Turbidimetric Determination of Fecal Calprotectin Using Two Table Top Chemistry Analyzers: Mindray BS-200E and Cobas® c111.

Abstract

Fecal calprotectin assays are widely used in diagnosis and monitoring of inflammatory bowel disease (IBD) in patients with suspected IBD. The most frequently used technique is ELISA and microtiter plates. Turbidimetric assays for analysis of fecal calprotectin can significantly reduce turnaround time. Many laboratories may be reluctant to run fecal samples on their large chemistry analyzers. The aim of this study was to evaluate fecal calprotectin particle enhanced turbidimetric immunoassay (PETIA) on smaller chemistry analyzers that could be dedicated for fecal samples. The BÜHLMANN fCAL® turbo assay was validated on two table top chemistry analyzers, Mindray BS-200E and cobas® c111. The assay was linear in the range between 20 and 1,900 µg/g with a limit of quantification around 20 µg/g on both instruments. The total coefficient of variation was < 7% in the range between 50 and 1,300 µg/g on both instruments. No antigen excess hook effect was observed up to 18,000 µg/g on the Mindray BS-200E and up to 20,000 µg/g on cobas® c111. The BÜHLMANN fCAL® turbo assay showed a high correlation with the BÜHLMANN fCAL® ELISA. Running the BÜHLMANN fCAL® turbo on Mindray BS-200E or cobas® c111 chemistry analyzers can provide rapid test results without exposing large routine chemistry analyzers to stool samples.