Clinical Performance of a Novel LIAISON Fecal Calprotectin Assay for Differentiation of Inflammatory Bowel Disease From Irritable Bowel Syndrome

The goal of this study was to assess the clinical performance of an investigational in vitro fecal calprotectin immunoassay for differentiating inflammatory bowel disease (IBD) from irritable bowel syndrome (IBS). BACKGROUND: Fecal calprotectin is a stool biomarker that can assist in the detection of intestinal inflammation and is utilized to identify individuals who have a higher chance of having IBD and who require further invasive tests. Current assays exhibit variable performance. MATERIALS AND METHODS: This study was a multicenter, cross-sectional analysis of prospectively collected stool samples from patients 4 years of age or older who presented with gastrointestinal (GI) symptoms and underwent colonoscopy for diagnostic confirmation. IBD was diagnosed based on clinical, endoscopic, and histologic findings. IBS was diagnosed based on Rome III Criteria and negative colonoscopy. Stool samples were extracted and tested on the DiaSorin LIAISON XL using the LIAISON Calprotectin Assay. RESULTS: A total of 240 patients (67% female) were included in the study. In total, 102 patients had IBD (54% ulcerative colitis), 67 had IBS, and 71 had other GI disorders. Median fecal calprotectin levels were significantly higher in patients with IBD [522 μg/g; 95% confidence interval (CI): 354-970 μg/g] compared with IBS (34.5 μg/g; 95% CI: 19.7-44.2 μg/g, P<0.001) and other GI disorders (28.6 μg/g; 95% CI: 18.7-40.3 μg/g, P<0.001). Receiver operating characteristic curve analysis indicated a fecal calprotectin cutoff of 94 μg/g for distinguishing IBD from other GI disorders with an area under the curve of 0.964 (sensitivity=92.2%, specificity=88.4%). CONCLUSION: The automated LIAISON Calprotectin assay brings efficient calprotectin testing to the laboratory with a time to the first result of 35 minutes and is a sensitive marker for distinguishing IBD from IBS with a cutoff of ∼100 μg/g.