Impaired endothelial function and increased carotid intima-media thickness in association with elevated von Willebrand antigen level in primary antiphospholipid syndrome.

Primary antiphospholipid syndrome (APS) is characterized by venous or arterial thrombotic events and/or recurrent abortions, fetal death, preeclasmpsia, eclampsia in the presence of anticardiolipin antibodies or lupus anticoagulant, in the absence of accompanying diseases. Antiphospholipid antibodies can activate endothelial cells, and were recently implicated in atherosclerosis. To assess potential endothelial impairment and early signs of atherosclerosis, flow-mediated (endothelium-dependent) and nitrate-mediated (endothelium independent) vasodilation, as well as von Willebrand factor antigen level and carotid artery intima-media thickness (IMT) were measured in patients with primary antiphospholipid syndrome and in healthy controls. Flow-mediated vasodilation in patients with primary APS was significantly lower than that of controls (3.43 +/- 2.86% versus 7.96 +/- 3.57%; P < 0.0001). We also found significantly higher von Willebrand antigen levels in patients with primary APS than in the control group (157.91 +/- 52.45% versus 125.87 +/- 32.8%; P = 0.012). Moreover, carotid artery IMT was significantly larger in the primary APS group compared to controls (0.714 +/- 0.2 mm versus 0.58 +/- 0.085 mm; P = 0.0037). Our results reflect ongoing endothelial damage and accelerated atherosclerosis in patients with primary APS, and suggest that vasoprotective therapy may be beneficial in the treatment of these patients.