C. De Cunto2, A.I. Leuci1, G. Grammatico1, C. Roveta1, G. Inzaina1, F.E.O. Ferrara1, M. Pirovano2, F. Magro2
1 CDI Centro Diagnostico Italiano SpA, Via Saint Bon, 20, 20147 Milano, Italy
2 Sentinel CH. SpA, Via Robert Koch, 2, 20152 Milano, Italy
Calprotectin is the main protein expressed by neutrophil cells and it’s considered one of the most interesting biomarkers of inflammation. Due to its district specificity, the measurement of calprotectin in stools is widely used to detect inflammatory process in the intestinal tract and it’s mainly used to differentiate inflammatory bowel diseases (IBD) from non-inflammatory disorders like irritable bowel syndrome (IBS). The aim of the study was to evaluate the analytical performances of Sentinel new generation CALiaGold® and to complete the Design Validation of the product in an external clinical lab and under routine conditions on fully automated SENTiFIT® 270 Analyzer.
It comprises of a barcoded Sampling Tube with universal shape and dimensions, Latex enhanced Immunoturbidimetric reagent, single high-level Calibrator with instrumental automatic dilution and Quality Controls. All reagents are liquid and ready to use.
Evaluation of the analytical performances of the second generation CALiaGold® has been based on respective CLSI evaluation guidelines by using 3 different production lots. Design Validation was performed at CDI Centro Diagnostico Italiano under preapproved and formally released protocol. Statistical analysis was performed with Analyse-it.
Lowest limit of the Analytical Measuring Range (AMR) was based on Limit of Quantitation.
Acceptance Criteria were defined as the analyte concentration with a ≤20% total imprecision CV%. LOQ
study format was: 8 dilutions x 10 replicates x 3 days. Worst cases are reported in the plot.
Lowest Limit of the AMR was 18.5 μg/g.
Accuracy of the second generation CALiaGold® was evaluated as per CLSI guidelines by Method Comparison against the first generation CALiaGold®.
The study has been done on SENTiFIT® 270 Analyzer with 3 reagent lots. Study format was based on at least 100 fecal samples and independent sampling between the two methods.
External design validation
Second generation CALiaGold® was compared to the previous CALiaGold® version in an external clinical laboratory on 306 patients’ samples from the routine.
BiasPlot of the samples around the clinically relevant range under 650 μg/g delivered a not significant mean Bias of -5,64 μg/g.
The study proved that the second generation CALiaGold® met specifications in terms of accuracy ±10% relative Bias or ±5.0 μg/g as absolute bias and total imprecision < 8.0% CV%.
External Design Validation proved substantial equivalence in comparison to the first CALiaGold® generation under routine conditions. Automatic dilution of the Calibrator on SENTiFIT® 270 and SENTiFOB® analyzers completes Sentinel offer of a fully integrated solution to the clinical labs for the measurement of fecal Calprotectin.