The Sensitivity and Specificity of Procalcitonin in Diagnosing Bacterial Sepsis in Neonates

Neonatal sepsis accounts for 15% of all neonatal deaths. Early detection enables prompt administration of antibiotic treatment, reducing morbidity and mortality. This study aims to review the sensitivity and specificity of procalcitonin in diagnosing microbiologically-proven sepsis in neonates to determine the optimal procalcitonin cut-off value for use in clinical practice.

Medline, EMBASE and PubMed were searched on 3 May 2023 for original studies in symptomatic neonates in whom both blood culture and procalcitonin levels were taken, and a procalcitonin cut-off with either sensitivity or specificity reported. Studies that included asymptomatic or culture-negative neonates in the proven sepsis group were excluded. Risk of bias was assessed using the Qualitative Assessment of Diagnostic Accuracy Studies 2 tool.

Nineteen original studies enrolling a total of 1920 symptomatic neonates (721 with proven sepsis) were included. Six studies used a procalcitonin cut-off of 0.5 ng/mL and found a sensitivity of 87% to 100% and specificity of 17% to 89%. Nine studies evaluated higher procalcitonin cut-off values between 0.99 ng/mL and 2 ng/mL, which were 67% to 98% sensitive and 41% to 89% specific. All other procalcitonin thresholds were neither sensitive nor specific. Meta-analysis was not performed because of high risk of bias within the identified studies.

This review found that procalcitonin was highly sensitive (87% to 100%) at a cut-off value of 0.5 ng/mL, although specificity varied greatly across all cut-off values reviewed. The variation in diagnostic accuracy between studies suggests that procalcitonin may be useful to guide antibiotic cessation but should not be used alone as a diagnostic marker for neonatal sepsis.