title: Procalcitonin as a marker of respiratory disorder in neonates.
abstract: BACKGROUND
  Serum procalcitonin (PCT) increases in various respiratory disorders such as acute respiratory distress syndrome. Elevated PCT is also observed in healthy neonates. In this study, we investigated whether PCT is a good marker of respiratory disorder in neonates.
  
  
  METHODS
  A total of 155 neonates with or without respiratory disorder, were eligible for the study. PCT was measured on electrochemiluminescence immunoassay. Each neonate was allocated to the non-respiratory disorder (control) group (n = 95), or a respiratory disorder group (n = 60). PCT was compared between the groups, and association with other markers, including C-reactive protein (CRP) and white blood cell (WBC) count, was analyzed.
  
  
  RESULTS
  Of the 60 neonates in the respiratory disorder group, 39, 10, five, one, two, two, and one neonates had transient tachypnea of the newborn, respiratory distress syndrome, air leak syndrome, meconium aspiration syndrome, 18-trisomy, neonatal asphyxia, and congenital diaphragmatic hernia, respectively. Mean PCT, CRP and WBC count in the respiratory disorder group were 9.01 ng/mL, 0.26 mg/dL, and 16,100 cells/μL, respectively. The area under the curve obtained for PCT in distinguishing between the respiratory disorder and control groups was 0.85 (sensitivity, 66.7%; specificity, 93.0%; optimum cut-off, 3.73 ng/mL), that for CRP was 0.72 (sensitivity, 75.0%; specificity, 64.6%; optimum cut-off, 0.14 mg/dL), and for WBC it was 0.44 (sensitivity, 60.0%; specificity, 29.6%; optimum cut-off, 15,000 cells/μL).
  
  
  CONCLUSIONS
  PCT is more susceptible, as a diagnostic parameter of infection, to the effect of respiratory disturbance than CRP and WBC.
authors.affiliation: Department of Pediatrics, Ehime University Graduate School of Medicine, Toon, Ehime, Japan.
authors.forename: Fumihiro
authors.initials: F
authors.lastname: Ochi
authors.forename: Takashi
authors.initials: T
authors.lastname: Higaki
authors.forename: Masaaki
authors.initials: M
authors.lastname: Ohta
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Yamauchi
authors.forename: Mari
authors.initials: M
authors.lastname: Tezuka
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Chisaka
authors.forename: Tomozo
authors.initials: T
authors.lastname: Moritani
authors.forename: Hisamichi
authors.initials: H
authors.lastname: Tauchi
authors.forename: Eiichi
authors.initials: E
authors.lastname: Ishii
mesh_terms: D015415:Biomarkers / Q000097:blood*; D002097:C-Reactive Protein / Q000378:metabolism; D002116:Calcitonin / Q000097:blood*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007958:Leukocyte Count; D008163:Luminescent Measurements; D008297:Male; D012372:ROC Curve; D012120:Respiration Disorders / Q000175:diagnosis*; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers; D002116:Calcitonin; D002097:C-Reactive Protein
keywords: C-reactive protein; neonate; procalcitonin electrochemiluminescence immunoassay; white blood cell count