The Gift of a Cure
Donating your newborn's umbilical cord might someday save a life
When 6-year-old Hayden Zavareei developed an aggressive form of leukemia, the odds were stacked against her. She desperately needed a bone marrow transplant to replace her cancerous blood cells, but neither her sisters nor the worldwide registry of willing donors could provide a match. Her frantic parents searched for other answers-and found one, to their relief, in a vial at a public blood bank at Duke University Medical Center. Today, 2
Plenty of parents-to-be have heard the pitch for banking their newborn's umbilical cord, in the event that the child might someday need it. Like the stem cells in bone marrow, cord-blood stem cells can give rise to any blood or immune cell; in addition, like embryonic stem cells, they have the potential to one day repair damaged tissue in the heart, say, or the brain. But children in need of a transplant can't typically benefit from their own cord blood-which is apt to carry the same genetic mutations that have caused the disease. So the real benefit of banking turns out to be the life-giving potential for somebody else. Congress, eager to build up a source of stem cells that doesn't destroy embryos, set aside $79 million 17 months ago to expand the collection of cord blood by public blood banks and launch a national electronic network to link the banks. And about half of the states have efforts in the works to encourage women to donate umbilical cords at local hospitals when they give birth.
Cord transplants are still less common than marrow transplants, though the number worldwide has nearly doubled to about 8,000 just in the past two years. The demand has grown along with a stack of studies showing cord blood's power against some 70 diseases, including leukemia, lymphoma, and sickle cell anemia; the hope is that someday it will provide a way to treat Parkinson's, diabetes, and heart disease. One big attraction: Unlike bone marrow recipients, people getting a cord-blood transplant don't require a perfectly matched specimen-which means more patients are apt to find a donor. While bone marrow isn't a match unless at least seven out of eight cell proteins are identical to the patient's proteins, cord blood requires matching just four out of six. That's because cord blood contains fewer and weaker immune cells than marrow, so there's less likelihood of a life-threatening complication in which the transplanted cells attack the patient's healthy tissues, explains Joanne Kurtzberg, chief of the blood and marrow transplantation program at Duke.
A national supply of cord blood will come as welcome news to the more than 8,000 Americans who need bone marrow transplants each year and are unable to find suitable donors. Many die waiting. The vast majority are African-Americans, Asians, and members of other minority groups, largely because they are underrepresented in the marrow donor registries. Blacks have only a 10 percent likelihood of finding a bone marrow match; Asians, only a 20 percent likelihood. Whites, by contrast, find a match 70 percent of the time.
"This increases the number of matches significantly," says Robertson Parkman, a pediatric immunologist at Children's Hospital in Los Angeles who performs stem cell transplants. But since minorities also make up the bulk of people who are unable to find a cord-blood match, the new federal law requires publicly funded donor banks to obtain a "genetically diverse" donor pool that includes a balanced representation of ethnic groups.
How to donate. At the moment, only about 120 hospitals around the country have a system in place for accepting donations on the spot. But parents can sign up to donate on their own through the cord-blood-storage company Cryobanks International (box). Parents must provide a detailed medical history, sign a consent form, and give a sample of mom's own blood to be screened for diseases. There's no cost to the donating family; Duke University Medical Center, for example, relies on federal grants to cover the $375,000 annual cost of collecting cords from about 2,700 babies. The donated cords are sent to storage facilities, where the blood is extracted and frozen in liquid nitrogen for months or even years until it's needed.
When the choice exists, most oncologists prefer to transplant perfectly matched bone marrow from a sibling; studies suggest that this approach offers cancer patients the greatest odds of survival. Also, hospital stays run two to four weeks shorter on average, says Parkman, since the higher number of stem and immune cells transplanted in bone marrow causes the blood supply to replenish itself at a faster rate.
But patients who must search for a match among strangers may well be safer using cord blood. The likelihood of "graft versus host" disease, in which the transplanted immune cells perceive the patient's tissues to be foreign and launch an attack, runs about 10 to 15 percent with cord blood from an unrelated donor and about 35 to 40 percent with bone marrow. Plus, cord blood can be more easily located and shipped to a patient, whereas a marrow donor must be tracked down and hospitalized to have the liquid marrow extracted from his or her bones.
One possible impediment to a national banking system could be that parents may assume it's better to privately store their child's cord blood. In ads mailed to pregnant women and on websites, storage companies promise that saving a newborn's cord-at a one-time cost of about $2,000 plus $125 annually-will protect the baby in case of serious illness. The ads play on parents'fears and are misleading, says Kurtzberg, in that when children develop blood diseases requiring a transplant, doctors in most cases would look for a donor. Studies have shown a leukemia relapse rate of 90 percent in patients who receive an infusion of their own cord blood, says Kurtzberg.
David Harris, scientific director of Cord Blood Registry, a private storage bank with branches in San Bruno, Calif., and Tucson, Ariz., argues that the biggest benefit of private banking will come in the future, when researchers are able to grow a new liver or pancreas, say, out of a person's own cord stem cells. Many stem cell experts, though, believe these medical advances are years or decades into the future, if they occur at all. Meantime, of the 170,000 units collected by the company over the past 15 years, 50 have been withdrawn for treatments, says Harris. Twelve of these benefited the child who banked it.
"I thought we should have stored his blood," says Teal Blackmon, 27, who panicked seven months ago when she first heard that her 2-month-old son, McClain, would need a cord-blood transplant to treat a rare and fatal disease in which his immune cells were annihilating other blood cells. "But then my doctor said he couldn't have used it anyway, because my son's stem cells also had the disease." A donor transplant seems to have put McClain, who lives in Hemet, Calif., on the road to recovery. "We're very lucky," Blackmon says. "The cord blood gave him a second chance."
This story appears in the May 21, 2007 print edition of U.S. News & World Report.