The authors did a comparison study of 682 adults with acute leukemia. All these patients received a hematopoietic stem-cell (HSC) transplant from a donor that was unrelated to them. The authors compared them to patients who received UCB instead of HSC. One of the important characteristics of UCB is that it does not have to match the donor, which makes it much more flexible in leukemia and other treatments.

The study covered two groups of people. The authors note, "98 received cord blood and 584 received bone marrow. The transplantations were performed from 1998 through 2002 and reported to Eurocord and the European Blood and Marrow Transplant Group" (Rocha, V., et al., 2004. p. 2276). They traced participants' ages, weights, level of severity of the disease, and other influences to discover what treatment worked best in treating adults with leukemia. They found that rates of mortality and relapse were very similar between the two groups. They discovered that cord-blood transplantation had delayed neutrophil recovery and a lower incidence of acute GVHD" (Rocha, V., et al., 2004. p. 2283). They also found that UCB was a good alternative form of treatment of acute adult leukemia, especially when they did not have a matched bone marrow donor.

In summary, this was an extensive study that looked at two groups of leukemia patients. UCB outcomes were similar to traditional treatments, and the group found that there were similarities between the two groups. UCB is a successful alternative to stem cell transplants in many patients.

Using partially matched donor hematopoietic stem cells (HSC) shows promise in patients who have hematologic cancer and are a relapse high risk. Often, the transplants can promote immune system reconstruction and control other related diseases. The authors studied 43 transplant patients and did follow-up studies on their condition after the transplants. These studies included "morphologic examination of bone marrow,...

478). The authors conducted monthly follow-ups on all the patients, and monitored their progress in many ways. There purpose was to try to discover what causes a patient to relapse with the disease.
Twenty-six of the patients studied had only one transplant, while 17 patients had two, and 25 of them were in relapse. After they concluded their study, they found that "Among the 43 patients, 17 patients -- 14 of whom received transplants when they had persistent disease -- had a leukemia relapse" (Vago, L., et al., 2009, p. 480). They also found that the donor t-cells could subdue most of the cancer cells, but that sometimes some of the cells escaped the t-cells somehow, and that caused the patient to relapse. They note, "After transplantation of haploidentical hematopoietic stem cells and infusion of donor T cells, leukemic cells can escape from the donor's antileukemic T cells through the loss of the mismatched HLA haplotype. This event leads to relapse" (Vago, L., et al., 2009, p. 478). Their studies were conclusive and detailed, so their results seem to be valid.

In summary, this group studied 43 patients who received stem cell transplants in an attempt to learn what caused patients to relapse with leukemia. They found that leukemia cells can escape from the donated t-cells and that leads to relapse. They recommend further studies in this area to confirm their results.