Early detection of an early onset infection in the neonate based on measurements of procalcitonin and C-reactive protein concentrations in cord blood.
BACKGROUND
The aim of this study was to test the diagnostic model of combining procalcitonin (PCT) and C-reactive protein (CRP) levels in the cord blood and routinely used biochemical parameters and clinical data in the prediction of early onset neonatal infection.


METHODS
PCT and CRP concentrations were measured in cord blood of neonates with infection (group A, n=46) and compared with uninfected neonates (group B, n=240). Inclusion criteria for group A were based on obstetric history, clinical data and results of laboratory tests. Logistic regression was applied. The receiver operating characteristic (ROC) curves were constructed for PCT, CRP and the diagnostic model.


RESULTS
There was a highly significant (p<0.000001) difference in PCT and CRP concentrations between both groups. The cut-off point for PCT in cord blood was 1.22 ng/mL [sensitivity % (SE%) 80.43, specificity % (SP%) 71.67, positive predictive value % (PPV%) 35.24, negative predictive value % (NPV%) 95.03], and 1.0 mg/L for CRP (SE% 73.91, SP% 77.92, PPV% 39.08, NPV% 93.97). In total, seven variables were included in the model (concentrations of PCT and CRP in cord blood, tocolysis, nutritional status of the newborn, Apgar score, neutrophil ratio and red blood cell count in neonatal venous blood), which proved to offer the highest sensitivity (91.3%; 95% CI: 83-99) and specificity (90%; 95% CI: 86-94) for the detection of early onset neonatal infection. The likelihood ratio for the model was high at 9.13, with PPV% 63.64 (95% CI: 52-75), NPV% 98.18 (95% CI: 96-100) and calculated area under the curve at 0.973.


CONCLUSIONS
The diagnostic model based on seven clinical and laboratory parameters, using the concentration of PCT and CRP measurements in the cord blood, could be a useful tool for the prediction of early onset neonatal infection.
Kordek
Agnieszka
A
Pomeranian Medical University, Szczecin, Poland. agkordek@sci.pam.szczecin.pl
Hałasa
Maciej
M
Podraza
Wojciech
W
D000328:Adult; D017668:Age of Onset; D019540:Area Under Curve; D001424:Bacterial Infections / Q000097:blood* / Q000175:diagnosis*; D002097:C-Reactive Protein / Q000378:metabolism*; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D042241:Early Diagnosis; D005260:Female; D005312:Fetal Blood / Q000378:metabolism*; D006801:Humans; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000097:blood* / Q000175:diagnosis*; D008297:Male; D011237:Predictive Value of Tests; D011247:Pregnancy; D011498:Protein Precursors / Q000097:blood*; D012372:ROC Curve; D013997:Time Factors
C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D002097:C-Reactive Protein; D015740:Calcitonin Gene-Related Peptide