Adult chicken hens (Gallus gallus) have measurable circulating plasma symmetric dimethylarginine via liquid chromatography–tandem mass spectrometry

OBJECTIVE To investigate whether chickens (Gallus gallus) have measurable plasma symmetric dimethylarginine (SDMA) and to establish the diagnostic utility of the commercially available immunoassay (IA) for measurement of SDMA. ANIMALS 245 chicken hens. METHODS Blood samples were assessed for renal-focused biochemistry analytes. Plasma SDMA was determined using liquid chromatography–tandem mass spectrometry (LC-MS/MS/MS) and a high-throughput IA. A Passing-Bablok regression was used to compare the results of IA to LC-MS/MS/MS and reference intervals SDMA values were calculated. RESULTS The reference interval for plasma SDMA measured by LC-MS/MS/MS is 5.58 to 10.62 μg/dL (range of values, 5 to 15 μg/dL). The concentration of SDMA measured by IA ranged from 1 to 12 μg/dL with a median of 7 μg/dL. Concentrations measured by SDMA-IA demonstrated a low correlation to the SDMA LC-MS/MS reference method. A Passing-Bablok linear regression analysis had a slope of 1.67 (95% CI, 1.35 to 2.14), an intercept of −5.76 (95% CI, −9.90 to −3.35), and a Kendall τ correlation of 0.39. CLINICAL RELEVANCE SDMA circulates in chicken plasma and should be investigated as a potential renal biomarker in future studies. Because SDMA-IA exhibits a low correlation to the reference method (LC-MS/MS) future assessments of SDMA in chickens should utilize LC-MS/MS assays and compare them to the reference interval created here.