title: Serum C-reactive protein (CRP) levels in young adults can be used to discriminate between inflammatory and non-inflammatory diarrhea.
abstract: OBJECTIVE
  To determine if the level of serum C-reactive protein (CRP) can be used to differentiate between inflammatory diarrhea and non-inflammatory diarrhea in patients with acute infectious diarrhea or acute gastrointestinal infection.
  
  
  METHODS
  This was a retrospective study based on medical records from a single military hospital located in Daejeon, Republic of Korea. The records of 1,085 patients who presented with abdominal pain, fever (≥ 37.8 °C), and diarrhea between May 2008 and May 2011 were reviewed, and 538 patients were selected. The eligible patients had undergone abdominal contrast tomography (CT) or colonoscopy within 3 days and blood sampling on the day of admission. The selected patients were divided into two groups on the basis of their abdominal CT or colonoscopy findings: group A, the inflammatory diarrhea group (n = 234), and group B, the non-inflammatory diarrhea group (n = 304). We then compared the clinical and laboratory characteristics of these two groups.
  
  
  RESULTS
  Erythrocyte sedimentation rate and CRP levels were significantly higher in group A (inflammatory diarrhea) patients than group B (non-inflammatory diarrhea) patients (16.47 ± 5.46 vs. 15.29 ± 5.72 (P < 0.05), respectively, and 4.92 ± 2.49 vs. 1.79 ± 0.95 (P < 0.05), respectively). Multivariate analysis revealed that CRP level on admission was the most important predictor of inflammatory diarrhea (OR 7.39, P < 0.05). Receiver operating characteristic analysis results also showed that CRP had the highest area-under-the-curve value (0.91; 95 % confidence interval 0.88-0.93; P < 0.05) for distinguishing inflammatory diarrhea from non-inflammatory diarrhea. At a cut-off level of 3.08 mg/dL, CRP had a sensitivity of 82 % and a specificity of 85 %.
  
  
  CONCLUSIONS
  CRP as a diagnostic marker of inflammatory diarrhea was superior to the other inflammatory markers and clinical characteristics we evaluated in this study. A patient's CRP level on admission may aid clinical decision-making, for example initiating empiric antibiotics therapy and/or performing additional clinical tests.
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Chungnam National University Hospital, Chungnam National University School of Medicine, 282 Munhwa-ro, 301-721, Jung-gu, Daejeon, Korea.
authors.forename: Dong Hwan
authors.initials: DH
authors.lastname: Kim
authors.forename: Sun Hyung
authors.initials: SH
authors.lastname: Kang
authors.forename: Woo Suk
authors.initials: WS
authors.lastname: Jeong
authors.forename: Hee Seok
authors.initials: HS
authors.lastname: Moon
authors.forename: Eaum Seok
authors.initials: ES
authors.lastname: Lee
authors.forename: Seok Hyun
authors.initials: SH
authors.lastname: Kim
authors.forename: Jae Kyu
authors.initials: JK
authors.lastname: Sung
authors.forename: Byung Seok
authors.initials: BS
authors.lastname: Lee
authors.forename: Hyun Yong
authors.initials: HY
authors.lastname: Jeong
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism*; D003937:Diagnosis, Differential; D003967:Diarrhea / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology*; D005260:Female; D005759:Gastroenteritis / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology*; D006801:Humans; D008297:Male; D008889:Military Personnel; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D012372:ROC Curve; D012189:Retrospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D015415:Biomarkers; D002097:C-Reactive Protein