Beneficial Effects of a Switch to a Lopinavir/ritonavir-Containing Regimen for Patients with Partial or No Immune Reconstitution with Highly Active Antiretroviral Therapy Despite Complete Viral Suppression

The purpose of this study was to determine if switching to an Lopinavir/ritonavir (LPV/r)-containing regimen resulted in greater immune reconstitution in patients with immunologic failure despite complete viral suppression with highly active antiretroviral therapy (HAART). Twenty patients with partial or no immune response to HAART despite viral suppression were enrolled. Ten were randomized to stay on their current regimen and 10 were randomized to LPV/r plus their current NRTI backbone. T cell subsets, ex vivo apoptosis, and the percent of circulating cells with detectable intracellular HIV-1 RNA were measured. The mean increase in CD4+ count at 6 months was 116/mm3 (172–288) for the LPV/r-containing arm versus 32/mm3 (264–296) for continuation regimens ( p=0.03). The number of patients with an increase ≥50 cells/mm3 was also greater in the LPV/r arm (7/9 versus 2/10, p¼0.01). This paralleled a decrease in ex vivo apoptosis of naive CD4þ T cells at 6 months (21.7–11.0% for the LPV/r arm versus 17.3–18.9% for the continuation arm, p=0.04) and memory cells (21.1–14.1% for LPV/r versus 20.2–17.9% for continuation arm, NSS). Switching patients to an LPV/r-containing regimen improved CD4+ counts in patients with prior immunologic failure, and this may be due to an effect of LPV/r on apoptosis.