Cell transplants look promising for stroke recovery

Using transplants of bone marrow cells improved the recovery from stroke in rat experiments, according to a study published in the August 27 issue of Neurology, the scientific journal of the American Academy of Neurology.

The rats treated with an intravenous transplant of adult human stromal cells (mature cells from bone marrow) had significant improvements in their ability to function 14 days after the stroke, compared to rats that did not receive transplants after a stroke.

“These are smart cells that selectively migrate to the site of injury and become little factories producing an array of helpful molecules to repair the tissue,” said study author Michael Chopp, PhD, of Henry Ford Hospital in Detroit, Mich., and Oakland University in Rochester, Mich. “We believe this therapy shows promise in treating stroke, Parkinson’s disease, spinal cord injury and traumatic brain injury.”

For the study, bone marrow cells were taken from three healthy human donors. Strokes were then induced in the rats and they were given the cells intravenously one day after the stroke. Other groups treated with fibroblast cells or not treated served as controls.

The rats were tested on their motor and sensory abilities and on their reflexes before the stroke and at one day, seven days and 14 days after the stroke. In a test of sensory abilities 14 days after the stroke, the rats treated with marrow stromal cells completed the test 60 percent faster than the non-treated rats. A detailed neurological examination showed that 14 days after the stroke the treated rats had a 30-percent improvement in overall neurological score compared to the control rats.

Compared to the control rats, the rats receiving marrow stromal cells produced more neurotrophic factors and nerve growth factors that stimulate cells to grow. They also had less cell death in the area of the stroke than the control rats. Chopp said the next step is to test the procedure in small numbers of humans to make sure it is safe. Marrow stromal cells have been used in human cancer patients.

The treatment is exciting in part because it appears to give doctors a longer time window to treat stroke patients than current treatments, according to neurologist and stroke recovery researcher Thomas A. Kent, MD, of the University of Texas Medical Branch in Galveston, Texas, who wrote an editorial accompanying the article.

“It’s very difficult to treat people with a stroke within a narrow time window,” he said. “Many people still don’t recognize the symptoms of stroke and get to an emergency room quickly enough for treatment. If this new treatment is effective, it could expand the treatment window by several hours or even longer.”

Kent cautioned, however, that more studies are needed to determine the long-term effects of the transplants.