A disorder caused by the presence of autoantibodies directed against phospholipids, causing a hypercoaguable state, which may result in blood clots, stroke, heart attack, and in women, significant pregnancy-related complications, including miscarriage and still birth. The syndrome is often associated with other autoimmune disorders, most commonly lupus erythematosus, and infections, including syphilis and Lyme disease. An autoimmune disease that is characterized by recurrent venous or arterial thrombosis and/or fetal losses associated with characteristic elevated levels of antibodies, including lupus anticoagulant (LAC), anticardiolipin (aCL) antibody, and anti-beta-2glycoprotein I antibody, directed against membrane anionic phospholipids.\n