Endothelial progenitor cells: mainly derived from the monocyte/macrophage-containing CD34- mononuclear cell population and only in part from the hematopoietic stem cell-containing CD34+ mononuclear cell population.

Abstract

To the Editor: In their very interesting paper, Rehman et al1 demonstrate that the vast majority of peripheral blood–derived acLDL+ Ulex-lectin+ cells in culture—often referred to as endothelial progenitor cells (EPC)—express monocyte/macrophage markers, indicating that they originate mainly from the monocyte/macrophage lineage. They suggest that only a small population of true stem cells/progenitor cells and endothelial cells exists that may originate directly from the hemangioblast or from hematopoietic stem cells. Our recent observations support their findings that the majority of EPC are derived from the monocyte/macrophage–containing CD34− mononuclear cell population. Nevertheless, we could also identify and quantify a minor proportion of EPC that has its origin in the hematopoietic stem …