Background: Fecal biomarkers in inflammatory bowel disease is emerging as a non-invasive test to replace colonoscopy. The aim of our study was to evaluate the efficacy of quantitative fecal immunochemical test (FIT) as predictive biomarker of mucosal healing in UC.
Methods: Between February 2013 and November 2014, a total of 82 FIT results, obtained in conjunction with colonoscopies, were retrospectively evaluated for 63 patients with UC. The efficacy of FIT for evaluation of disease activity was compared to colonoscopic findings. Quantitative fecal blood with automated equipment examined from collected feces. Endoscopic disease severity were assessed using the Mayo endoscopic subscore (MES) classification.
Results: All of 21 patients with MES 0 had negative FIT (<7 ng/ml), but 22 patients with MES 2 or 3 had a mean FIT of >134.89 ng/ml. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of negative FIT about mucosal healing were 73.33%, 81.82%, 91.49%, 51.43% and 73.17%, respectively. Among patients with clinical remission, FIT was negative in 31 (81.6%) of 38 cases, with a mean fecal hemoglobin concentration of 6.12 ng/ml (range, negative to 80.9 ng/ml) for this group of patients. Among patients with clinical active disease, FIT was negative in 16 (36.4%) out of 44 cases, with a mean fecal hemoglobin concentration >167.4 ng/ml for this group of patients. FIT was positively correlated with endoscopic activity (r=0.626, p<0.01) and clinical activity (r =0.496, p<0.01).
Conclusions: Quantitative FIT can be a non-invasive and effective biomarker to predict mucosal healing and clinical activity in UC.