Does this test have other names?

HLA antibody screening, HLA screening assay 

What is this test?

This test checks your blood for antibodies against a cell marker called a human leukocyte antigen (HLA). The test is done if you need an organ transplant, to help find a donor organ that will work in your body. Different forms of the HLA antibody are involved in autoimmune diseases. These are diseases in which the body attacks its own tissues. The HLA test has also been used to identify these diseases.

HLAs play an important role in protecting you from infections. But they also make organ transplantation more complex. HLAs are protein markers found on nearly all of your body's cells. They help tell your immune system which cells belong to your body—and shouldn't be attacked. And they tell which ones are invaders that your immune system needs to fight.

Before an organ transplant, health care providers match the recipient and donor HLAs.

Some people who need a transplant have antibodies against HLAs. Most people don't have these antibodies. But women who have been pregnant and people who have had blood transfusions or transplants may have these antibodies. These antibodies can cause your body to reject a transplanted organ right away. Or they may cause the organ to stop working over time.

To find an acceptable match, it's important that your provider measures any HLA antibodies in your bloodstream. 

Why do I need this test?

You may need this test if you need an organ transplant from someone else, if your kidney, lung, or other organ is no longer able to work correctly. This test helps give you the best possible chance that the transplant will work well in your body. This test is used after the transplant to determine if you have developed antibodies to the transplanted donor HLA antigens. Antibodies formed after transplant may increase the risk of graft failure. You may also need this test if your health care provider thinks that you have an autoimmune disease.

What other tests might I have along with this test?

In addition to the HLA test, you may have:

• A test that looks at the type of HLA molecules on the surface of your immune system cells. This helps make sure your donor is a good match.

• DNA testing of HLA-related genes. This test needs taking DNA from a sample of cells, usually immune system cells, from a blood sample.

What do my test results mean?

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 health care provider what your test results mean for you.

Your results will show if you have certain types of antibodies that could cause a problem after a transplant. Some people have these antibodies, and some don't. Your results will affect the search process for a transplant. 

How is this test done?

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

Does this test pose any risks?

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. 

What might affect my test results?

Past pregnancies, blood transfusions, and transplants can affect your results.

How do I get ready for this test?

Tell your health care provider if you have had:

• Pregnancy.

• Blood transfusion. 

• Transplanted tissue or organ.

Be sure your 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.