P223 The usefulness of tissue calprotectin in pediatric Crohn’s disease – a pilot study

Abstract Background Fecal calprotectin (FCP) is a highly sensitive biomarker of intestinal inflammation widely used in diagnostics and monitoring of inflammatory bowel disease (IBD). However, it cannot be used to localize the disease activity and its levels may be false negative or false positive in some cases. The aim of this study was to evaluate tissue calprotectin (TCP) in pediatric patients with Crohn’s disease (CD) and correlate it with FCP and clinical activity of the disease. Methods Fifty-seven pediatric patients with CD at the median age of 10.5 (1-17) years (yrs) were examined for fecal and tissue calaprotectin. Values were correlated to disease activity and histopathological changes of the patients’ endoscopic biopsies. Disease activity was assessed using Pediatric Crohn’s Disease Activity Index (PCDAI), fecal calprotectin (FCP) was measured with ELISA test and the immunohistochemical (IHC) staining for calprotectin antigen was performed on bioptic samples from 6 bowel segments and the number of TCP cells was counted per high power field (HPF). Non-parametric statistical tests were used for data analysis. Results Patients’ median PCDAI score was 10 (0-63.5), while median FCP was 535 (30-600) ug/g. The only observed correlation was between FCP level and disease activity. There was no associated neither between FCP and TCP, nor TCP and PCDAI. Conclusion Tissue calprotectin unlike FCP does not seem to be a good predictor of disease activity in Polish pediatric patients with CD.