VASCULAR RESPONSIVENESS IN THE MICROCIRCULATION OF PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS IS NOT IMPAIRED

Objectives. As endothelial dysfunction is one of the earliest signs of atherosclerosis, which is accelerated in SLE, we assessed whether vascular responses of the cutaneous microcirculation are disturbed in systemic lupus erythematosus (SLE) patients and influenced by Raynaud’s phenomenon (RP). Methods. Laser Doppler fluxmetry (LDF) was used combined with iontophoresis of acetylcholine (ACh) and sodium nitroprusside (SNP), an endothelium-dependent and endothelium-independent vasodilator, respectively. Forty-two SLE patients with quiescent disease, 12 of whom had RP, and 19 age- and sex-matched controls were included. Furthermore, traditional and non-traditional risk factors for cardiovascular disease (CVD) were assessed, and markers of inflammation and endothelial activation were measured. Results. Vascular responses of SLE patients without RP did not differ from controls. However, SLE patients with RP exhibited decreased vasodilatation compared to controls. SLE patients with RP also had longer arrival times of ACh and SNP than controls. Markers of inflammation and von Willebrand factor were increased in SLE patients. Smoking, the presence of SLE and RP were negatively associated with vascular responses in univariate analysis. In multivariate analyses, the only independent variable of vascular responses to ACh and SNP was the presence of RP. Conclusions. Despite signs of endothelial activation, SLE patients with quiescent disease do not have altered vascular responses in the microcirculation compared to controls. In SLE patients with RP, cutaneous vascular responses to both ACh and SNP are impaired. Therefore, LDF of the microcirculation seems not the appropriate method to distinguish those SLE patients with an increased risk to develop CVD. Laser Doppler fluxmetry in SLE 5