Immune defects in pediatric AIDS, their pathogenesis, and role of immunotherapy

Infection with the human immunodeficiency virus (HIV) results in a progressive immune deficiency involving many components of the immune system. The major target cells for infection are CD-4 antigen-bearing cells which include predominantly, but not exclusively, the helper T-cell subset and the monocyte-macrophage cell system. Defective cell-mediated immunity occurs in association with hypergammaglobulinemia, which is a common and early feature of HIV infection. Ability to mount specific antibody responses is often impaired and the in vitro B-cell differentiation responses to T-dependent and T-independent stimuli are depressed. Our investigations with HIV envelope proteins suggest that the viral proteins can exert both stimulatory and suppressive influences on B and T lymphocytes. In addition to the opportunistic infections, children with HIV disease frequently develop serious bacterial infections. Among the currently available immunotherapeutic strategies, iv immunoglobulin therapy has received the most attention as a means to provide antibody replacement in children with recurrent bacterial infections. This modality is likely to be most valuable as adjunctive therapy in treatment protocols directed at HIV and its disease complications.