In a breakthrough research on bleeding disorders, scientists have combined gene therapy and stem cell transplantation to successfully reverse the severe, crippling bleeding disorder hemophilia A in large animals. This could soon open the door to the development of new therapies for human patients.
Researchers at Wake Forest Baptist Medical Center's Institute for Regenerative Medicine, collaborating with other institutions, report in
Experimental Hematology that a single injection of genetically-modified adult stem cells in two sheep converted the severe disorder to a milder form. The journal is a publication of the Society for Hematology and Stem Cells
"A new approach to treating severe hemophilia is desperately needed," said lead author Christopher D. Porada, Ph.D., associate professor of regenerative medicine at Wake Forest Baptist. "About 75 percent of the world doesn't have access to the current treatment – therapy to replace missing clotting factors. This puts patients in most of the world at risk of severe and permanent disabilities."
Porada cautioned that challenges will need to be overcome before the treatment can be applied to humans, including that the sheep developed an immune response to the therapy that could decrease its effectiveness and duration.
There is currently no cure for the rare bleeding disorder hemophilia. People with this genetic disorder lack a protein, known as a clotting factor, needed for normal blood clotting. As a result, they may bleed for a longer time than others after an injury, as well as bleed internally, especially in joints such as the knees, ankles, and elbows. This bleeding can damage the organs and tissues and be life threatening. Even when life-threatening bleeds are prevented with replacement therapy, it doesn't prevent smaller bleeds within the joints that can cause pain and decreased mobility.