title: Evaluation of the clinical performance of an automated procalcitonin assay for the quantitative detection of bloodstream infection.
abstract: BACKGROUND
  Bloodstream infection (BSI) is associated with a high mortality rate. Since the origin of infection is demonstrated in approximately 2/3rds of cases, early and established biomarkers are warranted. We evaluated the clinical performances of automated procalcitonin (PCT) and C-reactive protein (CRP) assays for the quantitative detection of BSI. Analytical performance of the VIDAS(R) BRAHMS PCT assay (bioMérieux, France) was assessed and also compared with the semi-quantitative PCT-Q test (BRAHMS Aktiengesellschaft, Germany).
  
  
  METHODS
  We prospectively included consecutive patients divided into 3 groups at the Dong-A University Medical Center. Patients were categorized according to the criteria of the American College of Chest Physicians/Society of Critical Care Medicine Consensus Conference (ACCP/SCCM), and also on the basis of catheter-associated bacteremia.
  
  
  RESULTS
  A total 77 patients were enrolled. All mean values of PCT and PCT-Q were consistent with the reference value. Measured PCT concentrations showed good linearity (r=0.983). The between-run, within-run, and total imprecisions were below 5%. The PCT levels in gram-negative bacteremia were significantly higher than those in gram-positive bacteremia. Furthermore, the PCT concentrations were significantly different among non-infection, bacteremia, sepsis, severe sepsis, and septic shock groups. Our study showed that PCT >0.3 ng/mL had 95.0% sensitivity and 97.3% specificity, whereas CRP >5.46 mg/dL had 85.0% sensitivity and 86.5% specificity for diagnosing sepsis.
  
  
  CONCLUSIONS
  We suggest that, compared with CRP, PCT is a better diagnostic and discriminative biomarker of sepsis categorized according to the ACCP/SCCM. Moreover, catheter-associated bacteremia could be discriminated from sepsis using PCT concentration.
authors.affiliation: Department of Laboratory Medicine, Dong-A University College of Medicine, Busan, Korea.
authors.forename: Kyung Eun
authors.initials: KE
authors.lastname: Kim
authors.forename: Jin Yeong
authors.initials: JY
authors.lastname: Han
mesh_terms: D000328:Adult; D016470:Bacteremia / Q000175:diagnosis*; D015415:Biomarkers / Q000032:analysis / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011498:Protein Precursors / Q000097:blood*; D012372:ROC Curve; D012680:Sensitivity and Specificity; D018805:Sepsis / Q000175:diagnosis
chemical_list: D015415:Biomarkers; C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D002097:C-Reactive Protein; D015740:Calcitonin Gene-Related Peptide