Fecal calprotectin for detection of postoperative endoscopic recurrence in Crohn’s disease: systematic review and meta-analysis

BACKGROUND: Anastomotic recurrence is frequent in patients with Crohn’s disease (CD) following ileocecal resection. The degree of endoscopic recurrence, quantified by the Rutgeerts score (RS), correlates with risk of clinical and surgical recurrence. Several studies demonstrate the accuracy of fecal calprotectin (FC) for detection of endoscopic recurrence, however the optimal threshold FC value remains to be established. The aim of our meta-analysis was to evaluate the accuracy of common FC cut-offs for detection of endoscopic recurrence. METHODS: We performed a systematic literature search for studies evaluating postoperative recurrence in CD which reported RS and FC levels. Endoscopic recurrence was defined as RS = 2–4 (or RS ⩾ 2). We calculated pooled diagnostic sensitivity, specificity, diagnostic odds ratio (DOR) and constructed summary receiver operating characteristic (SROC) curves for each available FC cut-off value. RESULTS: A total of 54 studies were retrieved; 9 studies were eligible for analysis. Diagnostic accuracy was calculated for FC values of 50, 100, 150 and 200 µg/g. A significant threshold effect was observed for all FC values. The optimal diagnostic accuracy was obtained for FC value of 150 µg/g, with a pooled sensitivity of 70% [95% confidence interval (CI) 59–81%], specificity 69% (95% CI 61–77%), and DOR 5.92 (95% CI 2.61–12.17). The area under the SROC curve was 0.73. CONCLUSION: FC is an accurate surrogate marker of postoperative endoscopic recurrence in CD patients. The FC cut-off 150 μg/g appears to have the best overall accuracy. Serial FC evaluations may eliminate or defer the need for colonoscopic evaluation in up to 70% of postoperative CD patients.