Abstract 1941: Level and Value of Circulating Endothelial Progenitor Cells in Patients after Acute Ischemic Stroke

Background and Purpose Endothelial progenitor cells (EPCs) migrate from bone marrow to systemic circulation in response to tissue ischemia where they differentiate into mature endothelial cells for in situ angiogenesis. This study tested the hypothesis that the level of circulating EPCs is substantially increased and predictive of prognostic outcomes after acute ischemic stroke. Methods The level of circulating EPCs [staining markers: CD31/CD34 (E 1 ), CD62E/CD34 (E 2 ) and KDR/CD34 (E 3 )] was examined using flow cytometry at 48 h after acute ischemic stroke in 138 consecutive patients. The EPC level was also evaluated once in twenty healthy volunteers and in forty at-risk controls. Results Level of circulating EPCs (E 1–3 ) was significantly higher in ischemic stroke patients than in at-risk control subjects ( p <0.05). Additionally, EPC (E 1–3 ) level was significantly lower in patients with severe neurological impairment [defined as a score ≥12 on the National Institute of Health Stroke Scale (NIHSS)] than in patients with less severe impairment (NIHSS < score 12) at 48 h after ischemic stroke ( p <0.0001). Moreover, the EPC (E 3 ) level was strongly correlated with improved NIHSS ≥ 4 on day 21 after ischemic stroke ( p =0.0004). Furthermore, low circulating EPC level was independently predictive of severe neurological impairment (NIHSS ≥ 12) at 48 h (E 1–3 ) and combined major adverse clinical outcomes (defined as recurrent ischemic stroke, any cause of death, or NIHSS of ≥ 12) on day 90 (E 1 ) following ischemic stroke ( p <0.001). Conclusions Level of circulating EPCs is independently predictive of prognosis after ischemic stroke.