Diagnosis and Management of the Antiphospholipid Syndrome

The antiphospholipid syndrome is a systemic autoimmune disease defined by thrombotic or obstetrical events that occur in patients with persistent antiphospholipid antibodies.1 Thrombotic antiphospholipid syndrome is characterized by venous, arterial, or microvascular thrombosis. Patients with catastrophic antiphospholipid syndrome present with thrombosis involving multiple organs.2 Obstetrical antiphospholipid syndrome is characterized by fetal loss after the 10th week of gestation, recurrent early miscarriages, intrauterine growth restriction, or severe preeclampsia.1 The major nonthrombotic manifestations of antiphospholipid- antibody positivity include valvular heart disease, livedo, antiphospholipidantibody- related nephropathy, thrombocytopenia, hemolytic anemia, and cognitive dysfunction. The antiphospholipid syndrome is often associated with other systemic autoimmune diseases such as systemic lupus erythematosus (SLE); however, it commonly occurs without other autoimmune manifestations (primary antiphospholipid syndrome). Although criteria for classification of the antiphospholipid syndrome have been proposed, 1 the definition of clinically significant antiphospholipid-antibody positivity is not well established, and thrombosis is generally multifactorial. Our objectives are to help both general practitioners and specialty-based physicians recognize and accurately diagnose the antiphospholipid syndrome, as well as to provide basic recommendations for the treatment of patients who are persistently positive for antiphospholipid antibodies. Given the limited number of well-designed, randomized, controlled trials, our recommendations are evidence-based whenever possible but often reflect expert opinion. Copyright © 2018 Massachusetts Medical Society.