Evaluation of the diagnostic performance of estimated fecal calprotectin and serum intelectin-1 and C-reactive protein solo or in combination for differentiation between patients with query ulcerative colitis and irritable bowel syndrome

Abstract Objectives Evaluation of the ability of estimated levels of fecal calprotectin (FCP), serum intelectin-1 (ITLN1), and C-reactive protein (CRP) to differentiate between patients with ulcerative colitis (UC) and irritable bowel syndrome (IBS). Patients Three-hundred forty-two patients were evaluated clinically for diagnostic criteria of UC and IBD and underwent colonoscopic examination and grading according to Mayo endoscopic scores (MES). Colorectal biopsies were taken for microscopic examination. Fecal and blood samples were obtained for ELISA estimation of levels of the studied variate. Patients were grouped according to microscopic examination of the obtained biopsies as UC and IBD groups. Study outcome is the ability of the laboratory variate for prediction of the microscopic diagnosis. Results In UC patients, FCP and serum CRP levels were notably elevated compared to controls and IBS patients. Conversely, UC patients exhibited significantly reduced serum ITLN1 levels in comparison to controls and IBS patients with insignificantly lower levels in samples of IBS patients. Statistical analyses defined high FCP and low serum ITLN1 as the significant predictors for UC diagnosis with high specificity for FCP level > 150 µg/ml and high sensitivity for serum ITLN1 ≤ 30 and ≤ 18 ng/ml to predict colonoscopic and microscopic UC diagnosis, respectively. Conclusion The combination of high FCP and low serum ITLN1 could accurately predict the colonoscopic and microscopic findings of UC and can differentiate UC from IBS and may spare the need for colonoscopy and biopsy especially for IBS patients.