Characterization of viral dynamics in human immunodeficiency virus type 1-infected patients treated with combination antiretroviral therapy: Relationships to host factors, cellular restoration, and virologic end points

Biphasic plasma viral decays were modeled in 48 patients treated with ritonavir, zidovudine, and lamivudine, Estimated first- and second-phase decay rates were d(1) as 0.47/day and d(2) as 0.04/day. Interpatient differences in both decay rates were significant. The d(1) was directly correlated with baseline CD4(+), CD4(+)CD28(+), and CD8(+)CD28(+) T lymphocyte counts (P<.05) and inversely correlated with baseline virus load (P=.044) and the magnitude of CD4(+) and CD8(+) T lymphocyte recovery (P<.01). The d(2) was directly correlated with baseline percentage of CD8(+) T lymphocytes (P=.023), the CD8(+)CD38(+) cell number (P=.024), and the level of IgG that binds to human immunodeficiency virus (HIV) type 1 gp120 (P=.02), Viral decay rates were not predictive of treatment failure or durability of viral suppression. These exploratory findings are consistent with a model in which immunologic factors contribute to elimination of HIV-infected cells and suggest a dynamic interplay between regulation of HIV expression and lymphocyte activation and recovery.