Accuracy of fecal calprotectin for the prediction of endoscopic activity in patients with inflammatory bowel disease

Abstract

Background: Fecal calprotectin is a noninvasive marker of inflammatory bowel disease.

Aim: To evaluate the accuracy of calprotectin for prediction of endoscopic activity in inflammatory bowel disease.

Methods: One-hundred patients were prospectively included. Quantum Blue^® (Bühlmann) kits were used to determine calprotectin. Endoscopic activity was calculated. Various serum markers (platelets, leukocytes, C-reactive protein, and albumin) were recorded.

Results: Calprotectin was higher in patients with endoscopic activity than in those without activity: in ulcerative colitis, with the low- (29 ± 14 vs. 301 ± 174, p < 0.001) and high- (99 ± 727 vs. 617 ± 801, p < 0.001); and in Crohn's disease, with the low- (29 ± 59 vs. 124 ± 268, p < 0.01) and high-range kit (99 ± 37 vs. 287 ± 607, p < 0.01). Serological marker concentrations did not vary with endoscopic activity. The area under the ROC curve of calprotectin for the prediction of endoscopic activity was 0.9 in ulcerative colitis and 0.8 in Crohn's disease. The best cut-off points for the detection of activity in ulcerative colitis were 50 for the low- (sensitivity 85%, specificity 79%) and 102 for the high- (sensitivity 85%, specificity 79%); in Crohn's disease, 54 for the low- (sensitivity 71%, specificity 75%) and 122 for the high-range kit (sensitivity 71%, specificity 75%).

Conclusions: Fecal calprotectin concentration has good diagnostic accuracy for the detection of endoscopic activity in inflammatory bowel disease and performs better in ulcerative colitis than in Crohn's disease.

Keywords: Crohn’s disease; Endoscopic activity; Fecal calprotectin; Inflammatory bowel disease; Ulcerative colitis.