Characterization of altered patterns of endothelial progenitor cells in sickle cell disease related pulmonary arterial hypertension

AbstractEndothelial dysfunction plays an important role in the pathogenesis of pulmonary arterial hypertension (PAH) in sickle cell disease (SCD). A variety of evidence suggests that circulating endothelial progenitor cells (EPCs) play an integral role in vascular repair. We hypothesized that SCD patients with PAH are defcient in EPCs, potentially contributing to endothelial dysfunction and disease progression. The number of circulating CD34+/CD14−/CD106+ EPCs was signifcantly lower in SCD patients with PAH than without PAH (P=0.025). CD34+/CD14−/CD106+ numbers signifcantly correlated with tricuspid regurgitation velocity (TRV, r=-0.44, P=0.033) 6-minute walk distance (6MWD, r= 0.72, P=0.001), mean pulmonary artery pressure (mPAP, r= -0.43, P=0.05), and pulmonary vascular resistance (PVR, r=−0.45, P=0.05). Other EPC subsets including CD31+/CD133+/CD146+ were similar between both groups. Numbers of EPCs did not correlate with age, sex, hemoglobin, WBC count, reticulocyte count, lactate dehydrogenase (LDH),...