Cytokine production by human peripheral blood mononuclear cells exposed to low-frequency electromagnetic field

We evaluated the effects of a 50-Hz pulsed electromagnetic field with a peak magnetic field of 3 mT on the production of cytokines by resting peripheral blood mononuclear cells. Our results demonstrate no modification of interleukin-1β, interleukin-2, or interleukin-6 levels, evaluated 0, 24, and 48 h after exposure, compared with sham-exposed cells. Proliferation indices were also practically unchanged, suggesting the absence of any activating effect of the electromagnetic field. Indeed, concentrations of tumor necrosis factor-α and interferon-γ, evaluated during the same period after 12 h of EMF exposure, were significantly lower than those measured in supernatants of control cells. This was confirmed by evaluation of both cytokines during a 24-h exposure period and 24 h thereafter, in the supernatants of exposed and sham-exposed cells. Comparison between tumor necrosis factor-α biologic activity and the cytokine antigen present in our samples showed strong and reproducible correlation values, suggesting the absence of qualitative differences in this protein due to either proteolytic activity or electromagnetic field.