Sa1215 Fecal Calprotectin Can Predict Relapse in Inflammatory Bowel Disease Patients in Endoscopic Remission: A Plea for Extreme Deep Remission?

Abstract

Introduction: Mucosal healing has become the treatment goal in patients with ulcerative colitis (UC) and Crohn's disease (CD). Whether low fecal calprotectin levels and histological healing combined with mucosal healing is associated with a further reduced risk of relapses is currently unknown. Methods: Patients with CD, UC or IBD-unclassified (IBD-U) scheduled for a surveillance colonoscopy were asked to collect a stool sample prior to the start of bowel cleansing. Only patients with mucosal healing (MAYO endoscopic score of 0) and no inflammation in the terminal ileum (CD patients) were included. Fecal calprotectin was measured using a quantitative enzyme-linked immunosorbent assay (R-Biopharm, Germany). Biopsies were obtained from four colonic segments and the terminal ileum (CD patients) and histological disease severity was assessed using the Geboes scoring system by a single expert pathologist. Patients were followed until the last outpatient clinic visit or the development of a relapse, which was defined as IBD-related hospitalization, surgery or step-up in IBD medication. ROC statistics were used to determine the optimal cut-off value for calprotectin. Results: Of the 164 patients undergoing surveillance colonoscopy, 67 patients were excluded due to active inflammation and 25 patients because biopsies were missing or because intubation of the terminal ileum was not performed (CD patients). Of the remaining 72 patients (20 CD, 52 UC or IBD-U), six patients (8%) relapsed after a median follow-up of 11 months (range 5 15 months). Median fecal calprotectin levels at baseline were significantly higher for patients who relapsed compared to patients who maintained remission (284 mg/kg vs. 37 mg/kg. p 3.1) was not associated with an increased risk of relapse (p=0.94). A higher Geboes score was not associated with higher levels of calprotectin either (p=0.27). Fecal calprotectin above 56mg/kg predicted relapse during follow-up with 100% sensitivity and 64% specificity, whereas active histological inflammation (Geboes score >3.1) predicted relapse with 33% sensitivity and 68% specificity. Conclusion: Elevated fecal calprotectin levels reliably predict relapses in IBD patients with mucosal healing.