Early endothelial progenitor cells in bone marrow are a biomarker of cell therapy success in patients with critical limb ischemia

Background aims. Endothelial progenitor cells (EPC) have been proposed for autologous angiogenic therapy. The objectives of this study were to quantify EPC in the peripheral blood and bone marrow mononuclear cells (BM-MNC) of patients with critical limb ischemia that had received BM-MNC as a cell therapy product, and to study the putative relationship between the presence of EPC and the process of neovascularization in toe or transmetatarsal amputation specimens. Methods. Early and late endothelial progenitor cells (CFU-EC and ECFC) were cultivated and quantified according to published methods in peripheral blood and BM-MNC from patients with critical limb ischemia (CLI; n == 11) enrolled in the OPTIPEC trial (http://clinicaltrials.gov/ct2/show/NCT00377897) to receive BM-MNC as a cell therapy product. Results. Eight out of the 11 patients had undergone amputations. Three of the patients displayed a neoangiogenic process that was associated with a higher number of CFU-EC in BM-MNC, while CD3