Analytical Validation of a Novel Point-Of-Care Quantitative Immunoassay for Feline N-Terminal Pro-Brain Natriuretic Peptide.

Abstract

BACKGROUND: Point-of-care testing (POC) is widely utilized for rapid results for many different analytes. A new feline-specific N-terminal pro-brain natriuretic peptide (NT-proBNP) quantitative assay (Vcheck V200, Bionote Inc) is currently available but has not undergone independent validation. OBJECTIVE: To validate the Vcheck POC quantitative assay for feline NT-proBNP. METHODS: Validation was performed in accordance with the American Society for Veterinary Clinical Pathology guidelines utilizing serum samples from 62 cats. Precision was determined for low (50-100&#x2009;pmol/L), mid (101-300&#x2009;pmol/L), and high (>&#x2009;301&#x2009;pmol/L) pools short-term (20 repetitions) and long-term (5 repetitions each day for 5&#x2009;days). Linearity, methods comparison, interference testing, and sample stability were evaluated. RESULTS: The within-day coefficients of variability (CV) were low pool&#x2009;=&#x2009;12.6%, mid pool&#x2009;=&#x2009;10.4%, and high pool&#x2009;=&#x2009;8.7%. The within-week CV was low pool&#x2009;=&#x2009;9.9%, mid pool&#x2009;=&#x2009;14.9%, and high pool&#x2009;=&#x2009;6.9%. The assay was linear over the analytical range of 53-1488&#x2009;pmol/L (R&#x2009;=&#x2009;0.99, p&#x2009;<&#x2009;0.0001). Paired samples between the feline Cardiopet NT-proBNP (IDEXX) and Vcheck assays demonstrated a mean difference of 11&#x2009;pmol/L (2.3%), p&#x2009;=&#x2009;0.38, between assays with minimal constant or proportional bias. Hemolysis and lipemia did not affect assay performance, while all icteric samples were invalid. Significantly lower values were identified in samples after 2 and 4&#x2009;h when stored at 20&#xb0;C and 4&#xb0;C, respectively. CONCLUSIONS: The Vcheck V200 has acceptable precision, accuracy, and compares favorably with commercially available assays and is a viable POC quantitative assay for feline NT-proBNP.