title: Exposure to moderate air pollution during late pregnancy and cord blood cytokine secretion in healthy neonates.
abstract: OBJECTIVE
  Ambient air pollution can alter cytokine concentrations as shown in vitro and following short-term exposure to high air pollution levels in vivo. Exposure to pollution during late pregnancy has been shown to affect fetal lymphocytic immunophenotypes. However, effects of prenatal exposure to moderate levels of air pollutants on cytokine regulation in cord blood of healthy infants are unknown.
  
  
  METHODS
  In a birth cohort of 265 healthy term-born neonates, we assessed maternal exposure to particles with an aerodynamic diameter of 10 µm or less (PM₁₀), as well as to indoor air pollution during the last trimester, specifically the last 21, 14, 7, 3 and 1 days of pregnancy. As a proxy for traffic-related air pollution, we determined the distance of mothers' homes to major roads. We measured cytokine and chemokine levels (MCP-1, IL-6, IL-10, IL-1ß, TNF-α and GM-CSF) in cord blood serum using LUMINEX technology. Their association with pollution levels was assessed using regression analysis, adjusted for possible confounders.
  
  
  RESULTS
  Mean (95%-CI) PM₁₀ exposure for the last 7 days of pregnancy was 18.3 (10.3-38.4 µg/m³). PM₁₀ exposure during the last 3 days of pregnancy was significantly associated with reduced IL-10 and during the last 3 months of pregnancy with increased IL-1ß levels in cord blood after adjustment for relevant confounders. Maternal smoking was associated with reduced IL-6 levels. For the other cytokines no association was found.
  
  
  CONCLUSIONS
  Our results suggest that even naturally occurring prenatal exposure to moderate amounts of indoor and outdoor air pollution may lead to changes in cord blood cytokine levels in a population based cohort.
authors.affiliation: Division of Respiratory Medicine, Department of Paediatrics, Inselspital, University of Bern, Bern, Switzerland.
authors.forename: Philipp
authors.initials: P
authors.lastname: Latzin
authors.forename: Urs
authors.initials: U
authors.lastname: Frey
authors.forename: Jakob
authors.initials: J
authors.lastname: Armann
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Kieninger
authors.forename: Oliver
authors.initials: O
authors.lastname: Fuchs
authors.forename: Martin
authors.initials: M
authors.lastname: Röösli
authors.forename: Bianca
authors.initials: B
authors.lastname: Schaub
mesh_terms: D000397:Air Pollution / Q000009:adverse effects*; D016902:Air Pollution, Indoor / Q000009:adverse effects; D018932:Chemokine CCL2 / Q000378:metabolism; D005260:Female; D005312:Fetal Blood / Q000378:metabolism*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000378:metabolism; D006801:Humans; D007231:Infant, Newborn; D016753:Interleukin-10 / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D018811:Maternal Exposure / Q000009:adverse effects; D011247:Pregnancy; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D018932:Chemokine CCL2; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D016178:Granulocyte-Macrophage Colony-Stimulating Factor