Often, the most permanent and effective treatment for FA-related bone marrow failure (aplastic anemia) is an allogeneic bone marrow or stem cell transplant. This involves taking healthy marrow or stem cells from another person (a donor) and transfusing these cells into the FA patient. The healthy cells travel to the bone marrow, stick there, and start making new blood cells. This can be a life-saving procedure even though the patient remains at risk for other long-term FA problems such as cancer or growth defects.
This form of transplantation has been used successfully hundreds of times at Seattle Cancer Care Alliance to treat children suffering from aplastic anemia. But FA patients require special care before and after transplant. In particular, they are extremely sensitive to the effects of the powerful and toxic “conditioning” therapies typically required before the transplant. To avoid this problem, we have developed several low-dose conditioning therapies for FA patients. This has allowed us to have excellent results with FA patients, especially those with no matched sibling donor. (Transplants are generally less successful when the donor is not related to the patient compared to a transplant where the blood cells are from a related donor, usually a sibling.)
For the children who do not have an appropriate related donor, we have also developed other special transplant techniques and research protocols. For example, we are using half-matched parents and siblings as donors (“haploidentical” transplantation); we are eliminating radiation from the conditioning; and we are using umbilical cord blood stem cells instead of marrow.
Allogeneic transplantation also presents the risk of graft versus host disease (GVHD), in which the transplanted donor cells react against the patient, and graft rejection, in which the patient’s remaining immune system mounts a response to the transplanted donor cells. While there are available treatments that can be administered before, during, and after transplant to reduce the risk of GVHD and graft rejection, these therapies have associated toxicity and their dosing must often be modified for FA patients. Researchers at SCCA developed many of the special dosing strategies now used for FA patients and they are now developing other new therapies for FA patients to combat GVHD.