Antiviral Strategies

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i Viral Load
\V Fact Sheet

active infections, such as the flu or an herpes outbreak, because
previously HIV-infected, but inactive, CD4+ cells suddenly 'wake
up' (are activated by the flu or herpes virus) and start producing
HIV. Additionally, certain vaccines, such as the flu vaccine, can
cause short-term increases in HIV RNA levels. This has caused
some controversy around whether or not HIV-positive people
should get routine flu shots. In general, the guidance is that the
increase in viral levels resulting from vaccination are much lower
than the rises caused by the actual flu infection, and these increased viral levels are not sustained for more than a few weeks.
Viral levels can also be affected by antiviral therapy, making viral
load tests an important tool in making treatment decisions.
How Often Should Viral Load be
measured?
Initially two HIV RNA measurements should be taken approximately 2-4 weeks apart to establish a 'baseline' level. Afterwards,
tests should be repeated every 3-4 four months along with CD4+
cell counts. Because other infections, such as a common flu, can
cause a temporary increase in viral levels, any sudden rise in virus
should be checked with another test 2-4 weeks later. People should
generally avoid having viral load tests done during an active infection (e.g. active cold or flu), after routine immunizations (flu,
tetanus, and pneumococcus) or during flare-ups of genital herpes or other opportunistic infections. These factors can all cause
a 10 to 100 fold increase in viral levels that usually returns to
baseline within a few weeks after the end of the infection or after
vaccination. Tests should be performed more frequently when critical decisions are being made regarding treatment, and a test should
be performed 3-4 weeks after starting or changing therapies.
In addition, because the tests can vary slightly in their results,
people using a particular test should continue to use that test to
get reliable results and correct trends.
Getting Viral Load Tests
Both Roche and Chiron, manufacturers of Q-PCR and bDNA respectively, offer Patient Assistance Programs to supply their tests
free-of-charge to people who have no other means to pay for them
($150-250 each). The availability of these programs may be limited geographically, but you can call the following numbers for
more information:
Chiron (bDNA) 1-888-HIV-LOAD
Roche (Q-PCR) 1 -888-TEST-PCR
Roche's Q-PCR is FDA-approved, and most insurance providers
and Medicaid will pay for tests once they are approved by the FDA.
The bDNA test is still awaiting approval by the FDA. Check with
your personal provider for specific coverage details.

Commentary
Ongoing research will help us understand the best use of HIV
RNA tests in regular health monitoring. As more research is done,
we will obtain clearer and stricter guidelines as to the use of viral
load tests for monitoring responses to antiviral therapy and for
predicting disease progression. The combination of viral load tests,
CD4+ cell counts and other health markers help provide a clearer
picture of the risk of disease progression, immune status and the
body's fight against HIV. The increasingly widespread use of viral
load tests warrants that clearer guidelines be developed to assist
people in understanding viral activity.
It may be possible to eradicate the virus altogether in people with
sustained undetectable viral load levels (undetectable on the 20
copy-sensitive assay) and who are taking combination antiviral
therapies, but this idea is only theoretical. People should be warned
that stopping or reducing antiviral therapy because the viral load
is perceived as "undetectable" may result in the resurgence of the
virus because HIV may be hiding out in other reservoirs of the
body not detected by viral load tests. In fact, this has been seen in
people in clinical studies. Reducing antiviral therapy may also
lead to drug resistance. Researchers are looking into the development of another type of HIV test that would detect HIV inside a
cell, before it has had a chance to replicate and before it would be
detected by the new viral load test. If virus is present in cells despite undetectable HIV RNA plasma levels, it is more likely that
that viral levels will rise again at some point. If eradication is a
true possibility, a highly sensitive viral load test needs to be developed to make certain that no virus is present in the body.
HIV viral load is only the first area where these new testing technologies (Polymerase Chain Reaction, or PCR, and other amplification techniques) have been applied. Other tests based on these
techniques are similarly used in research to measure other viral
diseases, such as CMV, and bacterial diseases, such as tuberculosis (TB), both of which are of great concern for people living with
HIV. As these tests become standardized, understood and accepted
they will help us better understand the relationship between HIV,
opportunistic infections (Os) and the immune system.
The best predictor of disease progression is likely to be not one
single test but a combination of tests, including viral load tests,
CD4+ counts and other diagnostic tests, that each tell us about
different elements of the immune system's status and fight against
HIV. Whereas CD4+ cell counts tell us what has already happened
in the body, viral load levels allow us to predict what might happen in the future. Used together, these tests will allow physicians
and patients to make earlier and more definitive decisions about
treatment and health status.

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