Clinical value of fecal calprotectin in determining disease activity of ulcerative colitis

To investigate possibility and clinical application of fecal calprotectin in determining disease activity of ulcerative colitis (UC).

The enzyme-linked immunosorbent assay (ELISA) was used to measure the concentrations of calprotectin in feces obtained from 66 patients with UC and 20 controls. C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), acid glycoprotein (AGP) were also measured and were compared with calprotectin in determining disease activity of UC. The disease activity of UC was also determined by the Sutherland criteria.

The fecal calprotectin concentration in the patients with active UC was significantly higher than that in the inactive UC and in the controls (402.16 +/- 48.0 microg/g vs 35.93 +/- 3.39 microg/g, 11.5 +/- 3.42 microg/g, P < 0.01). The fecal calprotectin concentration in the inactive UC group was significantly higher than that in the control group (P < 0.05). A significant difference was also found in the patients with active UC of mild, moderate and severe degrees. The area under the curve of the receiver operating characteristics (AUCROC) was 0.975, 0.740, 0.692 and 0.737 for fecal calprotectin, CRP, ESR and AGP, respectively. There was a strong correlation between the fecal calprotectin concentration and the endoscopic gradings for UC (r = 0.866, P < 0.001).

Calprotectin in the patient's feces can reflect the disease activity of UC and can be used as a rational fecal marker for intestinal inflammation in clinical practice. This kind of marker is relatively precise, simple and noninvasive when compared with other commonly-used markers such as CRP, ESR and AGP.