Electromagnetic fields enhance the release of both interferon-gamma and interleukin-6 by peripheral blood mononuclear cells after phytohaemagglutinin stimulation

We evaluated the effect of pulsed electromagnetic fields on the eventual activation of peripheral blood mononuclear cells. The cells were exposed to electromagnetic fields with a frequency of 50 Hz and a potency of 3 mT for various times, after which, an exposure time of 12 h was decided on. The results clearly demonstrated that the release of either interferon gamma or interleukin-6 by normal cells exposed to electromagnetic fields for 12 and 24 h was not significantly increased. In contrast, after phytohaemagglutinin challenge, the cells expressed heightened responses to electromagnetic field exposure, with both the proliferative responses and the release of cytokines being significantly increased. In this case, the levels of interferon gamma measured by immunoenzymatic methods 48 h after the treatment were 4827 +/- 4300 pg ml(-1) and were significantly different from the control values (p < 0.05). Evaluation of the biological activity provided results that were practically identical to those of the immunoenzymatic assay, indicating the absence of quantitative and qualitative differences in these proteins. Also, interleukin-6 levels were always higher than in controls and became significant (p < 0.0006) 48 h after the exposure. On the whole, our results indicate that pulsed electromagnetic fields applied continuously for up to 24 h to phytohaemagglutinin-stimulated cells enhance their biological responses. (C) 1998 Elsevier Science S.A.