"The results of our studies are a triumph in a treatment that has been largely viewed as only possible in children and adolescents," said John Wagner, M.D., professor of pediatrics and scientific director of clinical research, Blood and Marrow Transplantation Program and Stem Cell Institute.
A major limitation of adult cord blood transplantation highlighted in the NEJM articles is the high likelihood of patients dying early after transplant. This likelihood is due to: poor recovery of the patient's blood cell counts as a result of the relatively low number of cells in cord blood compared to bone marrow, or toxicity from the high doses of chemotherapy and radiation used in conventional transplant regimens.
The University of Minnesota Blood and Marrow Transplant Program have addressed these issues in two separate studies. In the first study, the combined use of two cord blood units from different donors was investigated as a way to increase the number of cord blood cells given to the patient on transplant day. Thirty-one patients were given high-dose chemotherapy and radiation, in which all the patient's bone marrow is destroyed, and then transplanted with two partially matched umbilical cords. The matching criteria is less stringent in cord blood than bone marrow. All of the patients engrafted successfully with cord blood cells with a low incidence of serious transplant complications and very promising survival compared to the previous studies.
In the second study, a group of 59 patients who were not eligible for high doses of chemotherapy and radiation (due to their older age, extensive prior chemotherapy treatment, or other serious co-existing diseases) were treated with a "reduced intensity" regimen involving lower doses of chemotherapy and radiation. These patients were then transplanted with cord blood from either one or two donors. In this study, 89 percent of the patients engrafted successfully overall with 98 percent of patients engrafting if they had recent chemotherapy before the transplant or a prior transplant. Despite the high-risk nature of this patient group, the risk of life-threatening transplant complications was relatively low even in older patients or those with a prior transplant.
"These remarkable results represent a significant advance in the practice of adult cord blood transplantation. These approaches allow us to offer potentially life-saving transplant therapy to many patients who have previously been denied such treatment," said Juliet Barker, MBBS(Hons), assistant professor of medicine, Adult Blood and Marrow Transplant Program.
The studies were funded by the National Institutes of Health. The study on transplants from two partially HLA-matched umbilical cord blood units is being published in the February print edition of the journal Blood and is currently available online at www.bloodjournal.org.
The Academic Health Center is home to the University of Minnesota's six health professional schools and colleges as well as several health-related centers and institutes. Founded in 1851, the University is one of the oldest and largest land grant institutions in the country. The AHC prepares the new health professionals who improve the health of communities, discover and deliver new treatments and cures, and strengthen the health economy.