People paralyzed for two years or more have regained some feeling following an injection of stem cells harvested from their own body.
The early-stage study, led by Tarciscio Barros from the University of San Paulo in Brazil, represents the first time that stem cell therapy has been used to treat spinal cord injury in humans.
“Two to six months after treatment, we found that some patients were showing signs of responding to somatosensory evoked potential tests,” says Barros.
No embryos harmed
Human embryonic stem cells have already restored movement in paralyzed mice, but the use of human embryonic stem cells for human therapy remains controversial.
Instead, Barros and colleagues harvested stem cells from the blood of 30 patients with spinal cord injuries.
They then injected the stem cells into an artery that supplied the damaged area.
Twelve people who underwent the treatment showed brain activity when their paralyzed limbs were electrically stimulated a few months later.
And Barros thinks that the researchers may still see improvement in the other patients.
While promising, the research has raised concerns.
Sam Pfaff of the Salk Institute of Biological Sciences in San Diego, California, for example, warns that the approach could be dangerous.
“Our concern is that stems cells have the potential to keep growing,” he says. “They may even do more harm than good.”
The research by Barros and colleagues is now undergoing evaluation for publication in a peer reviewed journal while the University of San Paulo’s ethics committee has given permission to extend the work to new patients.