Antiphospholipid Syndrome
Overview
Plain-Language Overview
Antiphospholipid Syndrome is a condition that affects the body's blood clotting system. It involves the immune system mistakenly producing antibodies that target certain normal proteins in the blood, called antiphospholipid antibodies. These antibodies increase the risk of forming dangerous blood clots in veins and arteries, which can lead to serious problems like stroke, deep vein thrombosis, or pregnancy complications such as miscarriage. The condition primarily affects the circulatory system and can cause symptoms related to blocked blood flow. People with this syndrome may experience repeated clotting events or pregnancy losses. It is a chronic disorder that requires careful medical evaluation to manage the risks.
Clinical Definition
Antiphospholipid Syndrome is an autoimmune disorder characterized by the persistent presence of antiphospholipid antibodies (including lupus anticoagulant, anticardiolipin, and anti-β2 glycoprotein I antibodies) that promote a hypercoagulable state. The core pathology involves antibody-mediated activation of endothelial cells, platelets, and complement, leading to increased thrombosis in both arterial and venous systems. It can occur as a primary condition or secondary to autoimmune diseases such as systemic lupus erythematosus. Clinically, it is significant for causing recurrent venous thromboembolism, arterial thrombosis, and pregnancy morbidity including recurrent miscarriages, fetal death, or premature birth due to placental insufficiency. Diagnosis requires both clinical events and laboratory evidence of antibodies on two or more occasions at least 12 weeks apart. The syndrome is a major cause of acquired thrombophilia and requires lifelong management to prevent complications.