When you took the first step to become a bone marrow donor by joining the Be The Match Registry®, you were told patients are searching for a match.
But what exactly is being matched?
The short answer: HLA. Human leukocyte antigens (HLA) are proteins — or markers — found on most cells in your body. Your immune system uses these markers to recognize which cells belong in your body and which do not. A close HLA match between patient and donor is the most important factor in selecting the best bone marrow donor for a patient.
A close match
There are many HLA markers, but matching only a small number of them is critical to a successful transplant.
We test all new members for a minimum of 6 HLA markers when they join the Be The Match Registry. By testing for a basic level of HLA markers, we keep tissue-typing costs low — we want to be able to add as many registry members as possible to help all searching patients find a matching donor.
A patient’s doctor usually tries to select several potential donors who appear to match the patient at a basic level. The doctor then asks for additional testing to find a donor who matches the patient at a detailed level.
If more than one potential donor is a good HLA match for a patient, doctors will also consider other factors, such as the donor’s age, gender and size.
When you’re selected
To learn what happens if you are selected as the best donor for a patient, see When You’re Asked to Donate for a Patient.
About Be The Match
Be The Match Registry is operated by the National Marrow Donor Program® (NMDP). If you joined the NMDP Registry, either in person or online, you are a member of Be The Match Registry and do not need to join again. Learn more about Be The Match.