Inhaled corticosteroids (ICS) alone or in combination with bronchodilators are widely used in asthma [1]. ICS have potential immunosuppressive effects which may promote viral replication, delayed viral clearance and increased risks of secondary infections [2, 3]. Furthermore, ICS use in asthma is associated with an increased risk of upper respiratory tract infections [2, 3]. Therefore, in the face of the current coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) infection, concerns have been raised whether the use of ICS in asthmatic patients increase the risk of SARS CoV-2 infection and affect COVID-19 severity and mortality.

Purpose Ultrafine particles (UFP) are toxic due to their small size and penetration into deeper lung compartments. We aimed to evaluate the exhaled breath condensate (EBC)-UFP content as a reflection of inflammation and oxidative stress status in COPD patients and as an exacerbation risk marker. Methods EBC was collected by conventional methods. Particles were analyzed with NanoSight LM20. EBC carbonyl and 8-hydroxydeoxyguanosine (8-OHdG) levels were measured using ELISA kits. Study population (58 COPD patients and 40 healthy smoker and non-smoker controls) underwent spirometry, diffusion capacity, EBC testing, and blood sampling. Results Absolute eosinophil count, C-reactive protein (CRP), and lactate dehydrogenase in serum were elevated in the COPD group compared with the controls (224 U/L, 5 mg/L, and 391 U/L vs 154 U/L, 3 mg/L, and 330 U/L, P =0.009, P =0.05, and P =0.004, respectively). COPD patients had lower UFP concentrations in EBC compared with controls (0.24 E8/mL vs 0.51 E8/mL, P ≤0.001). A mirror image was detected in serum: COPD patients had higher UFP concentrations compared with controls (9.8 E8/mL vs 6.7 E8/mL, respectively, P =0.03). EBC carbonyl and 8-OHdG levels were higher among COPD patients compared with controls (5.1 per 1 µg/mL protein and 0.036 ng/mL vs 0.41 per 1 µg/mL protein and 0.003 ng/mL, P =0.001 and P ≤0.001, respectively). EBC UFP concentrations were negatively correlated with pack years ( R =−0.44, P ≤0.001) and positively correlated with FEV 1 and diffusing lung capacity for carbon monoxide ( R =0.46, 0.23, P ≤0.001 and P =0.04, respectively). Low EBC UFP concentrations (≤0.18 E8/mL) and CRP levels ≥5 mg/L were independent predictors of the frequent exacerbator phenotype (OR 3.6; 95% CI: 1.06–7.97; P =0.04 and OR 4.4; 95% CI: 1.24–10.2; P =0.02, respectively). Conclusion UFP content in EBC reflects the inflammatory state of airways. Low UFP concentrations in EBC and high in serum of COPD patients support our hypothesis that increased epithelial permeability could be the mechanism behind those findings.

IntroductionParticulate matter (PM) and cigarette-related cadmium exposure increases inflammation and smokers' susceptibility to developing lung diseases. The majority of inhaled metals are attached to the surface of ultrafine particles (UFPs). A low inhaled UFP content in exhaled breath condensate (EBC) reflects a high inflammatory status of airways.MethodsEBC was collected from 58 COPD patients and 40 healthy smokers and nonsmokers. Participants underwent spirometry, diffusion capacity, EBC and blood sampling. Environmental pollution data were collected from monitoring stations. UFPs were measured in EBC and serum, and cadmium content was quantified.ResultsSubjects with low UFP concentrations in EBC (<0.18×108·mL−1) had been exposed to higher long-term PM2.5 levels versus subjects with high UFP concentrations in EBC (>0.18×108·mL−1) (21.9 µg·m−3versus 17.4 µg·m−3, p≤0.001). Long-term PM2.5 exposure levels correlated negatively with UFP concentrations in EBC and positively with UFP concentrations in serum (r=−0.54, p≤0.001 and r=0.23, p=0.04, respectively). Healthy smokers had higher cadmium levels in EBC versus healthy nonsmokers and COPD patients (25.2 ppm versus 23.7 ppm and 23.3 ppm, p=0.02 and p=0.002, respectively). Subjects with low UFP concentrations in EBC also had low cadmium levels in EBC versus subjects with high UFP levels (22.8 ppm versus 24.2 ppm, p=0.004)ConclusionsLow UFP concentration in EBC is an indicator of high-level PM exposure. High cadmium levels in EBC among smokers and the association between cadmium and UFP content in EBC among COPD patients indicate cadmium lung toxicity.

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