Human Leukocyte Antigen (HLA) Matching and Stem Cell Transplants
More than 130,000 people are diagnosed with blood cancer in the United States every year. Bone marrow and umbilical cord blood stem cell transplants are some of the most common treatment options for these cancers. Transplants are a complicated surgery and require attaining a genetic match prior, but can warrant long-term, successful results for patients.
To participate in a transplant, patients must first find a donor that is a suitable genetic match to ensure their body will reject the donor stem cells.
Donors can be found a number of ways — through family, bone marrow registries, public cord blood banks, or family cord blood banking. To ensure that a transplant will be successful, the patient and the donor must go through HLA typing.
What is HLA Typing?
Human Leukocyte Antigen (HLA) typing is the matching of proteins or markers to ensure that a patient’s genetic code and immune system are compatible for donating to the specific recipient. A proper match through HLA typing increases the likelihood of a successful transplant, improves engraftment, and reduces complications after the transplant, like Graft-versus-host-disease (GvHD). For more general information on HLA typing and matching please visit Be The Match.
Cord Blood and HLA Typing
Cord blood has an advantage over bone marrow in HLA typing.To create the best possibilities for a successful transplant, cord blood must match 4 out of 6 proteins or markers. Bone marrow must meet 6 out of 8.This means an umbilical cord blood transplant does not need to match as closely as bone marrow.
Each parent contributes to a person’s HLA markers, so a sibling has a 25% chance of being a full match or a 50% chance of being a half match. A half match is sufficient for transplant in some cases, so many families choose to bank cord blood for all of their children, to increase the odds of being able to treat a serious medical condition.
Family cord blood banking is worth extra consideration if the odds of finding a match from a public cord blood or bone marrow registry are particularly low. For example, people with a multiethnic background are less likely to quickly find a suitable match. In the event of a serious medical condition, family banking could improve treatment options.