Hopes Raised For Using Stem Cells For Treating Muscular Dystrophy

The New York Times News

September 10, 2002

(The New York Times News Service) -- A rare natural experiment has given researchers hope of using stem cells to treat muscular dystrophy, a group of genetic diseases that cause progressive wasting of the muscles.

The subject of the experiment is a boy who at age 1 received a bone marrow transplant for an immune deficiency disease and at 12 was found to have a second serious genetic disease, Duchenne muscular dystrophy.

Cells from the donor of the marrow have now been detected in the boy's muscle fibers by Dr. Louis M. Kunkel, a dystrophy expert at Children's Hospital in Boston, and Dr. Kenneth Weinberg of Children's Hospital Los Angeles, a bone marrow transplant surgeon who is the boy's physician.

Three years ago, Kunkel and his colleagues showed that cells from a donor mouse's marrow would incorporate into the recipient mouse's muscles and contribute the correct form of dystrophin, the defective protein in muscular dystrophy.

That raised the question of whether a donor's marrow cells might also help people with muscular dystrophy. It seemed that additional years of animal experiments would be needed before the idea could ethically be tested in patients. But when Weinberg called with news of his patient, Kunkel saw the experiment had already been conducted, although for quite different reasons.

Although the boy's dystrophy is not very severe, Kunkel and his colleagues say, they believe that its mildness cannot be attributed to the donor cells, which are present in less than 1 percent of the muscle fibers, too few to make much of a difference. Nor is it clear whether the donor cells in the boy's muscle are actually producing the normal version of dystrophin protein, although they do possess a normal version of the gene.

The importance of the finding, Kunkel said, is that it confirms that human donor cells can be incorporated into a recipient's muscle fibers. If enough donor cells can be delivered efficiently to the muscle fibers in a patient's body, they may provide a treatment for the disease. Kunkel said he was exploring that possibility in experiments with mice but was not anywhere near ready to try such an approach in people.