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Preanalytical variables affecting the measurement of serum paraoxonase-1 activity in horses

Rossi, G.ORCID: 0000-0003-4879-9504, Richardson, A., Jamaludin, H. and Secombe, C. (2020) Preanalytical variables affecting the measurement of serum paraoxonase-1 activity in horses. Journal of Veterinary Diagnostic Investigation, 33 (1). pp. 59-66.

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Paraoxonase-1 (PON-1) activity is a new inflammatory and oxidative marker. Technical effects and biological factors could affect the accuracy of PON-1 activity measurement. We investigated the effects of storage at different temperatures, repeated freeze–thaw cycles, interferences from hemolytic, lipemic, and icteric samples, and seasonal effects on PON-1 activity in horses. We evaluated 2 substrates with an automated spectrophotometer. Ten equine serum samples were stored under different conditions. Although storage at room (21°C) or refrigeration (4°C) temperature induced a statistically significant decrease (p < 0.05) in PON-1 activity, this is not diagnostically relevant. PON-1 activity in frozen samples (−20°C) was stable for short-term storage; diagnostically significant (p < 0.01) fluctuations were observed after 1 mo. Four repeated freeze–thaw cycles were assessed, and all cycles affected PON-1 activity (p < 0.01); however, this was diagnostically significant only after the 4th cycle. Hemolysis induced an overestimation of PON-1 activity; lipemia and hyperbilirubinemia did not change PON-1 activity. Thirty-four horses were sampled monthly for 1 y, and PON-1 activity was higher in autumn (p < 0.05) and winter (p < 0.05) than in spring and summer.

Item Type: Journal Article
Murdoch Affiliation(s): Veterinary Medicine
Publisher: SAGE Publications
Copyright: © 2020 by American Association of Veterinary Laboratory Diagnosticians
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