Analytical Validation of Two Point-of-Care Assays for Serum Amyloid A Measurements in Cats

SIMPLE SUMMARY: Serum Amyloid A (SAA) is one of the most sensitive tests to detect inflammation in cats. In this study, two point-of-care assays for serum amyloid A measurements in cats were analytically evaluated. The two assays were accurate and showed significant correlations with an automated assay previously validated in cats, although one of them did not show an optimal precision. Both assays were able to detect higher SAA concentrations in cats with inflammatory diseases than in cats without inflammatory diseases. In conclusion, this manuscript provides data about the possible application of two point-of-care assays for the measurement of SAA concentration in cats. ABSTRACT: Serum Amyloid A (SAA) is one of the most sensitive tests to detect inflammation in cats. In this study, two point-of-care assays for SAA measurements in cats (FUJI DRI-CHEM IMMUNO AU CARTRIDGE vf-SAA (method A), and CUBE-VET analyser (Method B), were analytically evaluated. Regarding the imprecision precision only the method A showed intra-assay and inter-assay CV < 10% at all concentrations. Both assays showed linearity with r close to 1 and the recovery were in the range of 81–112% for assay A and 85–125% for assay B and the limit of detection were 3.75 and 0.5 mg/dL for method A and B, respectively. A previously validated method for SAA quantification SAATIA; LZ-SAA (method C) was used as gold-standard to evaluate the accuracy of the assays. Significant correlations (p < 0.0001) were found between assays A and C (r = 0.94) and B and C (r = 0.91). In addition, an overlap performance test was made using serum samples from cats with non-inflammatory and cats with inflammatory. Both assays showed higher median SAA concentrations in cats with inflammatory diseases than in cats without inflammatory diseases (p < 0.0001). In conclusion, this manuscript provides data about the possible application of two point-of-care assays for the measurement of SAA concentration in cats.