Correlation of Clinical Symptoms and Sputum Inflammatory Markers with Air Pollutants in Stable COPD Patients in Beijing Area

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. PM(2.5), NO(2) and CO were positively correlated with the COPD assessment test (CAT) score at lag 5, PM(10) was positively correlated with the CAT score at lag 3, MMP-9 and IL-8 were positively correlated with PM(2.5), PM(10) and NO(2) at lag 2, and CO was positively correlated with each other marker at lag 4. Short-term exposure to PM(2.5), PM(10), NO(2), and CO can cause a neutrophil-mediated airway inflammatory response, followed by increased clinical symptoms. If the PM(2.5), PM(10), NO(2) 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.