Normal values of peripheral lymphocyte populations and T cell subsets at a fixed time of day: a flow cytometric analysis with monoclonal antibodies in 210 healthy adults.

Using monoclonal antibodies and flow cytometry percentages and absolute number of lymphocyte populations and T cell subsets were enumerated in peripheral blood collected between 8:00 and 10:00 a.m. from 210 healthy adults. Although absolute numbers of total lymphocytes did not differ depending on age and sex, the numbers of T (Leu-4+) and natural killer (Leu-7+) cells as well as their percentages showed negative and positive correlations, respectively, with age. In Leu-7+ cells, the percentage was male-dominant irrespective of age, and the absolute number was male-dominant only in older subjects. Absolute numbers of suppressor/cytotoxic T (Leu-2a+) and helper/inducer T (Leu-3a+) cells and percentages of Leu-2a+ cells were negatively correlated with age in females. In males, only the percentage of Leu-2a+ cells was age-dependent. Leu-3a/Leu-2a was positively correlated with age in females, and was female-dominant depending on age. These results indicate that peripheral lymphocyte populations and T cell subsets vary remarkably in healthy adults even at a fixed time of day.