The objective of this Phase III, randomized, double-blind, placebo-controlled study in patients with immunologic deficiency is to determine the effect of isoprinosine in producing an immuno-restorative response within the study observation period (including the 2-month period following cessation of the 28 days of treatment), measured by one or more of the following immunologic parameters:

• Increase in natural killer (NK) cell activity.
• Increase in total T-cells (OKT-11).
• Increases in absolute number and percentages of T-helper cells (OKT-4).

Exclusion Criteria

Co-existing Condition:

Patients with the following are excluded:

• History of gout, uric acid urolithiasis, uric acid nephrolithiasis, renal dysfunction, and severe gastric ulcer.
• Lymphoid malignancy.
• Infectious mononucleosis caused by cytomegalovirus (CMV) or Epstein-Barr virus (EBV).
• Heart disease (especially if receiving cardiac glycosides).
• Hemophilia.

Patients with the following are excluded:

• Kaposi's sarcoma or overt opportunistic infections.
• Active evidence of infectious mononucleosis caused by Epstein-Barr virus (EBV) or cytomegalovirus (CMV) as determined by heterophile test (EBV) or cell culture (CMV).
• A history of gout, uric acid urolithiasis, uric acid nephrolithiasis, renal dysfunction, and severe gastric ulcer.
• Critical illness.
• Condition requiring hospitalization.
• Women of childbearing age are excluded.

Prior Medication:

Excluded:

• Steroids, cytotoxic immunosuppressive agents.
• Antiviral medicine.
• Excluded within 1 month of study entry:
• Immunomodulators (including Isoprinosine).

Prior Treatment:

Excluded:

• Radiotherapy.

Patients who have unexplained immunodepression and are at risk of developing AIDS.

• Patients with prolonged generalized lymphadenopathy for 3 or more months (greater than 1 cm at two or more noncontiguous sites).

IV drug abuse.