Influence of persistent organic pollutants on the complement system in a population-based human sample

Environ Int. 2014 Oct:71:94-100. doi: 10.1016/j.envint.2014.06.009. Epub 2014 Jul 2.

Abstract

Background: Persistent organic pollutants (POPs) are toxic compounds generated through various industrial activities and have adverse effects on human health. Studies performed in cell cultures and animals have revealed that POPs can alter immune-system functioning. The complement system is part of innate immune system that helps to clear pathogens from the body. We performed a large-scale population-based study to find out associations between summary measures of different POPs and different complement system markers.

Methods: In this cross-sectional study, 16 polychlorinated biphenyls (PCBs), 3 organochlorine (OC) pesticides, octachloro-p-dibenzodioxin, and 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) were analyzed for their association with levels of protein complement 3 (C3), 3a (C3a), 4 (C4) and C3a/C3 ratio. A total of 992 individuals (all aged 70 years, 50% females) were recruited from the Prospective Investigation of the Vasculature in Uppsala Seniors cohort. Regression analysis adjusting for a variety of confounders was performed to study the associations of different POP exposures (total toxic equivalency value or TEQ and sum of 16 PCBs) with protein complements.

Results: The TEQ values were found to be positively associated with C3a (β=0.07, 95% CI=0.017-0.131, p=0.01) and C3a/C3 ratio (β=0.07, 95% CI=0.015-0.126, p=0.01) taking possible confounders into account. The association observed was mainly driven by PCB-126.

Conclusion: In this study involving 992 elderly individuals from the general population, we showed that POPs, mainly PCB-126, were associated with levels of complement system markers indicating that the association of these toxic compounds with downstream disease could be mediated by activation of immune system.

Keywords: Complement system markers; Epidemiology; Persistent organic pollutants; TEQ.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Complement C3 / immunology*
  • Complement C3a / immunology*
  • Cross-Sectional Studies
  • Dioxins / analysis
  • Dioxins / toxicity
  • Environmental Pollutants / analysis
  • Environmental Pollutants / toxicity*
  • Female
  • Halogenated Diphenyl Ethers / analysis
  • Halogenated Diphenyl Ethers / toxicity
  • Humans
  • Hydrocarbons, Chlorinated / analysis
  • Hydrocarbons, Chlorinated / toxicity
  • Immune System / drug effects*
  • Male
  • Models, Statistical
  • Pesticides / analysis
  • Pesticides / toxicity
  • Polychlorinated Biphenyls / analysis
  • Polychlorinated Biphenyls / toxicity*
  • Polychlorinated Dibenzodioxins / analysis
  • Polychlorinated Dibenzodioxins / toxicity
  • Prospective Studies
  • Regression Analysis
  • Sweden

Substances

  • Complement C3
  • Dioxins
  • Environmental Pollutants
  • Halogenated Diphenyl Ethers
  • Hydrocarbons, Chlorinated
  • Pesticides
  • Polychlorinated Dibenzodioxins
  • 2,2',4,4'-tetrabromodiphenyl ether
  • Complement C3a
  • Polychlorinated Biphenyls
  • 3,4,5,3',4'-pentachlorobiphenyl