With the use of Leu-series monoclonal antibodies, peripheral blood lymphocyte subsets in aged and young humans were determined.
1) In comparison with young individuals, Leu-1+ cells and Leu-2a+ cells were decreased, whereas Leu-7+ cells and Leu-3a/Leu-2a were increased in aged individuals.
2) No sex difference could be observed in lymphocyte subsets.
3) PHA response of lymphocytes showed a negative correlation with Leu-2a+ cells and a positive correlation with Leu-3a/Leu-2a in aged individuals
