Throwaway Blood Helps Adults with Leukemia
Mismatched umbilical cord cells can rebuild marrow
WEDNESDAY, June 13, 2001 (HealthDayNews) -- Newborn blood cells that usually are thrown away after birth can help rebuild the bone marrow of adults who need intensive treatment for leukemia and other blood disorders, a study shows.
Until now, those patients could be saved only by wiping out their diseased bone marrow, where blood cells are made, and replacing it with transplanted, healthy blood-producing cells. A transplant usually requires marrow cells from a donor whose tissue type closely matches the patient's to avoid an immune attack on the new marrow.
Transplants of cord blood, as it is called, work about as well as conventional bone marrow transplants to rebuild the body's blood-cell manufacturing system, says a report in the June 14 New England Journal of Medicine, and they don't have to be matched as closely with a patient's immune cells as marrow transplants.
"That is one thing that makes cord blood so attractive," says Dr. Pablo Rubenstein, director of the placental blood program at the New York Blood Center and a member of the research team. "With the other transplants, you need to be very closely matched, or you have complications. With cord blood, a less close match is acceptable."
The study included 68 patients with life-threatening blood disorders. All had either intensive chemotherapy or radiation treatment to wipe out their diseased bone marrow. Then they received cord blood cells. While a conventional marrow transplant tries to match the new cells with six immune characteristics, 48, or 71 percent, of the transplants were mismatched for two of those characteristics.
The most dangerous complication is graft-versus-host disease (GVHD), in which the immune cells in the transplant attack the recipient's tissues. The incidence of GVHD was lower than expected, striking 11 of 55 patients who could be evaluated in the first 100 days after the transplants. The overall survival rate was comparable to conventional marrow transplants, with 19 of the 68 patients alive and 18 disease-free 40 months after the transplants.
"We have shown that cord-blood transplants can be successful even when the tissue types of the cord-blood recipient and donor are less well-matched than with conventional marrow transplants," says a statement by study leader Dr. Mary Joan Laughlin, assistant professor of medicine at Case Western Reserve University in Cleveland.
"Many patients with blood-related cancers don't have a matched sibling for bone marrow transplants, which are curative in many cases," says Alan Kinniburgh, vice president of research for the Leukemia & Lymphoma Society, which funded the study. Cord blood can help many of those patients, he says.
"There are 3 million live births in the United States every year. If only a fraction of the people giving birth every year donate cord blood, we may have enough to meet the need," Kinniburgh says.
Rubenstein says the proportion of parents who are willing to donate cord blood is very high, but many hospitals are not equipped to take the donations.
"To take, type and store cord blood so that it remains usable the capital investment is considerable, but, all in all, it is not out of line with what can be done with bone marrow transplants," he says.
A number of parents pay fees to have cord blood stored with commercial companies for use by their own children, Kinniburgh says. But the odds are about 1,000 to one that a child will ever need a cord blood transplant, he says. The American Academy of Pediatrics has a long-standing recommendation that cord-blood donations should go to nonprofit centers.
What To Do
"Parents should donate placenta and cord blood to nonprofit institutions that collect, preserve and make it available free to anyone," Kinniburgh suggests.
Read other HealthDay articles about research on leukemia.
Visit Veritas Medicine to learn about other experimental treatments for leukemia.