Extremely low frequency electromagnetic field (ELF-EMF) is produced extensively in modern technologies. Numerous in vitro and in vivo studies have shown that ELF-EMF has both stimulatory and inhibitory effects on the immune system response. This review was conducted on effects of ELF-EMF on cytokines of innate and adaptive immunity. Mechanisms of ELF-EMF, which may modulate immune cell responses, were also studied. Physical and biological parameters of ELF-EMF can interact with each other to create beneficial or harmful effect on the immune cell responses by interfering with the inflammatory or anti-inflammatory cytokines. According to the studies, it is supposed that short-term (2-24 h/d up to a week) exposure of ELF-EMF with strong density may increase innate immune response due to an increase of innate immunity cytokines. Furthermore, long-term (2-24 h/d up to 8 years) exposure to low-density ELF-EMF may cause a decrease in adaptive immune response, especially in T_h1 subset.

Investigations indicate a potential link between exposure to extremely low-frequency electromagnetic field (ELF-EMF) and some cancers. Carcinogenesis of ELF-EMF may be mediated by effect on the immune system. During an immune response, naïve T cells differentiate to effector type 1 helper T cells (T_H1), T_H2, or T_H17 subsets according to existence of different cytokines and T_H1 is important in defense against tumors. Therefore, it will be reasonable to test whether ELF-EMF can change cytokines like interferon gamma (IFN-γ), interleukin-4 (IL-4), IL-6, and IL-12 that regulate T_H1/T_H2/T_H17 balance. Forty adult male rats were randomly separated into ELF-EMF-exposed and sham-exposed control groups. The ELF-EMF group was exposed to a flux density of 100 μT, frequency 50 Hz, 2 h/day for 3 months. The controls were placed in identical chamber without ELF-EMF. The results showed there were no significant differences between the mean mass of rats, thymuses, and spleens in ELF-EMF exposed group compared with controls. Serum IL-12 level was decreased from 418 ± 47 pg/ml in controls to 300 ± 23 pg/ml (p < 0.05) in ELF-EMF-exposed group. Phytohemagglutinin activated of in vitro production of IL-6 by the whole spleen culture (1356 ± 92 pg/ml) and total blood culture (418 ± 40 pg/ml) of ELF-EMF-exposed rats were higher (p < 0.001) comparing with controls (905 ± 74 pg/ml), (182 ± 26 pg/ml), respectively. However, the levels of IFN-γ, IL-4, and IL-6 of serum and IFN-γ, IL-4, and IL-12 in spleen culture and total blood culture of two groups were not significantly different. It seems that ELF-EMF may change T_H1/T_H2/T_H17 balance toward down regulation of T_H1 and upregulation T_H17 type responses.

Background: One of the consequences of toxoplasmosis is the risk of passing it from mother to fetus and the onset of congenital toxoplasmosis during pregnancy. The purpose of this study was to evaluate the B1 gene of Toxoplasma gondii in the placental tissues of pregnant women with acute toxoplasmosis. Materials and Methods: The study was a cross-sectional study. Serum samples of pregnant women who attended to Fatemieh Hospital of Hamadan University of Medical Sciences were tested for immunoglobulin G (IgG) antibodies against T. gondii by enzyme-linked immunosorbent assay. Then, polymerase chain reaction was used to identify the specific B1 gene of T. gondii in IgG seropositive women. The placental tissues of the pregnant women with positive serum B1 gene examined for this gene. Anti-Toxoplasma immunoglobulin M (IgM) was performed on the umbilical cord and neonate blood. Results: Anti-Toxoplasma IgG was detected in 167 out of 653 (25.6%) pregnant women. T. gondii B1 gene was identified in 36 out of 167 (21.6%) of IgG seropositive women. After delivery, the B1 gene was evaluated in 15 out of 36 (41.7%) patients’ placental tissues, 13 of which were positive for this gene (86.7%). Anti-Toxoplasma IgM was detected neither in any umbilical cord nor in neonatal blood samples. All newborns, with the exception of one case, were born with normal birth weight and in term birth. Conclusion: The B1 gene was detected in 86.7% of the placental tissue of women who were involved in acute toxoplasmosis during pregnancy.

Background: Extremely low-frequency electromagnetic fields (ELF-EMFs) are abundantly produced in modern societies. In recent years, interest in the possible effects of ELF-EMFs on the immune system has progressively increased. Objective: To examine the effects of ELF-EMFs with magnetic flux densities of 1, 100, 500, and 2000 µT on the serum levels of interleukin (IL)-9, IL-10, and tumor necrosis factor-alpha (TNF-α). Methods: 80 adult male rats were exposed to ELF-EMFs at a frequency of 50 Hz for 2 h/day for 60 days. The serum cytokines were measured at two phases of pre- and post-stimulation of the immune system by human serum albumin (HSA). Results: Serum levels of IL-9 and TNF-α, as pro-inflammatory cytokines, were decreased due to 50 Hz EMFs exposure compared with the controls in the pre- and post-stimulation phases. On the contrary, exposures to 1 and 100 µT 50 Hz EMFs increased the levels of antiinflammatory cytokine, and IL-10 only in the pre-stimulation phase. In the post-stimulation phase, the mean level of serum IL-10 was not changed in the experimental groups. Conclusion: The magnetic flux densities of 1 and 100 µT 50 Hz EMFs had more immunological effects than EMFs with higher densities. Exposure to 50 Hz EMFs may activate anti-inflammatory effects in rats, by down-modulation of pro-inflammatory cytokines (IL-9 and TNF-α) and induction of the anti-inflammatory cytokine (IL-10).