Patients with COPD who have chronic bronchial infection caused by any pathogenic microorganism, in particular, Pseudomonas aeruginosa are at risk for a faster deterioration in lung function, according to a study published in the Annals of the American Thoracic Society.¹

A post-hoc analysis of 201 COPD patients was performed to examine the association between chronic bronchial infection and a decline in FEV1 in these patients. A correlation with Pseudomonas aeruginosa was also investigated. These patients were followed up every 3 to 6 months for a period of 84 months (~7 years). Patients who had three or more sputum positive cultures of the same pathogenic microorganism for 1 year were considered to be having chronic bronchial infection. Patients were categorized into two groups: one in whom the chronic bronchial infection was due to any pathogenic microorganism and the second, in whom P. aeruginosa was isolated one or more times.

Nearly 33% of the participants were found to have chronic bronchial infection by any pathogenic microorganism during follow-up. In almost 24% of subjects, pathogenic micro-organisms were isolated one time, while  in 43% patients, no pathogens were isolated. The overall decline in FEV1 was 33.7 ml per year. Patients who had chronic bronchial infection by any pathogenic micro-organism, the decline was significantly increased to 57.1 ml per year. Isolation of P. aeruginosa at least once was also associated with a decrease in FEV1 to 48.5 mg per year.

After adjusting for multiple factors such as pulmonary function at baseline, bronchiectasis, BMI, age, exacerbations of COPD, smoking status, symptoms, baseline treatment and comorbidities, the  decrease in FEV1 was rapid among patients who had chronic bronchial infection by any pathogenic micro-organism and in whom Pseudomonas aeruginosa was isolated at least a single time.

This prospective study has shown that isolation of P. aeruginosa even one time or presence of chronic bronchial infection with any pathogen in ≥3 sputum samples in 1 year were independent risk factors for decrease in FEV1 in patients with COPD. The authors also suggest further studies to examine if targeted antibiotic therapy halts the decline in lung function in these patients.

Reference

1. Miguel Ángel Martínez-García, et al. Chronic bronchial infection is associated with more rapid lung function decline in chronic obstructive pulmonary disease. Ann Am Thorac Soc. 2022 Nov;19(11):1842-1847. doi: 10.1513/AnnalsATS.202108-974OC.