Fecal calprotectin as a non-invasive biomarker for intestinal involvement of Behcet's disease.

BACKGROUND AND AIM: The diagnostic and prognostic values of fecal calprotectin (FC) levels in patients with inflammatory bowel diseases have been proven. However, little is known about the usefulness of FC measurement in predicting intestinal involvement of Behcet's disease (BD). METHODS: Forty-four consecutive patients with systemic BD who underwent colonoscopy for the evaluation of gastrointestinal symptoms were prospectively enrolled between November 2012 and March 2014 in a single tertiary medical center. Fecal specimens from the patients were obtained the day before bowel cleansing and 3 months after colonoscopy. RESULTS: Twenty-five patients showed intestinal ulcerations on colonoscopy (12 [48.0%] typical and 13 [52.0%] atypical ulcerations). The median FC level in the intestinal BD group was significantly higher than that in the non-diagnostic group (112.53 [6.86-1604.39] vs 31.64 [5.46-347.60] microg/g, respectively, P = 0.003). Moreover, the typical ulceration group showed a significantly higher median FC level than the atypical ulceration group in patients with intestinal BD (435.995 [75.65-1604.39] vs 71.42 [6.86-476.94] microg/g, respectively, P = 0.033). Multivariate analysis revealed higher FC as an independent predictor of intestinal BD (OR = 38.776; 95% CI = 2.306-652.021; P = 0.011). The cut-off level of FC for predicting intestinal BD was 68.89 microg/g (76% sensitivity and 79% specificity). The absolute changes between fecal calprotectin levels and the disease activity index of intestinal BD from initial diagnosis of intestinal BD to 3 months after diagnosis were significantly correlated (Pearson's correlation coefficient = 0.470, P = 0.027). CONCLUSION: The FC level might serve as a non-invasive surrogate marker of intestinal involvement of BD.