Background: Fecal calprotectin (FC) is a promising biomarker for diagnosis of inflammatory bowel disease (IBD). However, the utility of FC for assessment of IBD activity has yet to be clearly demonstrated. The aim of our study was to evaluate the diagnostic accuracy of FC for differentiating between patients with active IBD and those in remission.
Methods: We systematically searched the databases Medline, Web of Science, Cochrane Library, and EMBASE for eligible studies from December 2013 or earlier that evaluated activity in ulcerative colitis (UC) and Crohn's disease (CD). A hierarchical summary receiver operating characteristic model was performed to calculate the area under the curve to evaluate the overall diagnostic accuracy. The sensitivities and specificities of each commonly applied cutoff value were pooled using a random effects model.
Results: We included 13 studies (744 patients with UC and 727 with CD) in the final analysis. The area under the curve values were 0.89 (95% confidence interval, 0.86–0.92), 0.93 (0.89–0.97), and 0.88 (0.83–0.93) in the IBD, UC, and CD groups, respectively. For the IBD group at a cutoff value of 50 μg/g, the pooled sensitivity was 0.92 (0.90–0.94) and specificity 0.60 (0.52–0.67). For a cutoff value at 100 μg/g, the pooled sensitivity was 0.84 (0.80–0.88) and specificity was 0.66 (0.59–0.73). For a cutoff value at 250 μg/g, the pooled sensitivity was 0.80 (0.76–0.84) and specificity was 0.82 (0.77–0.86).
Conclusions: The FC test is a reliable marker for assessing IBD disease activity and may have greater ability to evaluate disease activity in UC than CD.