[Immunocompetence in the elderly].

Ageing is associated with a progressive decline of the immune systems, characterized by impaired T cells and changes in the antigenic repertory related to both the humoral and cell-mediated immune responses. The major alterations have been demonstrated in the T cells which undergo functional changes, such as a decrease in precursor frequencies of helper and cytotoxic T-cells, and accumulation of T cells which does not respond to activators. In general, T cell-dependent, cell-mediated responses decline with age. The elderly are at great risk for low consumption of proteins and of several micronutrients, such as zinc or vitamins C, E and B6 which play a critical role in the maintenance of normal immune function. As a consequence, the incidence of inflammatory and infectious disease, auto-immune disorders, cutaneous pathological changes, and skin cancers increases. Morbidity and mortality rates due to tetanus, pulmonary infections and influenza remain high in elderly populations. Depressing the rate of immunosenescence and restoring a normal immunocompetence in the elderly may involve improved nutrition through proteins, micronutrients and vitamins, and should deal with the economic and psychosocial problems of the elderly. Vaccinations against tetanus, pneumococcus and influenza proved to be efficacious and well-tolerated. Consequently, they should be applied systematically to non protected elderly individuals.