To determine the tolerance and side effects of a combination of lentinan and didanosine (ddI) in comparison with ddI alone. To determine whether the combination of lentinan and ddI produces a significant immunorestorative effect within the study observation period (6-12 months) as measured by an increase in one or more of the following: neutrophil count and activity, T-cell subsets, and a decrease in p24 antigen.

Patients are treated with daily oral ddI for 6 weeks, then are randomized to ddI in combination with intravenous lentinan or placebo (administered once weekly) for 26 weeks. Patients who are already stabilized on 400 mg/day ddI will proceed directly to randomization. Following completion of the combination therapy, patients may be offered 26 additional weeks of therapy on an optional basis.

• Drug: Lentinan
• Drug: Didanosine

Inclusion Criteria

Patients must have:

• HIV seropositivity.
• Absolute CD4 count of 200 - 500 cells/mm3.
• No active opportunistic infection or Kaposi's sarcoma.

Prior Medication:

Allowed:

• Prior ddI for no longer than 3 months.

Exclusion Criteria

Co-existing Condition:

Patients with the following symptoms or conditions are excluded:

• Lymphoid malignancy.
• Pancreatitis.
• Peripheral neuropathy.
• Critical illness.

Concurrent Medication:

Excluded:

• Antiretroviral agents other than ddI.
• Steroids.
• Cytotoxic agents.
• Immunosuppressive agents.
• Immunomodulators.
• 1-Thyroxine.

Concurrent Treatment:

Excluded:

• Radiotherapy.

Prior Medication:

Excluded within 1 month prior to study entry:

• Antiretroviral agents other than ddI (patients may have received prior ddI for no longer than 3 months total).
• Steroids.
• Cytotoxic agents.
• Immunosuppressive agents.
• Immunomodulators.

Prior Treatment:

Excluded:

• Radiotherapy within 1 month prior to study entry. Active IV drug abuse.