Link between erythropoietin release and mobilization of endothelial progenitor cells in acute myocardial infarction The opinions expressed in this article are not necessarily those of the Editors of the European Heart Journal or of the European Society of Cardiology.

Abstract

Myocardial infarction (MI) is associated with the increase in plasma levels of inflammatory and haematopoietic cytokines and mobilization of a heterogenous population of cells which consists predominantly of committed lineages (monocytes, polymorphonuclear granulocytes, and lymphocytes), as well as numerous types of stem/progenitor cells [endothelial progenitor cells (EPCs), haematopoietic stem cells (HSCs), and mesenchymal stem cells (MSCs)]. The number of circulating EPCs may have a prognostic value; however, this concept remains to be proved in large prospective studies.1,2 The number of circulating EPCs and mature endothelial cells (ECs) supposedly reflects the vascular endothelial injury and the repair mechanisms activated to restore the endothelial integrity. The article by Ferrario et al. 3 investigates the haemoglobin-independent increase of the plasma levels of erythropoietin (Epo) in patients with acute MI and seeks to confirm the hypothesis that changes of Epo levels are associated with the mobilization of EPCs and ECs from the bone marrow. The paper by Ferrario et al. confirms previous work by the same group, published in 2005, describing the mobilization of heterogenous population of progenitor cells in patients with acute MI.4 In the present paper the authors identify two populations of immature EPCs (CD34+CD133+VEGFR2+ and CD34+CD117+VEGFR2+), more mature EPCs, and mature ECs (CD34+VEGFR2+). This study continues the search for humoral factors involved in EPC mobilization following acute myocardial ischaemia and vascular injury. One of the important issues … *Corresponding author. Tel: +48 604188669; fax: +48 32 2523930. E-mail address: wojwoj{at}mp.pl