Marrow rebuilt with umbilical-cord blood.

Marrow rebuilt with umbilical-cord blood

Testing an alternative to bone marrow transplants, researchers have reconstituted the marrow of a seriously ill boy using blood drawn painlessly from the umbilical cord of his newborn sister.

A newborn's blood containes stem cells, the parent cells of marrow and blood cells, says Arleen D. Auerbach of Rockefeller University in New York City, who describes the procedure with French and U.S. colleagues in the Oct. 26 NEW ENGLAND JOURNAL OF MEDICINE. Children and adults have stem cells only in the bone marrow.

Physicians could use a sibling's cord blood as a source of stem cells to treat leukemia, aplastic anemia or any other disease normally treated by marrow transplants, Auerbach says. However, the newborn's tissue must match the recipient's. Auerbach proposes setting up banks to store cord blood for patients with no compatible sibling donor.

The 5-year-old boy suffered from Fanconi's anemia, an inherited aplastic anemia that depleted his marrow. After his sister's birth, the researchers froze blood drawn from the cut umbilical cord still attached to the mother. Theystored the blood for seven months, until the baby was old enough to provide marrow if the blood transplant failed.

Doctors then used drugs and radiation to destroy the remainder of the boy's marrow -- a standard step in marrow transplants-and infused the thawed cord blood. Healthy stem cells replenished the marrow and changed his B+ blood type to his sister's O+. The boy now "leads a normal life," the researchers report.

A year after his September 1988 transplant, the team successfully performed the procedure on another pair of siblings, Auerbach told SCIENCE NEWS.

The new approach offers several advantages over marrow transplants, Auerbach says. Using cord blood allows the sick child to receive a transplant soon after the birth of a compatible sibling, whereas candidates for marrow transplants must wait until the donor is at least 6 months old. In addition, the cord blood donor avoides painful marrow extraction. The researchers say they do not know whether cord blood contains enough stem cells to treat an adult or large child. They also note a slight risk of the mother's immune cells mixing with the cord blood and attacking the transplant recipient.

David G. Nathan of Children's Hospital in Boston does not envision board use of the procedure. "How many children are there," he asks, "who need a transplant and have a histocompatible sibling about to be delivered?"