title: Fecal calprotectin in clinical practice: a noninvasive screening tool for patients with chronic diarrhea.
abstract: BACKGROUND
  Surrogate markers of colorectal inflammation are increasingly being recognized as important in differentiating organic from functional intestinal disorders. Fecal calprotectin (FC) can be easily measured in the stool, being released by leukocytes in inflammatory conditions.
  
  
  OBJECTIVE
  We evaluated FC as an index of inflammation in consecutive outpatients referred for colonoscopy for chronic, nonbloody diarrhea.
  
  
  METHODS
  Stool specimens of 346 outpatients with chronic, nonbloody diarrhea, referred for colonoscopy, were measured for FC levels. The proportion of patients correctly diagnosed with the test and the relationship with endoscopic and histologic findings were measured.
  
  
  RESULTS
  Abnormal endoscopic findings were detected in 104 patients (30.1%). Histologic findings included 142 patients (41.0%) with inflammation and 204 (59.0%) without inflammation. Fecal excretion of calprotectin significantly correlated with the finding of inflammation at endoscopy and histology (P<0.0001). When 150 mcg/g of stool was used as the upper reference limit, FC showed 75.4% sensitivity and 88.3% specificity, with 81.7% positive and 83.7% negative predictive values for histologic inflammation.
  
  
  CONCLUSIONS
  In outpatients referred for colonoscopy a measurement of FC is accurate to identify those with histologic inflammation. Assay of FC may be a reliable and noninvasive screening tool to identify inflammatory causes of chronic, nonbloody diarrhea.
authors.affiliation: Sezione e U.O.C. di Gastroenterologia, Di.Bi.M.I.S, Università di Palermo, Palermo, Italy. annalisalicata@yahoo.com
authors.forename: Anna
authors.initials: A
authors.lastname: Licata
authors.forename: Claudia
authors.initials: C
authors.lastname: Randazzo
authors.forename: Maria
authors.initials: M
authors.lastname: Cappello
authors.forename: Vincenza
authors.initials: V
authors.lastname: Calvaruso
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Butera
authors.forename: Ada M
authors.initials: AM
authors.lastname: Florena
authors.forename: Sergio
authors.initials: S
authors.lastname: Peralta
authors.forename: Calogero
authors.initials: C
authors.lastname: Cammà
authors.forename: Antonio
authors.initials: A
authors.lastname: Craxì
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D003113:Colonoscopy / Q000379:methods; D003967:Diarrhea / Q000175:diagnosis* / Q000209:etiology; D005243:Feces / Q000737:chemistry*; D005260:Female; D006801:Humans; D007249:Inflammation / Q000175:diagnosis* / Q000209:etiology; D039841:Leukocyte L1 Antigen Complex / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D039841:Leukocyte L1 Antigen Complex