Stem cell donation is a medical process where specialized cells are collected from a healthy individual to treat serious diseases in another person. These donations offer a chance at recovery for patients facing life-threatening conditions, often impacting the blood or immune system. The process involves transferring healthy stem cells to replace diseased or damaged cells in the recipient. This act can be life-saving for individuals who have exhausted other treatment options.
Understanding Stem Cells and Their Role in Donation
Stem cells are unique cells with two distinct properties: the ability to self-renew (make more cells like themselves) and the capacity to differentiate into various specialized cell types, such as blood, bone, or nerve cells, depending on the stem cell type and its location. This versatility makes stem cells invaluable in medical treatments, especially in donation settings.
Stem cells’ regenerative capabilities are important for treating various diseases. For instance, hematopoietic stem cells, primarily found in bone marrow, produce all types of blood cells, including red blood cells, white blood cells, and platelets. When a patient’s own blood-forming cells are damaged or diseased, healthy donated stem cells can replace them, effectively rebuilding the patient’s blood and immune systems. This forms the basis for stem cell transplantation.
Types of Stem Cell Donation
Stem cells for transplantation can be sourced through three primary methods: Peripheral Blood Stem Cell (PBSC) donation, Bone Marrow donation, and Umbilical Cord Blood donation. Each method involves distinct collection procedures and sources for the stem cells.
Peripheral Blood Stem Cell (PBSC) donation is the most common method, accounting for approximately 90% of donations. This non-surgical procedure collects stem cells directly from the bloodstream, similar to donating plasma or platelets.
Bone Marrow donation is a surgical procedure, typically performed in a hospital. Liquid marrow is collected from the back of the donor’s pelvic bone using needles.
The third type is Umbilical Cord Blood donation, where stem cells are collected from the umbilical cord and placenta after a baby’s birth. These cells are then processed and frozen for future use in cord blood banks. Umbilical cord blood transplants are generally used for children and smaller adults due to the limited volume of blood collected.
The Donor Experience and Eligibility
Becoming a stem cell donor involves a careful process to ensure donor safety and transplant success for the recipient. Eligibility criteria typically require donors to be between 17 or 18 and 35 or 55 years old, depending on the registry, and in good general health. Certain medical conditions, such as severe heart or lung diseases, autoimmune disorders, or a history of cancer, may exclude individuals from donating. Potential donors are screened through health questionnaires, blood tests, and human leukocyte antigen (HLA) typing to find the best possible match for a patient.
For Peripheral Blood Stem Cell (PBSC) donation, preparation involves daily filgrastim injections for about four to five days before collection. These injections can cause temporary side effects such as bone pain, muscle aches, headaches, or fatigue, which typically subside within a few days after donation. The donation is an outpatient procedure called apheresis, lasting typically 4 to 8 hours. Blood is drawn from one arm, passed through a machine to separate stem cells, and the remaining blood is returned to the other arm. Donors usually resume normal activities within 1 to 3 days, with the body replenishing donated stem cells within weeks.
Bone Marrow donation, while less common, is a surgical procedure performed under general anesthesia. Needles are inserted into the back of the pelvic bone to withdraw liquid marrow. Donors may experience soreness or stiffness in the lower back or hips, fatigue, and mild nausea after the procedure. Recovery times vary, but most bone marrow donors can return to usual activities within 2 to 7 days, with full recovery sometimes taking a few weeks. Serious complications are rare, and the body naturally replaces the donated marrow within weeks.
Recipient Use of Donated Stem Cells
Once collected, donated stem cells are prepared for transplantation into the recipient. They are commonly used to treat blood cancers like leukemia, lymphoma, and multiple myeloma, as well as severe aplastic anemia, and other blood disorders. They can also address certain genetic or inherited disorders and immune deficiency diseases.
The healthy stem cells engraft in the recipient’s bone marrow, where they begin to produce new, healthy blood cells. This effectively rebuilds the patient’s blood system, offering a chance at recovery. This process provides a therapeutic option for patients whose own bone marrow has failed due to illness or intense treatments like chemotherapy.