title: Interleukin 27 as a sepsis diagnostic biomarker in critically ill adults.
abstract: OBJECTIVE
  We previously identified interleukin 27 (IL-27) as a sepsis diagnostic biomarker in critically ill children. The current study tested the performance of IL-27 alone and in combination with procalcitonin (PCT) for diagnosing sepsis in critically ill adults.
  
  
  METHODS
  Serum samples were made available from a prior prospective study of sepsis biomarkers in critically ill adults. The primary analysis used receiver operating characteristic curves to evaluate the performance of IL-27 and PCT. Secondary analysis explored IL-27 performance in subgroups of patients with sepsis secondary to lung and nonlung sources of infection. The net reclassification improvement was used to estimate the incremental predictive ability of IL-27 compared with PCT alone. Classification and regression tree analysis was used to generate an IL-27- and PCT-based decision tree.
  
  
  RESULTS
  There were 145 patients with sepsis and 125 without sepsis. The receiver operating characteristic curve for IL-27 was inferior (area under the curve [AUC], 0.68; 95% confidence interval [CI], 0.62-0.75) to that of PCT (AUC, 0.84; 95% CI, 0.79-0.89). Similar findings were observed when comparing patients with a lung source of infection and those without sepsis. For sepsis patients with a nonlung source of infection, adding IL-27 to PCT improved discrimination (net reclassification improvement = 0.685; P < 0.001). The AUC for the classification and regression tree-derived decision tree was 0.92 (95% CI, 0.88-0.96) and was significantly greater than that of PCT alone.
  
  
  CONCLUSIONS
  When used in combination with PCT, IL-27 may improve classification of critically ill adults with sepsis secondary to a nonlung source of infection.
authors.affiliation: *Division of Critical Care Medicine, Cincinnati Children's Hospital Medical Center and Cincinnati Children's Hospital Research Foundation; and Departments of †Pediatrics; and ‡Emergency Medicine, University of Cincinnati College of Medicine, Cincinnati, OH; and §Réanimation Médicale, Hôpital Central; and ∥INSERM UMR_S 1116, Equipe TREM, Faculté de Médecine, Université de Lorraine, Nancy, France.
authors.forename: Hector R
authors.initials: HR
authors.lastname: Wong
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Lindsell
authors.forename: Patrick
authors.initials: P
authors.lastname: Lahni
authors.forename: Kimberly W
authors.initials: KW
authors.lastname: Hart
authors.forename: Sebastien
authors.initials: S
authors.lastname: Gibot
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D002116:Calcitonin / Q000097:blood; D015740:Calcitonin Gene-Related Peptide; D003663:Decision Trees; D006801:Humans; D064094:Interleukin-27 / Q000097:blood*; D008171:Lung Diseases / Q000150:complications; D011237:Predictive Value of Tests; D011498:Protein Precursors / Q000097:blood; D012141:Respiratory Tract Infections / Q000150:complications; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D018805:Sepsis / Q000175:diagnosis* / Q000382:microbiology
chemical_list: D015415:Biomarkers; C000606589:CALCA protein, human; D064094:Interleukin-27; D011498:Protein Precursors; D002116:Calcitonin; D015740:Calcitonin Gene-Related Peptide
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