Stem cells are unique cells within the body that possess the remarkable ability to develop into many different cell types. They also have the capacity to self-renew, meaning they can divide and produce more stem cells. This dual capability makes them valuable in medical treatments, particularly for replacing diseased or damaged cells. In the context of transplants, stem cells can help restore a patient’s blood-forming system following high-dose chemotherapy or radiation.
Understanding Child Stem Cell Donation
A child can indeed donate stem cells to a parent. This donation primarily involves hematopoietic stem cells, which produce all types of blood cells. These stem cells can be collected from several sources.
Bone marrow is a common source, extracted from the hip bones under general anesthesia. Peripheral blood stem cells (PBSC) are another method, mobilized from bone marrow into the bloodstream with medication and collected via a process similar to blood donation. Umbilical cord blood, collected at birth, is also a rich source of hematopoietic stem cells for infants, which can be stored for future use.
Matching for a Successful Transplant
Stem cell transplant success relies on donor-recipient compatibility, determined by Human Leukocyte Antigen (HLA) matching. HLA proteins are cell surface markers that help the immune system distinguish self from foreign invaders. A close HLA match prevents rejection and reduces graft-versus-host disease, where donor immune cells attack recipient tissues.
HLA typing tests blood samples from donor and recipient to identify these markers. Children inherit half of their HLA markers from each parent. This inheritance pattern means there is a 25% chance that a child will be a full, identical HLA match with a sibling who shares both parents. Parents are always a half-match, also known as haploidentical, for their children. While a full match is preferred, haploidentical transplants are increasingly successful, especially when a fully matched donor is unavailable.
Ensuring the Child Donor’s Well-being
A child donor’s well-being is a primary consideration. Collection procedures vary by source. Bone marrow donation requires general anesthesia to extract marrow from the pelvic bone, potentially causing pain and bruising for a few days. Peripheral blood stem cell (PBSC) collection involves daily G-CSF injections to increase stem cell production, followed by apheresis. G-CSF can cause bone pain, muscle aches, and headaches.
Informed consent from parents or legal guardians is mandatory for any child donation. If old enough, the child’s assent (willingness to participate) is also sought, ensuring their voice is heard. Independent medical teams advocate for the child’s best interests, separate from the recipient’s team. Ethical review boards also review and approve cases, emphasizing child safety and minimizing risks.
Exploring Other Donor Options
If a child is not a suitable donor due to match, age, or other reasons, alternative transplant options exist. Unrelated donor registries, like Be The Match, offer a vast database of volunteers worldwide. These registries help find genetically matched donors when a family donor is unsuitable.
Another option, especially when a fully matched unrelated donor is unavailable, is haploidentical transplants from other family members who share half their HLA markers. Advances have made these partial matches more feasible and successful. For certain conditions, an autologous transplant uses a patient’s own collected and reinfused stem cells after high-dose therapy. This approach eliminates donor compatibility and graft-versus-host disease concerns.