Monoclonal antibody testing for fecal calprotectin is superior to polyclonal testing of fecal calprotectin and lactoferrin to identify organic intestinal disease in patients with abdominal discomfort

Background and aimsFecal calprotectin and lactoferrin are sensitive markers of mucosal inflammation. We compared three different assays in their ability to identify patients with organic intestinal disease.MethodsIn a post-hoc analysis of a prospective study, we examined 405 unselected patients with abdominal complaints referred for endoscopy to the University Hospital Basel, Switzerland. Calprotectin (EK-CAL, Bühlmann Laboratories, Switzerland; PhiCal, Calpro AS, Norway) and lactoferrin (IBD-Scan, Techlab, USA) were measured using enzyme-linked immunosorbent assays. The presence of a clinically significant endoscopic finding was the primary endpoint of the study. Final diagnoses were adjudicated blinded to calprotectin values.ResultsThe prevalence of organic intestinal disease was 35.3%. Receiver operating characteristics analysis calculated an area under the curve (AUC) for EK-CAL of 0.918, which was significantly better than for PhiCal (AUC 0.842, P < 0.001) and IBD-Scan (AUC 0.830, P = 0.003) to identify patients with organic intestinal disease. Overall test accuracy was 88.1% for EK-CAL, 83.7% for PhiCal, and 81.3% for IBD-Scan. Optimal cut-off value calculated for PhiCal and IBD-Scan were lower than recommended by the manufacturer.ConclusionsMonoclonal testing of calprotectin is superior to both polyclonal calprotectin testing and fecal lactoferrin in identifying symptomatic patients with organic intestinal disease.

► Fecal calprotectin and lactoferrin reliably identify organic intestinal disease.
► The diagnostic performance of monoclonal calprotectin testing is superior.
► Polycloncal calprotectin and lactoferrin testing have similar diagnostic accuracy.