Allogeneic Stem Cell Transplantation

What is an Allogeneic Stem Cell Transplant?

An allogeneic stem cell transplant replaces your stem cells with new, healthy ones from a donor. Before your allogeneic stem cell transplant, you will have chemotherapy, radiation therapy or both to kill your cancer and suppress your immune system. This will damage your normal bone marrow. You will then receive the transplant of the donor stem cells. They are given into a vein, usually through your central venous (IV) catheter. They may be infused from a bag, like a blood transfusion, or from a large syringe attached to your catheter. This will take place in your hospital room.

Allogeneic stem cell transplants are used to treat many diseases, including leukemia, lymphoma, aplastic anemia, other tumors and immune deficiencies that are present from birth. The care you need before a transplant depends on your disease. Your doctor will explain why a transplant is used, why you cannot use your own stem cells and what treatment plan is best for you.

Your Stem Cell Donor

Not everyone can be your donor. The right donor is someone whose tissue type most closely matches yours. Tissue typing is based on your human leukocyte antigens (HLA). These are found on the surface of your white blood cells.

HLA are important for immunity because they help your body recognize your own cells so they do not attack them. If foreign cells enter your body, your white blood cells will see them as foreign and will mount an attack to get rid of them.

A person with close HLA match is most often a brother or sister. Family members will have a blood test to see what tissue type they have. The person whose tissue type is most like yours is chosen to be the donor. If no one is a close match, your doctor will help you start a search with a donor registry, cord blood banks, or both. The donor gives stem cells for the transplant and may also be needed to donate platelets after the transplant.

People who are not related can have a close match by chance. If you do not have a family member with a matching tissue type, we look for an unrelated adult volunteer donor or cord blood units. The National Marrow Donor Program has millions of people registered who have had their blood typed for this purpose. However, the search for a donor may take weeks or even months to complete. If you will need stem cells from someone who is not related to you, your doctor will give you a more detailed explanation.