Older age and plasma viral load in HIV-1 infection.

Background: The purpose of the study was to examine the relationship between age and plasma viral load in HIV-1-infected individuals.

Design: The experimental method was to recruit older (> 50 years of age) and younger (18-39 years of age) HIV-1-infected individuals. The plasma viral load was measured using the Roche Molecular Systems UltraSensitive Roche HIV-1 Monitor test reflexively with the standard Amplicor HIV Monitor test to quantify viral load in the range of 50-750,000 copies of HIV-1 RNA/ml plasma.

Subjects: A total of 135 HIV-1-seropositive individuals (at Centers for Disease Control and Prevention early symptomatic stage B or late symptomatic stage/AIDS C) were enrolled as part of a larger cohort also consisting of HIV-1-seronegative individuals.

Results: A generalized linear models statistical analysis was conducted in order to evaluate age category as a predictor of plasma viral load. The result was a significant effect of age category, with older age associated with a lower plasma viral load. The association held controlling for antiretroviral therapy usage, disease stage, antiretroviral medication adherence, HIV-1 serostatus duration, alcohol and substance use, recent sexually transmitted disease, and sociodemographics (except income).

Conclusion: Older age was associated with lower levels of HIV-1 replication in this sample, independent of antiretroviral therapy usage, regimen adherence, and disease stage. It is suggested that the effect may be caused by changes in viral evolution or immunological monitoring specific to older individuals with HIV-1 infection.