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New predictor for blood transplant success
Medical Research News
11-May-2005 - The success of blood stem cell transplants used to treat diseases such as leukemia, Hodgkin's lymphoma and aplastic anemia may soon become more predictable, thanks to a discovery made by researchers at the University of British Columbia.
Donor blood stem cells -- cells that can produce red and white blood cells and platelets -- are injected into a recipient to produce new blood.
UBC scientists have identified a "molecular flag" that can help determine if T-cells - cells that drive the body's immune response - will be produced by the thymus following a blood stem cell transplant. T-cell progenitors, or master cells, are manufactured in bone marrow but must migrate to the thymus, an organ located near the heart, in order to mature into functional T-cells.
A common problem with blood stem cell transplants is the failure of progenitor cells to repopulate the thymus and generate T-cells. Without T-cells the patient is unable to fight infection and post-transplant prognosis is poor.
"We now have a signal that gives us critical information about how the body will respond to blood stem cell transplants," says principal investigator Fabio Rossi, UBC assistant professor of medical genetics and Canada Research Chair in Regenerative Medicine. "This gives us a molecular handle on whether the thymus will be receptive to migrating T-cell progenitors."
Rossi, along with Hermann Ziltener, a UBC professor of pathology and laboratory medicine, found that a molecule called P-selectin increases if the thymus is ready and able to accept migrating T-cells. Scientists refer to successful migration as passing through the "thymic gate." By tracking P-selectin, scientists can now detect if thymic gates are open or closed.
This research marks the first description of the thymic gate mechanism and was published recently in Nature Immunology. Rossi and Ziltener work at UBC's Biomedical Research Centre.
There are approximately 150 blood stem cell transplants in B.C. every year. The survival rate ranges from 25-75 per cent, according to the Leukemia/BMT Program of British Columbia.
Researchers estimate that it would be at least five years before the discovery can be translated into a clinical test.
For more information about bone marrow transplants, visit www.bloodservices.ca.
http://www.ubc.ca
Okinawa holding drive to find potential bone marrow donors
By Fred Zimmerman, Stars and Stripes
July 13, 2005 - CAMP LESTER, Okinawa — Servicemembers, their families and civilian employees soon will be able to donate a small amount of blood that could potentially save a life, but this isn’t a typical blood drive.
Members of the C.W. Bill Young/Department of Defense Marrow Donor Program will team up with Okinawa military medical personnel during the next few weeks to hold drives for the marrow donor program.
A total of four drives will be held on various Okinawa installations to collect blood from those willing to enter the marrow registry, according to Amanda Woodhead, U.S. Naval Hospital Okinawa spokeswoman.
The amount of blood taken is similar to having blood drawn for a test, she said. The entire donation/registration process — which includes filling out a registration form — should last about 15 minutes, Woodhead said.
An estimated 30,000 adults and children — about 500 of those within DOD — are diagnosed each year with leukemia, aplastic anemia or other potentially fatal blood diseases, according to C.W. Bill Young/DOD Marrow Donor Center literature. A bone marrow transplant is the only chance of survival for many such people, and about 70 percent can’t find a match within their family, which is why a large database is needed for identifying potential matches.
Once a blood sample is received, the center tests it to determine the human leukocyte antigen, or tissue type. The results then are added to the National Marrow Donor Registry.
If a preliminary match is found, the donor is contacted and additional tests are run, according to the center. If the donor is considered a “best match,” he or she is given details on the donation process and, if consenting, undergoes a physical examination. The center says less than five percent of the donor’s marrow is collected from the back of the pelvic bone using a special needle and syringe under general or local anesthesia.
“If at any time the donor decides to back out, they are able to,” Woodhead said. “They could [be] rolling down the hall on the way to the procedure and they could opt out.”
Woodhead said she’s planning to register at one of the drives.
“My father was recently diagnosed with bone cancer,” she said. “We still don’t know the extent of his treatment, but he may have to have a marrow transplant. I want to be in the registry just in case I’m a match.
“I encourage other people to register because it could save my dad’s life.”
The marrow donor center tries to recruit 25,000 potential donors each year, and as of May 31, more than 362,200 people within DOD had registered. More than 1,700 DOD personnel have given marrow through the center, and more than 180 DOD beneficiaries have received transplants, according to Marrow Donor Program literature.
Those eligible to register in the database through the C.W. Bill Young/Department of Defense Marrow Donor Program drives are: all active duty servicemembers and their immediate families; Civil Service employees; and Coast Guard, National Guard and reserve personnel. All potential donors must be in general good health and between the ages of 18 and 60.
Upcoming marrow donor registration drives
Camp Schwab: July 27 at the camp chapel from 8 a.m. to 4 p.m. Call Lt. Christopher Marazon at DSN 625-2105 for more information.
Camp Kinser: July 28 at the Kinser Medical Clinic from 8 a.m. to 4 p.m. Call Cmdr. David Castellano at DSN 637-1377.
Kadena Air Base: Aug. 2 at the Schilling Recreation Center from 8 a.m. to 4 p.m. Call Tech. Sgt. Ira Kest at at DSN 634-5688.
Camp Foster: Aug. 4, at the Globe & Anchor from 8 a.m. to 4 p.m. Call Cmdr. Kathy Natoli at DSN 645-6112.
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