COMPARISON BETWEEN SERUM INTERLEUKIN-2 CONCENTRATIONS IN HEALTHY ADULT AND ELDERLY SUBJECTS

The serum interleukin-2 (IL-2) concentrations were evaluated in health y elderly patients, enrolled under the SENIEUR protocol, and healthy a dult controls. The aim of the study was to ascertain whether the reduc ed immune response, described during aging, is linked to deficient pro duction of IL-2 or to its receptorial deficit, or if the reduced serum IL-2 concentrations observed during aging can be used as a biological immunodeficiency marker. The results obtained did not show any signif icant differences between the study groups, even if mean values were s lightly decreased in the elderly group, as compared to the adult one. This finding does not justify the age-dependent deficiency of the immu ne response, i.e., to explain this condition, one needs another pathog enetic hypothesis. It is suggested that one such hypothesis could be t he alteration of IL-2 receptors which undergo major cleavage and minor re-expression in the elderly, causing this way some receptorial chang es with consequent reduction of T-helper activation.