Application of faecal calprotectin as marker of gastrointestinal tract disorders

Calprotectin refers to the S100A8 and S100A9 protein complex, also known as the 27E10 antigen, L1L and L1H, MRP-8/14, or calgranulin A/B protein. Faecal calprotectin (FC) is a marker of intestinal inflammation and neutrophil infiltration. This article aimed to review the methods of FC measurement and the importance of the test in the diagnostic workup of children with different disorders of the GI tract, including GI involvement in COVID-19. We found that it is helpful in differentiating between functional and organic disorders and monitoring patients with inflammatory bowel diseases. Different cut-off values are applied in children depending on the patient’s age; hence, variability of the parameter for a given patient should be analysed.