title: Role of procalcitonin in infectious gastroenteritis and inflammatory bowel disease.
abstract: OBJECTIVE
  We have evaluated procalcitonin (PCT) as a diagnostic marker for bacterial gastroenteritis (GE) and as a disease activity marker in inflammatory bowel disease (IBD) patients.
  
  
  METHODS
  This was a prospective single-center study performed over a 1-year period. Venous blood samples were drawn from hospitalized patients with acute GE and tested for PCT, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and total white cell count (TWC); stools from the same patients were tested for standard pathogens. Venous blood samples from patients with IBD were tested for PCT, CRP, ESR, and platelet count. The PCT level was measured using an immunofluorescent assay, with normal being defined as <0.5 ng/ml.
  
  
  RESULTS
  The GE arm of study consisted of 81 patients, 18.5% of whom were diagnosed with bacterial GE. The PCT and CRP levels were good diagnostic markers of bacterial GE, with an area under the curve (AUC) of 0.727 [95% confidence interval (CI) 0.580-0.874] and 0.786 (95% CI 0.627-0.946), respectively. An elevated PCT > or =0.5 ng/ml was associated with a 13-fold increased risk of renal impairment. The IBD arm of study consisted of 72 IBD patients. The PCT levels were not significantly different between active and inactive IBD in this patient cohort.
  
  
  CONCLUSIONS
  Our results indicate that PCT and CRP are comparably good diagnostic markers of bacterial GE but that PCT is not useful as in monitoring disease activity in patients with IBD.
authors.affiliation: Department of Gastroenterology and Hepatology, Singapore General Hospital, Singapore, 169608, Singapore. ktjthia@gmail.com
authors.forename: Kelvin Teck-Joo
authors.initials: KT
authors.lastname: Thia
authors.forename: Edwin Shih-Yen
authors.initials: ES
authors.lastname: Chan
authors.forename: Khoon-Lin
authors.initials: KL
authors.lastname: Ling
authors.forename: Wai-Yoong
authors.initials: WY
authors.lastname: Ng
authors.forename: Edward
authors.initials: E
authors.lastname: Jacob
authors.forename: Choon-Jin
authors.initials: CJ
authors.lastname: Ooi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D001799:Blood Sedimentation; D002097:C-Reactive Protein / Q000378:metabolism; D002116:Calcitonin / Q000097:blood* / Q000502:physiology; D015740:Calcitonin Gene-Related Peptide; D005260:Female; D005759:Gastroenteritis / Q000097:blood* / Q000175:diagnosis* / Q000382:microbiology; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000097:blood* / Q000175:diagnosis*; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011498:Protein Precursors / Q000097:blood* / Q000502:physiology; D012372:ROC Curve; D012475:Salmonella / Q000472:pathogenicity; D055815:Young Adult
chemical_list: D015415:Biomarkers; C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D002097:C-Reactive Protein; D015740:Calcitonin Gene-Related Peptide