The purpose of this study is to determine if TNFR:Fc (a molecule that attaches to TNF) can lower the amount of IL-6 in HIV-positive patients. This study will also examine the effect of TNFR:Fc on TNF-alpha. IL-6 and TNF-alpha are 2 substances produced by the immune system that may increase the rate of HIV replication.

IL-6 and TNF-alpha are produced naturally by the body. High levels of TNF-alpha lead to increased IL-6 production and increased HIV replication, therefore helping the virus infect the body. HIV-positive patients who receive IL-2 (interleukin-2, a protein that helps the immune system fight infection) tend to have higher levels of IL-6 and TNF-alpha than patients not receiving IL-2. These increased levels may contribute to some of the flu-like symptoms related to IL-2 administration. TNFR:Fc can neutralize TNF-alpha to decrease the action of TNF-alpha and, in turn, decrease the amount of IL-6 in the body. TNFR:Fc may, therefore, have a role in the treatment of HIV disease or in relieving some of the symptoms related to IL-2 administration.

Both Interleukin-6 (IL-6) and Tumor necrosis factor-alpha (TNF-alpha) are substances naturally produced by the body's immune system. Evidence suggests that TNF-alpha production may be excessive or inappropriate in HIV-infected patients. Elevated TNF-alpha levels can result in increased IL-6 production and possibly increased HIV replication. TNFR:Fc is a modification of a natural substance that binds to TNF-alpha and neutralizes its activity. It is postulated that TNFR:Fc may result in decreased activity of TNF-alpha and lower IL-6 levels. HIV-infected patients who receive Interleukin-2 (IL-2) have been shown to have higher TNF-alpha and IL-6 levels than those who do not receive IL-2. It is thought that these higher levels of TNF-alpha and IL-6 may contribute to some of the flu-like symptoms experienced by patients receiving IL-2. By decreasing the amount of IL-6 in the body and by decreasing the action of TNF-alpha in the body, TNFR:Fc may have a role in the treatment of HIV disease or in alleviating some of the symptoms related to IL-2 administration.

Six patients from each of the 3 treatment arms of ACTG 328 (HAART alone, HAART plus intravenous (IV) rhIL-2, and HAART plus subcutaneous (SC) rhIL-2) who are about to be randomized to Step II of ACTG 328 may participate in this prospective, nested substudy. Patients randomized to the Interleukin-2 (IL-2) arms of ACTG 328 are pretreated with TNFR:Fc (administered by infusion over 30 minutes) at week 16 of ACTG 928 (Course 3, Week 28 of ACTG 328), just prior to initiation of IL-2. Those randomized to the highly active antiretroviral therapy (HAART) only arm of ACTG 328 receive treatment with TNFR:Fc at Week 16 of ACTG 928 (Week 28 of ACTG 328).

Inclusion Criteria

You may be eligible for this study if you:

• Are HIV-positive.
• Are enrolled in ACTG 328.
• Agree to practice abstinence or use barrier methods of birth control during the study.
• Are at least 18 years old.

Exclusion Criteria

You will not be eligible for this study if you:

• Have any active opportunistic (HIV-associated) infections.
• Have any medical condition or psychological issue that would interfere with study requirements.
• Are pregnant or breast-feeding.
• Are receiving any experimental drug other than IL-2.
• Are receiving certain other medications.