RESUMO
CONTEXT: Systemic lupus erythematosus (SLE) is associated with an increased risk of atherosclerosis; endothelial dysfunction represents the first step in its pathogenesis. OBJECTIVE: To assess endothelial dysfunction in SLE by circulating endothelial cells (CECs) and to characterize SLE-specific factors that contribute to its appearance. DESIGN: Case-control study was conducted on 60 subjects, divided into 2 groups: group A (30 patients with SLE) and group B (30 healthy sex- and age-matched controls). Total cholesterol, triglycerides, antinuclear antibodies, anti-double-stranded DNA antibodies, and C3 were determined in all patients. Systemic lupus erythematosus activity was assessed using the SLE Disease Activity Index. Endothelial function was assessed by means of flow-mediated dilation of the brachial artery using B-mode ultrasonography and relative quantification of CD 146 mRNA by real-time polymerase chain reaction. RESULTS: The group of SLE patients was formed of 20 females and 10 males, with a mean age of 31.16 ± 9.69 years. The values of SLE-specific tests and SLE Disease Activity Index were represented by anti-double-stranded DNA antibodies 160 ± 40.5, C3 68.91 ± 11.91 mg/dL, total cholesterol 188.66 ± 49.63 mg/dL, triglycerides 143.41 ± 46.26 mg/dL, and SLE Disease Activity Index 12.66 ± 3.70. Values for flow-mediated dilation were 8.85% ± 2.02% (group A) and 20.33% ± 6.19% (group B), P < .001, and CECs were 300 ± 40.5 µL⻹ blood (group A) and 10 ± 2.5 µL⻹ blood (group B). The statistical analysis showed a strong inverse correlation between CECs and SLE Disease Activity Index, a strong correlation between CECs and C3, a strong correlation between CECs and anti-double-stranded DNA antibodies, and a moderate inverse correlation between CECs and total cholesterol. CONCLUSION: Endothelial dysfunction is present in SLE patients even in the absence of traditional cardiovascular risk factors due to disease activity.