Comparison of feline serum amyloid A (SAA) measurements assessed by a point-of-care test analyzer to a validated immunoturbidimetric method

Serum amyloid A (SAA) is one of the most important acute phase proteins in cats and increases rapidly and significantly after an inflammatory stimulus. The objective of this study was to compare measurements of SAA concentration in feline blood specimens using the point-of-care Eurolyser Solo Analyzer (SOLO) with results of a validated immunoturbidimetric test. This prospective study was conducted between March 2014 and June 2015 at a university teaching hospital. Blood specimens were collected from a total of 61 cats including 45 client-owned cats with inflammatory diseases presenting to the emergency and critical care service and 16 client-owned healthy cats. Before SAA measurement, the blood was centrifuged and stored at − 80 °C (− 112 °F). The Eiken assay immunoturbidimetric method (EKITM) which uses latex sensitized anti-human SAA antibodies served as reference SAA test. Serum amyloid A measurements with the EKITM were performed in a reference laboratory. Serum amyloid A measurements with the SOLO were performed in an emergency laboratory. Thirty-six and 18 results were out of the analytical range with the EKITM and the SOLO, respectively. The correlation between the two methods was high (r = 0.87) and there was an intense mostly proportional bias, with results being approximately 2 times lower with the SOLO than the reference test. This study showed that the SOLO reliably and rapidly measures SAA in feline blood specimens; however, a “de novo” reference interval should be determined for proper interpretation of the results.