HLA Antigen

Human leukocyte antigen (HLA) typing

This test looks at the human leukocyte antigens (HLAs) in your blood. This test is used if you need an organ or stem cell transplant. It helps find an organ or stem cells that are as good a match to yours as possible. A bad match with a stem cell transplant could cause the stem cells to harm you. A bad match with an organ transplant can cause the organ to stop working and be attacked by your body’s immune system (rejected).

HLAs are proteins found on the surface of most of the cells in your body. They tell your immune system which cells are parts of your body and which cells may be harmful. They play an important role in protecting you from infections. But they can also make organ transplants more difficult.

HLAs are also involved in autoimmune diseases. These are diseases in which the body attacks its own cells and tissues. The HLA test can be used to show if you may have one of these diseases.

You may need 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 are to receive. You may also need this test if your healthcare provider suspects that you have an autoimmune disease.

You may also have 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 if they are likely to reject the transplant.

Test results may vary depending on your age, gender, health history, and other things. Your test results may be different depending on the lab used. They may not mean you have a problem. Ask your healthcare provider what your test results mean for you.

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.

The test is done with a blood sample. A needle is used to draw blood from a vein in your arm or hand.

Having a blood test with a needle carries some risks. These include bleeding, infection, bruising, and feeling lightheaded. When the needle pricks your arm or hand, you may feel a slight sting or pain. Afterward, the site may be sore.

Other factors aren't likely to affect your results.

You don't need to prepare for this test. Be sure your healthcare provider knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don’t need a prescription and any illegal drugs you may use.