Participants
The U-BIOPRED severe asthma cohort consisted of two groups of adult
severe asthmatics: non-smokers (SAn), and smokers or ex-smokers (SAs/ex)
together with non-smoking mild-moderate asthma (MMA) and non-smoking
healthy volunteers (HC), as previously described (15). Participants
provided induced sputum samples that passed quality control for
metagenomic analysis (16), at baseline and at 12-16 months later. Ethics
approval was obtained at the 14 participating centres and all
participants gave written informed consent (ClinicalTrials.gov
identifier:
NCT01982162).