The Effectiveness of Ritonavir Plus Zidovudine Plus Lamivudine in HIV-Infected Patients

To determine whether administration of a highly active antiretroviral treatment regimen consisting of ritonavir (ABT-538), zidovudine (AZT), and lamivudine (3TC) is associated with the restoration of delayed type hypersensitivity and lymphocyte proliferative responses in patients with moderately advanced HIV-1 infection. To better characterize in these patients the phenotype of the expanded lymphocyte subpopulations, as well as the genotype, phenotype, and cellular origin of viruses that persist after initiation of therapy, and the genotype and phenotype of drug-resistant isolates that emerge during therapy. Although plasma viral load drops dramatically after initiation of powerful antiretrovirals, it does not drop to zero. It appears that a new steady state is reached, suggesting that a reservoir may exist of virus-producing cells, possibly cells of monocyte/macrophage lineage, that continue to produce a low level of virus despite antiretroviral treatment. Although plasma viral load drops dramatically after initiation of powerful antiretrovirals, it does not drop to zero. It appears that a new steady state is reached, suggesting that a reservoir may exist of virus-producing cells, possibly cells of monocyte/macrophage lineage, that continue to produce a low level of virus despite antiretroviral treatment. Patients undergo 5 weeks of antiretroviral washout before initiating therapy with ritonavir alone for 9 days, followed by combination therapy with ritonavir, zidovudine, and lamivudine from day 10 through week 48. \[AS PER AMENDMENT 1/31/97: The availability of the current, open-label study treatment has been extended to allow patients who have completed 48 weeks of therapy to continue protocol therapy until the last enrolled patient completes 48 weeks of study treatment.\]