Umbilical Cord Blood Transplantation --- A New Way to Treat Leukemia

For Jill Hubach, the decision wasn't difficult at all.

 

Her daughter, Tonya, an 8-year-old leukemia patient, needed a bone marrow transplant. But finding a suitable donor through the National Marrow Donor Program Registry would take several months.

 

Because of the aggressive nature of Tonya's leukemia, her physician, Dr. Ka-Wah Chan, didn't believe they had the luxury to wait.

 

"He thought it would take too long to locate an unrelated bone marrow donor, so we decided to try a new procedure," Jill Hubach says.

 

Although it was a fairly new approach to providing the blood cells needed in the treatment of patients with leukemia, umbilical cord blood transplantation had a good track record. Earlier procedures performed throughout the world appeared to be as effective as, and safer than, bone marrow transplantation when there wasn't a perfect genetic match between the donor of the cells and the person receiving them.

 

In Tonya's case, cord blood was immediately available through the New York Blood Center. Within 24 hours after the request was submitted, the needed blood was flown to Houston and delivered to M. D. Anderson. She received the blood through her central catheter, similar to having a transfusion. About one month later, she was well enough to return to her Houston home.

 

"March 5 marked one year since Tonya had the transplant and we're very happy with the results," Jill Hubach says.

 

Most people who need their blood system "reconstituted" after treatment for cancer seek a bone marrow donation from a relative. When a relative with a good genetic match is not available, the chance of finding a suitable match among the two million people registered to donate marrow is only 40-50 percent. For ethnic minorities, the odds are even lower.

 

While a near-to-exact match is crucial for a successful bone marrow transplant, a less-than-perfect match using cord blood has been found to be acceptable and effective.

 

"It seems that with cord blood, you can step out of the boundaries a little and use slightly mismatched donors," says Dr. Chan, chief of the Bone Marrow Transplant Section in the Division of Pediatrics.

 

Umbilical cord blood, normally discarded after the delivery of a newborn, appears to have two important qualities that make it good for transplantation. It is rich in progenitor cells that can "reseed" a patient's ravaged blood system and it can then multiply a thousand-fold to restore it. Because the cells come from a donor who even at birth is still developing, they have a much weaker sense of "self" than marrow cells taken from an adult. That makes them much less likely to attack the body tissues of the person getting the transplant.

 

Another advantage of cord blood transplantation is that the procedure itself is non-invasive - especially for the donor. "Since the placenta and umbilical cord are normally discarded after birth, the blood is easily taken and placed in frozen storage. The patient then receives the cord blood through a simple transfusion," Dr. Chan explains.

 

The New York Blood Center has the largest supply of cord blood and also the most diverse donor population, which is important because patients are most likely to find a matched donor from the same ethnic background. For the past several years, M. D. Anderson has collected cord blood from some pregnant mothers of pediatric patients, says Dr. Chan.

 

While more than 200 cord blood transplants have been done in the United States and Europe since the first successful procedure in 1988, M. D. Anderson is one of only a handful of institutions in Texas that has performed cord blood pediatric transplants. Dr. Chan and others believe it soon will be the preferred method of doing transplants, especially for young patients.

 

"It is an excellent new option and, for some patients, it is the only option because of the time involved in locating a bone marrow donor," Dr. Chan says. "In our experience, cord blood transplantation also is a milder course to follow for unrelated donor transplants."

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