What is HLA matching?
HLA matching is used to match patients and donors for blood or marrow transplants. If 2 people share the same HLA type, they are considered a 'match'. It's much more complicated than blood typing.
How does matching happen?
- You and potential donors will have blood drawn or will have the inside of your cheek swabbed.
- The blood or cheek swab is tested in a lab to figure out your HLA type.
- Your HLA type will be compared to potential donors to see if there is a match. Your doctor will decide which donor has the best HLA match for you.
What are my chances of having a match?
There are many HLA markers. Each HLA marker has a name. The names are letters or combinations of letters and numbers.
Sometimes, it’s hard to find a match because some HLA types are less common. HLA types are inherited so siblings can sometimes be a match for each other. Each of your brothers and sisters who has the same mom and dad as you has a 1 in 4 chance (25%) of being a complete, or full, match. You’re more likely to match someone with a similar ethnic background or ancestry.
Where can I get my HLA tested?
You can have HLA typing done at your:
- Transplant center
- Cancer clinic or cancer center
If you haven't been to a transplant center yet, your doctor can test your HLA type for free through our HLA Today program.
Contact our Patient Support Center with any questions:
- Call or text: 1 (888) 999-6743
- Email: patientinfo@nmdp.org
If you are a hematologist or oncologist who would like to learn more about our HLA Today program, visit BeTheMatchclinical.org/HLAToday or email us at HLAToday@nmdp.org.
Why is finding the best donor or cord blood unit (CBU) important?
Your doctor wants to find the best possible donor or CBU for you. Usually, it’s a donor or CBU whose HLA are very closely matched to yours.
A close match is important because it:
- Improves the chances for a successful transplant.
- Helps your donor cells engraft (grow and make new blood cells in your body).
- Reduces the risk of complications like graft-versus-host disease (GVHD). GVHD happens when the immune cells from the donated cells (the graft) attack the recipient’s cells (the host).
There are times when a closely matched donor isn’t the best option. For some patients, a donor who matches exactly half of their HLA is best. This is called a haploidentical (or half-matched) transplant.