Acute Exacerbation and Respiratory InfectionS in COPD (AERIS): protocol for a prospective, observational cohort study

Bourne, Simon; Cohet, Catherine; Kim, Viktoriya; Barton, Anna; Tuck, Andy; Aris, Emmanuel; Mesia-Vela, Sonia; Devaster, Jeanne-Marie; Ballou, W Ripley; Clarke, Stuart; Wilkinson, Tom

A number of other epidemiological studies have been initiated in recent years to further characterize our understanding of the natural history of AECOPD. However, it is important to recognise that most of these studies have not included molecular microbiological assessments. Recent large observational studies focusing on biomarker discovery have involved close phenotyping of COPD patients, but have not studied the aetiology of exacerbations in depth. [37] [38] [39] In another study, potentially pathogenic bacterial strains were identified using molecular typing techniques, although viruses as potential airway pathogens were not investigated. 21 More recently, the prevalence and load of airway bacteria in stable and exacerbated AECOPD have been assessed in paired samples from 52 patients participating in the London COPD cohort study using modern molecular techniques. 19 Airway bacterial prevalence and load was found to increase significantly during AECOPD, with quantitative molecular techniques proving more discriminatory than culture. However, assessment was pneumoniae, and M. catarrhalis). However, other potential pathogens and the overall respiratory microbiome may also contribute and have not yet been studied in detail. 17, 18, 20, 40, 41 In AERIS, samples will be acquired during both AECOPD and stable disease and analysed for a wide range of potentially pathogenic bacteria and viruses using advanced PCR-based techniques as well as traditional culture-based methods.