Monitoring inflammatory bowel disease requires noninvasive and precise techniques. The study aimed to compare the performance of fecal calprotectin (FC) to three fecal inflammatory markers: S100A12 (FA12), tumor pyruvate kinase isoenzyme type M2 (FM2PK), and fecal osteoprotegerin (FOPG) as indicators of a variety of disease characteristics in a planned ancillary study of the prospective ImageKids cohort. The ImageKids research was a multicenter study that aimed to create two magnetic resonance enterography–based assessments for children with Crohn’s disease aged 6 to 18. All patients had magnetic resonance enterography, an ileocolonoscopic examination, and a fecal sample is taken. ELISA was used to test fecal samples for FC, FA12, FM2PK, and FOPG. 190 fecal samples were collected from 156 children. FC had a median of 602 g/g, FA12 had a median of 21 g/g, FM2PK had a median of 16 U/mL, and FOPG had a median of 125 g/g. All indicators associated with the Crohn’s disease simple endoscopic severity score and other categories of disease activity, although FC showed the strongest overall associations. When compared to FC, FA12 predicted mucosal healing with considerably greater specificity and similar sensitivity.

This study found that FC is a helpful and, in general, the best measure for monitoring mucosal inflammation in inflammatory bowel disease. FA12, on the other hand, appears to be a better predictor of mucosal healing in children.