Fecal calprotectin: towards a standardized use for inflammatory bowel disease management in routine practice.

Editorial Fecal calprotectin: towards a standardized use for inflammatory bowel disease management in routine practice. The measurement of fecal calprotectin has now been studied in clinical research for more than 10 years. Its ability to differentiate Inflammatory bowel disease (IBD) from irritable bowel syndrome (IBS) patients and to predict clinical relapse in patients with Crohn's disease or ulcerative colitis in clinical has been extensively showed. 1 More recently, its correlation with endoscopic lesions of IBD and to endoscopic scores of activity in both Crohn's disease (CDEIS and SESCD) and ulcerative colitis (endoscopic Mayo score) has been demonstrated. 2,3 Accordingly, a significant decrease of fecal calprotectin, after medical treatment, has been found in association with clinical response and also with mucosal healing. 4,5 For all these aspects fecal calprotectin is superior to classically used blood biomarkers, such as C-reactive protein, erythrocyte sedimentation rate or fibrinogen. Hence, some IBD clinicians and centers across the world have used it for several years in their routine practice as a companion diagnostic tool to help to diagnose, monitor and adapt treatment in Crohn's disease and ulcerative colitis. More specifically, it is used by some as a first line test to help decide when and in whom a more invasive endoscopic or magnetic resonance imaging should be performed. 6 Nevertheless, other less enthusiastic colleagues have not started yet and still advocate the need for more data, clarifying how to use this biomarker in routine practice. More particularly, the cutoff values that should be used in diagnosis and more importantly in patients follow-up and monitoring are not sufficiently defined; the intra-individual non specific variations and the best timing for stool sampling have not been enough characterized; finally the frequency at which fecal calprotectin should be measured in longitudinal follow up of patients has not been determined. Four independent studies published in the present issue of Journal of Crohn and Colitis tackle these pending questions and help to progress on the road towards a more standardized and evidence-based use of fecal calpro-tectin in the management of IBD in routine practice. 7–10 The first data published on fecal calprotectin consistently showed a significant increase in IBD as compared to healthy controls and IBS. 11 Hence the first broadly approved application of fecal calpro-tectin measurement has been the differential diagnosis between IBS and IBD with a sensitivity and specificity higher than 90%, allowing to sparing a significant number of colonoscopies, …