Procalcitonin in Preterm Neonates: A Different Threshold and Prolonged Interpretation.

Area of Science:

• Neonatal Medicine
• Clinical Chemistry
• Infectious Disease Diagnostics

Background:

• Early-onset sepsis is a critical concern in premature neonates (<32 weeks gestation).
• Accurate and timely diagnosis is essential for effective treatment and improved outcomes.
• Procalcitonin (PCT) is a biomarker used in sepsis diagnosis, but its optimal threshold in preterm infants requires further evaluation.

Purpose of the Study:

• To determine the positive threshold of procalcitonin (PCT) for diagnosing early-onset sepsis in neonates born before 32 weeks of gestation.
• To assess the utility of PCT levels collected within 6 hours of birth for sepsis diagnosis in this vulnerable population.

Main Methods:

• A retrospective, bicentric study involving 260 neonates (<32 weeks gestation) was conducted.
• Two groups were analyzed: PCT levels at birth (CordPCT) and within 6 hours of life (delPCT).
• Receiver Operating Characteristic (ROC) curves were used to determine PCT positive thresholds.

Main Results:

• The overall positive PCT threshold was determined to be 0.98 ng/mL.
• The threshold was 1.00 ng/mL for the CordPCT group and 0.98 ng/mL for the delPCT group.
• PCT levels sampled within 6 hours of life (delPCT) demonstrated significantly higher diagnostic accuracy (AUC=0.94) compared to cord blood samples (AUC=0.75).

Conclusions:

• The positive PCT threshold for early-onset sepsis in preterm neonates (<32 weeks gestation) is higher than in term infants.
• PCT levels measured within 6 hours of birth appear valuable for inclusion in sepsis screening algorithms for preterm neonates.