Antiphospholipid Syndrome

Antiphospholipid Syndrome (APS) is an autoimmune disorder in which the body produces antibodies that mistakenly attack phospholipids, increasing the risk of abnormal blood clots in arteries and veins, leading to serious complications such as deep vein thrombosis (DVT), stroke, heart attack, and pregnancy loss. APS can occur on its own (primary APS) or in association with another autoimmune condition, most often systemic lupus erythematosus (SLE).

Blood clot-related symptoms: Deep vein thrombosis, Pulmonary embolism, Stroke or TIA, Heart attack, Retinal vein thrombosis. Pregnancy-related symptoms: Recurrent miscarriages, Stillbirth, Preeclampsia, Intrauterine growth restriction. Other signs: Livedo reticularis, Chronic headaches or migraines, Low platelet count (thrombocytopenia), Cognitive or memory problems, Seizures (rare).

Caused by autoantibodies that target phospholipid-binding proteins, especially beta-2 glycoprotein I and prothrombin, leading to abnormal clot formation. Triggers may include genetic susceptibility, infections, medications, or other autoimmune diseases particularly lupus.

Requires both clinical criteria (evidence of blood clots or pregnancy complications) and laboratory criteria (positive antibody tests). Required lab tests: Lupus anticoagulant (LA); Anti-cardiolipin antibodies (aCL); Anti-beta-2 glycoprotein I antibodies. Must be positive on 2 occasions at least 12 weeks apart.

Lifelong anticoagulation with warfarin (target INR 2.0-3.0, or higher in high-risk cases); Low-dose aspirin may be added; Heparin and aspirin during pregnancy (warfarin avoided due to fetal risk); DOACs generally not recommended for APS with high-risk antibodies; Hydroxychloroquine in lupus-associated APS.

With proper anticoagulation, many patients live full, healthy lives. Risk of recurrence is high without treatment (up to 50%). Appropriate treatment significantly improves outcomes in pregnant women. Catastrophic APS (CAPS) carries a high mortality rate (30-50%) without immediate intensive care.

1-5% of the general population carry antiphospholipid antibodies. Symptomatic APS affects approximately 40-50 per 100,000 people. Women are affected 3-5 times more often than men.