title: Immunologic basis for susceptibility to infection in the aged.
abstract: Age-related immune dysfunction contributes to the vulnerability of old individuals to infection, e.g., animal model studies demonstrate the association between age-related decline in T cell-dependent immunologic responses and the decline in resistance against viral, bacterial, and parasitic infections. This review briefly describes age-related changes in the immune system at the systemic, tissue and cellular levels. At the systemic level, emphasis is on polymorphic effects of aging; at the tissue level, emphasis is on the vulnerability of primary tissues engaged in the generation of antigen-responsive cells and on the difference in the onset and rate of changes between different peripheral tissues of the system; and at the cellular level, emphasis is on the qualitative changes at the surface receptor, cytoplasmic and nuclear levels.
mesh_terms: D000368:Aged; D000375:Aging; D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D001853:Bone Marrow / Q000276:immunology; D002470:Cell Survival; D004260:DNA Repair; D004198:Disease Susceptibility; D006801:Humans; D007109:Immunity; D007239:Infections / Q000276:immunology*; D008198:Lymph Nodes / Q000276:immunology; D008264:Macrophages / Q000276:immunology; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D013950:Thymus Gland / Q000276:immunology