For some people with severe aplastic anemia, a bone marrow or cord blood transplant (also called a BMT) may offer the best chance for a cure. This page provides some data on patients' outcomes after a transplant to treat severe aplastic anemia. For a more complete overview of severe aplastic anemia and how it may be treated, see Aplastic Anemia (Severe).
The National Marrow Donor Program® (NMDP) and its research arm, the Center for International Blood and Marrow Transplant Research® (CIBMTR), collect and study data to learn how to improve patient outcomes. The NMDP also operates Be The Match®.
It is a good idea to ask your doctor for help interpreting these data and any other survival outcomes data you find. Your doctor can provide context for these data and discuss your specific situation with you. For more things to consider, see Understanding Survival Outcomes Data
Probability of Survival after Transplants for Severe Aplastic Anemia, 2000-2009, by donor type and age. (CIBMTR data)
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Severe Aplastic Anemia: Survival of marrow transplant patients, by age (pediatric or adult), unrelated donor transplants facilitated by the NMDP, 2000-2009. (NMDP data)
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Factors that affect transplant outcomes
Figure 1 above shows that children have a higher likelihood of survival than adults. In general, the risks of transplant tend to increase with age. Children and younger adults tend to be better able to tolerate a transplant. They also have a lower risk of developing graft-versus-host disease (GVHD). GVHD is a common transplant complication that can be life-threatening.
Figures 1-2 also show a higher likelihood of survival for patients who had sibling donors than those who had unrelated donors. One reason for this difference is that the closeness of the donor match can have a strong effect on outcomes. However, other factors also play a role. Most patients who received unrelated donor transplants were treated unsuccessfully with immunosuppressive therapy before transplant. The time between diagnosis and transplant was usually longer for patients who received unrelated donor transplants. A longer time between diagnosis and transplant leads to a lower likelihood of survival because a patient is more likely to have a:
- Higher number of transfusions, increasing the risk of graft failure or graft rejection (when the transplanted cells do not grow and make blood cells for the body).
- Higher likelihood of severe infections before transplant, increasing the risk of life-threatening infection after transplant.
Study results for aplastic anemia transplants
Some smaller studies that focused on the specific preparative regimen used before transplant and the treatment used for preventing GVHD after transplant have reported a higher likelihood of survival than shown in the figures above. In several studies, the chance of a cure with a sibling donor transplant was at or near 90% for some patients. [1, 2, 3] Patients who received a transplant sooner after diagnosis and had fewer transfusions had the best chance of survival. Younger patients also tended to do better than older patients. The preparative regimen used and treatment to prevent GVHD also made a difference in outcomes.
A small study of 50 patients treated with unrelated donor transplants had an overall 2-year survival rate of 57%.  Patients who received an unrelated donor transplant within a year of diagnosis had a higher likelihood of survival (73%) than those who received a transplant later. Patients who were 20 years of age or younger at the time of transplant also had a higher likelihood of 2-year survival (67%) compared to older patients (43%).
For more information about aplastic anemia and making treatment decisions, see Aplastic Anemia (Severe).
- Locatelli F, Bruno B, Zecca M, et al. Cyclosporin A and short-term methotrexate versus cyclosporin A as graft versus host disease prophylaxis in patients with severe aplastic anemia given allogeneic bone marrow transplantation from an HLA-identical sibling: results of a GITMO/EBMT randomized trial. Blood. 2000; 96(5):1690-1697.
- Ades L, Mary JY, Robin M, et al. Long-term outcome after bone marrow transplantation for severe aplastic anemia. Blood. 2004; 103(7):2490-2497.
- Storb R, Blume KG, O'Donnell MR, et al. Cyclophosphamide and antithymocyte globulin to condition patients with aplastic anemia for allogeneic marrow transplantations: The experience in four centers. Biol Blood Marrow Transplant. 2001; 7(1):39-44.
- Deeg HJ, Amylon ID, Harris RE, et al. Marrow transplants from unrelated donors for patients with aplastic anemia: Minimum effective dose of total body irradiation. Biol Blood Marrow Transplant. 2001; 7(4):208-215.
C. F. LeMaistre, M.D., Southwest Texas Methodist Hospital, San Antonio, Texas
Paul Shaughnessy, M.D., Texas Transplant Institute, San Antonio, Texas
Anthony S. Stein, M.D., City of Hope National Medical Center, Duarte, Calif