Fecal Calprotectin Levels Significantly Correlate with Polyp Size in Children and Adolescents with Juvenile Colorectal Polyps

PURPOSE: We aimed to investigate factors that correlate with fecal calprotectin (FC) levels in children and adolescents with colorectal polyps. METHODS: Pediatric patients aged <19 years who underwent colonoscopic polypectomy for a juvenile polyps (JPs) and FC tests were simultaneously conducted in a multicenter, retrospective study. Baseline demographics, colonoscopic and histological findings, and laboratory tests, including FC levels, were investigated. Correlations between the factors were investigated, and linear regression analysis revealed factors that correlated with FC levels. FC levels measured after polypectomies were investigated and the FC levels pre- and post-polypectomies were compared. RESULTS: A total of 33 patients were included in the study. According to Pearson correlation analysis, the polyp size was the only factor that showed a statistically significant correlation with FC levels (r=0.75, p<0.001). Furthermore, according to the multivariate linear regression analysis, polyp size was the only factor that showed a statistically significant correlation with FC levels (adjusted R(2) =0.5718, β=73.62, p<0.001). The median FC level was 400 mg/kg (interquartile range [IQR], 141.6–1,000 mg/kg), and the median polyp size was 14 mm (IQR, 9–20 mm). Nineteen patients underwent post-polypectomy FC tests. FC levels showed a significant decrease after polypectomy from a median of 445.2 mg/kg (IQR, 225–1,000) to 26.5 mg/kg (11.5–51) (p<0.001). CONCLUSION: FC levels significantly correlated with polyp size in children and adolescents with JPs.