Antiphospholipid Syndrome
Antiphospholipid syndrome (APS) is an autoimmune disorder characterized by venous and/or arterial thromboembolic events, pregnancy morbidity, and the presence of antiphospholipid antibodies. These autoantibodies bind to β2-glycoprotein I and other phospholipid-binding proteins, but the actual mechanism whereby they result in a hypercoagulable state remains uncertain. Antiphospholipid antibodies are detected in the clinical laboratory by serological assays (anticardiolipin and anti-β2-glycoprotein-I antibodies) and coagulation tests (lupus anticoagulant). Patients with venous and/or arterial thromboembolism are treated with chronic anticoagulant therapy. Low-molecular-weight heparin and aspirin therapy improves outcomes in patients with APS and recurrent pregnancy loss. Catastrophic APS is a rare presentation characterized by microvascular thrombotic occlusions affecting three or more organ systems and is frequently treated with corticosteroids, anticoagulation, plasmapheresis, and/or intravenous immunoglobulin.
