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Matching donors and patients is much more complex than matching blood types. Doctors match donors to patients based on their human leukocyte antigen (HLA) tissue type. 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 donor and patient is the most important matching factor.

Matching HLA Markers

There are many HLA markers that make each person’s tissue type unique. Certain markers are key to a successful bone marrow or cord blood transplant. All new members are tested for these specific markers when they join the NMDP Registry.

Selecting the best donor for a patient

Check out NMDP Blog  to learn how NMDP is improving the science of HLA matching to help more patients in need of a bone marrow transplant.

A patient’s doctor selects several potential donors whose HLA matches the patient at a basic level. The doctor then asks for additional testing to determine which donor most closely matches the patient.

If a patient has many matches, doctors will also consider other factors such as the donor's age, gender, blood type and BMI.

When you’re selected

To learn what happens if you are selected as the best donor for a patient, see the donation process.