Inclusion Criteria

Concurrent Medication:

Allowed:

• PCP prophylaxis with aerosolized pentamidine, trimethoprim / sulfamethoxazole, or dapsone.
• Clotrimazole troches or nystatin oral suspension for oral candidiasis.
• Acyclovir (up to 1000 mg/day for 10 days) for herpes lesions.
• Erythropoietin.

Patients must have:

• Documented HIV infection by ELISA confirmed by a second method. If a prior diagnosis of AIDS has not been established by CDC criteria, a confirmatory test is required.
• CD4 count = or < 300 cells/mm3 within 4 weeks prior to study entry.
• Positive p24 antigen.

Patients entering the AZT portion of the study only:

• Must be AZT naive or have had less than 2 months of AZT therapy.

Exclusion Criteria

Co-existing Condition:

Patients with the following symptoms and conditions are excluded:

• Hemophilia.
• Acute medical problems (including active opportunistic infections such as active cryptococcosis, Pneumocystis carinii, herpes zoster, histoplasmosis, or CMV or nonopportunistic diseases including liver disease, renal disease, or orthostatic hypotension) at time of study entry.
• Active pulmonary disease.
• Chronic active hepatitis B surface antigenemia or unstable hepatitis C.
• Current diagnosis of malignancy for which systemic therapy would be required during the study.
• Inadequate intravenous access.

Concurrent Medication:

Excluded:

• Hepatotoxic agents.
• Other antiretroviral or immunomodulator agents (including but not limited to AZT, ddI, ddC, interferon, and steroids).
• Other investigational drugs.
• Systemic therapy for malignancy.
• G-CSF and GM-CSF.

Prior Medication:

Excluded:

• Other antiretroviral or immunomodulator agents (including but not limited to AZT, ddI, ddC, interferon, and steroids) within 4 weeks prior to study entry.
• Ribavirin within 90 days prior to study entry.
• Cytotoxic chemotherapy within one month prior to study entry.
• Prior soluble CD4 or CD4-Ig.

Excluded in patients entering the AZT portion of the study:

• More than 2 months of prior AZT therapy.

Current active alcoholism or active substance abuse.