← All Pharmacogenomic Tests

HLA-B*5701/ abacavir Pharmacogenomic Lab Test

  • The HLA-B*5701 test is used to determine potential risk for serious side-effects [link to: http://www.mayoclinic.org/drugs-supplements/abacavir-oral-route/precautions/drg-20061463 ] to a medication called abacavir.

  • A positive test result means you have the HLA-B*5701 gene variant and have a higher risk of developing a potentially life-threatening reaction to abacavir. If your test result is positive, you should not take abacavir.

  • A negative test result means you do not have the HLA-B*5701 gene variant and abacavir may be taken.

Your health care provider evaluates your test results and uses this information, along with your other health information, to make recommendations for appropriate treatment options.

HLA-B*5701 Test Results

What should I do with my test results?

Talk to your health care provider or pharmacist about your test results. They may suggest you:

  • Keep taking a medication
  • Change the dose of a medication
  • Stop taking a medication
  • Take a different medication

What does my HLA-B*5701 result mean?

Positive

This means that you have the HLA-B*5701 gene variant. Abacavir is not recommended. Your health care provider can help to find a different medication that is safe for you. For more information, see the Medications tab.

Negative

This means that you do not have the HLA-B*5701 gene variant. Abacavir may be used. For more information, see the Medications tab.

Who will see my results?

Only health care professionals, and those individuals to whom you have given permission, see your genetic test results. If you are receiving care at another medical facility, Mayo Clinic recommends you share this information with your other health care providers.

Which gene affects my response to abacavir?

Variants in a gene called HLA-B can affect how you respond to abacavir. The HLA-B gene has hundreds of variations. Each variation is given a number. People with a certain variant in this gene called HLA-B*5701 have a higher risk of hypersensitivity reactions caused by abacavir.

How could the HLA-B*5701 test result affect my treatment?

If you test positive for the HLA-B*5701 gene variant, you should not take abacavir. Your health care provider can help to find an alternative medication that is safe for you.

If you test negative for the HLA-B*5701 gene variant, abacavir therapy may be recommended. It is still possible for you to have side effects with abacavir even if you do not have the HLA-B*5701 gene variant. If you have a negative test result and take abacavir, your health care provider should monitor you routinely for possible side effects.

If you are no longer taking abacavir, but have taken it in the past without any problems, you could develop a hypersensitivity reaction when re-starting abacavir. Testing for the HLA-B*5701 is recommended before taking abacavir again.

Do different populations respond differently?

There is no current evidence that different populations respond differently to abacavir based on the HLA-B*5701 gene variant.

What is Abacavir?

Abacavir (such as Ziagen, Trizivir, and Epzicom) is a medication used in the treatment of human immunodeficiency virus (HIV) infection. HIV is the virus that causes acquired immunodeficiency syndrome (AIDS).

Which gene affects my response to abacavir?

Variants in a gene called HLA-B can affect how you respond to abacavir. The HLA-B gene has hundreds of variations. Each variation is given a number. People with a certain variant in this gene, called HLA-B*5701 , have a higher risk of developing serious skin reactions, including conditions called toxic epidermal necrolysis (TEM) and Stevens-Johnson syndrome.

What problems can patients with the HLA-B*5701 variant have when taking abacavir?

Patients with the HLA-B*5701 gene variant can develop the hypersensitivity reaction, which affects multiple organs. Symptoms include fever, skin rashes, nausea, vomiting, diarrhea, abdominal pain, and respiratory problems. If the symptoms are not recognized and treatment with abavacir is continued, the reaction can be fatal.

How could the HLA-B* 5701 test result affect my treatment?

If you test positive for the HLA-B*5701 gene variant, you should not take abavacir. Your health care provider can help to find an alternative medication that is safe for you.

If you test negative for the HLA-B*5701 gene variant, abacavir therapy may be recommended. However, it is still possible for individuals to have problems with abacavir even if they don’t have the gene variant. Your health care provider should monitor you routinely for possible side effects.

People who are no longer taking abacavir but have taken it in the past without any problems, could develop the hypersensitivity reaction when re-starting abacavir. As a result, testing for the HLA-B*5701 is recommended.

Who is affected? Do different populations respond differently?

There is no current evidence that different populations respond differently to abacavir because of the HLA-B*5701 gene variant.

Where can I find more information about abacavir?

These resources may help you understand more about individualized medicine, genomics and drug-gene testing (pharmacogenomics):

If you have questions about your test results, ask to speak with your health care provider at your Mayo Clinic care location:

  • Minnesota 507-284-2511

  • Arizona 480-301-8000

  • Florida 904-953-2000