Secondhand smoke exposure and serum cytokine levels in healthy children

Cytokine. 2012 Oct;60(1):34-7. doi: 10.1016/j.cyto.2012.06.236. Epub 2012 Jul 16.

Abstract

Introduction: Exposure to secondhand smoke (SHS) is associated with morbidity in children. Alterations in immune responses may explain this relationship, but have not been well-studied in children. Our objective was to determine the association between SHS exposure and serum cytokine levels in healthy children.

Methods: We recruited 1-6 year old patients undergoing routine procedures. A parent interview assessed medical history and SHS exposure. Children with asthma were excluded. Blood was collected under anesthesia. We used Luminex Multiplex Assays to test for a panel of cytokines; cotinine was determined using an enzyme-linked immunosorbent assay. Children were categorized as no, intermediate, or high exposure. A mixed-effects model was fit to determine differences in cytokines by exposure level.

Results: Of the 40 children recruited, 65% (N=26) had SHS exposure; 16 intermediate, and 10 high. There were no differences by demographics. In bivariate analyses, children exposed to SHS had lower concentrations of IL-1β, IL-4, IL-5, and IFN-γ than those with no exposure. In the mixed-effects model, children with any SHS exposure had significantly lower concentrations of IL-1β (0.554 pg/mL vs. 0.249 pg/mL) and IFN-γ (4.193 pg/mL vs. 0.816 pg/mL), and children with high exposure had significantly lower mean concentrations of IL-4 (8.141 pg/mL vs. 0.135 pg/mL) than children with no exposure.

Conclusions: This study suggests that SHS exposure decreases expression of some pro-inflammatory cytokines in SHS exposed children, including IFN-γ. Further research to describe the acute and chronic effects of SHS on the immune systems of children is needed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chi-Square Distribution
  • Child
  • Child, Preschool
  • Cotinine / blood
  • Cytokines / blood*
  • Environmental Exposure / analysis*
  • Female
  • Humans
  • Infant
  • Inflammation Mediators / blood*
  • Interferon-gamma / blood
  • Interleukin-1beta / blood
  • Interleukin-4 / blood
  • Interleukin-5 / blood
  • Male
  • Multivariate Analysis
  • Tobacco Smoke Pollution*

Substances

  • Cytokines
  • Inflammation Mediators
  • Interleukin-1beta
  • Interleukin-5
  • Tobacco Smoke Pollution
  • Interleukin-4
  • Interferon-gamma
  • Cotinine