In Crohn’s disease (CD) few data are available on the usefulness of monitoring fecal calprotectin (FC) in the early postoperative setting. We assessed prospectively the accuracy of FC measured 3 months after surgery to predict the risk of endoscopic postoperative recurrence (POR) within 1 year after resection.
In 55 consecutive CD patients who had undergone ileocolonic resection samples were collected 3 months after surgery for measuring serum CRP and FC. Endoscopic POR was assessed by ileocolonoscopy within 6-12 months (median 7 months). Receiver operating characteristic (ROC) curves were generated to assess accuracy of the markers, to determine the best threshold and to calculate sensitivity, specificity, positive and negative predictive values.
In contrast with median CRP levels, median FC concentrations measured 3 months after surgery were significantly higher in patients who later experienced endoscopic POR (Rutgeerts ≥ i2) compared with those who stayed in endoscopic remission within the following 6-12 months (205 μg/g IQR [106-721] vs. 103 μg/g IQR [60-219], p = 0.008). Area under the ROC curve for FC was 0.71. The best cutoff value of FC to identify patients in subsequent endoscopic remission 3 months after surgery was 65 μg/g (96% sensitivity, 31% specificity, 50% positive and 91% negative predictive values). In multivariate analysis, FC < 65 µg/g at 3 months was the only factor associated with subsequent endoscopic remission.
FC measured 3 months after surgery below 65 μg/g is an accurate marker to identify CD patients who will later stay in endoscopic remission within 1 year after resection.