Clinical Significance Of Fecal Calprotectin In Ulcerative Colitis And Irritable Bowel Syndrome

Objective: Calprotectin is a calcium and zinc binding protein of the S100 family derived predominantly from neutrophils and macrophages. It is detectable in body fluids, tissue samples and cells. Fecal calprotectin concentration is about 6 times of normal plasma and has no relationship with sex. Calprotectin as a multi-potent biologically active molecule and a marker of activity of inflammatory cells has been studied in a variety of infective and inflammatory conditions.This study was to determine the concentration of fecal calprotectin and discuss its clinical significance as a simple marker in the diagnosis and differential diagnosis of ulcerative colitis (UC) and irritable bowel syndrome (IBS).Methods:1. Subjects: 32 patients with ulcerative colitis (UC) diagnosed between May in 2010 to January in 2011 in the First Affiliated Hospital of Dalian Medical University were enrolled in this study with an average age of 41 years old; 30 patients with irritable bowel syndrome (IBS) diagnosed between May 2010 to January 2011 in the same hospital were enrolled with an average age of 47 years old; 18 healthy adults with an average age of 46 years old were selected as controls.2. Sampling: 10-20g fresh fecal samples were collected from all subjects within one week before endoscopic examination. Fecal samples were extracted and vortex mixed, followed by centrifugation. At last, supernatants were frozen at—40℃in accordance with the instructions of the kit (CALPRO).3. Fecal Calprotectin of the 80 samples were measured quantitatively by ELISA.Results:1. The median fecal calprotectin concentrations were 109.43μg/g in irritable bowel syndrome and 103.92μg/g in healthy controls, respectively. There was no statistical significance of calprotectin concentration between patients with IBS and healthy controls (P>0.05). The median fecal calprotectin concentrations were 499.91μg/g in UC. There was statistical significance between patients with UC and IBS, and healthy controls (P< 0.01).2. Using a cut-off of 140.56μg/g, fecal calprotectin had 96.6% sensitivity and 63.3% specificity in differentiating UC and IBS.Conclusions: Fecal calprotectin has a high sensitivity in the differential diagnosis of IBS and UC. It can be used as a simple screening marker in diagnosis and differential diagnosis of IBS and UC.