The purpose of this study is to determine if stopping anti-HIV drugs for a period of time is safe and effective for enhancing the immune function of patients with HIV.

Our preliminary studies have shown that structured treatment interruption of highly active antiretroviral therapy (HAART) may boost patients' immune responses to HIV-1. In this study, we will test the hypothesis that repeated structured treatment interruptions will increase HIV-1 immunity and result in better control of viral replication than in controls. We will test this hypothesis by determining time to viral rebound after withdrawal of antiretroviral therapy in a randomized, non-blinded study of a well-characterized subject population from a single center. Patients in this study will be randomized to either treatment interruption or control groups. Patients will be monitored for adherence to therapy and changes in immune status following HAART interruption. CD4 percentage, CD 4 and CD8 mediated anti-HIV-1 responses, cell surface T-cell antigen expression, and thymic function will be assessed.

Inclusion Criteria

• HIV-1 positive
• HIV RNA < 500 copies/ml on a regimen of two nucleoside reverse transcriptase inhibitors (NRTIs) and either one protease inhibitor (PI) or one nonnucleoside reverse transcriptase inhibitor (NNRTI) for 6 months prior to study entry - HIV RNA < 50 copies/ml at study screening
• CD4 > 400 cells/mm3 with CD4 nadir of > 100 cells/mm3
• Agree to Medication Event Monitoring System monitoring of one component of antiretroviral regimen
• HIV-1 viral load >10,000 copies/ml at any time prior to initiating the current uninterrupted HAART regimen
• Willing to abstain from all immunomodulatory drugs during the study