Cellular DNA content of T helper, T suppressor and B lymphocytes in SLE.

The ratio of in vivo activated T helper, T suppressor and B cells in the blood of patients with SLE has been studied through simultaneous subset specific immunofluorescence labelling and the analysis of cellular DNA content with the help of flow fluorimetry. In the active stage of the disease an increase was observed in the proportion of proliferating cells either among the T helper cells or the B cells. Occasionally, however, the rate of proliferation in both subsets grew at the same time. Cases with a high number of activated B cells have proved to be more serious. The percentage of the T suppressor cells in the S-G2-M phase of the cell cycle increased moderately in both the active and the inactive stages of the disease. Our results are also discussed in relation to the pathogenetic mechanism of SLE.