Diagnosis of Neonatal Sepsis: The Role of Inflammatory Markers

Abstract

This is a narrative review on the role of biomarkers in the diagnosis of neonatal sepsis. We describe the difficulties to obtain standardized definitions in neonatal sepsis and discuss the limitations of published evidence of cut-off values and their sensitivities and specificities. Maternal risk factors influence the results of inflammatory markers as do gestational age, the time of sampling, the use of either cord blood or neonatal peripheral blood, and some non-infectious causes. Current evidence suggests that the use of promising diagnostic markers such as CD11b, CD64, IL-6, IL-8, PCT, and CRP, either alone or in combination, might enable clinicians discontinuing antibiotics confidently within 24-48 h. However, none of the current diagnostic markers is sensitive and specific enough to support the decision of withholding antibiotic treatment without considering clinical findings. It therefore seems to be justified that antibiotics are often initiated in ill term and especially preterm infants. Early markers like IL-6 and later markers like CRP are helpful in the diagnosis of neonatal sepsis considering the clinical aspect of the neonate, the gestational age, maternal risk factors and the time (age of the neonate regarding early-onset sepsis) of blood sampling.

Keywords: C-reactive protein (CRP); early onset sepsis; inflammatory marker; interleukin-6; late onset sepsis; preterm/full term infants.

Figure 1

Initiation of infectious/inflammatory processes and release of inflammatory markers over the first 48 h of life in early onset neonatal sepsis. IL, interleukin; PCT, procalcitonin; CRP, C-reactive protein; CD64, cluster of differentiation (neutrophil surface expression).