Therapeutic angiogenesis in patients with severe limb ischemia by transplantation of a combination stem cell product.
OBJECTIVE
Angiogenesis involves the interplay of endothelial progenitor cells, pericytes, growth factors, and cellular matrix components. The use of mesenchymal stem cells, which are closely related to pericytes and produce diverse angiogenic growth factors and matrix molecules, seems to be a promising therapeutic modality. We postulate that the use of a combination cell product (mesenchymal stem cells in conjunction with a source of endothelial progenitor cells) is safe and efficient and may optimize the clinical results obtained with the use of endothelial progenitor cells alone. This study assessed whether the intramuscular infusion of a combination cell product represents a viable, effective, and lasting therapeutic modality to improve perfusion in severely ischemic limbs.


METHODS
Patients with limb ischemia (n=26) received an intramuscular (gastrocnemius) infusion of the combination cell product in the most ischemic leg and a placebo product in the (less ischemic) contralateral leg. Clinical follow-up (months 0.5, 1, 2, and 4 postinfusion) included evaluation of pain-free walking time, ankle-brachial index, perfusion scintigraphy, and quality of life survey.


RESULTS
No adverse events occurred after infusion. Efficacy assessment indicated that after cell infusion there was a significant improvement in walking time and ankle-brachial index. In addition, technetium-99m-tetrofosmin scintigraphy demonstrated a significant increase of perfusion in the treated limbs compared with the respective control legs.


CONCLUSIONS
This phase II clinical trial shows that the use of a combination cell therapy is safe and effective in increasing blood flow in the ischemic legs of patients with limb ischemia.