Background We, recently, reported that granulocyte-colony stimulating factor(G-CSF) could be used as a stem cell mobilizer to enhance myocardial regeneration in patients with myocardial infarction(MI). However, it has remained controversial whether G-CSF may induce harmful systemic inflammation, which impairs endothelial function and transiently increases the risk of cardiovascular event. Therefore, we evaluated the influence of stem cell mobilization on endothelial dysfunction and inflammation.
Methods and Results We injected G-CSF(10關g/kg/day) for 3 days in patients with acute, old MI, and healthy volunteers, as a part of ongoing stem cell clinical trial(MAGIC cell trial, the effect of intracoronary infusion of peripheral blood stem cells mobilized with G-CSF). Endothelial function was assessed by high-resolution brachial artery ultrasound before and after G-CSF. Flow-mediated dilation(FMD) during reactive hyperemia was defined as the % change in arterial diameter following 5-min arterial occlusion. WBC count, C-reactive protein(CRP), Interleukin-6(IL-6) were measured as biomarkers of inflammation. G-CSF resulted in significant elevation in WBC count in all groups. Serum levels of CRP and IL-6 increased in patients with old MI, and healthy group, however, FMD did not decrease after G-CSF. Most importantly, G-CSF did not increase serum levels of CRP and IL-6, also did not decrease FMD in patients with acute MI(see Table 1). The change of FMD after G-CSF was associated with change of serum levels of CRP(r=-0.688, p<0.001).
Conclusions Despite marked leukocytosis, endothelial function was not deteriorated by short-term G-CSF treatment. This finding suggests that G-CSF may be used safely in patients with MI.