Menu   WellSpan Health

Health Library

Health Library

HIV Genotypic Resistance

Does this test have other names?

Genotypic resistance assay

What is this test?

This blood test looks at the genetic makeup of a strain of HIV, the virus that causes AIDS.

If you are infected with HIV, this test may be done before you start taking antiviral medicine. It can help your healthcare provider figure out the best treatment to use. This helps because drug-resistant HIV strains continue to change.

The test can also help figure out if a medicine you are taking works for your type of HIV and whether your virus has mutated, or changed, in an effort to survive treatments. This test is only able to find known mutations.

Why do I need this test?

You may need this test if your healthcare provider suspects that the amount of HIV in your body is steadily increasing. This could happen even though you're taking antiviral medicines if you have a type of HIV that's resistant to treatment.

You may also have this test before starting HIV treatment. You might also be given this test if you are pregnant and need HIV medicines.

What other tests might I have along with this test?

Your healthcare provider may also do HIV phenotype resistance testing. But it takes longer to get the results for this test and the cost is higher. Also resistance measurements have not been set for all HIV medicines.

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.

Test results include a combination of numbers and letters—for instance, K103N. Not all mutations of HIV resist drug treatment, but some are commonly found in HIV.

To get the best test results, you typically need to have at least 1,000 copies of the virus per milliliter of blood. The test may not be useful if you don't have enough copies of the virus in your blood.

This test may not find mutations that infect less than 20% of the virus population.  

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?

Not taking your HIV medicines as prescribed can cause what may look like an error in your results (false-positive).

How do I get ready for this test?

You don't need to prepare for this test.

 

HIV Genotypic Resistance - WellSpan Health

Author: Fisher, Steve
Online Medical Reviewer: Moloney Johns, Amanda, PA-C, MPAS, BBA
Online Medical Reviewer: Snyder, Mandy, APRN
Last Review Date: 2015-10-18T00:00:00
Last Modified Date: 2015-12-07T00:00:00
Published Date: 2015-12-07T00:00:00
Last Review Date: 2012-07-05T00:00:00
© 2016 WellSpan Health. All Rights Reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.

I would like to:

Are you sure you would like to cancel?

All information will be lost.

Yes No ×

About the provider search

This search will provide you with WellSpan Medical Group and Northern Lancaster County (Ephrata) Medical Group primary care physicians and specialists. If we don’t have a WellSpan Medical Group physician to meet your criteria, the search will expand to include community physicians who partner with WellSpan Medical Group physicians through the WellSpan Provider Network or provide care to patients on the Medical Staffs of WellSpan’s Hospitals.

×

Schedule Your Next Appointment Online with MyWellSpan

Use your MyWellSpan patient portal any time to view available appointments, and pick the date and time that best suits your schedule.

Go to MyWellSpan

New to this practice?

If you don't have a WellSpan primary care provider and would like to schedule a new patient appointment with a provider who is accepting patients, just log into your MyWellSpan account, and go to the Appointment Center section. As you progress through the scheduling process, you will be able to see the offices that are accepting new patients in relation to your zip code. If you are not enrolled in MyWellSpan, go to www.mywellspan.org, call 1-866-638-1842 or speak with a member of the staff at a participating facility to sign up. New patient scheduling not available at all practices/programs.

Already a patient at this practice?

If you already have a relationship with a WellSpan practice, simply log into your account, and go to the Appointment Center section. As you progress through the scheduling process, you will be able to schedule an appointment with any provider or practice that already counts you as a patient. Online scheduling varies by practice/program.

×