Validation of the newly FDA-approved Buhlmann fCal Turbo assay for measurement of fecal calprotectin in a pediatric population

Abstract

Objectives Inflammatory bowel disease (IBD) is an increasingly prevalent disorder marked by chronic intestinal inflammation. Fecal calprotectin has emerged as a useful biomarker for differential diagnostics and monitoring IBD activity. We validated the newly FDA-approved fCal Turbo fecal calprotectin assay in our pediatric hospital. Design and methods The performance of the fCal Turbo assay was assessed on the Vitros 5600 analyzer (Ortho Clinical Diagnostics, USA), including limit of quantitation, linearity, precision, and interference studies. Method comparison was performed with 20 fecal samples with the Buhlmann fCal ELISA, and reference range verification was performed with 33 fecal samples. Results The fCal Turbo assay on the Vitros 5600 was linear between 33.1 and 14,182.5 ​μg/g, with dilution studies extending the range to 33.1–22,000 ​μg/g, Reproducibility of the assay met acceptability criteria, with intra-assay CV of 0.3–3.2% and inter-assay CV of 5.2–8.9%. Interference studies identified acceptable thresholds for protein, bilirubin, and lipids. We verified a reference range of 33.1–60 ​μg/g in our patient population. Deming regression identified acceptable correlation with minor positive bias (2.7%) between the fCal Turbo and fCal ELISA methods. Conclusions The fCal Turbo assay performs well on the Vitros 5600 analyzer in our patient population, with the assay being easy to use in our routine chemistry workflow. We anticipate that the fCal Turbo assay will be useful as a rapid screening method for differential diagnostics and disease monitoring of IBD in our patient population.

Verification of the Bühlmann fCAL turbo faecal calprotectin assay on the Binding Site Optilite benchtop analyser

“…The Lower Limit of Quantitation (LLoQ) was assessed by diluting (non-serial) an extracted patient sample (calprotectin concentration 200 μg/g) with Calex Cap stool extraction buffer to provide nominal calprotectin concentrations of 10, 25, 50, and 100 μg/g, and analysed in triplicate. Acceptance criteria of <10% inaccuracy between the measured and nominal concentrations, and <10% imprecision ([standard deviation x 100]/mean) [ 4 ].…”

“…Linearity was assessed by diluting (non-serial) an extracted patient sample (calprotectin concentration 10,000 μg/g) with Calex Cap stool extraction buffer to provide nominal calprotectin concentrations of 10, 25, 125, 250, 500, 1000, 5,000 μg/g. Differences were calculated between the nominal and measured concentrations, with acceptance criteria being within 10% (mean of triplicates) [ 4 ].…”

“…Whereas IBS is an idiopathic functional disorder, IBD is organic in nature involving chronic inflammation of all or part of the colon and small intestine. Differentiation of IBS from IBD is important as they have different treatment strategies, and IBD has an increased risk of colorectal cancer and surgical resection compared to IBS [ [3] , [4] ]. Widely used markers for IBD include; C-reactive protein, erythrocyte sedimentation rate, imaging studies, endoscopy, and biopsy [ 3 , 5 ].…”

Changes in Calprotectin (S100A8-A9) and Aldolase in the Saliva of Horses with Equine Gastric Ulcer Syndrome

“…Currently, there are commercially available assays that allow the measurement of CALP [ 17 ] and aldolase [ 18 ], having the advantages associated with automation, such as higher precision and faster sample processing. The hypotheses of this work are that CALP and aldolase can be measured in the saliva of horses with commercially available assays and, furthermore, that these assays can detect the changes in these analytes that occur in horses with EGUS.…”

Chicken antibodies are highly suitable for particle enhanced turbidimetric assays

“…Fecal calprotectin is today widely used for the detection of inflammatory bowel diseases (17)(18)(19). One of the most frequently used tests is fCal Turbo which is an IgY based PETIA (20)(21)(22)(23). The assay has also been used for the detection of fecal calprotectin in dogs and cats (24).…”