Objectives: The protein calprotectin is mainly derived from neutrophils. Increased fecal excretion of calprotectin has been reported in inflammatory bowel disease. The recommended cut-off level in adults (<50 microg/g feces) seems to be applicable in children aged 4 to 17 years. The aim of this study was to evaluate the use of fecal calprotectin to detect colorectal inflammation in children with gastrointestinal symptoms.
Methods: We obtained stool samples on thirty-six children with gastrointestinal symptoms and suspected inflammation of the colon before they underwent colonoscopy. The samples were examined with an improved fecal calprotectin enzyme-linked immunosorbent assay method (Calprest, Eurospital). The results were correlated with the histopathologic findings in the colon.
Results: In children with colorectal inflammation (n = 22) the median fecal calprotectin concentration was 349 microg/g (range, 15.4-1860 microg/g). The most common diagnosis in this group was inflammatory bowel disease. Median fecal calprotectin was 16.5 microg/g (range, 5.0-65 microg/g) in children with no inflammation (n = 14). When <50 microg/g was used as upper reference limit the fecal calprotectin test had a sensitivity of 95%, specificity 93%, positive predictive value 95% and negative predictive value 93% to detect colorectal inflammation.
Conclusions: The improved fecal calprotectin enzyme-linked immunosorbent assay is a simple test with potential use in children. Increased fecal calprotectin strongly predicted the presence of colorectal inflammation in children with gastrointestinal symptoms. Fecal calprotectin can be used to select patients who should undergo diagnostic colonoscopy for investigation of colorectal inflammation, including inflammatory bowel disease.