Endobronchial Ultrasound Reliably Quantifies Airway Smooth Muscle Remodeling in an Equine Asthma Model.
Authors: Bullone Michela, Beauchamp Guy, Godbout Mireille, Martin James G, Lavoie Jean-Pierre
Journal: PloS one
Summary
# Editorial Summary: Endobronchial Ultrasound for Assessing Airway Remodelling in Equine Asthma Chronic airway remodelling—particularly thickening of the airway smooth muscle layer—is a hallmark of equine asthma (heaves), yet non-invasive methods to quantify this change have been limited. Bullone and colleagues examined whether endobronchial ultrasound (EBUS) using a high-frequency 30 MHz probe could reliably detect and measure smooth muscle remodelling by comparing ultrasound measurements against histological samples from 109 bronchi collected from 13 horses, then validating the technique in live horses with and without heaves. The key finding was that the L2 layer thickness (representing subepithelial tissues) normalised to airway perimeter squared (L2 area/Pi²)—a measurement independent of airway size—significantly increased in asthmatic horses compared to controls both in ex vivo and in vivo studies, with histology confirming these findings. Importantly, this non-invasive ultrasound parameter reliably predicted the extent of smooth muscle thickening without the need for bronchoscopic biopsy, offering equine practitioners a practical method to assess disease severity and potentially monitor therapeutic response in clinical cases of asthma.
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Practical Takeaways
- •EBUS with a 30 MHz probe offers a non-invasive diagnostic method to reliably detect airway smooth muscle remodeling in equine asthma, potentially enabling earlier detection and monitoring of disease progression
- •The L2 area/Pi² measurement is the most reliable EBUS parameter for assessing ASM remodeling regardless of airway size, which improves clinical applicability across different horses
- •This imaging technique could support clinical decision-making for asthmatic horses by providing objective measures of central airway pathology without requiring lung biopsy
Key Findings
- •L2 area measured by EBUS was significantly associated with histological ASM area (p<0.0001) without airway-size bias
- •L2 area/Pi² was the EBUS parameter most reliable for detecting ASM remodeling across different airway sizes
- •L2 area/Pi² was significantly increased in asthmatic horse airways compared to controls both ex vivo and in vivo (p<0.05)
- •L2 layer composition was 75% ASM and 25% extracellular matrix in both asthmatic and control horses