title: Fecal calprotectin is a surrogate marker for endoscopic lesions in inflammatory bowel disease.
abstract: BACKGROUND
  Fecal calprotectin is a marker of inflammation in inflammatory bowel disease (IBD). Since mucosal healing has become a goal of treatment in IBD we examined how reliably calprotectin levels reflect mucosal disease activity.
  
  
  METHODS
  In all, 126 IBD patients and 32 irritable bowel syndrome (IBS) patients needing colonoscopy delivered a sample of feces prior to the start of bowel cleansing. Besides collection of symptom scores and blood tests, experienced endoscopists recorded the Simple Endoscopic Score for Crohn's Disease (SES-CD) and the Crohn's Disease Endoscopic Index of Severity (CDEIS) in Crohn's disease (CD) patients and the Mayo endoscopic score in ulcerative colitis (UC) patients. Stool samples were shipped for central calprotectin PhiCal Assay (enzyme-linked immunosorbent assay [ELISA]). Correlation analysis was done with Pearson statistics.
  
  
  RESULTS
  The median (interquartile range [IQR]) fecal calprotectin levels were 175 (44-938) μg/g in CD, 465 (61-1128) μg/g in UC, and 54 (16-139) μg/g in IBS. Correlations were significant with endoscopic disease scores in both CD and in UC. Using ROC statistics, a cutoff value of 250 μg/g indicated the presence of large ulcers with a sensitivity of 60.4% and a specificity of 79.5% (positive predictive value [PPV] 78.4%, negative predictive value [NPV] 62.0%) in CD. Levels ≤ 250 μg/g predicted endoscopic remission (CDEIS ≤ 3) with 94.1% sensitivity and 62.2% specificity (PPV 48.5%, NPV 96.6%). In UC, a fecal calprotectin >250 μg/g gave a sensitivity of 71.0% and a specificity of 100.0% (PPV 100.0%, NPV 47.1%) for active mucosal disease activity (Mayo >0). Calprotectin levels significantly correlated with symptom scores in UC (r = 0.561, P < 0.001), but not in CD.
  
  
  CONCLUSIONS
  Fecal calprotectin levels correlate significantly with endoscopic disease activity in IBD. The test appears useful in clinical practice for assessment of endoscopic activity and remission.
authors.affiliation: Department of Gastroenterology, Academic Medical Centre, Amsterdam, The Netherlands. g.dhaens@amc.uva.nl
authors.forename: Geert
authors.initials: G
authors.lastname: D'Haens
authors.forename: Marc
authors.initials: M
authors.lastname: Ferrante
authors.forename: Severine
authors.initials: S
authors.lastname: Vermeire
authors.forename: Filip
authors.initials: F
authors.lastname: Baert
authors.forename: Maja
authors.initials: M
authors.lastname: Noman
authors.forename: Liesbeth
authors.initials: L
authors.lastname: Moortgat
authors.forename: Patricia
authors.initials: P
authors.lastname: Geens
authors.forename: Doreen
authors.initials: D
authors.lastname: Iwens
authors.forename: Isolde
authors.initials: I
authors.lastname: Aerden
authors.forename: Gert
authors.initials: G
authors.lastname: Van Assche
authors.forename: Gust
authors.initials: G
authors.lastname: Van Olmen
authors.forename: Paul
authors.initials: P
authors.lastname: Rutgeerts
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000032:analysis; D003093:Colitis, Ulcerative / Q000175:diagnosis / Q000473:pathology; D003106:Colon / Q000473:pathology; D003113:Colonoscopy; D003424:Crohn Disease / Q000175:diagnosis / Q000473:pathology; D004797:Enzyme-Linked Immunosorbent Assay; D005243:Feces / Q000737:chemistry*; D005260:Female; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000175:diagnosis / Q000473:pathology*; D007413:Intestinal Mucosa / Q000473:pathology; D043183:Irritable Bowel Syndrome / Q000473:pathology; D039841:Leukocyte L1 Antigen Complex / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D015415:Biomarkers; D039841:Leukocyte L1 Antigen Complex