Impact of 5 years of maximally successful highly active antiretroviral therapy on CD4 cell count and HIV-1 DNA level

Abstract

To evaluate the impact on CD4 cell count and HIV-1 DNA level in peripheral blood mononuclear cells (PBMC) of long-term highly active antiretroviral therapy (HAART) in the setting of maximal success, i.e., constant plasma HIV-1 RNA load suppression. Retrospective analysis of patients selected for a constantly undetectable plasma HIV-1 RNA load since HAART initiation. HIV-1 DNA was measured in PBMC using a real-time polymerase chain reaction assay. Loess estimates and regression analysis were used for modelling the variations of the CD4 cell count and HIV DNA level over time. The study included 41 patients chronically infected with HIV-1 who had been taking HAART for a median duration of 60.4 months and had an undetectable plasma HIV RNA load ever since the first 6 months of HAART; 25 were tested for HIV-1 DNA. The mean CD4 cell count increase was high during the first 18 months on therapy (168 × 106 cells/l per year), much lower afterwards (38 × 106 cells/l per year), independently of the baseline CD4 cell count. Most of the patients (73.2%) reached a CD4 cell count constantly ≥ 400 × 106/l during follow-up. HIV-1 DNA showed a mean decrease of 0.48 log10 copies/106 PBMC during the first year, of 0.18 log10 copies/106 PBMC per year during the 2nd and 3rd years, but no significant decrease afterwards. These results question the benefit of very long-term maintenance of HAART in terms of CD4 gain and HIV-1 DNA reduction.