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.

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 transplantation more difficult.

This test matches the HLA between the donor stem-cells or organs and the people who will receive them. An improper match in a stem-cell transplant could cause the stem cells to harm the recipient. A mismatched organ transplant can cause the organ to fail and be rejected.

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 necessary if your own organ is no longer able to function properly. Testing ensures the best possible match between your HLA antigens and those on the organ you receive.

What other tests might I have along with this test?

Your doctor 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 received 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 transplantation 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 health care 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.