Comparison of lipopolysaccharides and soluble CD14 measurement between clinically endotoxaemic and nonendotoxaemic horses.
Authors: Fogle J, Jacob M, Blikslager A, Edwards A, Wagner B, Dean K, Fogle C
Journal: Equine veterinary journal
Summary
# Editorial Summary: Soluble CD14 as an Endotoxaemia Biomarker in Horses Early detection of endotoxaemia remains clinically challenging in equine practice, prompting investigation into biomarkers that might improve diagnostic accuracy beyond traditional clinical parameters. Fogle and colleagues conducted a prospective observational study comparing plasma lipopolysaccharide (LPS) and soluble CD14 (sCD14) levels in 20 healthy horses and 35 emergency cases, stratifying animals according to established clinical endotoxaemia criteria (heart rate >70 bpm, packed cell volume >45%, and/or predisposing lesions). Whilst sCD14 was significantly elevated in clinically endotoxaemic horses (median 1102 ng/ml versus 692 ng/ml in non-endotoxaemic animals, P=0.03), LPS concentrations showed no significant difference between groups (7.2 versus 5.4 EU/ml, P=0.2), and critically, sCD14 and LPS did not correlate with one another. When evaluated via receiver operating characteristic analysis, both biomarkers performed poorly as individual predictors of clinical endotoxaemia (area under curve <0.7). These findings suggest that neither sCD14 nor LPS alone offers sufficient diagnostic discrimination for clinical endotoxaemia, despite the biological rationale supporting sCD14's role in the inflammatory cascade—highlighting the complexity of endotoxaemic disease and the need for multi-parameter assessment strategies in clinical decision-making.
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Practical Takeaways
- •Measuring sCD14 alone is not yet reliable enough to diagnose endotoxaemia in clinical practice; continue relying on clinical signs (heart rate, PCV, lesion assessment)
- •LPS measurement by LAL assay appears unsuitable for identifying endotoxaemic horses in clinical settings
- •Better biomarkers are still needed for early detection of endotoxaemia in emergency horses
Key Findings
- •Soluble CD14 was significantly higher in clinically endotoxaemic horses (median 1102 ng/ml) compared to nonendotoxaemic horses (median 692 ng/ml, P = 0.03)
- •LPS concentrations showed no significant difference between endotoxaemic and nonendotoxaemic groups (P = 0.2)
- •Both sCD14 and LPS were poor predictors of clinical endotoxaemia with area under ROC curve <0.7
- •No correlation was found between sCD14 and LPS values in paired serum samples