COVID-19 Lockdown in Israel: The Environmental Effect on Ultrafine Particle Content in the Airway

Inhaled ultrafine particle (UFP) content in exhaled breath condensate (EBC) was observed as an airway inflammatory marker and an indicator of exposure to particulate matter (PM). The exceptional decline in air pollution during the COVID-19 lockdown was an opportunity to evaluate the effect of environmental changes on UFP airway content. We collected EBC samples from 30 healthy subjects during the first lockdown due to COVID-19 in Israel (March–April 2020) and compared them to EBC samples retrieved during April–June 2016 from 25 other healthy subjects (controls) living in the same northern Israeli district. All participants underwent EBC collection and blood sampling. Ambient air pollutant levels were collected from the Israeli Ministry of Environmental Protection’s online database. Data were acquired from the monitoring station closest to each subject’s home address, and means were calculated for a duration of 1 month preceding EBC collection. UFP contents were measured in the EBC and blood samples by means of the NanoSight LM20 system. There was a dramatic reduction in NO, NO2, SO2, and O3 levels during lockdown compared to a similar period in 2016 (by 61%, 26%, 50%, and 45%, respectively). The specific NO2 levels were 8.3 ppb for the lockdown group and 11.2 ppb for the controls (p = 0.01). The lockdown group had higher UFP concentrations in EBC and lower UFP concentrations in serum compared to controls (0.58 × 108/mL and 4.3 × 108/mL vs. 0.43 × 108/mL and 6.7 × 108/mL, p = 0.05 and p = 0.03, respectively). In this observational study, reduced levels of air pollution during the COVID-19 lockdown were reflected in increased levels of UFP airway contents. The suggested mechanism is that low airway inflammation levels during lockdown resulted in a decreased UFP translocation to serum. Further studies are needed to confirm this hypothesis

Bronchiectasis with Chronic Rhinosinusitis Is Associated with Eosinophilic Airway Inflammation and Is Distinct from Asthma

RATIONALE: Bronchiectasis is an airway inflammatory disease frequently associated with chronic rhinosinusitis (CRS). An eosinophilic endotype of bronchiectasis has recently been described, but detailed testing to differentiate eosinophilic bronchiectasis from asthma has not been performed.OBJECTIVE: This prospective observational study aimed to test the hypotheses that bronchiectasis with CRS is enriched for the eosinophilic phenotype in comparison with bronchiectasis alone and that the eosinophilic bronchiectasis phenotype exists as a separate entity from bronchiectasis associated with asthma.METHODS: People with idiopathic or post-infectious bronchiectasis were assessed for concomitant CRS. We excluded people with asthma, PCD, and smokers. We assessed sputum and blood cell counts, nasal NO and fractional excreted NO, methacholine reactivity, skin allergy testing and total and specific IgE, cytokines in sputum and serum, and microbiome in sputum and nasopharynx.RESULTS: 22 people with CRS (BE+CRS) and 17 without CRS (BE-CRS) were included. Sex, age, Reiff score, and bronchiectasis severity were similar. Median (IQR) sputum eosinophil percentages were 0 (0-1.5)% in BE-CRS, and 3(1-12)% in BE+CRS (p=0.012). Blood eosinophil counts were predictive of sputum eosinophilia (counts ≥3%; AUC 0.68, 95% CI 0.50-0.85) inclusion of CRS improved the prediction of sputum eosinophilia by blood eosinophils (AUC 0.79 (95%CI 0.65-0.94). Methacholine tests were negative in 85.7% BE-CRS and 85.2% BE+CRS (p&gt;0.99). Specific IgE and skin testing were similar between the groups, but total IgE levels were elevated in people with elevated sputum eosinophils. Microbiome analysis demonstrated distinct microbiota in nasopharyngeal and airway samples in both BE+CRS and BE-CRS without significant differences between groups, however, interactome analysis revealed altered interactomes in individuals with high sputum eosinophils and CRS.CONCLUSION: Bronchiectasis with CRS is associated with an eosinophilic airway inflammation that is distinct from asthma.</p