title: Fecal calprotectin and S100A12 have low utility in prediction of small bowel Crohn's disease detected by wireless capsule endoscopy.
abstract: OBJECTIVE
  Data on fecal calprotectin and S100A12 in predicting wireless capsule endoscopy (WCE) findings in suspicion of Crohn's disease (CD) are scarce. Our aim was to study the role of calprotectin and S100A12 in predicting inflammatory lesions of small bowel in patients undergoing WCE.
  
  
  METHODS
  84 patients undergoing WCE (77 for suspicion of CD and 7 CD patients for evaluation of disease extent) were prospectively recruited. WCE findings were scored. Patients provided a stool sample for measurements of biomarkers. Patients underwent an esophagogastroduodenoscopy and ileocolonoscopy before WCE.
  
  
  RESULTS
  WCE was abnormal in 35 (42%) of 84 patients: 14 patients with CD, 8 with NSAID enteropathies, 8 with angioectasias, 4 with polyps or tumors, and 1 with ischemic stricture. Median calprotectin concentration in the study population was 22 μg/g (range 2-342) and S100A12 concentration 0.048 μg/g (range 0.003-1.215). Fecal calprotectin was significantly higher in CD patients (median 91, range 2-312) compared with those with normal WCE or other abnormalities (p = 0.008), whereas fecal S100A12 (0.087 μg/g, range 0.008-0.896) did not differ between the groups (p = 0.166). In detecting inflammatory small bowel lesions, sensitivity, specificity, positive predictive value, and negative predictive value for fecal calprotectin (cutoff 50 μg/g) were 59%, 71%, 42%, and 83%, and for S100A12 (cutoff 0.06 μg/g) these were 59%, 66%, 38%, and 82%.
  
  
  CONCLUSIONS
  In predicting small bowel inflammatory changes, fecal biomarkers calprotectin and S100A12 have moderate specificity, but low sensitivity. Neither fecal calprotectin nor S100A12 can be used for screening or excluding small bowel CD.
authors.affiliation: Department of Medicine, Division of Gastroenterology, Helsinki University Central Hospital, P.O.B 340, 00029 HUS, Helsinki, Finland. taina.sipponen@hus.fi
authors.forename: Taina
authors.initials: T
authors.lastname: Sipponen
authors.forename: Johanna
authors.initials: J
authors.lastname: Haapamäki
authors.forename: Erkki
authors.initials: E
authors.lastname: Savilahti
authors.forename: Henrik
authors.initials: H
authors.lastname: Alfthan
authors.forename: Esa
authors.initials: E
authors.lastname: Hämäläinen
authors.forename: Henna
authors.initials: H
authors.lastname: Rautiainen
authors.forename: Jari
authors.initials: J
authors.lastname: Koskenpato
authors.forename: Hannu
authors.initials: H
authors.lastname: Nuutinen
authors.forename: Martti
authors.initials: M
authors.lastname: Färkkilä
mesh_terms: D000328:Adult; D000368:Aged; D019540:Area Under Curve; D015415:Biomarkers / Q000032:analysis; D053704:Capsule Endoscopy; D003424:Crohn Disease / Q000175:diagnosis* / Q000473:pathology; D005243:Feces / Q000737:chemistry*; D005260:Female; D006801:Humans; D007421:Intestine, Small / Q000473:pathology; D039841:Leukocyte L1 Antigen Complex / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D009418:S100 Proteins / Q000032:analysis*; D000067616:S100A12 Protein; D018709:Statistics, Nonparametric; D055815:Young Adult
chemical_list: D015415:Biomarkers; D039841:Leukocyte L1 Antigen Complex; D009418:S100 Proteins; D000067616:S100A12 Protein; C090441:S100A12 protein, human