Mammalian aging is associated with a complex derangement of the immune system. In particular, an impaired capability of T lymphocytes to proliferate when stimulated with a variety of mitogens has been reported. This defect was ascribed to a defective production and utilization of a lymphokirie that is crucial for T-cell proliferation, that is, interleukin-2 (IL-2). I

However, immune responses are modulated and regulated by a variety of cytokines other than IL-2, whose production and utilization have not been properly studied during immunosenescence, particularly in humans. For this reason, we thought it worthwhile to study the production of other cytokines in supernatants from peripheral blood mononuclear cell cultures from old subjects. As the production of these cytokines can be deeply affected by the presence of clinical or subclinical pathological conditions, particular attention was paid to the selection of the subjects admitted to the study.