Procalcitonin is not sufficiently reliable to be the sole marker of neonatal sepsis of nosocomial origin.
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.
López Sastre
José B
JB
Service of Neonatology, Hospital Universitario Central de Asturias, Oviedo, Spain. jblopez@uniovi.es
Pérez Solís
David
D
Roqués Serradilla
Vicente
V
Fernández Colomer
Belén
B
Coto Cotallo
Gil D
GD
Krauel Vidal
Xavier
X
Narbona López
Eduardo
E
García del Río
Manuel
M
Sánchez Luna
Manuel
M
Belaustegui Cueto
Antonio
A
Moro Serrano
Manuel
M
Urbón Artero
Alfonso
A
Alvaro Iglesias
Emilio
E
Cotero Lavín
Angel
A
Martínez Vilalta
Eduardo
E
Jiménez Cobos
Bartolomé
B
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
D015415:Biomarkers; C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D015740:Calcitonin Gene-Related Peptide