Viviane D. Lima ¹, Valeria Fink ¹, Benita Yip ¹, Robert S. Hogg ¹, P. Richard Harrigan ¹, Julio S.G. Montaner ^1*

¹ British Columbia Centre for Excellence in HIV/AIDS

^* To whom correspondence should be addressed. E-mail: jmontaner{at}cfenet.ubc.ca.

	Abstract

Objectives. We examined the significance of plasma HIV-1 RNA levels (or viral load alone) in predicting CD4 cell decline in untreated HIV-infected individuals.

Methods. Data were obtained from the British Columbia Centre for Excellence in HIV/AIDS. Participants included all residents who ever had a viral load determination in the province and who had never taken antiretroviral drugs (N=890). We analyzed a total of 2074 viral load measurements and 2332 CD4 cell counts. Linear mixed-effects models were used to predict CD4 cell decline over time.

Results. Longitudinal viral load was strongly associated with CD4 cell decline over time; an average of 1 log₁₀ increase in viral load was associated with a 55-cell/mm³ decrease in CD4 cell count.

Conclusions. Our results support the combined use of CD4 cell count and viral load as prognostic markers in HIV-infected individuals before the introduction of antiretroviral therapy.

Key Words: Epidemiology, HIV/AIDS, Statistics/Evaluation/Research