Monoclonal Antibody—Defined Lymphocyte Subsets in Normal Nigerians

Lymphocyte subsets using monoclonal antibodies have hitherto not been re ported in normal Nigerian subjects. In all 8 subjects, the average number of lymphocytes showed a clear rhythmicity with higher values in the morning (8 AM) than in the afternoon (2 PM). The time of day variation in circulating lymphocytes appears to affect T cells rather than B cells. The absolute numbers of 0KT4+ cells at 8 AM was significantly higher than at 2 PM (p < 0.05). It would appear that the 0KT4+ cells are largely responsible for the time of day variation in peripheral blood lymphocytes, owing probably to a greater sensitivity to changes in plasma cortisol levels.