What should patients know about antiphospholipid antibodies and antiphospholipid syndrome?

Abstract

Antiphospholipid syndrome (APS) is a systemic autoimmune disorder in which the immune system makes antibodies (antiphospholipid antibodies or aPL) that increase the risk to form blood clots. The most commonly used tests to detect aPL are Lupus Anticoagulant test, Anticardiolipin Antibody Test, and Anti-Beta-2-gylycoprotein-I Test. Among the various manifestations of APS, the most common clinical problems are blood clots in the veins of the legs, strokes, and miscarriages. Antiphospholipid antibodies can occur in otherwise healthy individuals or in patients with other autoimmune disorders such as systemic lupus erythematosus (SLE). Having a positive aPL test does not mean the person has APS; 30–40% of SLE patients may have aPL, but only a small percentage develop APS. For all aPL-positive patients with or without SLE, whether or not they have had a blood clot in the past, the first essential step in the management is understanding the risk of thrombosis and eliminating reversible risk factors known to increase risk of clotting. Further management of aPL-positive patients depends on the individual patient, his or her aPL-related clinical manifestations, and additional medical conditions.