A discovery by Medical College of Wisconsin and BloodCenter of Wisconsin researchers in Milwaukee may be a key to a permanent genetic cure for hemophilia A patients, including a subset who do not respond to conventional blood transfusions. The study of genetically altered hemophilia mice is published in the July 2006 edition of The Journal of Clinical Investigation.
Hemophilia A affects about one in 5,000 males who lack the hereditary blood clotting protein, Factor VIII (FVIII). Traditional treatment requires infusion of synthetic FVIII two to three times a week to control bleeding episodes. However, about 30 percent of these patients develop antibodies to FVIII, selectively inactivating its clotting properties and negating its therapeutic role. Treatment for adults who have these inhibitory antibodies can cost over $1 million annually if there is a major bleeding episode.
"We developed a Trojan horse approach cloaking FVIII in a platelet so that it is undetected by the antibodies and its clotting properties are preserved until the platelet sticks to a damaged blood vessel and releases its stored protein which now includes FVIII.," explains senior author Robert R. Montgomery, M.D., senior investigator at the BloodCenter of Wisconsin and professor of pediatric hematology at the Medical College. He is also affiliated with the Children's Research Institute.
"This is truly a landmark development for hemophilia A patients," says hematologist, Joan Gill, M.D., professor of pediatric hematology at the Medical College, and director of the Comprehensive Center for Bleeding Disorders at the BloodCenter and Children's Hospital of Wisconsin. "We look forward to the day when basic research is completed and clinical trials can begin in patients."
Normally in an injury, platelets circulating in plasma - the liquid portion of the blood - stick to the site of the blood vessel wound, activating its surface and rapidly stoppi
Contact: Toranj Marphetia
Medical College of Wisconsin