Stress Response, Immunity, and Aging
process is accompanied by increasing physical and mental frailty producing an elevated risk of physical and psychological stress in old age. Stress is a potent modulator of immune function, which in youth can be compensated for by the presence of an optimal immune response. In the elderly the immune response is blunted as a result of the decline in several components of the immune system (immune senescence) and a shifting to a chronic pro-inflammatory status (the so-called 'inflamm-aging' effect). We discuss here what is known of the effects of both stress and aging upon the innate immune system, focusing in particular upon the age-related alterations in the hypopituitary-adrenal axis. We propose a double hit model for age and stress in which the age-related increase in the
cortisol/sulphated dehydroepiandrosterone ratio synergizes with elevated cortisol during stress to reduce immunity in the elderly significantly.
Butcher SK, Lord JM.
Stress responses and innate immunity: aging as a contributory factor.
Department of Immunology, Birmingham University Medical School, Birmingham B15