Upper Airway Mucociliary Clearance is Impaired in Dyspneic COVID-19 Patients.

Covid-19 is transmitted mainly by respiratory droplets and as the upper airway mucosa is the first innate immune barrier, it is crucial to understand the effects of SARS-CoV-2 on this system. In the current study, we aimed to evaluate the nasal mucociliary clearance in patients with SARS-CoV-2 infection and their symptom development. Observational cross-sectional study. The nasal mucociliary clearance (NMC) time was evaluated by the saccharin test and the results were compared between patients with SARS-CoV-2 infection (group 1) and controls (group 2, asymptomatic patients with a negative polymerase chain reaction test). We also compared the NMC time for each specific symptom suffered by participants in group 1 with the NMC time of the control group as well as with the patients in group 1 who were asymptomatic. There was a significant increase in NMC time in group 1 with dyspnea when compared to the control group (p = 0.032) and also when compared to patients who were infected were not dyspneic (p = 0.04). There were no differences in the clearance times when considering other symptoms. COVID-19 patients with dyspnea present with altered nasal mucociliary clearance.

The Effects in the Upper Airway of Heat and Exposure to Combustion Byproducts of Burning Materials on Larynx of Firefighters.

INTRODUCTION: High exposure to heat and combustion byproducts is associated with health problems and an increased risk of cancer. OBJECTIVE: To study the effects of heat and smoke derived from burning on the upper airway of firefighters. METHODS: Thirteen firefighters underwent a 4-week training program in Compartment Fire Behavior Training simulators while working with live fire, heat, and smoke from pallets and oriented-strand board sheet burns. The firefighters were evaluated before exposure and at the end of the first and fourth weeks of training. The larynx was assessed by the Voice Handicap Index GRBASI scale, laryngoscopy, and peak expiratory flow. RESULTS: There was no change in Voice Handicap Index and GRBASI (only one in three speech therapists judged tension as worse by one point). Laryngoscopy showed alterations in one-third of the firefighters, with the most frequent being increased viscous mucus. Peak expiratory flow decreased significantly from 685 to 552 and 550 L/min in the first and fourth weeks, respectively. CONCLUSIONS: Although participants were protected from gases and smoke during the exercises, which proved to be very effective, the airway was slightly impacted by heat and combustion-derived byproducts.

Impact of SARS-CoV-2 on saliva: TNF-⍺, IL-6, IL-10, lactoferrin, lysozyme, IgG, IgA, and IgM.

OBJECTIVES: Understanding the role of certain salivary components, such as TNF-⍺, IL-6, IL-10, lactoferrin, lysozyme, IgG, IgA, and IgM, in airway defense during the ongoing SARS-CoV-2 pandemic is essential. The salivary immune barrier of patients with COVID-19 may play a role in their prognosis. The present study aims to evaluate the impact of SARS-CoV-2 on saliva composition. METHODS: A longitudinal study was carried out with male and female firefighters aged 24-48 years. The study sample (n = 34) was divided into 3 groups: asymptomatic volunteers with a negative polymerase chain reaction (PCR) test for SARS-CoV-2 (group 1, Control, n = 21); patients with symptoms of COVID-19 of less than 7 days' duration and a diagnosis of SARS-CoV-2 infection by PCR (group 2, COVID-19, n = 13); and recovered patients from group 2 who were free of COVID-19 symptoms for at least 2 months (group 3, post-COVID-19 recovery, n = 13). All groups underwent real-time PCR to detect the presence of SARS-CoV-2, as well as analysis of the salivary concentrations of TNF-⍺, IL-6, IL-10, lactoferrin, lysozyme, IgG, IgA, and IgM by the ELISA method. RESULTS: Lactoferrin concentrations were significantly decreased in the infected group (COVID-19) when compared to those not infected by SARS-CoV-2 (control) (p = 0.032). IgA concentrations were decreased in the COVID-19 and post-COVID-19 groups compared to the control group (p = 0.005 and p = 0.016, respectively). Comparison of the COVID-19 and post-COVID-19 groups also revealed an increase in IgM concentrations during acute SARS-CoV-2 infection (p = 0.010). CONCLUSION: SARS-CoV-2 alters the composition of the salivary immune barrier.