A new rapid test for fecal calprotectin predicts endoscopic remission and postoperative recurrence in Crohn's disease

Abstract

IntroductionFecal calprotectin (FC), as determined by the enzyme-linked immunoassay (ELISA) test, has been proposed as a promising biomarker of endoscopic activity in Crohn's disease (CD). However data on its accuracy in predicting endoscopic remission according to location and postoperative recurrence (POR) is scarce.Our objective was to evaluate the ability of FC determined by a new quantitative point-of-care test (FC-QPOCT) to predict endoscopic remission and POR in CD patients. MethodsFC was determined simultaneously by an enzyme-linked immunoassay test (FC-ELISA) and a FC-QPOCT in CD patients undergoing colonoscopy. Clinical disease activity was assessed according to the Crohn's Disease Activity Index (CDAI). Endoscopic results were assessed according to the Crohn's Disease Endoscopic Activity Index of Severity (CDEIS) and postoperative recurrence according to the Rutgeerts' score. ResultsA total of 115 ileocolonoscopies were performed (29 on patients with ileocolonic resection). FC levels correlated more closely with the CDEIS than leucocytes, platelets or CRP. The prediction of “endoscopic remission” (CDEIS<3), using FC-QPOCT (cut-off 272μg/g) and FC-ELISA (cut-off 274μg/g) presented an AUC of 0.933 and 0.935 respectively. FC-QPOCT results correlated better with endoscopic activity in the ileocolonic location (Pearson's correlation, r=0.879; P<0.001), than the colonic (r=0.725; P<0.001) or the ileal location (r=0.437; P=0.016). Median FC-QPOCT levels discriminated Rutgeerts' score i0–i1 from i2–i4 (98 (range 30–306)μg/g vs. 234.5 (range 100–612)μg/g respectively, P=0.012). ConclusionsFC determined by rapid quantitative test predicts “endoscopic remission” and endoscopic postoperative recurrence in CD patients.