• New or recurrent serious HIV disease progression event including death [ Time Frame: Throughout study and 4 to 6 years from the beginning of the study ] [ Designated as safety issue: Yes ]
• All-cause mortality [ Time Frame: Throughout study and 4 to 6 years from the beginning of the study ] [ Designated as safety issue: Yes ]
• New disease progression event including death [ Time Frame: Throughout study and 4 to 6 years from the beginning of the study ] [ Designated as safety issue: Yes ]
• Absolute CD4 cell counts and percent CD4+ of lymphocytes [ Time Frame: Throughout study and 4 to 6 years from the beginning of the study ] [ Designated as safety issue: Yes ]
• Plasma HIV RNA levels [ Time Frame: Throughout study and 4 to 6 years from the beginning of the study ] [ Designated as safety issue: No ]
• Changes in antiretroviral treatment [ Time Frame: Throughout study and 4 to 6 years from the beginning of the study ] [ Designated as safety issue: No ]
• Grade 4 signs and symptoms [ Time Frame: Throughout study and 4 to 6 years from the beginning of the study ] [ Designated as safety issue: Yes ]
• Pattern of use of prophylaxis for opportunistic infections [ Time Frame: Throughout study and 4 to 6 years from the beginning of the study ] [ Designated as safety issue: No ]
• Hepatic, metabolic, and cardiac conditions [ Time Frame: Throughout study and 4 to 6 years from the beginning of the study ] [ Designated as safety issue: Yes ]

• New or recurrent serious HIV disease progression event including death
• all-cause mortality
• new disease progression event including death
• absolute CD4 cell counts and percent CD4+ of lymphocytes
• plasma HIV RNA levels
• changes in antiretroviral treatment
• Grade 4 signs and symptoms
• pattern of use of prophylaxis for opportunistic infections
• hepatic, metabolic, and cardiac conditions

The purpose of this study is to see if it is effective to give HIV positive patients interleukin-2 (rIL-2) in addition to anti-HIV therapy. Patients will be followed over a period of 5 years to study the long-term effects of rIL-2 on their HIV disease progression.

Anti-HIV therapy has been very successful in treating HIV positive patients and in keeping viral load (level of HIV in the blood) low. However, anti-HIV drugs cannot completely rid the body of the virus, and the immune system is never completely restored in HIV positive patients. Doctors hope that giving patients rIL-2 plus anti-HIV therapy will help improve their immune systems and keep them healthier over a longer period of time. IL-2 is a protein found naturally in the blood that helps boost the immune system.

Much progress has been made in implementing potent antiretroviral therapy that is able to maximally suppress viral replication. However, these drug combinations do not result in viral eradication and, for many patients, virologic and immunologic control cannot be maintained. Even among patients with apparent virologic control, a "ceiling effect" seems to exist with failure of CD4 cell counts to rise on average more than 100 to 150 cells/mm3, at least during the first 2 years of therapy. The incomplete recovery of immune function after initiation of therapy remains an obstacle in the management of HIV. Preservation of immune function by direct expansion of CD4 lymphocytes with IL-2 could represent a significant additional treatment strategy. It also has been speculated recently that IL-2 in combination with potent antiretroviral therapy may be a useful approach for purging HIV from the latently infected CD4 cells. It is hoped that intervention with rIL-2 therapy in combination with antiretroviral therapy at an early stage of HIV infection can prevent CD4 T-cell depletion and result in fewer AIDS-defining illnesses than with antiretroviral therapy alone.

Patients are randomized to receive SC rIL-2 therapy or no SC rIL-2 therapy. All patients must receive combination antiretroviral treatment, with the choice of therapy at the discretion of the treating clinician. However, antiretroviral medications are not provided by this study. Recombinant IL-2 is given SC for 5 consecutive days every 8 weeks for at least 3 cycles unless toxicities or other contraindications develop. After the first three cycles, additional cycles are given at the discretion of each patient's physician, with a general goal of maintaining the patient's CD4 cell count at twice the baseline level or at 1,000 cells/mm3 or above for as long as possible. Patients in the no SC rIL-2 group receive no injections. Patients in both treatment groups are seen every 4 months for follow-up data collection to monitor viral load and CD4 cell counts. All patients are followed for an average of 5 years. During the trial, patients in the no SC rIL-2 group are not given rIL-2 at any point. However, at the end of the study, if rIL-2 is found to be effective in reducing the rate of disease progression [AS PER AMENDMENT 12/15/00: (new and recurrent events)], including death, all patients are offered rIL-2.

• Arduino RC, Nannini EC, Rodriguez-Barradas M, Schrader S, Losso M, Ruxrungtham K, Allende MC, Emery S, Fosdick L, Neaton J, Tavel JA, Davey RT, Lane HC; Evaluation of Subcutaneous Proleukin in a Randomized International Trial (ESPRIT) Vanguard Group; ESPRIT Executive Committee. CD4 cell response to 3 doses of subcutaneous interleukin 2: meta-analysis of 3 Vanguard studies. Clin Infect Dis. 2004 Jul 1;39(1):115-22. Epub 2004 Jun 14.
• Chun TW, Engel D, Mizell SB, Hallahan CW, Fischette M, Park S, Davey RT Jr, Dybul M, Kovacs JA, Metcalf JA, Mican JM, Berrey MM, Corey L, Lane HC, Fauci AS. Effect of interleukin-2 on the pool of latently infected, resting CD4+ T cells in HIV-1-infected patients receiving highly active anti-retroviral therapy. Nat Med. 1999 Jun;5(6):651-5.
• Connors M, Kovacs JA, Krevat S, Gea-Banacloche JC, Sneller MC, Flanigan M, Metcalf JA, Walker RE, Falloon J, Baseler M, Feuerstein I, Masur H, Lane HC. HIV infection induces changes in CD4+ T-cell phenotype and depletions within the CD4+ T-cell repertoire that are not immediately restored by antiviral or immune-based therapies. Nat Med. 1997 May;3(5):533-40.
• Emery S, Abrams DI, Cooper DA, Darbyshire JH, Lane HC, Lundgren JD, Neaton JD; ESPRIT Study Group. The evaluation of subcutaneous proleukin (interleukin-2) in a randomized international trial: rationale, design, and methods of ESPRIT. Control Clin Trials. 2002 Apr;23(2):198-220.
• INSIGHT-ESPRIT Study Group; SILCAAT Scientific Committee; Abrams D, Lévy Y, Losso MH, Babiker A, Collins G, Cooper DA, Darbyshire J, Emery S, Fox L, Gordin F, Lane HC, Lundgren JD, Mitsuyasu R, Neaton JD, Phillips A, Routy JP, Tambussi G, Wentworth D. Interleukin-2 therapy in patients with HIV infection. N Engl J Med. 2009 Oct 15;361(16):1548-59.

Inclusion Criteria:

• HIV positive
• Have a CD4 cell count of 300 cells/mm3 or more within 45 days of study entry
• Are on combination anti-HIV therapy or are beginning anti-HIV therapy at the time of study entry
• Are at least 18 years old

Exclusion Criteria:

• Have received IL-2 before
• Have cancer requiring chemotherapy
• Have evidence of active clinical disease within the past year for any AIDS-defining illness or certain other conditions such as herpes zoster or Chagas disease. (This study has been changed. Previously, patients were ineligible if they had a history of any AIDS-defining illness or certain other conditions.)
• Have used certain medications, such as corticosteroids or drugs affecting the immune system, in the 45 days before study entry
• Have a nervous system disorder requiring antiseizure medication
• Have an autoimmune or inflammatory disease such as inflammatory bowel disease (e.g., Crohn's disease or ulcerative colitis), psoriasis, optic neuritis, or any autoimmune/inflammatory diseases with potentially life-threatening complications
• Are pregnant or breastfeeding