HLA Antigen

By Metcalf, Eric 
March 22, 2017

HLA Antigen

Does this test have other names?

Human leukocyte antigen (HLA) typing

What is this test?

This test looks at the human leukocyte antigens (HLA) in your blood. This test is used if you need an organ or stem-cell transplant, to find an organ or stem cells that are as close to yours as possible. An improper match if you need a stem-cell transplant could cause the stem cells to harm you. A mismatched organ transplant can cause the organ to fail and be rejected.

HLAs are proteins found on the surface of most of the cells in your body. They signal to your immune system which cells are parts of your body and which cells are potentially harmful organisms. They play an important role in protecting you from infections, but they also make organ transplants more difficult.

HLAs are also involved in autoimmune diseases. These are diseases in which the body attacks its own tissues. The HLA test can be used to identify these diseases.

Why do I need this test?

You may have this test if you need an organ or stem-cell transplant. A heart, lung, or kidney transplant may be needed if your own organ is no longer able to work as it should. Testing helps make sure you have the best possible match between your HLA antigens and those on the organ you receive. You may also need this test if your healthcare provider suspects that you have an autoimmune disease.

What other tests might I have along with this test?

Your healthcare provider may also order these tests:

  • DNA test of HLA-related genes. This looks at the DNA from immune system cells taken from a blood sample.

  • HLA antibodies. People who have been pregnant or get a blood transfusion or organ transplant may have antibodies that will react with HLA antigens on a new transplant. It's common to test people for these antibodies before the transplant to find out whether they are likely to reject the transplant.

What do my test results mean?

Many things may affect your lab test results. These include the method each lab uses to do the test. Even if your test results are different from the normal value, you may not have a problem. To learn what the results mean for you, talk with your healthcare provider.

Results of HLA typing vary according to a number of factors, including your age, the type of transplant, and your underlying disease. The results will show the degree to which HLA antigens match between you and the donor.

How is this test done?

The test requires a blood sample, which is drawn through a needle from a vein in your arm.

Does this test pose any risks?

Taking a blood sample with a needle carries risks that include bleeding, infection, bruising, or feeling dizzy. When the needle pricks your arm, you may feel a slight stinging sensation or pain. Afterward, the site may be slightly sore.

What might affect my test results?

Other factors aren't likely to affect your results.

How do I get ready for this test?

You don't need to prepare for this test.



March 22, 2017


Human leukocyte antigens (HLA): A roadmap. UpToDate., The HLA system: immunobiology, HLA typing, antibody screening and crossmatching techniques. Howell WM. Journal of Clinical Pathology. 2010;63:387-90.

Reviewed By:  

Moloney Johns, Amanda, PA-C, MPAS, BBA,Snyder, Mandy, APRN