Innate and adaptive immunosenescence

Objective: To review the effect of increasing age on the immune system and some of its clinical implications. Data Sources: MEDLINE and PubMed searches were performed cross-referencing the keywords immunosenescence, aging, and immunity. Articles were reviewed for additional citations. Study Selection: Articles were reviewed and selected based on relevance to subject matter. Results: The study of immunosenescence is complex and not completely understood. Aging affects both the innate and adaptive arms of the immune response. With increased age, there may be a decrease in phagocytosis, alteration of cellular migration, changes in cell populations and numbers, and a decreased ability to produce specific antibodies. Clinically, these changes potentially increase morbidity and mortality in elderly individuals through an increased rate of infections, malignancy, and autoimmunity. Conclusions: The process of aging is accompanied by diverse changes in immunity. Several therapeutic approaches are under investigation, including cytokine therapy, hormonal replacement, antioxidant supplementation, and caloric restriction, to attenuate or potentially reverse immunosenescence.