Limb Ischemia: Follow the leader

Nagoya, Japan -

Readers of StemCellPatents.com will be familiar with a previous publication stating that cord blood derived stem cells can accelerate reconstitution of hematopoietic stem cells. This concept of one type of stem cell helping other types of stem cells was demonstrated in a recent paper by Kajiguchi et al (Safety and efficacy of autologous progenitor cell transplantation for therapeutic angiogenesis in patients with critical limb ischemia. Circ J. 2007 Feb;71(2):196-201).

The researchers used stem cells to treat a disease called critical limb ischemia. This is occurs when blood vessels of the lower extremities become occluded due to atherosclerosis. Usually patients with this condition are treated with surgery or endovascular procedures to either graft new blood vessels or try to open existing ones. Unfortunately many patients with this conditions are unable to undergo surgery due to co-existing morbidity factors. The rate of amputation in these patients is between 20-40%.

The Japanese investigators administered autologous bone marrow cells in the muscles surrounding area of ischemia as determined by contrast angiography. It was noticed that the patients which responded had an increase in the concentration of circulating CD34 and CD133 positive cells over the period of 28 days. The increase in circulating cells was postulated by the authors to be due to chemoattraction of the endogenous bone marrow cells by the cells that have recently been injected into the muscle.

It will be interesting to see if other studies with stem cell therapies also result in mobilization of endogenous circulating stem cells.

It will be especially interesting to see if administration of allogeneic cells into the hindlimb can also result in such mobilization.