Second Follow-up Study of COPD Patients and Healthy Controls for Evaluation of Predictive Non-coding RNA Biomarkers

Inclusion Criteria: 1. Participation in the study "11-03 Ribolution". 2. Able and willing to give written informed consent. 3. Females will be considered for inclusion if they are: not pregnant, as confirmed by pregnancy test (see flow chart), and not nursing. Exclusion Criteria: 1. Any clinically relevant abnormal findings in physical examination, clinical chemistry, hematology, urinalysis, vital signs, lung function or ECG at screening visit, which, in the opinion of the investigator, may either put the subject at risk because of participation in the study or may influence the results of the study, or the subject's ability to participate in the study. 2. Past or present disease developed after the participation in "11-03 Ribolution" or "15-01 Ribolution II", which might interfere with study procedures. 3. Participation in another clinical trial 30 days prior to enrollment. 4. Current drug or alcohol abuse. 5. Risk of non-compliance with study procedures. 6. Suspected inability to understand the protocol requirements, instructions and study-related restrictions, the nature, scope, and possible consequences of the study. 7. History of an acute infection four weeks prior to the study procedures, including - but not limited to - moderate or severe exacerbation (requiring oral corticosteroid, antibiotics or hospitalization). All courses of oral corticosteroids and antibiotics must be completed at least four weeks prior to all study procedures (with the exception of the informed consent). In case of significant acute infections or moderate or severe exacerbation, the study participation can be split in two separate visits (1. Informed consent visit, 2. Study procedures visit, when subject is fully resolved, at least four weeks after the end of infection/ exacerbation). 8. If performed according to SOP FHI-1-18, positive SARS-CoV-2 rapid antigen test on Day 1. Subjects may be re-screened when confirmatory nucleic acid amplification test was negative or when officially ordered quarantine has ended. 9. Being a vulnerable subject (dependent, in detention or without mental capacity).