A fundamental paradox of HIV disease is the progressive diminution in CD4+ lymphocytes despite the fact that only a small fraction of cells are infected. The mechanisms of T-cell depletion in HIV disease are divers. These include immune and autoimmune destruction of infected and uninfected cells, signaling derangements inducing clonal anergy and apoptosis, and direct cytotoxic effects of viral particles. These phenomena are reviewed as they pertain to the different clinical stages of HIV infection.
