Quantification of hypoglycin A in serum using aTRAQ® assay

Background: Hypoglycin A has been recently identified has the causal agent of atypical myopathy (AM) in horses. Its identification and quantification in equine's biological fluids is thus a major concern to confirm maple poisoning and to provide insight into the poorly understood mechanism of hypoglycin A intoxication. Methods: Quantification of hypoglycin A has been achieved with the aTRAQ kit for amino acid analysis of physiological fluids (AB Sciex). Acquisition method on mass spectrometer has been updated to record the hypoglycin A specific MRM transition. Results: Outlined accuracy profiles demonstrated very reliable data. A good linearity was observed from 0.09 to 50. μmol/L and precision was very good with coefficient of variation below 8%. Fifty-five samples collected from 25 confirmed AM horses revealed significant hypoglycin A concentrations, while toxin was not found in serum of 8 control animals. Conclusions: The described aTRAQ variant method has been analytically and clinically validated. The reliability of our approach is thus demonstrated into the workup of atypical myopathy.