Cytokine profiles in cord blood in relation to prenatal traffic-related air pollution: The NELA cohort.

BACKGROUND: Outdoor air pollution may disturb immune system development. We investigated whether gestational exposure to traffic-related air pollutants (TRAP) is associated with unstimulated cytokine profiles in newborns. METHODS: Data come from 235 newborns of the NELA cohort. Innate response-related cytokines (IL-6, IFN-α, IL1-ß, and TNF-α), Th1-related (IFN-γ and IL-2), Th2-related (IL-4, IL-5, and IL-13), Th17-related (IL-17 and IL-23), and immunomodulatory cytokine IL-10 were quantified in the supernatant of unstimulated whole umbilical cord blood cells after 7 days of culture using the Luminex technology. Dispersion/chemical transport modeling was used to estimate long-term (whole pregnancy and trimesters) and short-term (15 days before delivery) residential exposures to traffic-related nitrogen dioxide (NO2 ), particulate matter (PM2.5 and PM10 ), and ozone (O3 ). We fitted multivariable logistic regression, Bayesian kernel machine regression (BKMR), and weighted quantile sum (WQS) regression models. RESULTS: NO2 during the whole pregnancy increased the odds of detection of IL-1ß (OR per 10 µg/m3 increase = 1.37; 95% CI, 1.02, 1.85) and IL-6 (OR per 10 µg/m3 increase = 1.32; 95% CI 1.00, 1.75). Increased odds of detected concentrations of IL-10 was found in newborns exposed during whole pregnancy to higher levels of NO2 (OR per 10 µg/m3 increase = 1.30; 95% CI 0.99, 1.69), PM10 (OR per 10 µg/m3 increase = 1.49; 95% CI 0.95, 2.33), and PM2.5 (OR per 5 µg/m3 increase = 1.56; 95% CI 0.97, 2.51). Exposure to O3 during the whole pregnancy increased the odds of detected IL-13 (OR per 10 µg/m3 increase = 1.22; 95% CI 1.01, 1.49). WQS model revealed first and third trimesters of gestation as windows of higher susceptibility. CONCLUSIONS: Gestational exposure to TRAP may increase detection of pro-inflammatory, Th2-related, and T regulatory cytokines in newborns. These changes might influence immune system responses later in life.