Age- and gender-related values of lymphocyte subsets in subjects from northern and southern Italy

Changes in the T-lymphocyte (identified by CD3 surface marker) compartment represent the most critical component of immunological aging. Many studies have demonstrated that the age-related decline in T-cell mediated immunity is accompanied by a reduced number of lymphocytes. Moreover, the enumeration of lymphocyte subsets is extensively used in the diagnosis and monitoring of various disease states. The use of flow cytometric technology and whole blood analysis by fluorochrome-labeled monoclonal antibodies is successfully applied for these purposes. It is so important to establish reference intervals in normal, healthy individuals of different ages using this technique. The present study was undertaken in order to establish age-related differences in lymphocyte subpopulations by simultaneously measuring common surface antigens in healthy individuals from several ages including very olds, taking into account the gender of the studied subjects. In particular, we analyzed 274 subjects separated in male and female groups, for the T helper (identified by CD4 surface marker) and cytotoxic cells (CD8), B (CD19) and NK (CD16) lymphocytes. In 138 individuals of different age and gender groups, we also evaluated the number of lymphocytes bearing the T-cell receptor gamma delta. Our data confirm the literary data on lymphocyte subpopulations and show that the reported differences in the number of CD16 and CD19 lymphocytes is not sex-related. The analysis was performed on the whole blood obtained from subjects from Northern and Southern Italy.