Fecal Calprotectin Assay at an Early Stage of Treatment Can Be Used as a Surrogate Marker to Predict Clinical Remission and Mucosal Healing in Pediatric Crohn’s Disease

PURPOSE: This study evaluated the predictive role of fecal calprotectin (FC) measured at an early stage of treatment for monitoring clinical remission (CR) after six months and endoscopic remission (ER) after one year of treatment in pediatric Crohn’s disease (CD). METHODS: This retrospective study included 45 patients who simultaneously underwent ileocolonoscopy and FC testing during follow-up. FC levels were measured before and after six weeks of treatment. CR was assessed after six months of treatment using Pediatric Crohn’ s Disease Activity Index and acute-phase reactants. ER was assessed after one year using the Simple Endoscopic Score for Crohn’s Disease. RESULTS: Twenty-nine (64.4%) patients used oral prednisolone for remission induction and 16 (35.6%) patients used anti-tumor necrosis factor-alpha. Thirty (66.7%) patients achieved CR, while 24 (53.3%) achieved ER. The FC level measured after six weeks of treatment could predict CR (χ(2)=9.15, p=0.0025) and ER (χ(2)=12.31, p=0.0004). The δFC could predict CR (χ(2)=7.91, p=0.0049), but not ER (χ(2)=1.85, p=0.1738). With a threshold of ≤950.4 µg/g, FC at week six could predict CR with 76.7% sensitivity and 73.3% specificity. The area under the curve (AUC) was 0.769 (standard error 0.0773, p=0.0005). The same threshold predicted ER with 87.5% sensitivity and 71.4% specificity. The AUC was 0.774 (standard error 0.074, p=0.0002). CONCLUSION: FC assay at an early stage of treatment can be used as a surrogate marker to predict CR and mucosal healing in pediatric CD.