If your child needs stem cells from someone else, we will determine the best donor possible using HLA typing. HLA typing is the process of determining each person's transplant antigens. Antigens are "fingerprints" on the surface of almost all cells of the body.
The typing process has two steps. The first is called serological typing, which provides a broad definition of your tissue type. The second step, which is more refined and specific, is performed using a DNA method. Although no two people have exactly the same antigens on all of their cells (except for identical twins), it is helpful to find a donor whose HLA type is as similar as possible to the patient's HLA type. The first step is to draw blood from and HLA type the patient and the immediate family members.
Matched or closely matched family donor
About 25 percent of patients have a family member who is a match at the ten major sites tested. If a family member matches, he or she may be selected as a donor. If more than one family member matches, the transplant doctor will choose the most appropriate donor using blood tests and clinical information. There is a one in four chance that a full sibling will be a perfect match, but a very low chance that a half brother or sister will be a perfect match. It is also very unlikely, but possible, that a parent might be a perfect match for their child.
If no acceptable match is found within the family, the transplant team may conduct a preliminary search for an unrelated donor through the National Marrow Donor Program (NMDP) and more than 46 international and cord bank computerized database registries. The preliminary search is free.
The transplant team will ask the registries to contact potential matched donors for further testing. This is a formal search and this requires insurance coverage or a financial down-payment. The transplant team meets at least weekly to review the status of the donor search.
The Lowder Blood and Marrow Transplant Unit at Children's Hospital conducts an annual Bone Marrow Donor drive.