Background: The objective of this study was to assess inflammatory and immune responses in patients with asthma and healthy controls exposed to a polluted and a nonpolluted environment over a short period. Material and Methods: We performed a randomized crossover study in patients with asthma (n=20) and in healthy controls (n=15). Participants were exposed for 2 hours to a polluted environment and, after 14 days, to a nonpolluted environment. Pollution levels were assessed at each exposure. Subsequently, serum levels of 8-isoprostane and glutathione peroxidase were measured as markers of oxidative stress, as were 48 cytokines involved in inflammation and the immune response. Results: In the polluted environment, significantly higher levels of PM1, PM10, NO2, NO, and CO were observed (P=.0026, .0337, <.0001, <.0001, and .0004, respectively) than in the nonpolluted environment. After exposure to a polluted environment, both groups (healthy controls and asthma patients) presented higher values of IL-17F (P=.0285 and .0348, respectively) and CSF2 (P=.0425 and 0.0305, respectively). After exposure to high levels of pollution, healthy controls presented reductions in glutathione peroxidase (with antioxidant activity), CSF3, HGF, and OSM (P=.0038, P=.0123, 0.0353, and 0.0256, respectively) and increased levels of IL-7, CXCL8, and CCL2 (P=.0015, 0.0119 and 0.0215, respectively). Asthma patients had higher serum levels of IL-1ß and IL-15 (P=.0232 and 0.0497, respectively). Conclusion: Healthy individuals and asthma patients respond differently to exposure to pollutants. Healthy individuals are characterized by adaptive suppression of immune activity, whereas asthma patients present a more marked inflammatory response.
Soler-Segovia et al. (Wed,) studied this question.