Background: The clinical utility of non-invasive markers in the diagnosis and monitoring of ulcerative colitis (UC) has been intensively studied. The aim of our study was to evaluate the value of fecal calprotectin (FC) in differentiating between UC and irritable bowel syndrome (IBS), and in estimating inflammatory activity in UC.
Method: A total number of 140 patients were included in the study. All patients underwent ileocolonoscopy with biopsies, quantitative determination of FC, and blood tests (white blood cell count, CRP, ESR). The severity of UC was assessed by using the Ulcerative Colitis Disease Activity Index (UCDAI) and Mayo endoscopic score.
Results: In patients with active UC the mean values of FC were 373.8 +/- 146.3 μg/g, significantly higher than those in the inactive UC (mean values 36.04 +/- 13.25 μg/g), and in IBS (42.9 +/- 16.00 μg/g). In univariate regression analysis, elevated FC levels strongly correlated with pancolitis (p=0.0001), UCDAI and Mayo scores (p=0.0001), and elevated CRP levels. In multivariate regression model, FC was positively associated with severe pancolitis, and elevated CRP. The optimal cutoff value of FC for the prediction of severe pancolitis (Mayo score˃ 3) was 540 μg/g. We obtained 71.4% sensitivity (CI95%: 41.95-91.6) and 96.1% specificity (CI95%: 89.2 -99.2) of FC in assessing the severity of inflammation in UC patients.
Conclusion: FC is a promising marker that can be used in clinical practice to select patients with organic intestinal disorders, compared with those with functional disorders. It also correlates very well with the extent of lesions and the severity of clinical symptoms in UC, with increased sensitivity and specificity.