Copd_a_254129 1507..1517

*These authors contributed equally to this work Abstract: Short-term exposure to major air pollutants can increase the risk of acute exacerbation in chronic obstructive pulmonary disease (COPD) patients. However, evidence on the mechanism of acute exacerbation of COPD (AECOPD) caused by air pollutants is still limited. A total of 78 patients with stable COPD and 58 healthy controls were recruited in Peking University Third Hospital in China from December 2014 to January 2015. The correlation and lag effect over 7 days (lag1–7) of 6 air pollutants with clinical symptoms and inflammatory markers in induced sputum were analyzed. PM2.5, NO2 and CO were positively correlated with the COPD assessment test (CAT) score at lag 5, PM10 was positively correlated with the CAT score at lag 3, MMP-9 and IL-8 were positively correlated with PM2.5, PM10 and NO2 at lag 2, and CO was positively correlated with each other marker at lag 4. Short-term exposure to PM2.5, PM10, NO2, and CO can cause a neutrophil-mediated airway inflammatory response, followed by increased clinical symptoms. If the PM2.5, PM10, NO2 and CO exposure levels increase during air pollution monitoring, the early usage of medication or reduction of exposure to pollutants can effectively reduce the clinical symptoms of patients.