Circulating endothelial cells are associated with future vascular events in hemodialysis patients

Abstract

Background. Endothelial dysfunction and injury are thought to have a key role in the pathogenesis of cardiovascular disease. We hypothesized that the presence of circulating endothelial cells, as a reflection of ongoing endothelial injury, might provide a novel means for predicting cardiovascular events in hemodialysis subjects who are known to be at marked increased risk for cardiovascular disease. Methods. Circulating endothelial cell number was determined in 29 hemodialysis patients who were then followed for vascular events for 470 172 days. In a second cohort of 44 hemodialysis patients, circulating endothelial cell number was correlated with markers of inflammation, namely high sensitivity C-reactive protein (hs-CRP), interleukin (IL)-6, IL-10, and monocyte chemoattractant protein-1 (MCP-1), and endothelial dysfunction, soluble vascular cellular adhesion molecule-1 (VCAM-1). Results. Seven of the 19 subjects with elevated circulating endothelial cells (defined as > 19 cells per mL) had cardiovascular (N = 5) or vascular (N = 5) events during follow-up, whereas no events occurred in subjects with a low number of circulating endothelial cells (less than or equal to19 CECs per mL) (P = 0.04 by Fisher Exact Test). In the second cohort, the number of circulating endothelial cells was independent of all markers of inflammation and endothelial dysfunction. Conclusion. In this hemodialysis population, an increase in circulating endothelial cells was found to predict the development of cardiovascular and vascular events, and to be independent of other known markers of inflammation or endothelial dysfunction. These studies suggest that circulating endothelial cells may be a novel way to assess endothelial health and cardiovascular risk. Further studies to investigate the utility of circulating endothelial cells in predicting cardiovascular risk are needed.