SAN DIEGO, Calif--Investigators have demonstrated that umbilical cord blood contains cells capable of instituting long-term, donor-derived hematopoiesis--with a very low probability of producing graft-versus-host disease (GVHD), John E. Wagner, MD, said at a conference sponsored by the University of California, San Diego Cancer Center and the UCSD School of Medicine.
Human umbilical cord and placental blood is known to contain hematopoietic progenitor cells at a frequency that is equal to or greater than that in adult bone marrow. This led to investigations of its use to help "remedy, or at least reduce, some of the risks associated with allogeneic bone marrow transplantation (BMT)," said Dr. Wagner, associate professor of pediatrics, University of Minnesota School of Medicine, Minneapolis.
The first successful umbilical cord blood transplant from a sibling donor was performed in 1988, and since that time, 43 additional transplants have been performed worldwide and reported to the International Cord Blood Transplant Registry. These patients had a variety of malignant (primarily childhood leukemias) and nonmalignant disorders. Their median age was 4 years, and median weight, 18.6 kg.
The children received high-dose chemoradiation and were infused with umbilical cord blood from sibling donors. The majority of these transplants (77%) were HLA-identical grafts.
Engraftment Same as With BMT
Evidence of hematopoietic recovery was seen in 85% of those transplanted. "The range of hematopoietic recovery was exactly the same range as you would see with BMT; however, the median time to recovery was 22.5 days, which may be somewhat prolonged as compared with BMT," Dr. Wagner said.
With a median follow-up of 1.6 years, the overall survival of the group was 70%, he said. Event-free survival was 49% for those patients with malignant diseases, and 76% for those with nonmalignant conditions, although some relapses did occur over time.