A British biotechnology company has been given approval to conduct what it says is the world's first trial into stem cell therapy for human stroke victims.

The ReNeuron group said Sunday it received permission from the U.K. Medicines and Healthcare Products Regulatory Agency to carry out the tests using fetal stem cells.

Selected patients who have suffered a stroke will have the cells injected directly into the affected areas of their brains. The researchers hope they will eventually be able to regenerate parts of the brain destroyed in the stroke.

The mid-year trials will be carried out on a group of patients by a team of researchers at Southern General Hospital in Glasgow. Twelve patients, split into four groups of three each, will receive the stem cells between six and 24 months after suffering a stroke.

ReNeuron says the primary aim will be to test the safety and efficacy of the therapy. Patients will be injected with a variety of doses, starting with a low dose of around two million cells. Doses will increase as the study goes on, to a maximum of 20 million brain cells, thought to be a high enough dose to begin cell regeneration.

Patients will be monitored for a year after, and if the trials prove safe and effective, ReNeuron plans to hold larger trials.

Prior research has shown that stem cells can improve stroke recovery in rats. Scientists have also been able to use embryonic stem cells to treat a Parkinson's-like condition in rats.

"If it works, as it has done in animal model systems, it may allow new nerve cells to grow or regeneration of existing cells and actual recovery of function in patients who would not otherwise be able to regain function," Keith Muir, the consultant who will be leading the trial, told BBC News.

Controversy over research

Stem cells can be thought of as blank slates or cells that have yet to become specialized. They are in an early stage of development and have the ability to become any type of cell to form skin, bones, organs or other body parts.

The stem cells used in the trials will be taken from a cell line derived from aborted fetal tissue. Using human material, such as aborted fetuses, in research is a contentious issue because it can be construed as the sacrifice of human life for scientific progress.

The Catholic Church in Scotland, said it supported stem cell research from "ethical sources," like those from an adult donor. But Scottish newspaper the Herald quoted a spokesperson as saying: "If they're from an aborted fetus, then that is immoral and unethical."

Muir has said there are a substantial number of patients who are comfortable with the trials.

"And we're not in the business of doing anything which is going to be against any individual's ethical concerns," the Herald quoted him as saying.

Between 40,000 and 50,000 Canadians suffer a stroke every year, according to the Heart and Stroke Foundation of Canada. Stroke is the fourth leading cause of death in Canada.

  • 15 per cent of strokes are fatal.
  • 10 per cent of stroke victims recover completely.
  • 50 per cent are left with a moderate or severe impairment.
  • 25 per cent recover with a minor impairment.

Physiotherapy is the only treatment currently available to restore brain and motor function. Drug treatments, if given to a stroke victim soon enough, can reverse symptoms.