Assessment of endothelial damage/dysfunction: a focus on circulating endothelial cells

Endothelial injury represents a major initiating step in the pathogenesis of vascular disease and atherosclerosis. The identification and quantification of circulating endothelial cells (CECs) has evolved as a novel marker of endothelial function. As a technique, it correlates with other markers of endothelial function such as flow-mediated dilation, the measurement of von Willebrand factor, and tissue plasminogen activator. Quantification of CECs is difficult due to low numbers, variable morphology, and a lack of standardization in current techniques used. CECs appear to be a different population of cells to endothelial progenitor cells. Increased CECs have been noted in a number of disease states and is evolving as a novel method of assessment of both disease severity and response to treatment.