¹Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA

Correspondence: Dr MC Yoder, Departments of Pediatrics, Biochemistry and Molecular Biology, Indiana University School of Medicine, Herman B Wells Center for Pediatric Research, Cancer Research Institute, 1044 W Walnut Street, R4/402E, Indianapolis, IN, USA. E-mail: myoder@iupui.edu

Received 7 February 2007; Revised 28 February 2007; Accepted 1 March 2007; Published online 29 March 2007.

Abstract

Since 1997, postnatal vasculogenesis has been purported to be an important mechanism for neoangiogenesis via bone marrow (BM)-derived circulating endothelial progenitor cells (EPCs). Based on this paradigm, EPCs have been extensively studied as biomarkers to assess severity of cardiovascular disease and as a cell-based therapy for several human cardiovascular disorders. In the majority of studies to date, EPCs were identified and enumerated by two primary methodologies; EPCs were obtained and quantified following in vitro cell culture, or EPCs were identified and enumerated by flow cytometry. Both methods have proven controversial. This review will attempt to outline the definition of EPCs from some of the most widely cited published reports in an effort to provide a framework for understanding subsequent studies in this rapidly evolving field. We will focus this review on studies that used cell culture techniques to define EPCs.