Stimulating properties of lynestrenol on normal human blood T-lymphocytes and other leucocytes

Abstract

The influence of lynestrenol, a synthetic progesterone-like drug, has been investigated on normal human blood leucocytes in vitro. Lynestrenol significantly increased the percentage of active T rosettes (a test for T-cell competence) at concentrations of 10 −1 to 10 −4 μg/ml (controls: 16.5%; drug at 10 −1 μg/ml: 23.6%; P<0.001). It did not alter the percentage of total T rosettes (a quantitative measure of T cells) and the percentage of EAC rosettes. It increased the non-adherent cells in the leucocyte adherence inhibition test (LAI) over a dose range between 10 −1 and 10 −3 μg/ml (controls: 360,000 compared to 517,000 in the presence of 10 −2 μg/ml; P<0.001) suggesting some leucocyte activation. Finally, it also increased the phagocytic properties of monocytes. These results indicate the lynestrenol acts upon normal human blood T lymphocytes, monocytes and possibly neutrophils. Therefore, lynestrenol appears to posses immunostimulatory properties.