Abstract Objectives SLE patients have an enhanced risk of atherosclerosis and cardiovascular disease. However, the increased prevalence of cardiovascular disease is not fully explained by traditional Framingham cardiovascular risk factors. Specific features of low-density lipoprotein (LDL) particles, other than plasma concentration, may induce accelerated atherosclerosis at early stages in these patients. Thus, we aimed to explore the impact of LDL from both active and inactive SLE patients on human aortic endothelial cells. Methods Human aortic endothelial cells were stimulated with the same concentration of LDL particles isolated from pooled serum that was collected from 13 SLE patients during both active and inactive states. Gene expression and cell migration assays were performed. Results Circulating LDL particles obtained from healthy volunteers and SLE patients in both remission and flare states were comparable in terms of number, cholesterol and triglyceride content, and net electric charge. Stimulation of cells with LDL from active SLE patients induced the expression of vascular cell adhesion molecule 1 (∼2.0-fold, P < 0.05), monocyte chemoattractant protein 1 (∼2.0-fold, P < 0.05) and matrix metallopeptidase 2 (∼1.6-fold, P < 0.01) compared with cells stimulated with LDL from inactive SLE patients. Additionally, LDL extracted from active patients increased cell migration in a wound-healing assay (1.4-fold, P < 0.05). Conclusion Our data show that, at the same LDL concentration, LDL from active SLE patients had increased proatherogenic effects on endothelial cells compared with LDL from the same patients when in an inactive or remission state.