Monitoring HIV Disease Progression and Treatment

An important part of your HIV health care involves lab work at regular intervals to monitor the progression of your HIV disease and to provide information that will help your specialist make decisions regarding your treatment plan. Knowing and understanding the results of lab tests is an important way for you to understand and learn to live with HIV.

The HIV viral load test measures the amount of HIV in your blood and shows how actively the virus is reproducing in the body. The viral load is counted and reported in the form of copies per milliliter (ml) of blood. There are two different types of HIV viral load tests: polymerase chain reaction (PCR) test and the branched DNA (b-DNA) test. It is not necessary to understand how the tests differ, but you should know that the different test methods will give different results for the same sample and the tests are not interchangeable. Both tests measure the amount of HIV in the blood, but the results of the two tests do not correlate and it is like trying to compare apples to oranges. Because of this, you should have the same test done by the same lab each time; your provider will always order the same test.

When used in combination with the CD4 cell count (T cell) test, the HIV viral load test is used to monitor the status of HIV disease and to predict the future course of HIV. It is essential in determining when to start treatment for HIV with antiretroviral medications. It is also useful in monitoring the effectiveness of the medications. This test is done when you are first diagnosed with HIV as a baseline and then every 3 months, but it may be done more frequently if you are beginning medications, are changing medications, or have been missing doses of medications. To monitor stable long term therapy, the viral load and CD4 counts are done every 3-6 months, with most HIV treatment specialists preferring to do them at 3 month intervals.