Changes in the number and biological ability of endothelial progenitor cells from peripheral blood of patients with systemic lupus erythematosus (SLE)

Objective To analyze the changes in number and biological ability of endothelial progenitor cells (EPCs) from peripheral blood of SLE patients. Methods Mononuclear cells (MNCs) were isolated by Ficoll density gradient centrifugation from peripheral blood of 20 female SLE patients and 20 healthy female controls. EPCs were identified by double staining using antibodies to CD34 and CD133, or antibodies to CD133 and vascular endothelial growth factor receptor 2 (VEGFR2). Phycoerythrin (PE) conjugated antiCD34, fluorescein isothiocyanate (FITC) conjugated anti-CD133 and APC conjugated anti-VEGFR2 antibodies were used in a three color flow cytometric analysis to determine the percentage of EPCs in peripheral MNCs.The proliferation and migration ability of EPCs were measured by MTT assay and modified millicell chamber assay, respectively. The adhesion activity of EPCs was evaluated by counting the number of adherent cells.Results The percentage and proliferation rate of EPCs in peripheral MNCs from female SLE patients were significantly lower than those from the healthy controls(4.49% ± 1.66% vs 20.81% ± 4.14%, 23.11% ± 3.16%vs 35.65% ± 1.74%, both P ＜ 0.01 ). The migration and adhesion ability of EPCs from SLE patients was impaired compared with those from the healthy controls (12.00 ± 2.12 vs 23.60 ± 3.0 cells/field, 22.43 ± 4.43vs 36.43 ± 3.69 cells/filed, both P ＜ 0.01 ). Conclusion There is a decrease in the number and an impairment in biological ability of EPCs in SLE patients. Key words: Lupus erythematosus, systemic;  Endothelium;  Stem cells;  Biology