Inhibition of endothelial progenitor cells in the first 24 hours of an acute ischemic cerebrovascular event

Background: Endothelial progenitor cells may have a role in ongoing endothelial repair. Impaired mobilization or depletion of these cells may contribute to progression of vascular disease. Our hypothesis was that endothelial progenitor cells would be suppressed in patients with acute cerebrovascular event based on our previous study that found severe endothelial dysfunction in those patients. Objectives: To study the ability of patients with acute stroke to build colonies of endothelial progenitor cells. Methods: We studied the number of colony-forming units in endothelial progenitor cells (CFU-EPCs) from the peripheral blood of 22 male patients with a first-time acute stroke (age 58.09 ± 9.8 years) and 13 healthy men (34 ± 6.7 years), 8 female patients with a first-time acute stroke (54.6 ± 10.3 years) and 6 healthy women (38.3 ± 11.6 years). Endotheliumdependent function was assessed by high-resolution ultrasonography of the brachial artery that measured the change in diameter of the artery by flow-mediated diameter percent change (FMD%). All patients had strokes demonstrated by a brain computed tomography (CT) scan done on admission. Peripheral blood was drawn soon after admission and was processed for endothelial progenitor cells in culture. Results: Thirty patients without known cardiovascular risk factors and who did not take any medications were admitted with a first-time acute stroke. All demonstrated a strong correlation between CFU-EPCs grown in culture and endothelial dysfunction (r = 0.827, P < 0.01). Endothelial dysfunction with an FMD% of -2.2 ± 9.7% was noted in male patients vs. 17.5 ± 6.8% in healthy males (P = 0.0001), and -7.2 ± 10.1% in female patients vs. 25.1 ± 7.1% in healthy females (P = 0.0001). CFU-EPCs were 5.5 ± 6.3 in men with stroke vs. 23.75 ± 5.3 in healthy males (P = 0.0001), and 7.6 ± 4.9 in women with stroke vs. 22.25 ± 6.7 in healthy females (P = 0.0004). Conclusions: Patients with acute stroke had an impaired ability to grow CFU-EPCs in culture and exhibited endothelial dysfunction. The novelty of this study was the discovery of the phenomenon of depressed numbers of EPCs and the poor ability to grow colonies of EPCs in the first 24 hours of the cerebrovascular event.