Detection of hypoglycin A and MCPA-carnitine in equine serum and muscle tissue: Optimisation and validation of a LC-MS-based method without derivatisation.
Authors: González-Medina Sonia, Hyde Carolyne, Lovera Imogen, Piercy Richard J
Journal: Equine veterinary journal
Summary
# Diagnostic Detection of Hypoglycin A and MCPA in Equine Atypical Myopathy Atypical myopathy represents a serious pasture-associated condition in horses, typically triggered by ingestion of sycamore seeds and other Acer species, with diagnosis currently relying on indirect markers such as acyl-carnitine profiles and urine organic acids rather than direct confirmation of the toxic compounds responsible. González-Medina and colleagues refined an LC-MS analytical method to detect both hypoglycin A (the plant toxin) and MCPA-carnitine (its pathogenic metabolite) in equine serum and muscle tissue, eliminating the labour-intensive derivatisation step that previously characterised these assays. The validated protocol successfully identified both toxins across their target tissues without sacrificing sensitivity or specificity, meaningfully reducing turnaround time and laboratory costs whilst maintaining the precision needed for clinical diagnosis. For practitioners managing suspect atypical myopathy cases, this advancement enables faster confirmation of poisoning versus other causes of rhabdomyolysis, potentially supporting more rapid clinical decisions during treatment of these high-mortality presentations. Wider adoption of this streamlined diagnostic approach could facilitate earlier identification of contaminated pastures and improve epidemiological understanding of AM outbreaks across different grazing systems.
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Practical Takeaways
- •Faster and more cost-effective diagnostic confirmation of atypical myopathy is now available, enabling quicker clinical decision-making in suspected cases
- •Practitioners can rely on direct HGA/MCPA measurement as a specific diagnostic test for AM, rather than non-specific acyl-carnitine or organic acid profiling alone
- •Grazing management should prioritise exclusion of Acer trees from pastures, particularly during periods when AM cases cluster
Key Findings
- •LC-MS method developed for detecting hypoglycin A and MCPA-carnitine in equine serum and muscle tissue without requiring derivatisation
- •The optimised method reduces testing time and costs compared to previously reported derivatising techniques
- •Detection of HGA and MCPA metabolites confirms diagnosis of atypical myopathy linked to Acer tree ingestion