Impact of concomitant nontuberculous mycobacteria and pseudomonas aeruginosa isolates in non-cystic fibrosis bronchiectasis

Purpose: Pseudomonas aeruginosa is associated with pulmonary function decline and high disease severity in non-cystic fibrosis (CF) bronchiectasis. The prevalence of nontuberculous mycobacteria (NTM) in non-CF bronchiectasis patients has increased recently. This study investigated the impact of NTM with or without P. aeruginosa isolates in non-CF bronchiectasis patients. Patients and methods: Our retrospective study included 96 non-CF bronchiectasis patients from January 2005 to December 2014. We recorded the presentation, exacerbations, emergency department (ED) visits, hospitalization, serial pulmonary function, radiologic studies, and sputum culture results. All patients were followed up for at least 2 years. Results: The 96 patients were divided into four groups: patients with concomitant negative NTM and P. aeruginosa isolates (n=41; group 1), patients with positive NTM isolates (n=20; group 2), patients with positive P. aeruginosa isolates (n=20; group 3), and patients with concomitant positive NTM and P. aeruginosa isolates (n=15; group 4). Compared with group 1 patients, patients in groups 2 and 3 showed a significant decline in forced expiratory volume in 1 second (FEV₁). They also had more frequent annual acute exacerbations (AE), ED visits, and hospitalization. Group 4 patients had the greatest FEV₁ and forced vital capacity (FVC) decline and the most frequent AE, ED visits, and hospitalization. Conclusion: Concomitant NTM and P. aeruginosa isolates in non-CF bronchiectasis are associated with the greatest pulmonary function decline and the worst disease severity. This result suggested that early recognition and prompt treatment of concomitant NTM and P. aeruginosa isolates may improve the outcome in non-CF bronchiectasis patients.