Antibodies against phospholipids and β2-glycoprotein I increase the risk of recurrent venous thromboembolism in patients without systemic lupus erythematosus

Abstract

We studied the prognostic significance of antiphospholipid antibodies for recurrence of venous thromboembolism (VTE), in 71 patients admitted for acute VTE (deep-vein thrombosis or pulmonary embolism) in a single internal medicine unit. Lupus anticoagulant (LA), antibodies directed against β2-glycoprotein I (β2GPI) and antibodies against both β2GPI and a mixture of phospholipids (cardiolipin, phosphatidylserine and phosphatidic acid) (APAs) were measured. The patients were followed-up (mean 4.9 years) to determine the time to the next VTE. We found LA in nine patients, anti-β2GPI antibodies seven patients and APAs in six patients. The cumulative risk of recurring VTE was higher in patients with β2GPI-binding antibodies (hazard ratio 12.6, 95% CI 1.5-104.9; p = 0.0029). The risk associated with APAs was 11.5 (95% CI 1.3-98.9; p = 0.0049) and that for LA was 3.7 (95% CI 0.9-15.6; p = 0.055). The risk of VTE recurring was higher both in patients with antibodies directed against β2GPI, and in patients with antibodies directed against β2GPI and a mixture of phospholipids, than in patients without these antibodies.