Acute and durable effect of inhaled hypertonic saline on mucociliary clearance in adult asthma

UNC Libraries · 2025-07-31

BACKGROUND: Impaired mucus clearance and airway mucus plugging have been shown to occur in moderate-severe asthma, especially during acute exacerbations. In cystic fibrosis, where airway mucus is dehydrated, it has been shown that inhaled hypertonic saline (HS) produces both acute and sustained enhancement of mucociliary clearance (MCC). The current study was designed to assess the acute and sustained effect of inhaled 7% HS on MCC in adult asthma. METHODS: Well-controlled, moderate-severe female asthmatic patients (n=8) were screened with a single test dose of albuterol (four puffs by metered-dose inhaler) followed by HS (7% sodium chloride, 4 mL using PARI LC Star nebuliser). Spirometry was measured pre-treatment and 5 and 30 min post-treatment for safety. MCC was measured using &gamma;-scintigraphy on three separate visits: at baseline, during inhalation and 4 h after a single dose of HS. RESULTS: MCC was acutely enhanced during HS treatment; mean&plusmn;sd clearance over 60 min of dynamic imaging (Ave60Clr) was 8.9&plusmn;7.9% (baseline) <em>versus</em> 23.4&plusmn;7.6% (acute HS) (p&lt;0.005). However, this enhancement was not maintained over a 4-h period where post-HS treatment Ave60Clr was 9.3&plusmn;8.2%. In this small cohort we found no decrements in lung function up to 30 min post-treatment (forced expiratory volume in 1 s 97.4&plusmn;10.0% predicted pre-treatment and 98.9&plusmn;10.7% predicted 30 min post-treatment). CONCLUSION: While MCC was rapidly enhanced during 7% HS treatment there was no effect on MCC at 4 h post-treatment. While these findings may not support aerosolised HS use for maintenance therapy, they do suggest a benefit of treating acute exacerbations in patients with moderate-severe asthma.

Human Sputum Microbiome Composition and Sputum Inflammatory Cell Profiles Are Altered with Controlled Wood Smoke Exposure as a Model for Wildfire Smoke

American Journal of Respiratory and Critical Care Medicine · 2025-06-13 · 3 citations

Abstract Rationale Wood smoke exposure is increasing worldwide because of the increase in wildfire events. Various studies have associated exposure to wildfire-derived smoke with adverse respiratory conditions. However, the mechanism by which this occurs is unknown. Previous studies using wood smoke as a model of wildfire smoke have focused on the respiratory immune response and have reported increased neutrophil percentage and cytokine production in airway samples. The effect of wood smoke on the respiratory microbiome, however, has not been examined. Objectives The objective of this study was to evaluate whether inhaled wood smoke exposure can alter the respiratory microbiome in humans. Methods Healthy volunteers (N = 54) were subjected to controlled wood smoke exposure (500 μg/m3) for 2 hours, and induced sputum samples were collected and processed for microbiome analysis, immune mediators, and cell differentials at baseline and at 6 hours and 24 hours after exposure. A negative binomial mixed model analysis examined associations between microbiome components and inflammatory cells in sputum. Measurements and Main Results After wood smoke exposure, although sputum microbiome diversity remained unchanged, the microbiome composition was altered, particularly the abundance of several low-abundance bacteria, including Fretibacterium and Selenomonas, indicating that this inhalational exposure can alter the composition of the sputum microbiome. In addition, a significant decrease in macrophage cells was observed at 24 hours without a significant change in neutrophils. We further found small but significant associations between different taxa and macrophages (per milligram of sputum), including a negative association with Fretibacterium. Conclusions Together, these findings demonstrate that inhalational wood smoke exposure can modify several low-abundance bacteria within the respiratory microbiome and that these changes are associated with sputum inflammatory cell alterations, providing insights for future studies to focus on respiratory innate immune host–microbiome crosstalk in the context of environmental exposures.

WAO - ARIA consensus on chronic cough: Executive summary

World Allergy Organization Journal · 2025-02-24 · 8 citations

Acute cough is a highly prevalent symptom in clinical practice. Chronic cough is a complex disease with significant impact on quality of life. The mechanistic pathways of chronic cough in cough-comorbid clinical phenotypes are elusive. Mounting evidence suggests presence of a hypersensitive cough reflex and implication of transient receptor potential channels and P2X receptors in cough neuronal pathways. Previously, the World Allergy Organization (WAO)/Allergic Rhinitis and its Impact on Asthma (ARIA) Joint Committee on Chronic Cough published updated experimental and clinical data on chronic cough, in addition to a multidisciplinary care pathway approach to its management. The goal of this manuscript is to provide clinicians with a succinct summary of chronic cough pathophysiology, clinical phenotypes, and management strategies in both primary and cough specialty care. This executive summary is a primer for clinicians on chronic cough. Increasing awareness on the topic among primary care physicians will improve the outcome of management of patients with chronic cough.

COVID-19, asthma, and biological therapies: What we need to know

El Repositorio Academico Digital de la UANL (Universidad Autónoma de Nuevo León) · 2025-06-26

Treating asthma in the time of COVID

UNC Libraries · 2025-04-29

Acute asthma management during SARS-CoV2-pandemic 2020

UNC Libraries · 2025-06-28

Predictive Modelling for Allergic Rhinitis: A Real-World Study on the Association Between Level of Allergens and Symptoms Occurrence &amp; Severity

Journal of Allergy and Clinical Immunology · 2025-02-01

Low-level ozone has both respiratory and systemic effects in African American adolescents with asthma despite asthma controller therapy

UNC Libraries · 2025-09-05