Prognostic, diagnostic and therapeutic potential of endothelial progenitor cells for patients with ischaemic stroke: Hype or Hope

Ischaemic stroke is a debilitating disease with immense personal, societal and economic impact. Thrombolysis with recombinant tissue plasminogen activator remains the only approved pharmacotherapy for this disease. As each year less than 1% of eligible patients receive this therapy worldwide, efficacious new therapeutics are desperately needed. Emerging evidence suggest endothelial progenitor cells (EPCs), capable of repairing damaged vasculature, as one such therapeutics. However, questions regarding their optimal dose, delivery route and in vivo survivability remain largely unanswered. Outgrowth endothelial cells, generated in large numbers by ex vivo expansion of EPCs, enable effective assessment of these issues and may eventually serve as off-the-shelf therapeutics. Correlations between circulating EPC levels and stroke outcome imply that EPCs may also serve as clinical biomarkers for stroke. This viewpoint briefly evaluates the current evidence, pinpoints the gaps in the literature and proposes new directions for research.