Objective: Endothelial progenitor cells (EPCs) play an important role in vascular damage repair and it has been suggested that a decreased number of these cells is associated with increased subclinical atherosclerosis. Our study aim was to evaluate whether the number of circulating EPCs in patients with SLE is associated with subclinical atherosclerosis, the presence of cardiovascular (CV) risk factors and SLE-specific factors.
Methods: Forty-six female SLE patients were included. At the time of each patient's appointment, CV risk factors, SLE-specific factors and EPCs were assessed in peripheral blood by flow cytometry. Simultaneously, atherosclerosis was assessed by measuring the carotid-femoral pulse wave velocity (PWV) by Doppler velocimetry, intima media thickness (IMT) and carotid plaque by B-mode US scanning.
Results: Patients were classificated according to PWV following the reference values adjusted by age and blood pressure published by the European Society of Cardiology. Patients with pathological values of PWV showed a significant decrease of circulating EPC percentage compared with normal PWV patients. Decreased EPC counts were also associated with certain risk factors, including hypertension, tobacco use, impaired glucose metabolism, and metabolic syndrome, and correlate with high levels of high-sensitivity CRP (hsCRP) or fibrinogen. The presence of carotid plaque and IMT measurement were unrelated with EPC quantification.
Conclusion: Patients with a reduced percentage of EPCs showed pathological arterial stiffness and association with certain CV risk factors, suggesting that the measurement of circulating EPCs can be used as a biological marker to determine subclinical atherosclerosis in SLE.
Keywords: arterial stiffness; endothelial progenitor cells; subclinical atherosclerosis; systemic lupus erythematosus.