title: Procalcitonin is not sufficiently reliable to be the sole marker of neonatal sepsis of nosocomial origin.
abstract: BACKGROUND
  It has recently been suggested that serum procalcitonin (PCT) is of value in the diagnosis of neonatal sepsis, with varying results. The aim of this prospective multicenter study was to assess the usefulness of PCT as a marker of neonatal sepsis of nosocomial origin.
  
  
  METHODS
  One hundred infants aged between 4 and 28 days of life admitted to the Neonatology Services of 13 acute-care teaching hospitals in Spain over 1-year with clinical suspicion of neonatal sepsis of nosocomial origin were included in the study. Serum PCT concentrations were determined by a specific immunoluminometric assay. The reliability of PCT for the diagnosis of nosocomial neonatal sepsis at the time of suspicion of infection and at 12-24 h and 36-48 h after the onset of symptoms was calculated by receiver-operating characteristics (ROC) curves. The Youden's index (sensitivity + specificity - 1) was used for determination of optimal cutoff values of the diagnostic tests in the different postnatal periods. Sensitivity, specificity, and the likelihood ratio of a positive and negative result with the 95% confidence interval (CI) were calculated.
  
  
  RESULTS
  The diagnosis of nosocomial sepsis was confirmed in 61 neonates. Serum PCT concentrations were significantly higher at initial suspicion and at 12-24 h and 36-48 h after the onset of symptoms in neonates with confirmed sepsis than in neonates with clinically suspected but not confirmed sepsis. Optimal PCT thresholds according to ROC curves were 0.59 ng/mL at the time of suspicion of sepsis (sensitivity 81.4%, specificity 80.6%); 1.34 ng/mL within 12-24 h of birth (sensitivity 73.7%, specificity 80.6%), and 0.69 ng/mL within 36-48 h of birth (sensitivity 86.5%, specificity 72.7%).
  
  
  CONCLUSIONS
  Serum PCT concentrations showed a moderate diagnostic reliability for the detection of nosocomial neonatal sepsis from the time of suspicion of infection. PCT is not sufficiently reliable to be the sole marker of sepsis, but would be useful as part of a full sepsis evaluation.
authors.affiliation: Service of Neonatology, Hospital Universitario Central de Asturias, Oviedo, Spain. jblopez@uniovi.es
authors.forename: José B
authors.initials: JB
authors.lastname: López Sastre
authors.forename: David
authors.initials: D
authors.lastname: Pérez Solís
authors.forename: Vicente
authors.initials: V
authors.lastname: Roqués Serradilla
authors.forename: Belén
authors.initials: B
authors.lastname: Fernández Colomer
authors.forename: Gil D
authors.initials: GD
authors.lastname: Coto Cotallo
authors.forename: Xavier
authors.initials: X
authors.lastname: Krauel Vidal
authors.forename: Eduardo
authors.initials: E
authors.lastname: Narbona López
authors.forename: Manuel
authors.initials: M
authors.lastname: García del Río
authors.forename: Manuel
authors.initials: M
authors.lastname: Sánchez Luna
authors.forename: Antonio
authors.initials: A
authors.lastname: Belaustegui Cueto
authors.forename: Manuel
authors.initials: M
authors.lastname: Moro Serrano
authors.forename: Alfonso
authors.initials: A
authors.lastname: Urbón Artero
authors.forename: Emilio
authors.initials: E
authors.lastname: Alvaro Iglesias
authors.forename: Angel
authors.initials: A
authors.lastname: Cotero Lavín
authors.forename: Eduardo
authors.initials: E
authors.lastname: Martínez Vilalta
authors.forename: Bartolomé
authors.initials: B
authors.lastname: Jiménez Cobos
mesh_terms: D015415:Biomarkers / Q000097:blood; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D003428:Cross Infection / Q000097:blood / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases; D008297:Male; D011446:Prospective Studies; D011498:Protein Precursors / Q000097:blood*; D012680:Sensitivity and Specificity; D018805:Sepsis / Q000097:blood / Q000175:diagnosis*; D013030:Spain
chemical_list: D015415:Biomarkers; C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D015740:Calcitonin Gene-Related Peptide