When people talk of bone marrow donations, they mean one of two things: an actual bone marrow transplant (BMT) during which a sample of bone marrow is removed from the pelvic area of the donor, or peripheral blood stem cell transplantation (PBSCT) which draws stem cells from the blood of the donor. The latter is more commonly used.
Bone marrow is the soft, spongy tissue inside major bones. When a person agrees to donate bone marrow, doctors will extract hematopoietic stem cells from his or her blood. These stem cells are important in blood production and help treat life-threatening illnesses, like leukemia, sickle cell anemia, and immune system disorders. PBSCT is also often necessary after undergoing a procedure that damages healthy cells, such as chemotherapy, to boost the production of healthy blood cells.
While most doctors prefer using bone marrow from close relatives of the patients, not all of them have relatives that are matches. Bone marrow registries are set up to form a database of people willing to donate. If a patient needs a transplant, a donor from the registry with a matching human leukocyte antigen (HLA) tissue type is contacted. HLA is a protein marker that plays an important part in the body’s immune response to the transplanted cells. The donor’s HLA must be as close of a match as possible to minimize the chances of the patient’s body rejecting the transplant.
For PBSCT donations, donors will need to receive a daily injection for several days prior to the procedure to stimulate the production of stem cells in their blood. During the donation itself, donors will be hooked up to a machine that separates the stem cells from their blood and returns the filtered through an IV. This process is called apheresis and can last from two to five hours. The process often needs to be repeated.
PBSCT has few risks and is relatively painless. But most importantly, it has the potential to save lives. PBSCT donations might seem like an inconvenience, but to someone suffering from a blood disease, it is the greatest gift that one can give.
Will McHale served as co-chair of the Yale Bone Marrow Registration Drive, helping add more than 2,000 people to the national bone marrow registry. For more discussions on bone marrow donation, follow this Twitter account.