Accuracy of dog kidney blood tests by 2 analyzers and labs

Abstract

OBJECTIVE: To determine the concordance of 2 point-of-care (POC) analyzers and 2 reference laboratories (RLs) for serum symmetric dimethylarginine (SDMA) analysis in dogs. We hypothesized that the Vcheck V200 POC, IDEXX Catalyst POC, and Eurolyser assays would have an acceptable agreement with the IDEXX RL SDMA results. METHODS: This was a prospective study conducted between August 2019 and March 2023. Blood collected from dogs treated at a referral hospital underwent SDMA analysis by 2 POC analyzers (IDEXX Catalyst and Vcheck V200) and 2 RL methods (Eurolyser and IDEXX). Dogs with suspected or known renal disease were preferentially included later in the study. RESULTS: 75 samples were included in the final analysis. There was a difference in SDMA results obtained from Eurolyser assays but not IDEXX Catalyst POC and Vcheck V200 POC assay compared to IDEXX RL results. When applied to the International Renal Interest Society chronic kidney disease staging classification, there was almost perfect agreement between Eurolyser and Vcheck V200 POC SDMA compared to IDEXX RL SDMA. CONCLUSIONS: While there was a strong to excellent correlation between assays, the results obtained via each assay demonstrated that there may be significant bias and analytical variation affecting the results. However, this may have minimal effect when applied clinically. CLINICAL RELEVANCE: Analyzer and method-specific reference intervals should be established for SDMA analysis. There is preliminary evidence to support the use of Eurolyser and Vcheck V200 POC SDMA assays in the staging of canine chronic kidney disease.