Adolescent Stem Cell Donors: Benefits, Burdens, and Risks of Being a Lifeline for a Sibling

A young person decides to donate stem cells to an HLA-matched sibling in need of a bone marrow transplant. It is such a selfless gift. But for an adolescent in the midst of the emotional turmoil that comes with that age, just how easy a decision is it to decide to give such a complex gift?

A multidisciplinary team explored the conundrum with the goal of identifying how to help these generous persons through a very difficult decision.¹ The team members were, from St. Jude Children’s Research Hospital in Memphis, Tennessee, Meaghann S. Weaver, MD, MPH, from the Department of Oncology; Ashley Carr, CCLS, from the Child Life Program; and Brandon Triplett, MD, from the Department of Bone Marrow Transplantation and Cellular Therapy; and Douglas S. Diekema, MD, MPH, attending physician and director of education for the Treuman Katz Center for Pediatric Bioethics at the Seattle Children’s Research Institute in Seattle, Washington.¹

Potential sibling donors of hematopoietic cells often feel they exist in the shadow cast by their ill siblings. The care team has a unique responsibility to bring their situation into the light. Theirs is not an easy gift to give, and the potential donor’s decision process is often emotionally fraught.¹

Human leukocyte antigen (HLA) matching is the most important donor-related determinant of a patient’s outcome. When researchers compare rates of complications, relapse, and survival among patients who receive an HLA-matched donation from a sibling vs. an HLA-matched donation from an unrelated source, the results are obvious: the outcome is more successful when the donor is a sibling. Risks for graft-versus-host disease, rates of infection, and treatment-related mortality are all lower, and survival rates are far superior. Weaver and colleagues report that because of the success rates, sibling donors have been recruited in 39% to 48% of all childhood bone marrow transplants to date, and that number is on the rise.¹

Deciding to donate may not be easy for a young person, since donating stem cells is a challenging, time-consuming, and sometimes painful procedure. Even the initial evaluation is difficult, as any potential donor begins the process with extensive medical tests and physical examinations. Any donor must have normal pulmonary, hepatic, renal, and cardiovascular function and be free of active infectious diseases. The donor sibling must also be immunocompatible with the patient.

Once compatibility has been determined, the donor sibling needs to decide if she or he wants to continue the process. A person making a decision like this requires a considerable amount of information and support. To that end, the transplant team should explain the next steps.

Potential donors must understand that hematopoietic progenitor cells are collected from the their bone marrow or peripheral blood, and their experience can vary from discomfort to actual pain. For example, once donor eligibility is confirmed and the sibling decides to proceed, the next step is usually administration of granulocyte-colony stimulating factor (G-CSF). This medication stimulates the bone marrow to increase the proliferation of hematopoietic stem cells prior to leukapheresis, the procedure used to collect white blood cells. G-CSF is usually administered as a daily subcutaneous injection, and it can cause muscle aches, headache, nausea, and bone pain.

If the G-CSF is successful, leukapheresis is usually the next step. Educating the potential donor is vital. The donor sibling should know that leukapheresis takes approximately 4 hours for each session. The procedure might be painful and cause racing heartbeat, low blood pressure, clotting difficulty, low platelets, and temporary symptomatic hypocalcemia. In addition, the donor could be exposed to blood products during the priming of the apheresis equipment.

When actual bone marrow collection is used instead of leukapheresis, 50% of sibling donors experience pain severe enough to require analgesia, 9% experience lumbar region stiffness, and 7% of the young donors have sore throats as a result of intubation.¹ In addition, if the sibling is much larger in size, the donor may need a blood transfusion, although this complication occurs less frequently.¹

Potential donors should be aware of these possible side effects. These factors may affect their decision to continue with the process.