Quantification of circulating CD34+/KDR+/CD45dim endothelial progenitor cells: analytical considerations

Int J Cardiol. 2013 Sep 1;167(5):1688-95. doi: 10.1016/j.ijcard.2012.10.047. Epub 2012 Nov 19.


The discovery of peripheral circulating cells that contribute to vasculogenesis and endothelial repair was one of the most fascinating breakthroughs in the domain of vascular research during the last two decades. The population of vasculogenic cells however, is heterogeneous and can be analyzed using different approaches including in vitro culture and flow cytometry. Circulating CD34(+)/KDR(+)/CD45(dim) endothelial progenitor cells (EPC) have a great potential as biomarkers in various cardiovascular diseases. With the expanding interest in this field, the development of standardized protocols is critical. In this review we describe in detail the pre-analytical and analytical factors that should be taken into account when quantifying CD34(+)/KDR(+)/CD45(dim) EPC using flow cytometry. Moreover, technical suggestions in order to enhance accuracy and reproducibility of this enumeration are provided.

Keywords: Analysis; Biomarker; Endothelial progenitor cells; Flow cytometry.

Publication types

  • Review

MeSH terms

  • Animals
  • Antigens, CD34 / blood*
  • Cardiovascular Diseases / blood
  • Cardiovascular Diseases / immunology
  • Cardiovascular Diseases / pathology
  • Cell Movement / immunology
  • Endothelial Cells / chemistry
  • Endothelial Cells / metabolism*
  • Endothelial Cells / pathology
  • Flow Cytometry / methods*
  • Flow Cytometry / standards
  • Humans
  • Leukocyte Common Antigens / blood*
  • Neovascularization, Physiologic
  • Stem Cells / chemistry
  • Stem Cells / metabolism*
  • Stem Cells / pathology
  • Vascular Endothelial Growth Factor Receptor-2 / blood*


  • Antigens, CD34
  • Vascular Endothelial Growth Factor Receptor-2
  • Leukocyte Common Antigens
  • PTPRC protein, human