Summary

Increased numbers of circulating endothelial cells (CEC) in peripheral blood have been observed in diseases with vascular involvement, and are considered a promising surrogate marker for vascular damage. It was the objective of this study to evaluate the correlation between putative soluble markers of endothelial injury, activation, and endothelial proliferation, and absolute numbers of CEC. CEC were evaluated in 125 healthy donors and 40 patients with metastatic carcinoma by automated CD146 driven immunomagnetic isolation. Plasma concentrations of E-selectin, endoglin, and thrombomodulin were assessed by ELISA in plasma obtained from 40 healthy donors and 40 patients. CEC numbers in blood were positively correlated with plasma thrombomodulin levels, but not with levels of E-selectin and endoglin. Multivariate analysis demonstrated a significant increase in CEC numbers with age. The levels of plasma biomarkers were not influenced by age. Higher levels of thrombomodulin and E-selectin were observed in males when compared to females. In conclusion, CEC numbers correlate positively with plasma levels of thrombomodulin.