Salivary Calprotectin as a Biomarker in Early Onset Inflammatory Bowel Disease: A Pilot Study

Objectives: This study aimed to evaluate the potential of salivary calprotectin (SCP) as a novel biomarker in the management of Early Onset Inflammatory Bowel Disease (EOIBD), comparing EOIBD and healthy controls and differentiating patients based on their history of oral manifestations (OM). We correlated SCP and fecal calprotectin (FCP) in EOIBD and assessed the prognostic accuracy of SCP in predicting disease relapses. Methods: A sample of stimulated saliva was collected at baseline by 27 EOIBD and 9 healthy controls and then processed by ELISA for SCP determination. At sampling, a stool specimen was also provided by each patient for routine FCP assessment. Clinical disease activity was measured through Pediatric Ulcerative Colitis Activity Index (PUCAI) or Pediatric Crohn's Disease Activity Index (PCDAI) at baseline and during follow-up at 4, 8 and 12 weeks. Results: A history of OM was described by 13 EOIBD. EOIBD with OM reported significantly higher SCP than EOIBD without OM (p < 0.01**) and controls (p < 0.05*). When evaluating the correlation between SCP and FCP in EOIBD with OM, positive FCP values (>120 mg/kg) were found to be associated with higher SCP concentrations (p < 0.05*), while in EOIBD without OM, a negative correlation was described (p < 0.05*). Lastly, EOIBD with OM who reported higher SCP were found to have significantly increased risk of relapse (p < 0.05*). Conclusions: In EOIBD with OM SCP was significantly more elevated and was correlated to intestinal inflammation and flare-up risk. Our results suggest the potential use of SCP as prognostic biomarker in children with intestinal and oral disease.