Immunoendocrinologic abnormalities in human immunodeficiency virus infection

Alterations in the production of adrenal steroids and a complex pattern of dysregulation in cytokine profiles accompany the progression of HIV infection. Cortisol levels increase in HIV infection, while those of dehydroepiandrosterone (DHEA), a physiologic antagonist of the immunoregulatory activities of cortisol, decrease. A shift from type-1 to type-2 cytokine production is also detected in most patients during disease progression. This shift is summarized as a defective production of interferon gamma (IFN gamma), interleukin-2 (IL), and IL-12 accompained by increased production of IL-4, IL-5, IL-6, and IL-10. IFN gamma and IL-2 are suppressed, while the generation of IL-4 is stimulated by cortisol and pharmacological doses of glucocorticoids (GC). GC and IL-4 stimulate the differentiation of B lymphocytes into IgE-producing plasma cells, the concentration of which augments in HIV infection. Finally, GC induces programmed cell death (PCD) in a variety of different cells, including mature T lymphocytes. Because (1) TH1 but not TH2 undergo rapid Fas-mediated PCD upon antigen-stimulation, and (2) TH2 clones preferentially survive in vitro cell cultures, the progressive shift from type-1 to type-2 cytokine production observed in HIV infection could be at least partially provoked by the increase in the production of cortisol and the reduction of DHEA. Progression of HIV infection to AIDS can be controlled by highly active antiretroviral therapy (HAART); HAART drastically reduces HIV plasma viremia, but is less effective in immune reconstitution. Additionally HAART is associated in a sizable portion of patients by complex lypodistropyc phenomena that often involve the endocrine system.