Diagnostic Accuracy of Immunochromatographic Fecal Calprotectin Assay Evaluated

The diagnostic performance of the recently introduced immunochromatographic assay has been evaluated in comparison to the well-known enzyme-linked immunosorbent assay (ELISA) tests for calprotectin assay to obtain a rapid diagnosis of bowel inflammation in pediatric patients.

Scientists at the Burlo Garofolo Pediatric Institute (Trieste, Italy) obtained fecal samples from 148 pediatric subjects ranging in ages from 2 to 18 years, 70 were males and 78 were females, 44 of which were affected by intestinal diseases. The pediatric subjects included 104 healthy subjects, 29 with and Crohn’s disease (CD), and 15 with Ulcerative colitis (UC). All patients were diagnosed in acute phase. All stool samples were collected in plastic containers and frozen at -20 °C without urine contamination.

The commercial kits used were the PhiCal Calprotectin ELISA based on two-site sandwich technique with two selected monoclonal antibodies, cutoff of 50 mg/kg (Pantec Immunodiagnostic; Milan, Italy); Calprest ELISA based on polyclonal antibodies against fecal calprotectin, cutoff of 100 mg/kg (Eurospital; Trieste, Italy); and Eurospital’s CalFast Immunochromatographic assay with a cutoff of 100 mg/kg combined with a mixture of anti-calprotectin polyclonal and monoclonal antibodies. Once extracted, the sample is diluted and transferred into the diagnostic device. A dedicated reader provides the concentration of calprotectin in the sample in just 15 minutes.

The scientists found that the sensitivity and specificity of CalFast, CalPrest, and PhiCal were 86.4%, 88.6%, and 93.2% and 86.6%, 74%, and 64.4%, respectively. The area under the curve, obtained from receiver operating characteristic analysis, indicated the lack of significant difference among all the kits used. The authors concluded that the immunochromatographic assay demonstrated good diagnostic predictive values, comparable to those of the ELISA methods, and may represent a valid alternative in order to save operators' time. The test, in fact, has a short turnaround time and does not need a specific ELISA instrumentation. The study was published on February 15, 2016, in the Journal of Clinical Laboratory Analysis.

Related Links:
Burlo Garofolo Pediatric Institute
Pantec Immunodiagnostic 
Eurospital