Nanoparticles in induced sputum – a window to airway inflammation among active smokers - Supplementary data

Aims: To evaluate the role of nanoparticles (NP) in sputum samples of active smokers as markers of
inflammation and disease. Materials & methods: 29 active smokers were included (14 with chronic
obstructive pulmonary disease [COPD]) and underwent clinical assessment, pulmonary function tests,
sputum induction (with NP analysis) and blood sampling. Results: Higher particle and NP concentrations
and smaller mean size directly correlated with clinical parameters such as the COPD Assessment Test score
and impulse oscillometry results. Similar correlations were found between NPs and increased sputum IL-
1β, IL-6 and TNF-α. Among COPD patients, higher IL-8 and lower IL-10 serum levels also correlated with
NP concentrations. Conclusion: This proof-of-concept study shows the potential of sputum NPs as markers
of airway inflammation and disease.