Double Umbilical Cord Blood Transplantation Offers Promise for Leukemia Patients
New treatment is being used with patients who have a high risk of leukemia recurrence.
University of Minnesota researchers pioneered a method of infusing two umbilical cord blood units (UCB) in transplants for adolescent and adult patients. The mixing of two healthy umbilical cord blood units had not previously been performed. Results are encouraging and double UCB transplantation is now being used with patients who are at very high risk for leukemia recurrence. Without this procedure, the vast majority of these patients would have no other reasonable option to treat their leukemia.
Advantages of Umbilical Cord Blood Transplantation
The University of Minnesota is a world leader in bone marrow transplantation — a procedure used to treat a number of diseases including acute leukemia. During bone marrow transplantation, patients receive very high doses of chemotherapy and radiation. These treatments eradicate the leukemia and allow the donor bone marrow cells to engraft and assume normal bone marrow function. Unfortunately, only one-third of patients have a suitably matched family member who can serve as a donor.
During the past 10 to 15 years, the value of UCB has been realized. Cord blood is now collected and stored for patients without matched family members, and is routinely used throughout the world as an alternative to bone marrow for transplantation.
Umbilical cord blood is collected during the birth of newborn infants and has advantages over other types of bone marrow sources, including:
- No collection risks to the donor.
- Rapid availability.
- Less stringent matching requirements (compared to bone marrow).
Limitations of Umbilical Cord Blood Transplantation
The most significant limitation of UCB transplantation is that each UCB unit contains limited volumes of blood, which translates into fewer cells for transplantation. The number of infused UCB cells is the single most important predictor of success. The number of cells needed for a successful transplant varies with the patient’s weight — larger patients need more cells. UCB transplants have been successfully applied to younger children, but have been less successful for adolescents and adults with leukemia and lymphoma who require larger numbers of cells.
Double UCB Transplants Makes Treatment Available to Adults and Adolescents with Leukemia
Researchers at the University of Minnesota developed double UCB transplantations to increase the availability of UCB transplantation. By infusing two healthy UCB units, researchers can increase the number of available cells for transplant. The mixing of two healthy UCB units had not previously been performed.
In late 2001, a series of high-risk adolescent and adult patients received two UCB units after high dose chemotherapy and radiation. As hoped, the patients’ blood counts recovered more rapidly.
Now, more than 300 patients have received double UCB transplantation at the University of Minnesota. Double UCB transplantation is used in young children as well as older children and adults who are at very high risk for leukemia recurrence. patients come from across the country to the University of Minnesota for this new treatment approach. Without this procedure, the vast majority of these patients would have no other reasonable option to treat their leukemia.
Promising Results; More Research Needed
In a study to determine the effect of double UCB transplantation on survival, double UCB transplant patients had improved survival rates and were less likely to relapse with leukemia. While encouraging, results need to be confirmed in a larger series of patients at other institutions. A national trial funded by the National Institutes of Health is in the final stages of planning and will be conducted by University of Minnesota investigators.
Funding from Children’s Cancer Research Fund continues to play a key role in this research. Future work will focus on determining the exact mechanism responsible for improved engraftment, reduced risk of relapse and high rate of survival. Further research can ultimately translate into safer and more effective methods of treating our patients with leukemia.
