AURORA, Colo., July 27 (UPI) -- Although doctors prefer bone marrow transplants for leukemia patients, a new study suggests cord blood transplants offer patients a better outcome.
Researchers at the University of Colorado report the rate of rejection, infection and hospitalization are lower among patients receiving cord blood than those with a matched, unrelated bone marrow donor. Their recent study's results, they say, may shift the conventional wisdom when deciding on transplant options for their patients.
Doctors often seek to wipe the cancerous blood system of leukemia patients by replacing bone marrow using donor stem cells. The first choice of donor is a sibling, because of a 25 percent chance of a match.
Generally, the second choice for a donor is an unrelated person, with the chances for a match ranging from 70 percent for white patients and about 10 percent for other or mixed ethnicities.
The closer the match between patient and donor, the less of a chance for graft-versus-host disease, which occurs when the new blood cells to attack the patient's tissues, and is prevented using immunosuppressive drugs.
Using donated umbilical cord blood -- young stem cells -- is easier because it does not need to be as closely matched to a patient, but can take longer to create a new blood system in a patient after the transplant.
Researchers at the University of Colorado say the added expense of caring for a patient often makes cord blood transplants the last resort, but the long-term benefits could be much better.
For the study, published in the journal Bone Marrow Transplantation, researchers compared the incidence of GVHD, immunosuppression and infections leading to hospitalization between 51 patients receiving cord blood transplants and 57 receiving marrow from a matched, unrelated donor.
Three years after transplant, the researchers found the incidence of severe GVHD was 48 percent for patients with unrelated donors and 8 percent for cord blood recipients, and the overall incidence of GVHD was 68 percent for those with donors and 32 percent for cord blood recipients.
Additionally, cord blood recipients were off immunosuppressant drugs by a median of 268 days after surgery, while unrelated donor recipients had not been taken off the drugs.
"A lot of centers reserved cord blood transplants for their worst cases, and so it got an early reputation for being less successful," Dr. Jonathan Gutman, a researcher at the University of Colorado, said in a press release. "It also costs a bit more -- it takes cord blood cells a little longer to get going and so patients need to be supported a little longer. However, when you look past the first 100 days -- a point at which many centers stop collecting data -- there is clear evidence that cord blood outperforms cells from matched, unrelated donors."