggering procoagulant effects on endothelial cells and platelets, leading to thrombosis. The heterogeneity of these antiphospholipid antibodies appears to explain various clinical manifestations in patients with APS. The preliminary classification criteria for definite APS and a general management policy have been proposed, although successful treatment of patients with antiphospholipid antibodies have only been shown by retrospective studies. Further prospective investigations are required to confirm the diagnostic and therapeutic criteria for patients with APS.