Hemolysis, icterus and lipemia interfere with the determination of two oxidative stress biomarkers in canine serum.

BACKGROUND

Oxidative stress has been proven to play a role in numerous human and canine diseases. Among the biomarkers of oxidative stress, Thiobarbituric Acid Reactive Substances (TBARS) and Total Antioxidant Status (TAS) are two of the most widely used. Preanalytical factors are crucial for obtaining accurate results in these assays. Hemolysis, icterus and lipemia (HIL) are common sources of preanalytical errors in the laboratory; however, limited information is available regarding the considerations for canine specimens. Therefore, the objective of this study was to evaluate the potential interferences of HIL in the determination of TBARS and TAS in canine serum.

METHODS

Solutions of pooled canine serum samples were prepared by adding increasing concentrations of hemolysate, bilirubin and a synthetic lipid emulsion. TBARS and TAS were determined, and biases from the control value caused by the interfering substances were calculated.

RESULTS

Hemolysis, icterus and lipemia induced significant interferences on TBARS and TAS, albeit to varying degrees depending on the specific biomarker and interfering substance. TBARS appeared to be more susceptible to interferences in this study. Slight hemolysis, moderate icterus and slight lipemia caused notable deviations in TBARS values, surpassing the acceptable threshold for interference. TAS assay was also affected by HIL, although to a lesser extent compared to TBARS. Significant biases from TAS control value were observed when icterus was moderate, and when hemolysis and lipemia were more pronounced.

CONCLUSIONS

In light of our results, we conclude that hemolyzed, icteric and lipemic specimens are not suitable for TBARS and TAS determination in canine serum. Our findings hold considerable practical utility, as a simple visual inspection would be sufficient for identifying and excluding such specimens.