In a prospective study of children with Crohn’s disease (CD), one-third had healing in only the mucosa or the bowel wall but not both, while levels of fecal calprotectin below 300 μg identified children with mucosal healing, but not deep healing. The study included 151 children (mean age 14.2±2.4 years); all patients underwent magnetic resonance enterography (MRE) and a complete ileocolonoscopic evaluation; fecal levels of calprotectin and blood levels of c-reactive protein were measured. Researchers found:

• Mucosal healing with transmural inflammation was identified in 9 children (6%), transmural healing with mucosal inflammation in 38 children (25%), deep healing in 21 children (14%), and mucosal and transmural inflammation in 83 children (55%).
• The median level of calprotectin was lowest in children with deep healing, followed by children with either transmural or mucosal inflammation, and highest in children with mucosal and transmural inflammation.
• Levels of fecal calprotectin <300 μg identify children with mucosal healing, however, a lower cutoff value <100 μg/g is needed to identify children with deep healing.