Airway Hyperresponsiveness Is Severe and Persistent in an Equine Model of Neutrophilic Asthma.

The research article presents findings on the severity and persistence of airway hyperresponsiveness (AHR) in an equine model of neutrophilic asthma, which is relevant for understanding human asthma and its treatment.

Research Context

• AHR, found in humans suffering from asthma, is marked by heightened sensitivity and an abnormal response to stimuli leading to airway constriction.
• Existing research on AHR mostly focuses on eosinophilic asthma, characterized by T-helper cell type 2–dominated eosinophilic inflammation.
• However, severe asthma often manifests as neutrophilic inflammation, showing intense AHR, reduced atopic response, increased medical care requirements, and resistance to glucocorticoids.
• It is imperative to study AHR in the context of severe/neutrophilic asthma, but its severity often prevents bronchoprovocation—a stimulus to monitor airway reactivity, making it hard to gain insights.
• The few existing nonallergic and neutrophilic mouse models of asthma are limited by anatomical differences, short life spans, variations in airway smooth muscle remodeling, and transient AHR, making them less suitable for this research.

Equine Model of Asthma

• The researchers turn to a pasture-associated severe equine asthma (PA) model, which features naturally occurring severe asthma with neutrophilic airway inflammation.
• This model exhibits complex airway remodeling, including an increase in airway smooth muscle (ASM), making it a promising focus for the investigation of severe/neutrophilic asthma.

Aim and Significance

• The aim of this research is to investigate the degree and persistence of AHR in the PA model.
• The findings of this study could provide valuable insights into the treatment and management of severe asthma in humans, particularly those cases characterized by neutrophilic inflammation.