Antiphospholipid Antibodies Do Not Seem to Be Associated With Deep Vein Thrombosis: A Case Control Study

Antiphospholipid antibodies (APAs) are associated with venous thromboembolism in patients with systemic lupus erythematosus (SLE). In patients without SLE, but with deep vein thrombosis (DVT) this association is established only for patients with lupus anticoagulant (LA). In a case-controlled study APAs were determined in 171 consecutive outpatients who underwent phlebography at the first episode of clinically suspected DVT of lower limbs. Phlebography confirmed the presence of DVT in 54 (32%) patients and excluded it in 117. Antiphospholipid antibodies (exluding LA) were detected in 5 (9.2%) of the 54 patients with DVT and in 7 (5.9%) of the 117 subjects without DVT, The prevalence of APAs tended to be higher in patients with DVT than in patients without DVT, but the difference was not statistically significant (p = 0.3%). Antiphospholipid antibodies in the absence of LA are not associated with DVT in symptomatic patients. Therefore future studies should be performed before changing our clinical approach in APA-A positive but LA-negative patients. Key Words: Antiphospholipid antibodies-Deep vein thrombosis.