title: Neopterin is a novel reliable fecal marker as accurate as calprotectin for predicting endoscopic disease activity in patients with inflammatory bowel diseases.
abstract: BACKGROUND
  Fecal biomarkers have emerged as an important tool for assessing and monitoring disease activity in patients with inflammatory bowel diseases (IBDs). We performed a prospective head-to-head comparison of the diagnostic accuracy of both fecal calprotectin (fCal) and neopterin (fNeo), and serum C-reactive protein in predicting endoscopic disease severity in patients with IBD.
  
  
  METHODS
  A total of 133 consecutive patients with IBD (78 Crohn's disease [CD] and 55 ulcerative colitis [UC]) undergoing a colonoscopy provided fecal samples for the measurement of fCal and fNeo concentrations and a blood sample for the serum C-reactive protein measurement. Endoscopic disease activities were scored independently according to the Simple Endoscopic Score for CD in patients with CD and to the Rachmilewitz Index in patients with UC. The respective performances of the fecal markers with respect to endoscopic disease severity were assessed by computing correlations, sensitivities, specificities, and overall accuracies at adjusted cutoffs and also test operating characteristics.
  
  
  RESULTS
  The fCal and fNeo concentrations differed significantly in clinically and endoscopically active IBD when compared with those in patients with inactive disease. Both fCal and fNeo concentrations correlated closer with endoscopic scores in UC (r = 0.75 and r = 0.72, respectively; P < 0.0001 for both) than in CD (r = 0.53 and r = 0.47, respectively; P < 0.0001 for both). Using cutoffs of 250 μg/g for fCal and 200 pmol/g for fNeo, both fecal markers had similar overall accuracies to predict endoscopic activity in patients with CD (74%) and also a higher and similar accuracies (88% and 90%, respectively) in patients with UC, whereas accuracies of C-reactive protein were slightly lower in patients with CD and UC.
  
  
  CONCLUSIONS
  The fNeo is a novel reliable surrogate biomarker with the potential to identify patients with IBD with active mucosal lesions and represents an alternative marker as accurate as fCal to predict and monitor the severity of mucosal damages in patients with IBD.
authors.affiliation: Department of Gastroenterology, Hospices Civils de Lyon and University Claude Bernard Lyon 1, Pierre-Benite, France. stephane.nancey@chu-lyon.fr
authors.forename: Stephane
authors.initials: S
authors.lastname: Nancey
authors.forename: Gilles
authors.initials: G
authors.lastname: Boschetti
authors.forename: Driffa
authors.initials: D
authors.lastname: Moussata
authors.forename: Eddy
authors.initials: E
authors.lastname: Cotte
authors.forename: Julie
authors.initials: J
authors.lastname: Peyras
authors.forename: Charlotte
authors.initials: C
authors.lastname: Cuerq
authors.forename: Julie
authors.initials: J
authors.lastname: Haybrard
authors.forename: Anne-Laure
authors.initials: AL
authors.lastname: Charlois
authors.forename: Anne
authors.initials: A
authors.lastname: Mialon
authors.forename: Marion
authors.initials: M
authors.lastname: Chauvenet
authors.forename: Karine
authors.initials: K
authors.lastname: Stroeymeyt
authors.forename: Dominique
authors.initials: D
authors.lastname: Kaiserlian
authors.forename: Jocelyne
authors.initials: J
authors.lastname: Drai
authors.forename: Bernard
authors.initials: B
authors.lastname: Flourié
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis*; D002097:C-Reactive Protein / Q000378:metabolism; D003093:Colitis, Ulcerative / Q000175:diagnosis* / Q000378:metabolism; D003113:Colonoscopy; D003424:Crohn Disease / Q000175:diagnosis* / Q000378:metabolism; D004724:Endoscopy; D004797:Enzyme-Linked Immunosorbent Assay; D005243:Feces / Q000737:chemistry*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D039841:Leukocyte L1 Antigen Complex / Q000032:analysis / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D019798:Neopterin / Q000032:analysis / Q000378:metabolism*; D011379:Prognosis; D011446:Prospective Studies; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D015415:Biomarkers; D039841:Leukocyte L1 Antigen Complex; D019798:Neopterin; D002097:C-Reactive Protein