title: Faecal calprotectin: a noninvasive diagnostic tool and marker of severity in pouchitis.
abstract: BACKGROUND
  In pouchitis, the mucosa is infiltrated by activated polymorphonuclear neutrophils capable of producing calprotectin, a stable antimicrobial myelomonocytic protein.
  
  
  OBJECTIVE
  The aim is to assess the ability of faecal calprotectin to differentiate between inflamed and noninflamed ileal pouches, and to correlate this with inflammation severity using the newly developed Objective Pouchitis Score.
  
  
  METHODS
  Fifty-four stool samples were collected from patients who had undergone restorative proctocolectomy; 46 from patients with ulcerative colitis and eight from those with familial adenomatous polyposis coli. Faecal calprotectin concentrations were determined by quantitative enzyme-linked immunosorbant assay.
  
  
  RESULTS
  Of the ulcerative colitis patients, six were diagnosed with pouchitis and pre-pouch ileitis (median faecal calprotectin: 865 microg/g, with a range of 95-2350 microg/g); 13 had pouchitis alone (145, 33-3350 microg/g) and 27 were uninflamed (56, 4-705 microg/g). Of the familial adenomatous polyposis patients, one had pouchitis and pre-pouch ileitis (305 microg/g), and seven had noninflamed pouches (9, 6-26 microg/g). Stool samples obtained from pouchitis patients had significantly higher calprotectin concentrations compared with those obtained from uninflamed pouches (Mann-Whitney: P<0.0001). Faecal calprotectin concentrations correlated closely with the Objective Pouchitis Score, the Pouch Disease Activity Index and endoscopic and histological inflammatory scores (Spearman rank test: P values <0.0001). Using a faecal calprotectin threshold of >or=92.5 microg/g to define a positive result, Receiver Operating Characteristic analysis demonstrated a sensitivity of 90% and a specificity of 76.5%.
  
  
  CONCLUSIONS
  Faecal calprotectin measurement is a useful noninvasive tool in the diagnosis of acutely inflamed ileal pouches and correlates well with the severity of pouchitis.
authors.affiliation: Gastroenterology/Surgical Unit, St Mark's Hospital, Harrow, Middlesex, UK. mattcat1_@hotmail.com
authors.forename: Matt W
authors.initials: MW
authors.lastname: Johnson
authors.forename: Susan
authors.initials: S
authors.lastname: Maestranzi
authors.forename: Audrey M
authors.initials: AM
authors.lastname: Duffy
authors.forename: David H
authors.initials: DH
authors.lastname: Dewar
authors.forename: Alastair
authors.initials: A
authors.lastname: Forbes
authors.forename: Ingvar
authors.initials: I
authors.lastname: Bjarnason
authors.forename: Roy A
authors.initials: RA
authors.lastname: Sherwood
authors.forename: Paul
authors.initials: P
authors.lastname: Ciclitira
authors.forename: John R
authors.initials: JR
authors.lastname: Nicholls
mesh_terms: D011125:Adenomatous Polyposis Coli / Q000601:surgery; D000328:Adult; D015415:Biomarkers / Q000032:analysis; D003093:Colitis, Ulcerative / Q000601:surgery; D003937:Diagnosis, Differential; D016099:Endoscopy, Gastrointestinal; D005243:Feces / Q000737:chemistry*; D005260:Female; D006801:Humans; D039841:Leukocyte L1 Antigen Complex / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D019449:Pouchitis / Q000175:diagnosis* / Q000473:pathology; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; D039841:Leukocyte L1 Antigen Complex