Air pollution and pathogen-specific acute exacerbations of COPD

Background Air pollution plays a critical role in disease progression and acute exacerbations of chronic obstructive pulmonary disease (AECOPD). However, the interaction between air pollution and infectious pathogens in triggering AECOPD remains incompletely understood. We investigated associations between air pollution levels and specific respiratory pathogens in patients with AECOPD. Methods We conducted a multicenter retrospective cohort study of 657 patients with moderate-to-severe AECOPD between 2015 and 2019. Air pollutant data and respiratory viral pathogen data were analyzed using Spearman correlation, dynamic time warping (DTW), and Poisson regression models with lagged variables to assess both temporal similarity and short-term exposure effects. Results Spearman correlation analysis showed that influenza virus (IFV) and respiratory syncytial virus (RSV) were positively correlated with PM 2.5 and NO 3 − . Parainfluenza virus was positively correlated with SO 4 2– and negatively correlated with NO 3 − . DTW analysis demonstrated strong seasonal synchronization between air pollutants and IFV and rhinovirus (RV). In Poisson regression models, a 1-μg·m −3 increase in PM 2.5 was associated with an 8.0% increase in RV incidence (p=0.013) and a 6.2% increase in IFV incidence (p=0.032). By contrast, RSV incidence decreased by 13.0% per 0.1-ppb increase in SO 4 2− (p=0.040). Conclusions Air pollution shows association with viral-induced AECOPD, with the magnitude and direction of effects varying by pollutant, viral pathogen, and temporal context.