The median level of calprotectin was lowest in children with deep healing (mean level, 10 μg/g), followed by children with either transmural or mucosal inflammation. The highest median level of calprotectin was in children with mucosal and transmural inflammation (810 μg/g).
Fecal level of calprotectin identified children with deep healing with an area under the receiver operating characteristic curve (AUROC) value of 0.93. Level of C-reactive protein identified children with deep healing with an AUROC value of 0.81.
A calprotectin cutoff value of 100 μg/g identified children with deep healing with 71% sensitivity and 92% specificity; a cutoff value of 300 μg/g identified children with mucosal healing with 80% sensitivity and 81% specificity.
In the 21 children with deep healing, the median calprotectin level was 10 μg/g and the median C-reactive protein level was 1 mg/L . These values were significantly lower than in children with either mucosal or transmural inflammation (see Figure).
A C-reative protein cutoff value <3 mg/L best identified children with deep healing.