Background: Fecal calprotectin (FC) has been proposed as a noninvasive surrogate marker to determine the degree of intestinal inflammation and predicting relapse in patients with inflammatory bowel disease (IBD). The aim was to compare FC levels in IBD and healthy controls, to correlate FC levels with clinical disease activity, and to assess whether FC levels can be used to predict clinical relapse in children with IBD.
Methods: Enzyme-linked immunosorbent assay (ELISA) determined levels of FC were measured in more than 1 stool samples (n) from 32 IBD patients (n = 97) and from 34 healthy controls (n = 37). Disease activity was assessed by the Harvey-Bradshaw index in Crohn's disease (CD) and by Physician's Global Assessment (PGA) in both CD and ulcerative colitis (UC). Clinical events were recorded up to 9 months following stool collection in CD patients. Wilcoxon rank sum test and Fisher's exact tests were used to compare FC levels in IBD patients and in control. Kaplan-Meyer analysis was used to determine a risk of clinical relapse in relation to FC levels.
Results: The IBD group had higher FC levels (range 17-7500 g/g) compared with control (16-750 g/g, P < 0.0001). FC levels were higher during relapse (CD, 3214 +/- 2186; UC, 2819 +/- 1610) compared to remission (CD, 1373 +/- 1630; UC, 764 +/- 869; P < 0.0001). Among those with clinical relapse, 90% had FC levels more than 400 mug/g in CD. Eighty-nine percent of CD encounters with FC levels less than 400 mug/g remained in clinical remission.
Conclusions: FC levels differentiate active IBD from controls. Among children with CD and in remission, FC levels may be useful in predicting impending clinical relapse.