Increased circulating endothelial progenitor cells in septic patients:Correlation with survival

Objective: Endothelial damage and detachment of endothelial cells are known to occur in septic patients. Thus, recruitment of circulating enclothelial progenitor cells (cEPCs) to these lesions might have a beneficial effect on the clinical course in septic patients. Therefore, we were interested in whether EPCs, detected by flow cytometry, are increasingly mobilized during sepsis and if this mobilization is associated with clinical outcome.Design: Prospective, nonrandomized study.Setting. Intensive care unit of a university hospital.Patients: Patients with (n = 32) and without (n = 15) sepsis and healthy volunteers (n = 15).Interventions: Peripheral blood mononuclear cells were isolated by Ficoll density gradient centrifugation, and cEPCs were characterized by three-color fluorescence flow cytometry using antibodies against CD133, CD34, and vascular endothelial growth factor receptor-2. Serum concentrations of vascular endothelial growth factor, granulocyte macrophage-colony stimulating factor, and erythropoietin were determined by enzyme-linked immunosorbent assay. Severity of sepsis was assessed according to Acute Physiology and Chronic Health Evaluation II scoring.Measurements and Main Results: In septic patients, the number of cEPCs was significantly higher than in nonseptic intensive care unit patients (p <.05) and healthy controls (p <.02). Nonsurvivors (n = 8), defined as death within 28 days after onset of sepsis, had significantly lower numbers of cEPCs than survivors (n = 24) (p <.0001). The number of cEPCs was correlated with survival in septic patients. Serum vascular endothelial growth factor concentrations were significantly higher in septic patients compared with nonseptic intensive care unit patients and healthy controls (p <.01) and correlated with the cEPC numbers (p <.0001). Similar findings were observed for granulocyte macrophage-colony stimulating factor and erythropoietin.Conclusions: Our data suggest that cEPC enumeration in peripheral blood of septic patients might be a valuable marker to assess the clinical outcome in these patients.