The Antiphospholipid Syndrome

The antiphospholipid (aPL) antibody syndrome is an autoimmune condition in which vascular thrombosis and/or recurrent pregnancy losses occur in patients with laboratory evidence for antibodies that bind to phospholipids. There have been significant advances in the recognition of the role of phospholipid- binding cofactors, primarily β₂GPI, as the true immunologic targets of the antibodies. Recent evidence suggests that the antibodies disrupt phospholipid-dependent anticoagulant mechanisms and/or that aPL antibodies induce the expression of procoagulant and proadhesive molecules on endothelial cells. Current diagnosis is based on clinical findings and empirically derived tests, such as assays for antibodies that bind to phospholipids or putative cofactors and coagulation assays that detect inhibition of phospholipid- dependent coagulation reactions. Current treatment relies primarily on anticoagulant therapy. Research advances are expected to bring mechanistically based diagnostic tests and improved therapy that target the roots of the disease process.