Fecal calprotection in the pediatric population: a 2020 update.

INTRODUCTION Calprotectin is a calcium and zinc-binding protein, formed by a hetero complex of S100A8 and S100A9 proteins, which belong to the S-100 protein family consisting in more than 20 different proteins with a tissue-specific expression pattern. This protein is secreted extracellularly from stimulated neutrophils or released by cell disruption or death. The presence of calprotectin in feces quantitatively relates to neutrophil migration toward the GI tract; thus, it represents a useful marker of intestinal inflammation. EVIDENCE ACQUISITION Fecal calprotectin (FC) has been proven largely useful for etermining the inflammatory origin of GI symptoms differentiating between organic and non-organic diseases. Indeed, increased FC levels are also seen in gastroenteritis, microscopic colitis, polyps, malignancies and cystic fibrosis. EVIDENCE SYNTHESIS To date, there are many evidences regarding usefulness in the detection of fecal calprotectin (FC) for the management of gastrointestinal (GI) disorders, both in children and adults but, especially in the pediatric population, still clear indications for its use are lacking. Its incorporation in primary care reduces the risk of missing an organic disease, and facilitates the indication for expensive and invasive investigations as colonoscopy. CONCLUSIONS We herein review and discuss the last evidences on the usefulness of FC in children, with its current indications and future prospective.