Chronic obstructive pulmonary disease due to aerosols containing nanoparticles: inflammation and phenotype features

Abstract

Introduction. Influence of incidental nanoparticles of industrial aerosols on occupational lung diseases development is not studied enough. As nanoparticles has properties to induce inflammation and fibrosis, it is hypothesized that they affect occupational chronic obstructive pulmonary disease (COPD) phenotype. The aim was to establish monocyte subsets, airway inflammation, clinical and functional features in occupational COPD due to aerosols containing nanoparticles exposure. Materials and methods. Study design was a single center prospective cohort observational. Subjects with occupational COPD (GOLD 2011-2021 criteria) exposed to aerosols containing nanoparticles (n=50) enrolled. Comparison group - COPD in tobacco smokers (n=50), control group - healthy people (n=50). Groups were matched by demographics and COPD duration. Nanoparticles at workplaces air were measured by inductively coupled plasma atomic emission spectrometry and by scanning electron microscopy. Of participants 26 were exposed to maximal concentrations of metal nanoparticles and 24 - of silica nanoparticles. Spirography, body pletysmography, lung diffusing capacity (DLco/Va), Doppler-ehocardiography, induced sputum cytology, COPD exacerbations assessment were done. Monocyte subsets were determined by flow cytometry. Linear regression model was used to explore relationships. Results. COPD due to aerosols containing metal nanoparticles was characterized by most severe airflow limitation, lung hyperinflation, pulmonary hypertension, most prominent decrease in DLco/Va, frequent and severe COPD exacerbations, eosinophilic inflammation. The largest proportion of «classical» CD14+CD16- monocytes subset, 96,4% (90,3%; 97,2%), high level of CCR5 expression were seen in this group. The features of COPD due to aerosols containing silica nanoparticles were substantial decrease in DLco/Va, the least airflow limitation, mild lung hyperinflation, rare COPD exacerbations, paucigranulocytic inflammation. The largest proportion of «non-classical» CD14DimCD16+ monocytes with high level of CCR2 expression revealed. Mass concentration of metal nanoparticles was associated with «classical» monocytes, (B=1,5), silica nanoparticles - with «non-classical» monocytes (B=1,4). On their turn, «classical» monocytes were associated with DLco (B=-1,6), functional residual volume (B=1,2), mean pulmonary artery pressure (B=-1,4), eosinophilic inflammation. «Non-classical» monocytes were associated with DLco (B=-1,5) and paucigranulocytic inflammation (B=1,2), p<0,015. Conclusions. Exposure of incidental nanoparticles was associated with circulated monocyte subsets, airway inflammation and occupaitonal CODP phenotype.