Bone marrow is the soft, spongy tissue found inside certain bones, such as the hip and thigh bones. It is where the body produces various blood cells, including red blood cells, white blood cells, and platelets, from specialized stem cells. Bone marrow donation is a procedure that involves collecting these healthy stem cells to replace diseased or damaged bone marrow in patients.
Understanding Bone Marrow and Donation Methods
Bone marrow plays a central role in maintaining overall health by continuously generating the blood cells necessary for oxygen transport, infection fighting, and blood clotting. When diseases like leukemia, lymphoma, sickle cell anemia, aplastic anemia, or immune deficiency disorders impair the bone marrow’s function, it can no longer produce healthy blood cells. A bone marrow transplant replaces this unhealthy marrow with healthy cells, allowing the body to regenerate a new, functioning blood system.
There are two primary methods for bone marrow donation. Peripheral Blood Stem Cell (PBSC) donation is the more common method, accounting for about 90% of all donations. The alternative is a direct bone marrow (marrow) donation, which is a surgical procedure. Both methods collect hematopoietic stem cells, which are blood-forming stem cells.
The Donor’s Process
The journey to becoming a bone marrow donor begins by joining a registry, which involves completing a health history questionnaire and providing a cheek swab or blood sample for initial testing. This initial test, Human Leukocyte Antigen (HLA) typing, analyzes specific proteins on your cells. Matching these HLA markers between donor and patient is essential for a successful transplant, as a close match minimizes the risk of the patient’s body rejecting the donated cells.
If a preliminary match is found, the donor undergoes confirmatory typing, which involves a more detailed blood test to re-verify the HLA match and screen for infectious diseases like HIV or hepatitis. Following successful confirmatory typing, a comprehensive medical examination is conducted to ensure the donor’s overall health and suitability for the donation procedure.
For PBSC donation, the donor receives daily injections of a medication called Granulocyte Colony-Stimulating Factor (G-CSF) for about four to five days before the procedure. This medication stimulates the bone marrow to produce more stem cells and release them into the bloodstream. The donation itself is an outpatient procedure called apheresis, where blood is drawn from one arm, passed through a machine that separates the stem cells, and the remaining blood is returned to the donor through the other arm. This process lasts between four to eight hours and may require two sessions.
In contrast, a marrow donation is a surgical procedure performed under general anesthesia. A surgeon uses hollow needles to extract liquid marrow from the back of the donor’s pelvic bones. Multiple insertions may be needed to collect the required amount, around one to two pints, which is about 10% of the donor’s total marrow supply. The body naturally replaces the donated marrow within a few weeks. Donors are discharged the same day or after an overnight stay for observation.
Who Can Donate and What to Expect
General eligibility criteria for joining a bone marrow registry include being between 18 and 55 years old, being in general good health, and having a Body Mass Index (BMI) under 40. Individuals with certain serious conditions, such as severe heart, lung, or kidney diseases, autoimmune disorders, or a history of cancer, are not eligible to donate.
The screening process is thorough and involves blood tests, an electrocardiogram (ECG), and a chest X-ray to ensure the donor’s health and safety. This evaluation identifies any underlying health issues that could pose a risk to the donor or recipient.
Potential side effects vary depending on the donation method. PBSC donors may experience temporary flu-like symptoms, including bone or muscle aches, headaches, fatigue, and nausea, from the G-CSF injections. These symptoms subside within a few days after the donation. Some donors might also experience bruising easily due to temporary low platelet levels, which normalize quickly.
For marrow donation, common side effects include soreness or bruising in the lower back or hip area, fatigue, and stiffness for a few days to a couple of weeks. Since it involves general anesthesia, there are also minimal anesthesia-related risks, such as nausea or vomiting upon waking. Donors recover quickly with rest and mild pain management, returning to normal activities within one to two weeks, while PBSC donors recover within one to three days.
The Lifesaving Impact
Bone marrow donation offers a chance at a new life for patients battling various blood cancers and disorders. For many, a stem cell transplant replaces diseased bone marrow with healthy cells, offering a chance for a cure and regenerating a fully functioning blood system. This can lead to recovery, allowing patients to live healthy lives.
The need for more donors is continuous, as finding a matching donor can be challenging, particularly for patients from diverse ethnic backgrounds. Despite millions of registered donors worldwide, a significant percentage of patients do not find a match within their family and rely on unrelated donors. Every new donor added to the registry increases the chances of finding a match for a patient waiting for this life-saving treatment.