The natural history and pathogenesis of HIV infection.

Infection with human immunodeficiency virus (HIV) results in progressive deterioration of the cell-mediated immune system characterized by T-helper-cell dysfunction and loss in the face of signs of generalized immune-system activation. The final stage of HIV disease, AIDS, has a myriad of opportunistic infections and malignancies as its hallmarks. The causal relationship between HIV and this complex disease pattern is clear but the mechanisms by which it occurs are not well understood. There are a number of new developments in our understanding of the natural history of HIV infection from a laboratory standpoint. Our review of this information raises further questions as to the validity of the conventional "cytopathic" model and all its direct descendants. In response to these conflicts, we have developed and present an alternative hypothesis in which AIDS pathogenesis, in all its manifestations, is seen as the outcome of one central process, excess immune activation generated by the interaction of virus with the CD4 receptor. The implications of this hypothesis on therapy of HIV infections are discussed.