A team led by Dr. Jacques P. Tremblay, a researcher with the Human Genetics Department at Quebec City's Centre Hospitalier Universitaire de Québec (CHUQ) and professor with Université Laval's Faculty of Medicine, has taken an important step toward a cure for Duchenne muscular dystrophy. After performing the first successful muscle cell transplant in young patients two years ago, professor Tremblay announced that eight out of the nine patients have shown promising results.
Duchenne muscular dystrophy is a progressive weakening and degeneration of the muscles, caused by a mutation in a gene coding for a protein called dystrophin. This protein is absent in the muscles of people affected with the disorder. With the healthy muscle cells grafted by the team of researchers, a considerable proportion of patients' muscle fibers are now able to synthesize the missing protein. Analyses showed that between 4% and 26% of muscle cells in the cubic centimeter of treated muscle eventually produce the protein produced by the fusion of the donor cells. The results are published in the latest issue of the Journal of Neuropathology and Experimental Neurology. Dr. Tremblay's team is the first in the world to achieve this level of dystrophin expression in so many patients, and in such a high percentage of fibers.
Duchenne muscular dystrophy is a hereditary disease affecting one boy in 3,500. The first signs appear in childhood, between the ages of two and five. Its victims are confined to a wheelchair by their early teens. The disease progressively weakens all muscles, notably respiratory muscles, compromising life expectancy. Most sufferers die between the ages of 20 and 30. Today, there is no treatment--only rehabilitation, surgical procedures and prednisone to enhance patients' quality of life.
New clinical trial: seeking ten patients
Based on these results, professor Tremblay has received authorization to conduct a second round of clinical trials. These new trials are supported financially by SOVAR, CellGene Inc., and Association Française contre les Myopathies. In this second trial, some 300 million donor cells will be transplanted into a complete muscle in the recipient's forearm. Patients' strength will be measured before their grafts, then three and six months after. This experiment will enable researchers to determine whether the transplant significantly increases the strength of the grafted muscle.
Dr. Tremblay's team is seeking ten patients over the age of 18 who suffer from Duchenne or Becker muscular dystrophy. Patients are asked to talk to their neurologists, who can help them contact the researchers.
Dr. Tremblay received the 2005 Sirius research award for his work on Duchenne muscular dystrophy. More recently, the Royal College of Physicians and Surgeons of Canada and the Canadian Society for Clinical Investigation together awarded him the Henry-Friesen Award honoring a distinguished scientist whose biomedical research is recognizable on the international stage as novel and original and of the highest caliber.
The multidisciplinary CHUQ team headed by Dr. Jacques P. Tremblay includes Dr. Daniel Skuk, Dr. Michel Sylvain, Dr. Jack Puymirat, Dr. Jean-Pierre Bouchard, Dr. Louise Deschènes, Dr. Hélène Senay, Dr. Jean-Guy Lachance, Dr. Raynald Roy, and Dr. Pierre Dalens.
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