A prospective, observational cohort study of the seasonal dynamics of airway pathogens in the aetiology of exacerbations in COPD

Abstract

BackgroundThe aetiology of acute exacerbations of COPD (AECOPD) is incompletely understood. Understanding the relationship between chronic bacterial airway infection and viral exposure may explain the incidence and seasonality of these events.MethodsIn this prospective, observational cohort study (NCT01360398), patients with COPD aged 40–85 years underwent sputum sampling monthly and at exacerbation for detection of bacteria and viruses. Results are presented for subjects in the full cohort, followed for 1 year. Interactions between exacerbation occurrence and pathogens were investigated by generalised estimating equation and stratified conditional logistic regression analyses.FindingsThe mean exacerbation rate per patient-year was 3.04 (95% CI 2.63 to 3.50). At AECOPD, the most common bacterial species were non-typeable Haemophilus influenzae (NTHi) and Moraxella catarrhalis, and the most common virus was rhinovirus. Logistic regression analyses (culture bacterial detection) showed significant OR for AECOPD occurrence when M. catarrhalis was detected regardless of season (5.09 (95% CI 2.76 to 9.41)). When NTHi was detected, the increased risk of exacerbation was greater in high season (October–March, OR 3.04 (1.80 to 5.13)) than low season (OR 1.22 (0.68 to 2.22)). Bacterial and viral coinfection was more frequent at exacerbation (24.9%) than stable state (8.6%). A significant interaction was detected between NTHi and rhinovirus presence and AECOPD risk (OR 5.18 (1.92 to 13.99); p=0.031).ConclusionsAECOPD aetiology varies with season. Rises in incidence in winter may be driven by increased pathogen presence as well as an interaction between NTHi airway infection and effects of viral infection.Trial registration numberResults, NCT01360398.

Arpin is critical for phagocytosis in macrophages and is targeted by human rhinovirus

“…There are reports indicating that HRV can infect monocytes/macrophages in vitro and in vivo [7,14,15,20,21,23]. We first found that post-HRV16 exposure, macrophages did not internalise a range of gram-positive and gramnegative bacteria that are frequently associated with exacerbations [20]. We first found that post-HRV16 exposure, macrophages did not internalise a range of gram-positive and gramnegative bacteria that are frequently associated with exacerbations [20].…”

“…A recent study demonstrated that epithelial cells directly enhance the replication of rhinovirus in monocytes [15]. However, mounting evidence shows that HRV can infect the lower respiratory tract in patients with chronic inflammatory diseases including chronic obstructive pulmonary disease (COPD) driving disease exacerbations [17][18][19][20]. However, mounting evidence shows that HRV can infect the lower respiratory tract in patients with chronic inflammatory diseases including chronic obstructive pulmonary disease (COPD) driving disease exacerbations [17][18][19][20].…”

Macrophages and neutrophils: dynamic duo or partners in crime?

“…Severe infections are often associated with chronic lung diseases, like severe asthma and chronic obstructive pulmonary disease (COPD), both of which are not only associated with neutrophilia and increased LL-3716 17 but also a dysbiosis of the lung microbiome,18 with increased abundance of Proteobacteria spp and non-typeable Haemophilus influenzae (NTHi) in particular. IL-1β is already increased in the lungs of patients with COPD who are colonised with NTHi,19 and compellingly in a longitudinal cohort of patients with COPD, we observed that NTHi colonisation increased the risk of a viral infection being associated with an exacerbation compared with the presence of virus alone 20. NTHi is also frequently detected in the sputum of hospitalised patients with pneumonia 21.…”

Factors Affecting Influenza Vaccination Rates among Patients with Chronic Obstructive Pulmonary Disease in Rize, Turkey

“…Another study investigating etiologic agents causing AECOPD found Haemophilus influenzae, Moraxella catarrhalis, and rhinovirus as the most incident pathogens. Therefore, the vaccination spectrum for COPD should be more diverse to enclose other potential pathogens causing AECOPD [14], and new vaccines against these pathogens should be developed.…”