Panpicha Sattasathuchana1,2, Nora Berghoff3, Niels Grützner3, Naris Thengchaisri4, Venkat R Rangachari3, Jan S Suchodolski3, Jörg M Steiner3. 1. Gastrointestinal Laboratory, Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA. psatta@cvm.tamu.edu. 2. Department of Companion Animal Clinical Sciences, Faculty of Veterinary Medicine, Kasetsart University, Bangkok, Thailand. psatta@cvm.tamu.edu. 3. Gastrointestinal Laboratory, Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA. 4. Department of Companion Animal Clinical Sciences, Faculty of Veterinary Medicine, Kasetsart University, Bangkok, Thailand.
Abstract
BACKGROUND: The activation of eosinophils causes the release of eosinophil peroxidase and subsequent production of 3-bromotyrosine (3-BrY), a stable byproduct. In people, 3-BrY is used as a biomarker for eosinophil activation. The method for measuring 3-BrY concentrations in biologic samples from dogs has not previously been described. OBJECTIVES: The objective of this study was to develop and analytically validate an electron ionization gas chromatography/mass spectrometry (EI-GC/MS) method for the measurement of 3-BrY in canine serum samples. METHODS: Pooled canine serum samples were utilized to validate the assay. Serum samples from healthy control dogs (n = 41) were used to evaluate 3-BrY concentrations and establish a reference interval. RESULTS: The analytic validation revealed that the limit of blank and limit of detection were 0.33 and 0.63 μmol/L, respectively. The coefficients of variation for precision and reproducibility for 3-BrY were < 13.9% and < 11.0%, respectively. The means ± SD of observed-to-expected ratios for linearity and accuracy were 109.6 ± 17.2% and 98.7 ± 11.3%, respectively. The reference interval was determined as ≤ 1.12 μmol/L (median [range]: ≤ 0.63 μmol/L [≤ 0.63-1.13]). CONCLUSIONS: The EI-GC/MS assay described here for the measurement of 3-BrY in canine serum samples was precise, reproducible, linear, and accurate. Further studies are underway to determine the diagnostic utilities in canine patients with eosinophilic diseases.
BACKGROUND: The activation of eosinophils causes the release of eosinophil peroxidase and subsequent production of 3-bromotyrosine (3-BrY), a stable byproduct. In people, 3-BrY is used as a biomarker for eosinophil activation. The method for measuring 3-BrY concentrations in biologic samples from dogs has not previously been described. OBJECTIVES: The objective of this study was to develop and analytically validate an electron ionization gas chromatography/mass spectrometry (EI-GC/MS) method for the measurement of 3-BrY in canine serum samples. METHODS: Pooled canine serum samples were utilized to validate the assay. Serum samples from healthy control dogs (n = 41) were used to evaluate 3-BrY concentrations and establish a reference interval. RESULTS: The analytic validation revealed that the limit of blank and limit of detection were 0.33 and 0.63 μmol/L, respectively. The coefficients of variation for precision and reproducibility for 3-BrY were < 13.9% and < 11.0%, respectively. The means ± SD of observed-to-expected ratios for linearity and accuracy were 109.6 ± 17.2% and 98.7 ± 11.3%, respectively. The reference interval was determined as ≤ 1.12 μmol/L (median [range]: ≤ 0.63 μmol/L [≤ 0.63-1.13]). CONCLUSIONS: The EI-GC/MS assay described here for the measurement of 3-BrY in canine serum samples was precise, reproducible, linear, and accurate. Further studies are underway to determine the diagnostic utilities in caninepatients with eosinophilic diseases.
Authors: Panpicha Sattasathuchana; Naris Thengchaisri; Jan S Suchodolski; Jonathan A Lidbury; Jörg M Steiner Journal: J Vet Diagn Invest Date: 2019-02-15 Impact factor: 1.279
Authors: Romy M Heilmann; Panagiotis G Xenoulis; Katrin Müller; Eva M Stavroulaki; Jan S Suchodolski; Jörg M Steiner Journal: J Vet Intern Med Date: 2019-02-20 Impact factor: 3.333