What is a Stem Cell Transplant?
Another type of treatment for DBA is to undergo a stem cell transplant. Stem cell transplants (“SCT”) are also known as bone marrow or cord blood or peripheral blood stem cell transplantation (depending on the donor source). A SCT involves replacing a DBA patient’s unhealthy bone marrow with healthy cells from a donor. The donor’s stem cells can be obtained from bone marrow, peripheral blood, or cord blood. This is a complicated medical procedure that requires several months in the hospital and is not without risk. The reward for a successful bone marrow transplant is that the patient’s bone marrow will function normally and the patient will not need chronic blood transfusion therapy or corticosteroid medication.
Stem Cell Transplant Outcomes
Stem cell transplantation (SCT), is a potentially curative, but dangerous procedure. The role of transplantation for patients with DBA remains complex and controversial. In general, patients with DBA, whether steroid-responsive or transfusion-dependent, may be considered for transplant prior to age 10 years, and preferably between the ages of 2 and 5 years, if an HLA-matched related donor is available. As of the last published analysis, most of the sibling transplants used chemotherapy alone as a conditioning regimen, while most of the alternative donor (mismatched family or unrelated donor) transplants used a combination of chemotherapy with radiation therapy for pre-transplant conditioning. Data from the DBAR show overall survival of 77% for allogeneic sibling SCT (94% for allogeneic sibling SCT age 9 years and less) and 36% for alternative donor SCT (86% for alternative SCT done after 2000).
Preimplantation Genetic Diagnosis (PGD) and Invitro Fertilization (IVF)
The ideal donor for a DBA patient choosing to undergo a SCT is a healthy, HLA perfectly matched sibling. Discoveries of “DBA genes” in approximately 50-60% of patients and advances in Preimplantation Genetic Diagnosis (PGD) technology, improves the likelihood of a pregnancy using Invitro Fertilization (IVF) resulting in an ideal donor. This process allows the embryos created through IVF to be analyzed for the known defective gene and/or HLA compatibility. The “healthy matches” are then implanted with the hope of a pregnancy and the birth of a child. IVF with PGD is an option for some DBA families; however, there are many ethical, monetary, and health considerations that need to be considered.
Important Points to Consider
Stem cell transplant can lead to normal red blood cell production, but it is risky. Matching bone marrow donors take time to find, and patients sometimes die of complications of the treatment. A stem cell transplant also can lead to severe chronic illness (such as GVHD) in some patients. Physical problems associated with DBA but not related to the bone marrow, such as a cleft palate or a heart defect, will not change. In addition, the person’s genes will still have DBA, so there is still a 50 percent chance of passing the disorder to any future children, if fertility is retained. Stem cell transplant is not an easy fix. Please educate yourself and explore all your options. If you choose transplantation, speak to SCT doctors that also deal with DBA. There are conditions and complications related to DBA that can occur during a transplant, so it is important your transplant team is DBA educated.