Serum concentration of pancreatic lipase immunoreactivity (cPLI, measured by Spec cPL®, IDEXX Laboratories) is the most reliable diagnostic tool currently available for the diagnosis of pancreatitis in dogs. A new in-clinic cPLI test (VCheck cPL®, BioNote), claims similar performance to Spec cPL. However, no analytical validation data are available for this assay.
To partially analytically validate the VCheck cPL® assay.
Leftover clinical serum samples were used. VCheck cPL® testing (with a V200 analyzer) was performed according to manufacturer’s instructions. Linearity was evaluated by diluting 2 samples 3 times. Precision was evaluated by determining intra-assay variability for two samples analyzed 12 times on the same day. Reproducibility was evaluated by calculating inter-assay variability for 6 samples measured 10 times on different days. Samples (n=42) throughout the working range were assessed for correlation with Spec cPL.
Mean ± SD observed/expected ratio for dilutions were 47.6%±16.1%. Intra-assay variability for the two samples were 23% and 36%. Inter-assay variability for the 6 samples were 27, 32, 37, 44, 46, and 56%. Furthermore, repeated measurements often changed diagnostic bins for the samples tested. Of 42 clinical samples, 34 (81%) returned lower cPL values by VCheck® compared to Spec cPL (Figure 1).
Figure 1 Correlation of VCheck cPL® with Spec cPL.
The new VCheck cPL® assay lacked linearity, precision, and reproducibility, suggesting that this assay is not reliable for clinical use. It also frequently provided lower results than Spec cPL, suggesting that reference intervals and cut-off values established for Spec cPL cannot be utilized for the VCheck cPL® assay.