Evaluation of an automated immunoturbidimetric assay for detecting canine C-reactive protein

C-reactive protein (CRP) is a major acute-phase protein, and it is produced by the liver in response to a pro-inflammatory stimulus. Given that human and canine CRP have a similar molecular structure, the assays used for human CRP detection have been used to measure CRP concentrations in dogs. We evaluated the use of a human CRP assay (Biotecnica CRP assay) and validated its application in dogs. We analyzed 91 canine serum samples with a fully automated analyzer. Our validation was based on the evaluation of imprecision, limits of linearity, limits of quantification, and an evaluation of interferences. The new assay was also compared with the Randox CRP assay, a validated assay for the measurement of CRP. Intra- and inter-assay repeatability were <8% and <11%, respectively. The tested assay proportionally measured canine CRP in an analytical range up to 60 mg/L; however, hemoglobin, triglycerides, and bilirubin interfered with the determination. Good agreement, with the presence of proportional systematic bias, was observed between Biotecnica and Randox assays. The Biotecnica CRP assay provides reliable measurement of CRP in canine serum, provided that samples are free of interferents.