In vitro modulation of activation antigens on human lymphocytes by beta-estradiol

PROBLEM: The possible in vitro immunomodulating effect of beta-estradiol on phytohemagglutinin-stimulated human lymphocyte cultures was studied. METHOD OF STUDY: Lymphocyte cultures from 12 healthy men and women aged 25- 35 years were set up for 12 hr in the presence and in the absence of P-estr adiol, and the expression of the activation markers CD25, CD69, and CD71 wa s examined by flow cytometric analysis with specific fluorescent conjugated antibodies. RESULTS: Although the number of cases is small, in 10 of 12 cases in the pr esence of beta-estradiol in two different concentrations, a significantly d ecreased expression of CD69 could be observed. A slight decrease could also be observed for the Interleukin-2 receptor expression; however, the differ ence, in the presence or absence of beta-estradiol, was not significant. CONCLUSIONS: The results suggest that in vitro addition of beta-estradiol c an inhibit, to a certain degree, specific activation markers on phytohemagg lutinin-stimulated lymphocytes from young men and women. The present study could not define the role of sex differences because of the small number of samples. A comparison between men and women at various ages in a greater n umber of cases, as well as studies on activation markers after treatments w ith estrogens, would be useful.