Pulsed electromagnetic fields enhance the induction of cytokines by peripheral blood mononuclear cells challenged with phytohemagglutinin.

Bioelectromagnetics · 1998 · Mixed · Low evidence

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MixedLow evidencePaper 5376

Study snapshot

PublicationBioelectromagnetics · 1998

Study typein_vitro

Reported directionMixed

Evidence ratingLow

Abstract

We evaluated the effects of a 50-Hz pulsed electromagnetic field on the production of cytokines by both resting and mitogen-treated peripheral blood mononuclear cells. Our results demonstrate that after exposure of normal cells to EMFs for 12 h, the levels of neither interleukin-1beta, nor interleukin-2 were increased. Indeed, the concentration of tumor necrosis factor alpha decreased significantly immediately after the exposure period. The results were, however, markedly different when cells were stimulated with phytohemagglutinin immediately before the exposure to EMFs. In this case the levels of cytokines, measured 24 and 48 h after the treatment, were 630 +/- 440 pg/ml and 910 +/- 530 pg/ml for interleukin-1beta, 530 +/- 330 pg/ml, and 860 +/- 560 pg/ml for tumor necrosis factor alpha, respectively. These values were significantly higher (P < 0.05) when compared with the controls. Interleukin-2 levels were significantly higher at the end of the EMF exposure only in supernatants of phytohemagglutinin-stimulated cells and, as a consequence of this increase, the proliferation indexes also were significantly increased 48 h after the EMFs' treatment. The comparison between biological activity and the cytokine antigen present in our samples indicated that the amount of antigen was paralleled by an equal recovery of biological activity. This suggests either the absence of qualitative differences in these proteins or the impairment of both the transcriptional and translational processes.

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AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typein_vitro

Effect directionmixed

PopulationNot supplied

Sample sizeNot supplied

ExposureELF · 12 h

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

After 12 h exposure of resting peripheral blood mononuclear cells to a 50-Hz pulsed electromagnetic field, IL-1β and IL-2 levels were not increased, while TNF-α concentration decreased significantly immediately after exposure. When cells were stimulated with phytohemagglutinin immediately before EMF exposure, IL-1β and TNF-α levels measured 24 and 48 h after treatment were significantly higher than controls (P < 0.05), IL-2 was significantly higher at the end of exposure, and proliferation indexes were significantly increased 48 h after treatment.

Outcomes measured

Interleukin-1beta (IL-1β) production
Interleukin-2 (IL-2) production
Tumor necrosis factor alpha (TNF-α) production
Cell proliferation index

Limitations

Sample size not reported in abstract
Exposure intensity/field strength not reported
In vitro study; generalizability to humans not addressed in abstract
Timing of cytokine measurements differs across conditions (immediate vs 24/48 h)

View raw extracted JSON

{
  "study_type": "in_vitro",
  "exposure": {
    "band": "ELF",
    "source": "pulsed electromagnetic field",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "12 h"
  },
  "population": null,
  "sample_size": null,
  "outcomes": [
    "Interleukin-1beta (IL-1β) production",
    "Interleukin-2 (IL-2) production",
    "Tumor necrosis factor alpha (TNF-α) production",
    "Cell proliferation index"
  ],
  "main_findings": "After 12 h exposure of resting peripheral blood mononuclear cells to a 50-Hz pulsed electromagnetic field, IL-1β and IL-2 levels were not increased, while TNF-α concentration decreased significantly immediately after exposure. When cells were stimulated with phytohemagglutinin immediately before EMF exposure, IL-1β and TNF-α levels measured 24 and 48 h after treatment were significantly higher than controls (P < 0.05), IL-2 was significantly higher at the end of exposure, and proliferation indexes were significantly increased 48 h after treatment.",
  "effect_direction": "mixed",
  "limitations": [
    "Sample size not reported in abstract",
    "Exposure intensity/field strength not reported",
    "In vitro study; generalizability to humans not addressed in abstract",
    "Timing of cytokine measurements differs across conditions (immediate vs 24/48 h)"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "50-Hz",
    "pulsed electromagnetic field",
    "ELF-EMF",
    "peripheral blood mononuclear cells",
    "phytohemagglutinin",
    "cytokines",
    "interleukin-1beta",
    "interleukin-2",
    "tumor necrosis factor alpha",
    "proliferation"
  ],
  "suggested_hubs": [
    {
      "slug": "occupational-exposure",
      "weight": 0.2,
      "reason": "Study involves 50-Hz ELF pulsed EMF exposure, which can be relevant to occupational ELF contexts, though the work is in vitro and no workplace setting is described."
    }
  ]
}

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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: Not supplied
PubMed: 9849913

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