Faecal calprotectin as reliable non-invasive marker to assess the severity of mucosal inflammation in children with inflammatory bowel disease.

Background: An accurate monitoring of mucosal inflammation is important for an effective management of patients with inflammatory bowel disease. Intestinal inflammation can be detected by faecal calprotectin level determination.

Aim: To comparatively evaluate the accuracy of faecal calprotectin, clinical scores, common serum markers and endoscopy in the assessment of the severity of intestinal mucosa inflammation in children with inflammatory bowel disease.

Methods: Fifty-eight paediatric patients (mean age 13.9 years, 95% CI 2.9-14.8; male 28) with confirmed inflammatory bowel disease (26 Crohn's disease, 32 ulcerative colitis) were enrolled. Before endoscopy, all patients underwent a complete evaluation including: clinical scores, erythrocyte sedimentation rate, C-reactive protein and faecal calprotectin determination. The severity of mucosal inflammation was assessed using specific endoscopic and histologic scores.

Results: Faecal calprotectin showed a high correlation (r=0.655) with the histologic grade of mucosal inflammation, similar to that observed for endoscopy (r=0.699), and it resulted the most accurate tool (sensitivity 94%, specificity 64%, positive predictive value 81%, negative predictive value 87%) to detect the presence of active mucosal inflammation when compared to clinical scores and common serum markers. In patients with apparent clinical and laboratory remission the accuracy of faecal calprotectin resulted further improved (sensitivity 100%, specificity 80%, positive predictive value 67%, negative predictive value 100%).

Conclusions: A more accurate assessment of the severity of mucosal inflammation can be achieved by the determination of faecal calprotectin levels compared to other common clinical and laboratory indices. This non-invasive and objective method could be particular useful in patients with apparent clinical and laboratory remission.