Stem cell donation is a medical procedure offering a chance at life for individuals facing various serious diseases. These conditions include specific blood cancers like leukemia and lymphoma, other blood disorders, and certain immune system deficiencies. A stem cell transplant replaces a patient’s damaged or unhealthy blood-forming cells with healthy ones from a donor.
Becoming a Stem Cell Donor
Becoming a stem cell donor requires meeting specific eligibility criteria. Most registries, such as DKMS or the National Marrow Donor Program (NMDP), require donors to be between 18 and 55 years old and in general good health. Certain medical conditions, including severe heart, lung, or kidney diseases, autoimmune disorders, or a history of most cancers, may prevent someone from donating. Health status is confirmed via questionnaire.
Registration is straightforward for those who meet initial health guidelines. It involves ordering a cheek swab kit online to collect cells from inside the mouth. These swabs are sent to a laboratory to determine the donor’s Human Leukocyte Antigen (HLA) type. HLA markers are proteins that help the immune system distinguish between its own cells and foreign invaders. A close match between donor and patient is vital for a successful transplant.
Once HLA typing is complete, donor information is added to a global registry. If a patient’s HLA type closely matches, the donor is contacted for further testing and a comprehensive health evaluation to confirm the best match. While a sibling has about a 25% chance of being a full match, the majority of patients rely on finding an unrelated donor through these registries.
Methods of Stem Cell Collection
Once a donor is confirmed as a match, stem cells are collected using one of two methods: peripheral blood stem cell (PBSC) donation or bone marrow donation. The choice of method depends on the patient’s condition and the medical team’s preference. Peripheral blood stem cell donation is the more common method, accounting for approximately 80-90% of all donations.
PBSC donation involves daily injections of a growth factor medication, such as filgrastim, for about five days. This medication stimulates the bone marrow to produce more blood-forming stem cells and release them into the bloodstream. Donors can administer these injections at home.
The collection process, known as apheresis, is similar to donating plasma. Blood is drawn from a vein in one arm, passed through a machine that separates and collects the stem cells, and the remaining blood components are returned to the other arm. This outpatient procedure typically takes between four to eight hours per session and may require one or two sessions to collect enough cells. Donors can relax, read, or watch movies during the process.
Bone marrow donation, a less frequent method, accounts for approximately 10-20% of donations. This procedure takes place in a hospital operating room under general or regional anesthesia, ensuring no pain during collection. Doctors use sterile needles to withdraw liquid marrow directly from the back of the pelvic bone.
The bone marrow collection procedure typically lasts between one to two hours. Unlike PBSC donation, this is a one-time surgical procedure. Donors are monitored in a recovery room afterward, and while many can go home the same day, some may stay overnight for observation.
Donor Experience and Aftercare
Following a stem cell donation, donors may experience temporary side effects, varying by collection method. For PBSC donors, common side effects from the filgrastim injections include flu-like symptoms, headache, bone or muscle aches, fatigue, and sometimes nausea. These symptoms generally subside shortly after the injections cease and the donation is complete.
During apheresis, some donors might experience tingling around the mouth, fingers, or toes, or mild muscle cramps, often due to a temporary drop in calcium levels caused by the anticoagulant. Recovery from PBSC donation is typically quick, with many donors returning to their usual activities within a few days to a week. Bruising at needle sites is possible, and temporary low platelet levels might lead to easier bruising, though these resolve as the body replenishes cells. Donors are advised to avoid strenuous activity for a short period.
Bone marrow donors can expect soreness, discomfort, or bruising in the lower back or hip area where the marrow was collected. Fatigue, low back pain, and general anesthesia side effects like a sore throat or mild nausea are also common. While pain relievers can help manage discomfort, it may take a couple of weeks for donors to feel fully recovered, though some can resume light activities within days.
Donor registries and medical teams provide comprehensive support and follow-up care throughout the donation process. This includes detailed information, medical evaluations, and ongoing monitoring after the donation. Donors often feel a profound sense of fulfillment, knowing they have offered a chance at life to someone in need.