Embargo for Release:
Saturday, June 14, 5 pm Eastern
Contact: Lisbeth Pettengill
410-955-6878 [email protected]
A combination of measuring plasma viral load
(the amount of genetic material in circulating virus)
and CD4+ lymphocytes in people who are HIV-infected
gives the most accurate prediction of the time when
those people will develop AIDS. This information
forms a critical part of the decision about when to
begin antiretroviral therapy.
The combined measurements, of both HIV-1
RNA (viral load) and CD4+ lymphocyte counts
provided better outcome discrimination than either
marker alone, according to researchers at the
University of Pittsburgh and the Johns Hopkins School
of Public Health. The study also confirmed that viral
load is the single best predictor of progression to full
blown AIDS and death. Their results were published in
the June 15 issue of Annals of Internal Medicine.
#Not only does the amount of virus in the blood
provide great prognostic information in combination
with the level of immune deficiency, but it also
precisely predicts how fast the immune system
declines in HIV-infected individuals,# said Alvaro
Munoz, PhD, professor, Epidemiology, Johns Hopkins
School of Public Health. #Rather than guessing about
when a patient with HIV infection will develop AIDS,
with these findings we can look into the future with
much greater accuracy,# said lead author John
Mellors, MD, co-investigator of the Pittsburgh site of
the Multicenter AIDS Cohort Study (MACS).
Because the progression to AIDS differs among
people who are infected with HIV, it has been difficult
to determine which markers of the progression offer
the most accurate indication of when a person might
expect to have full blown AIDS.
The study looked at 1604 HIV-infected men at
four university-based MACS clinical centers. The men
were assigned to one of 12 categories according to
their viral load measurements and CD4+ counts. Two
time intervals were used to analyze the disease: time
to development of AIDS and time to AIDS-related
death. At the six -year marks, only 1.7 percent of
those with the lowest viral load measurements and the
highest CD4+ counts had developed AIDS. In
contrast, 97.9 percent of those with the highest viral
load and the lowest CD4+ counts developed AIDS.
The relationship is depicted on the attached graph.
The study was funded by the National Institute of
Allergy and Infectious Diseases (NIAID) MACS project.
The Johns Hopkins School of Public Health is one of
four NIAID MACS centers.
-end-
RSS