A Phase II Study of Intermittent Recombinant Human Interleukin-2 (rhIL-2) by Intravenous or Subcutaneous Administration in Subjects With HIV Infection on Highly Active Antiretroviral Therapy (HAART) Compared to HAART Alone

Inclusion Criteria Concurrent Medication: Required: Patients must be able to initiate one of the following nucleoside analogue regimens of which at least one of the drugs must be new to the patient: * ZDV + 3TC, ZDV + ddI, d4T + 3TC, or d4T + ddI. \[AS PER AMENDMENT 4/5/00: ddI is contraindicated in patients with serum amylase or lipase values greater than 1.5 x ULN or who have a history of pancreatitis. ddI should also be used with extreme caution and only if clinically indicated in patients with known risk factors. For more information, see package insert.\] Allowed: * Prophylaxis for Pneumocystis carinii pneumonia and other opportunistic infections according to current CDC recommendations. Prophylaxis, once started, should be continued despite increases in CD4 counts during the course of the study. * Any standard regimen for an opportunistic infection. * Maintenance therapy for opportunistic infections that develop on study treatment is permitted according to standard medical care; except for foscarnet during rhIL-2 administration and rifabutin and rifampin. * Maintenance therapy with \<= 1000 mg/day of acyclovir is permitted for recurrent genital herpes. * Erythropoietin and filgrastim (G-CSF) are permitted when clinically indicated. * Antibiotics for bacterial infections are permitted as clinically indicated. * Medications for symptomatic treatment such as antipyretics and analgesics are permitted. Ibuprofen and acetaminophen are the preferred agents. * Any elective standard immunizations, e.g., flu shot, should be given no less than 4 weeks prior to any blood draw for HIV RNA by bDNA assay. * Topical corticosteroid use provided applied to a site separate from any skin test or rhIL-2 injection site (if frequent therapy is required for large surface area, protocol chair must be contacted). Concurrent Treatment: Allowed: * Local radiation therapy. Patients must have: * Prior or current documentation of HIV seropositivity by any licensed ELISA and confirmation by either Western blot, positive HIV antigen, positive HIV culture, or a second positive antibody test by a method other than ELISA. * CD4+ cell count 50 to 300 cells/mm3 \[AS PER AMENDMENT 10/31/97: 50 to 350 cells/mm3\] once within 30 days prior to study entry, as measured in an ACTG-certified laboratory. * Ability to initiate one of the following nucleoside analogue regimens of which one of the drugs must be new to the patient: * zidovudine (ZDV) + lamivudine (3TC), ZDV + didanosine (ddI), stavudine (d4T) + 3TC, or d4T + ddI. \[AS PER AMENDMENT 10/31/97: A nucleoside analogue is considered "new" if it was never taken previously or if prior exposure to the nucleoside analogue was for less than 30 days and occurred more than 3 months prior to entry, with the exception of 3TC. For 3TC exposure to be considered "new", prior exposure must have been less than 1 week and must have occurred more than 3 months prior to entry.\] Patients must have the following conditions for the randomization step of the study: * Completion of 11 weeks of HAART. * HIV RNA of 5,000 copies/ml or less within approximately 1 week (Week 10) prior to randomization at week 11. Exclusion Criteria Co-existing Condition: Patients with the following symptoms and conditions are excluded: * Any active AIDS-defining illness by the CDC case definition with the exception of minimal (less than 10 lesions) cutaneous Kaposi's sarcoma. * Significant cardiac insufficiency (NYHA grade 2). Patients with isolated hypertension controlled by antihypertensive medication but no cardiac disease are eligible. * Untreated thyroid disease (treated and stable hyperthyroidism or hypothyroidism for at least 4 weeks prior to study entry is permitted). * Sensitivity to albumin or allergy to albumin. Concurrent Medication: Excluded: * Concurrent treatment with investigational antiretroviral agents other than FDA-sanctioned treatment IND drugs. * Treatment for active cardiac disease, with the following medications: anti-anginal agents such as nitrates, calcium channel blockers, beta blockers, antiarrhythmics including digitalis and afterload reducers. * Patients with malignancy requiring treatment with systemic or local cytotoxic chemotherapy. Prohibited medications: * interferons, interleukins (other than the study rhIL-2), sargramostim, dinitrochlorobenzene, thymosin alpha 1, thymopentin, inosiplex, polyribonucleoside, ditiocarb sodium, thalidomide, rifabutin, rifampin, midazolam, triazolam, oral ketoconazole, cisapride, terfenadine, astemizole, any investigational drug, therapy with foscarnet, systemic corticosteroids (systemic corticosteroids for \<= 21 days are permitted for treatment of Pneumocystis carinii pneumonia; for other indications, contact the Protocol Chair), and other protease inhibitors. \[AS PER AMENDMENT 4/5/00: St. John's wort is also excluded.\] Patients with the following prior conditions are excluded: * History of autoimmune disease, including inflammatory bowel disease and psoriasis (stable autoimmune thyroid disease is permitted). * Clinically significant CNS disease or seizures that have been active within 1 year prior to entry. Prior Medication: Excluded: * Use of any known immunomodulatory therapy within 4 weeks prior to study entry including but not limited to drugs such as systemic corticosteroids; interferons; interleukins; thalidomide; sargramostim (GM-CSF); dinitrochlorobenzene (DNCB); thymosin alpha 1 (thymosin alpha); thymopentin; inosiplex (Isoprinosine); polyribonucleoside (Ampligen); ditiocarb sodium (Imuthiol). * Any prior systemic treatment with rhIL-2. * Any prior treatment with any protease inhibitor. \[AS PER AMENDMENT 10/31/97: More than 14 days total prior treatment with any protease inhibitor.\] * Use of rifampin or rifabutin within 7 days prior to study entry. * Use of cisapride (Propulsid), terfenadine (Seldane), astemizole (Hismanal), midazolam (Versed), triazolam (Halcion), ketoconazole (Nizoral), \[itraconazole (Sporanox) AS PER AMENDMENT 10/31/97\], or delavirdine within 2 weeks prior to study entry. Active alcohol or substance abuse that, in the opinion of the investigator, will seriously compromise the patient's ability to adhere to the demands of the study.