CD4 Cell Recovery in HIV-1 Patients Comparing 2 Treatment Regimes

Therapy guidelines recommend the use of either the non-nucleoside reverse transcriptase inhibitor (NNRTI) efavirenz or a ritonavir-boostered protease inhibitor (PI) plus 2 nucleoside reverse transcriptase inhibitors (NRTI) as first-line treatment regimes of HIV-1 infection. Recent clinical studies suggest potential advantages of NNRTI- over PI-based regimes in therapy initiation due to lower rates of virologic failure and less metabolic side-effects. In contrast, PI regimes were claimed to cause greater increases in CD4 cell count than NNRTI regimes, which has been attributed to intrinsic antiapoptotic effects of the PI. However, it is still unclear whether the immunological response to a PI-containing regime is greater than to an NNRTI-containing regime, whether there is a difference in the extent of reduction of apoptosis between PI and NNRTI regimes and whether a difference in apoptosis is associated with a difference in CD4 cell recovery. We conducted a controlled, long-term, random matched pair design study in HIV-1 infected individuals under sustained virologic suppression to evaluate in head-to-head comparison the clinical effects of a constant PI-based or NNRTI-based regime on CD4 cell recovery and the underlying molecular, biochemical and functional mechanisms.