[Age and immunity].

Immunodeficiency cannot be considered today as an obligatory consequence of human ageing. When present it strikes mainly primary immune response (humoral as well as cellular). Ageing of regulation, as exhaustive of repertoire through idiotypic network saturation for instance, plays a major role in the disorders of ageing immune system. Other age associated conditions as malnutrition, infection, renal disease, stress, also influence deeply immune responses.