Circannual variations in the B cell/T cell ratio in normal human peripheral blood

In previous studies we have shown that B cells and subpopulations of T cells can be identified in blood smears with bacteria used as markers that bind spontaneously to lymphocytes. We have also identified Ig-bearing cells by using an Escherichia coli coated with anti-human Ig antibody. Here we determined the absolute values and the percentage of B cells and of other lymphocyte subpopulations in the peripheral blood of six normal donors every 2 mo for 1 yr. we found that the total leukocyte counts and the total number of lymphocytes remained unchanged throughout the year, whereas the percentage of B cells in the coldest month was at almost twice the level observed in summer. The percentage of cells that bind Arizona hinshawii ans Salmonella schottmülleri remained practically unchanged during the entire year. A variation was noted in the ratio between T1 and T2 cells, which also appears to be seasonally related. We speculate that hormonal factors, probably corticosteroids, are responsible for changes in the traffic of some lymphocyte subpopulations.