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

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.

To validate the Vcheck POC quantitative assay for feline NT-proBNP.

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 pmol/L), mid (101-300 pmol/L), and high (> 301 pmol/L) pools short-term (20 repetitions) and long-term (5 repetitions each day for 5 days). Linearity, methods comparison, interference testing, and sample stability were evaluated.

The within-day coefficients of variability (CV) were low pool = 12.6%, mid pool = 10.4%, and high pool = 8.7%. The within-week CV was low pool = 9.9%, mid pool = 14.9%, and high pool = 6.9%. The assay was linear over the analytical range of 53-1488 pmol/L (R² = 0.99, p < 0.0001). Paired samples between the feline Cardiopet NT-proBNP (IDEXX) and Vcheck assays demonstrated a mean difference of 11 pmol/L (2.3%), p = 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 h when stored at 20°C and 4°C, respectively.

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.