Residual HIV-RNA levels persist for up to 2.5 years in peripheral blood mononuclear cells of patients on potent antiretroviral therapy

The long-term response of 10 asymptomatic, antiretroviral therapy-naive HIV -1-infected patients to potent combination antiretroviral therapy was chara cterized by monitoring levels of HIV-1 RNA in plasma, peripheral blood mono nuclear cells (PBMC), and lymphoid tissue using highly sensitive HIV-1 RNA assays. Although plasma viral loads were continuously suppressed to levels below 50 HIV-1 RNA copies/ml for up to 2.5 years (60-128 weeks), HIV-1 RNA was still detectable at very low levels (1 to 49 HIV-1 RNA copies/ml) in 25 % of the samples. In corresponding PBMC specimens, residual HIV-RNA was det ectable in as much as 91% of samples tested (1 to 420 HIV-1 RNA copies/mu g total RNA). Similarly, HIV-1 RNA levels in lymphoid tissue also remained d etectable at a high frequency (86%), A highly significant correlation was d emonstrated between therapy-induced change in PBMC HIV-1 RNA levels and cha nge in plasma HIV-1 RNA levels (r(2) = 0.69; p = 0.003). These findings sup port the concept that measurement of HIV-1 RNA in the easily accessible PBM C compartment is relevant for evaluating the potency of current and future antiretroviral therapies.