Neutrophil gelatinase-associated lipocalin as a potential biomarker for equine asthma.
Authors: Hansen Sanni, Otten Nina D, Spang-Hanssen Liv, Bendorff Christine, Jacobsen Stine
Journal: Equine veterinary journal
Summary
# Editorial Summary: NGAL as a Biomarker for Equine Asthma Neutrophil gelatinase-associated lipocalin (NGAL) has proven useful in human respiratory medicine for identifying asthma and classifying disease severity, yet its application in equine practice remained unexplored until this 2024 investigation. Hansen and colleagues analysed bronchoalveolar lavage (BAL) fluid and serum samples from 227 horses—73 controls, 98 with mild-to-moderate asthma (MEA), and 56 with severe asthma (SEA)—measuring NGAL concentrations and correlating these with tracheal mucus scores and BAL cytology findings. BAL NGAL emerged as a robust discriminator: control horses showed median concentrations of 13.3 μg/L, MEA horses 18.5 μg/L, and SEA horses 54.1 μg/L (all comparisons p<0.001), with higher BAL NGAL also associated with increased tracheal mucus scores. Serum NGAL, conversely, showed no meaningful differences between groups, limiting its diagnostic utility. For practitioners, these findings suggest BAL NGAL warrants investigation as an objective severity grading tool during endoscopic assessment, potentially refining case management and prognosis discussions—though further research is needed before adopting NGAL as routine clinical practice.
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Practical Takeaways
- •BAL NGAL appears promising as a potential diagnostic biomarker to differentiate equine asthma from healthy horses and to assess disease severity, though further validation is needed before clinical implementation
- •BAL sampling (rather than serum sampling) would be required to utilize NGAL as a biomarker, as serum NGAL did not distinguish between groups
- •This research supports the need for larger prospective studies to establish reference ranges and clinical thresholds for NGAL in equine respiratory diagnostics
Key Findings
- •BAL NGAL concentrations were significantly higher in horses with equine asthma (median 25.6 μg/L) compared to control horses (13.3 μg/L, p<0.001)
- •BAL NGAL concentrations progressively increased with disease severity: control (13.3 μg/L) < mild-moderate asthma (18.5 μg/L) < severe asthma (54.1 μg/L)
- •BAL NGAL concentration correlated with tracheal mucus score, with higher NGAL in horses with TMS >2 (21.1 μg/L) versus ≤2 (15.6 μg/L, p=0.004)
- •Serum NGAL concentrations showed no significant differences between any groups, limiting its clinical utility