Circulating mesenchymal stem cells in patients with hypertrophic cardiomyopathy

Background: This study examines the mobilization of mesenchymal stemcells (MSCs) in patients with hypertrophic cardiomyopathy (HCM) compared to healthy individuals. The pathogenesis of myocardial hypertrophy in HCM is not fully understood. MSCs are involved in the process of neovascularization, fibrosis, and ventricular wall remodeling. Methods and results: We included 40 patients with HCM and 23 healthy individuals. Using flow cytometry, we measured MSCs in peripheral blood, as a population of CD45-/CD34-/CD90+ cells and also as a population of CD45-/CD34-/CD105+ cells. The resulting MSC counts were expressed as percentages of the total cells. Patients with HCM were found to have a greater percentage of circulating CD45-/CD34-CD34-/CD90+ cells compared to controls (0.0041 +/- 0.005% vs. 0.0007 +/- 0.001%, respectively, Pb<.001). No significant difference in circulating CD45-/CD34-/CD105+ cells in the peripheral blood was found between HCM patients and controls (0.016 +/- 0.018% vs. 0.012 +/- 0.014%, respectively, P=.4). Notably, circulating CD45-/CD34-/CD90+ cells were positively correlated with left ventricular mass index (r=0.54, Pb<.001). Conclusions: Patients with HCM reveal an increased mobilization of MSCs compared to healthy individuals. Although further research is needed to reveal the clinical significance of our findings, our data open a new dimension in the pathophysiology of the disease and may indicate new future therapeutic possibilities. (C) 2015 Elsevier Inc. All rights reserved.