Fecal calprotectin is a strong predictive marker of relapse in Chinese patients with Crohn's disease: a two-year prospective study

Objective: To evaluate the predictive value of fecal calprotectin (FC) for clinical relapse in Chinese patients with quiescent Crohn's disease (CD) and to further investigate the correlation between FC and intestinal inflammation. Methods: Sixty-two patients with a diagnosis of quiescent CD were consecutively enrolled in this prospective study. Fecal samples were collected and enteroscopy were performed to detect mucosal lesions at the beginning of the study. Patients were followed until the first relapse or by the end of the two-year follow-up. The calprotectin concentration was measured using a quantitative enzyme-linked immunoassay. Results: Of the 62 CD patients, 29 had a relapse (median time of relapse: 8.44 months). The median follow-up months was 8.16 (4.98-13.59). The cut off level of 225 mu g/g provided the maximal area under the receiver operating characteristic curve (AUC) of .775 for detecting the relapse of CD patients. Meanwhile, fecal occult blood had an added value. The multivariate Cox regression model showed that FC was the strongest predictor of the risk of relapse (risk ratio (RR): 6.315; p = .001). FC correlated most closely with the simple endoscopic score for Crohn's disease (SES-CD) (r = 0.524, p < .001). Conclusions: FC correlated significantly with gut inflammation and could be a reliable predictor of relapse in Chinese patients with CD.