| tsip29 2006-12-06, 9:27 pm |
| The Failure of Viral Load Tests
JAMA Study Shakes AIDS Science, Angers HIV Advocates
A nationwide team of orthodox AIDS researchers led by doctors Benigno
Rodriguez and Michael Lederman of Case Western Reserve university in
Cleveland are disputing the value of viral load testsa standard used since
1996 to assess health, predict progression to disease, and grant
approval to new AIDS drugsafter their study of 2,800 HIV positives
concluded
viral load measures failed in more than 90% of cases to predict or
explain immune status.
Published in the September 27, 2006 issue of the Journal of the
American Medical Association (JAMA), the findings by Rodriguez et al shake
the
foundation of the past decade of AIDS science to its core, inciting
skepticism and anger among many HIV adherents.
Belief in viral load spread quickly following the 1996 publication of a
paper in the journal Science authored by Dr John Mellors and colleagues
at the university of Pittsburgh. Mellor et al claimed that numbers
produced by the viral load test could accurately predict progression to
disease in HIV positives. Soon, use of this new technology extended far
beyond conclusions drawn by the study and its approval by the FDA as a
prognostic tool.
Claiming viral load numbers corresponded to actual amounts of
infectious virus, scientists used the test as a glib response to
unanswered
questions about how HIV could cause AIDS (Its the virus, stupid!).
Pharmaceutical companies jumped on the bandwagon, using changes in viral
load
numbers in place of actual health or survival benefits to gain FDA
approval of highly toxic protease inhibitors, a primary ingredient of
todays
HAART. Treatment advocates began using viral load to encourage healthy
HIV positives with unhealthy numbers to hit early and hard with the
newly approved drugs, while AIDS doctors throughout the world started
using viral load for everything from diagnosing illness to confirming HIV
infection.
The new uses for viral load emerged and gained popular acceptance
despite the fact that, according to manufacturers literature, the viral
load
test is not intended to be used as a screening test for HIV or as a
diagnostic to confirm the presence of HIV infection.
In a September 29th news article regarding the Rodriguez study, Mellors
announced he doesn't agree with the paper at all, insisting that viral
load is the most powerful predictor of time to AIDS and death." Some
AIDS rethinkers note that in defending his opinion, Mellors describes
viral load as powerful, an adjective frequently found in the headlines of
AIDS drug ads--drugs approved for use based on their ability to affect
viral load numbers rather than to produce clinical health benefits or
increase survival.
While Mellors and others protest or down play the significance of the
JAMA article, Rodriguez's group stands by its conclusion that viral load
is only able to predict progression to disease in 4% to 6% of
HIV-positives studied, challenging much of the basis for current AIDS
science
and treatment policy.
For further information see: Cohen J. Study says HIV blood levels don't
predict immune decline. Science 313(5795):1868, 2006; Rodriquez B,
Sethi AK, Cheruvu VK, et al. Predictive value of plasma HIV RNA level on
rate of CD4 T-cell decline in untreated HIV infection. JAMA
296(12):1498-506, 2006
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