The effect of opportunistic illness on HIV RNA viral load and CD4+ T cell count among HIV-positive adults taking antiretroviral therapy.

introductionHIV RNA viral load (VL) has been shown to increase during opportunistic illnesses (OIs), suggesting active HIV replication in response to infection among patients not taking antiretroviral therapy (ART). We assessed the effects of OIs on HIV RNA VL and CD4+ T cell counts among patients on ART with initially suppressed VL.

methodsBetween 2003 and 2007, we enrolled and followed 1094 HIV-1-infected adults who initiated ART and had quarterly blood draws for VL and CD4+ T cell count. In VL/CD4+ T cell measurement intervals following undetectable VL, we compared the elevation in VL to detectable levels and CD4+ T cell count changes between intervals when participants had episodes of OIs and intervals when they did not have OIs.

resultsVL was more likely to be detectable if participants had OIs in the prior three months compared to when they did not (OR=4.0 (95% CI=1.9-8.6)). The CD4+ T cell counts declined 24.1 cells/µL per three months in intervals where the participants had OIs compared to an increase of 21.3 cells/µL per three months in intervals where they did not have OIs (adjusted difference in the rate of CD4+ T cell count change of 61.7 cells/µL per three months (95% CI=13.7-109.7), P value=0.012). The rate of CD4+ T cell count increase was 25.6 cells/µL per three months (95% CI=11.6-39.6) higher for females compared to males (p value=<0.001), 1.4 cells/µL per three months lower per one year increase in age (p value=0.046) and 4 cells/µL per three months lower per 10 cells/µL increase in the starting CD4+ T cell count value (p value=<0.001).

conclusionEpisodes of opportunistic infections among patients taking ART with undetectable VL were associated with elevation of HIV RNA VL to detectable levels and decline in CD4+ T cell counts. CLINICAL TRIAL NUMBER: NCT00119093.