Endothelial Progenitor Cells Are Decreased in Blood of Cardiac Allograft Patients With Vasculopathy and Endothelial Cells of Noncardiac Origin Are Enriched in Transplant Atherosclerosis

Abstract

Background— Recent studies in animals suggest that circulating recipient endothelial precursors may participate in the biology of transplant vasculopathy. It is currently unknown whether a similar interaction between recipient endothelial cells and the vessel wall occurs in human subjects undergoing allogeneic cardiac transplantation. Methods and Results— Circulating endothelial cells and endothelial progenitor cells (EPCs) were quantified in 15 cardiac transplantation subjects with and without angiographic evidence of vasculopathy. In a separate series of experiments, the origin (donor or recipient) of transplant plaque endothelial cells was assessed in subjects who had undergone a gender-mismatched cardiac transplantation and had histological evidence of severe vasculopathy at the time of heart explantation. Circulating EPC outgrowth colonies in peripheral blood were significantly reduced in subjects with transplant vasculopathy compared with those without angiographic evidence of disease (EPC colony-forming units [CFU _EPC ]: 4.5±1.9 versus 15.1±3.7, P Conclusions— These data suggest that the human cardiac transplant arteriopathy is associated with reduction in circulating endothelial precursors and with seeding of recipient-derived endothelial cells at the site of plaque development.