Assessing the correlation between fecal calprotectin, blood markers and disease activity in pediatric inflammatory bowel disease

Background: Crohn's disease (CD) and ulcerative colitis (UC) are the 2 main types of inflammatory bowel disease (IBD), a chronic inflammatory condition of the gastrointestinal tract. Management of IBD necessitates frequent clinical monitoring, including blood tests and occasionally endoscopy. Fecal calprotectin (FC) is a non-invasive measurement of luminal inflammatory activity, and can therefore be used as a useful monitoring tool. This study aimed to assess the relationship between FC, IBD activity indices and the commonly used blood markers in pediatric IBD. Methods: Electronic patient records were accessed to retrospectively collect patient data from a tertiary pediatric hospital from 2015-2021. CD and UC disease activity was quantified using the Pediatric CD Activity Index (PCDAI) and Pediatric UC Activity Index (PUCAI), respectively. The Paris classification was used for phenotype identification. FC and activity indices were correlated positively with inflammatory markers/platelets and negatively with albumin and hemoglobin. FC correlated positively with PCDAI in all CD phenotypes, including isolated ileal disease. Conclusion: In pediatric IBD, FC shows a positive correlation with the clinical picture and blood markers in all disease phenotypes, and can provide an accurate non-invasive measure of disease activity.