title: Fecal calprotectin correlates more closely with the Simple Endoscopic Score for Crohn's disease (SES-CD) than CRP, blood leukocytes, and the CDAI.
abstract: OBJECTIVE
  Studies evaluating the correlation between the widely used Simple Endoscopic Score for Crohn's disease (SES-CD) and noninvasive markers are scarce. The aim of this study was to evaluate the correlation between the SES-CD and fecal calprotectin, C-reactive protein (CRP), blood leukocytes, and the Crohn's disease activity index (CDAI).
  
  
  METHODS
  Crohn's disease patients undergoing complete ileocolonoscopy were prospectively enrolled and scored independently according to the SES-CD and the CDAI. SES-CD was defined as follows: inactive 0-3; mild 4-10; moderate 11-19; and high > or =20.
  
  
  RESULTS
  Values in CD patients (n=140 ileocolonoscopies) compared with controls (n=43) are as follows: calprotectin, 334+/-322 vs. 18+/-5 microg/g; CRP, 26+/-29 vs. 3+/-2 mg/l; and blood leukocytes, 9.1+/-3.4 vs. 5.4+/-1.9 g/l (all P<0.001). The SES-CD correlated closest with calprotectin (Spearman's rank correlation coefficient r=0.75), followed by CRP (r=0.53), blood leukocytes (r=0.42), and the CDAI (r=0.38). Calprotectin was the only marker that could discriminate inactive endoscopic disease from mild activity (104+/-138 vs. 231+/-244 microg/g, P<0.001), mild from moderate activity (231+/-244 vs. 395+/-256 microg/g, P=0.008), and moderate from high activity (395+/-256 vs. 718+/-320 microg/g, P<0.001). The overall accuracy for the detection of endoscopically active disease was 87% for calprotectin (cutoff 70 microg/g), 66% for elevated CRP, 54% for blood leukocytosis, and 40% for the CDAI > or =150.
  
  
  CONCLUSIONS
  Fecal calprotectin correlated closest with SES-CD, followed by CRP, blood leukocytes, and the CDAI. Furthermore, fecal calprotectin was the only marker that reliably discriminated inactive from mild, moderate, and highly active disease, which underlines its usefulness for activity monitoring.
authors.affiliation: Farncombe Family Institute of Digestive Health Research, McMaster University, Hamilton, Ontario, Canada. schoepf@mcmaster.ca
authors.forename: Alain M
authors.initials: AM
authors.lastname: Schoepfer
authors.forename: Christoph
authors.initials: C
authors.lastname: Beglinger
authors.forename: Alex
authors.initials: A
authors.lastname: Straumann
authors.forename: Michael
authors.initials: M
authors.lastname: Trummler
authors.forename: Stephan R
authors.initials: SR
authors.lastname: Vavricka
authors.forename: Lukas E
authors.initials: LE
authors.lastname: Bruegger
authors.forename: Frank
authors.initials: F
authors.lastname: Seibold
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000032:analysis; D002097:C-Reactive Protein / Q000032:analysis; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D003113:Colonoscopy; D003424:Crohn Disease / Q000175:diagnosis* / Q000473:pathology; D004797:Enzyme-Linked Immunosorbent Assay; D005243:Feces / Q000737:chemistry*; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D039841:Leukocyte L1 Antigen Complex / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric
chemical_list: D015415:Biomarkers; D039841:Leukocyte L1 Antigen Complex; D002097:C-Reactive Protein