Procalcitonin measurement at 24 hours of age may be helpful in the prompt diagnosis of early-onset neonatal sepsis

Background: The clinical signs of early-onset neonatal sepsis (EONS) are nonspecific and indistinguishable from those of noninfectious disorders. The early diagnosis of EONS is difficult, but is essential to improve outcomes. The aim of this study was to determine the diagnostic value of procalcitonin (PCT) at birth and at 24 h of age in the prompt diagnosis of EONS. Methods: The patient group consisted of neonates with a Tollner score of >= 10 or a Tollner score of 5-10 but with the presence of prolonged rupture of the membranes (>18 h) or chorioamnionitis or maternal fever (n = 171). The control group (n = 89) comprised neonates admitted to the neonatal intensive care unit for different disease entities. Procalcitonin levels at birth (first) and at 24 h of age (second) were measured for each neonate in both of the study groups. Results: There was no difference between the two groups in terms of gender, birth weight, or gestational age. The mean (min-max) first PCT level was 0.48 (0.07-3.48) ng/ml in the controls and 0.51 (0.09-28.6) ng/ml in patients. The mean (min-max) second PCT level was 1.72 (0.21-18.23) ng/ml in the controls and 16.17 (0.17-100) ng/ml in patients. There was no statistically significant difference in PCT levels between the patient and control groups at birth. However, at 24 h of age, PCT levels were significantly higher in the patient group than in the control group (p < 0.001). Serum PCT levels in controls at 24 h of age were slightly increased compared to levels at birth, but as a normal reaction. PCT thresholds for the diagnosis of sepsis were 0.59 ng/ml at birth (sensitivity 48.7%, specificity 68.6%) and 5.38 ng/ml at 24 h of life (sensitivity 83.3%, specificity 88.6%). Conclusions: In EONS, PCT measurements at birth may initially be normal; a serial PCT measurement at 24 h of age may be more helpful for an early diagnosis. During the first 24 h of life PCT is a more sensitive marker of infection than C-reactive protein. Further studies are needed to confirm our findings. (C) 2011 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.