[Immune dysfunctions in aging (author's transl)].

The frequency of certain infectious diseases, autoimmune disorders and neoplasias reveals a correlation to age. Therefore, the potential pathogentic role of a series of humoral and cellular immune functions is discussed. The concentrations of immunoglobulins increase with age. Though the humoral immune response appears to be rather undisturbed, there is a definite and progressive reduction of delayed type hypersensitivity reactions in the elderly. Based upon own investigations the significance of cell-inherent factors on age-dependence of cell-mediated immunity is underlined, consisting of an age-correlated alteration of a T-cell subpopulation The increasing morbidity or mortality of infectious diseases, i.e. tuberculosis, salmonellosis and viral hepatitis in the older age-group, additionally, may be explained by a reduced cell-mediated immunity known to play an important role in immune defense mechanisms particulary in these diseases.