P119 Diagnostic performance of different calprotectin assays
A. A. Wulandari1, J. Schulz1, F. Hartmann2,3, A. Dignass2, 3, J. Stein*1,3
1DGD Clinics Sachsenhausen, Frankfurt/Main, Germany, 2Agaplesion Markus Krankenhaus, Frankfurt/Main, Germany, 3Interdisciplinary Crohn Colitis Centre Rhein-Main, Frankfurt/Main, Germany
Calprotectin is a dimer of the calcium- and zinc-binding proteins S100A8 and S100A9. It is released by activated neutrophils in the bowel in the presence of inflammation. Calprotectin is considered the gold standard for differentiating organic inflammatory bowel disease (IBD) from functional disorders such as irritable bowel syndrome (IBS). This study aimed at comparing the diagnostic performance of 5 different calprotectin assays currently available on the market.
In the study, 98 patients with IBD (UC n = 45 and MC n = 53) and a control group of 83 patients with functional disorders were included. Calprotectin was determined using 5 different calprotectin assays (ELiA2 Calprotectin, Thermofischer; PhiCal, Calpro AS; Immundiagnostik; EK-Cal, Bühlmann; and Calpro, Eurospital).
Three assays (Thermofischer, Immundiagnostik, and Eurospital) showed comparable performance with 96%–99% sensitivity and 71%–78% specificity, whereas 2 assays (Calpro AS and Bühlmann) had comparable sensitivity (96%–97%) but a lower specificity of 62%–63%.
All 5 assays are very sensitive for detection of mucosal inflammation, but specificity varies considerably. Further efforts are needed to standardise calprotectin assays. It is highly advisable to use the same assay for diagnosis and disease activity monitoring.