Bone marrow donation is a life-saving medical procedure that offers hope to thousands of patients worldwide. It provides healthy blood-forming stem cells to individuals suffering from various life-threatening conditions, including blood cancers like leukemia and lymphoma, and other blood disorders such as aplastic anemia and sickle cell anemia. Many patients rely on an unrelated donor because only a small percentage find a suitable match within their own family. Donating bone marrow can replace diseased or non-functioning marrow, regenerate a new immune system, and restore normal blood cell production after intensive treatments.
Eligibility to Donate
Becoming a bone marrow donor involves meeting specific health and age criteria designed to ensure the safety of both the donor and the recipient. Most registries prefer donors between the ages of 18 and 40, though some accept individuals up to 60 years old. Research indicates that stem cells from younger donors generally lead to more successful transplant outcomes for patients.
Individuals must be in good overall health. Certain medical conditions can disqualify a potential donor, including HIV/AIDS, Hepatitis B or C, severe autoimmune diseases like rheumatoid arthritis or lupus, and some chronic conditions such as severe heart disease or insulin-dependent diabetes. A history of cancer, certain bleeding disorders, or significant brain injury can also prevent donation.
The Donor Registration Process
The process of joining a bone marrow donor registry typically begins with requesting a registration kit, often available online or at local drives. This kit usually contains a cheek swab for collecting a tissue sample. After swabbing the inside of the cheeks, the sample is mailed back for analysis.
This sample undergoes Human Leukocyte Antigen (HLA) typing, a genetic test that identifies specific proteins on cell surfaces. HLA markers are inherited, and a close match between donor and recipient is crucial to minimize the risk of transplant rejection and complications like graft-versus-host disease (GVHD). Once HLA typed, the donor’s information is added to the national registry, making them available as a potential match for patients in need. Potential donors are contacted only if their HLA type closely matches that of a patient.
Types of Bone Marrow Donation
There are two primary methods for collecting blood-forming stem cells for transplantation: Peripheral Blood Stem Cell (PBSC) donation and bone marrow donation. The choice of method depends on the patient’s medical needs and the doctor’s recommendation. PBSC donation is the more common method, accounting for approximately 90% of donations.
PBSC donation is a non-surgical, outpatient procedure. For several days before the donation, the donor receives injections of a medication called filgrastim (G-CSF), which increases the number of blood stem cells circulating from the bone marrow into the bloodstream. Blood is drawn from one arm and passed through a machine that separates the stem cells, returning the remaining blood components to the other arm. This process, known as apheresis, typically takes 4-8 hours and may require one or two sessions.
In contrast, traditional bone marrow donation is a surgical procedure performed under general anesthesia. A doctor uses hollow needles to collect liquid marrow directly from the back of the donor’s hip bones (pelvis). This collection typically takes about an hour, and approximately 1 to 2 pints of liquid marrow are collected, representing about 10% of the donor’s total marrow supply. This method may be preferred for pediatric patients or to reduce the risk of GVHD for the recipient.
The Donation and Recovery Experience
Before any donation, donors undergo a thorough health screening to ensure their suitability and safety. For PBSC donation, temporary side effects from the filgrastim injections may include bone or muscle aches, headaches, fatigue, or flu-like symptoms, which usually subside shortly after the donation. During the apheresis procedure, donors might experience tingling sensations or mild muscle cramps. Most PBSC donors can resume their normal activities within 1 to 3 days after the procedure.
For bone marrow donation, donors receive general anesthesia, so they experience no pain during the procedure itself. After the surgery, common side effects include soreness, bruising, or stiffness in the lower back or hip area where the marrow was collected. Donors might also feel tired, weak, or experience mild nausea from the anesthesia. While recovery times vary, most bone marrow donors can return to work or school within a few days to a couple of weeks, with full recovery sometimes taking several weeks. The body naturally replenishes the donated marrow within a few weeks to months.