Authors: du Preez S, Raidal S L, Doran G S, Prescott M, Hughes K J
Journal: Equine veterinary journal
Summary
# Editorial Summary: Exhaled Breath Condensate as a Tool for Assessing Lower Airway Inflammation in Horses Du Preez and colleagues investigated whether biomarkers collected from exhaled breath condensate (EBC)—a non-invasive sampling method—could reliably detect lower airway inflammation and correlate with traditional diagnostic methods in 47 horses. The researchers collected EBC samples and compared pH, hydrogen peroxide (H₂O₂) and leukotriene B4 (LTB4) concentrations against endoscopic findings and airway cytology from tracheal aspirates and bronchoalveolar lavage fluid, whilst accounting for environmental and procedural variables. Horses with airway inflammation showed higher EBC pH and H₂O₂ levels, both positively correlating with neutrophil percentages in bronchoalveolar lavage fluid (P<0.05); additionally, mast cell percentages were negatively associated with pH, and eosinophils with LTB4. Critically, ambient temperature, humidity and assay methodology significantly influenced results, suggesting these factors require careful standardisation in clinical application. For practitioners, whilst EBC analysis shows promise as a non-invasive monitoring tool for airway disease progression, results must be interpreted cautiously and within consistent environmental and methodological protocols to ensure reliability.
Read the full abstract on PubMed
Practical Takeaways
- •EBC pH and H2O2 levels may be useful noninvasive diagnostic tools for detecting lower airway inflammation when endoscopy or bronchoalveolar lavage is not immediately available
- •Environmental conditions (temperature and humidity) during sample collection can significantly affect biomarker results, so standardization of collection procedures is important for reliable interpretation
- •This technique offers a potentially less invasive alternative to traditional airway sampling methods for monitoring airway disease progression and treatment response in individual horses
Key Findings
- •EBC pH and H2O2 concentrations were significantly higher in horses with lower airway inflammation and positively associated with neutrophil percentage in bronchoalveolar lavage fluid
- •Mast cell percentage in BALF was negatively associated with EBC pH, while eosinophil percentage was positively associated with EBC LTB4
- •Ambient temperature, relative humidity, and assay methodology significantly impacted EBC biomarker measurements
- •EBC analysis shows promise as a noninvasive biomarker for detecting and monitoring airway inflammation in horses