Exploratory proteomics study identifies candidate biomarkers for late-onset neonatal sepsis

Early diagnosis of late-onset neonatal sepsis remains difficult in preterm infants. An exploratory study reported in Pediatric Research used targeted proteomics to identify candidate biomarkers and assess whether pathogen stimulation could reproduce the observed changes. Researchers collected longitudinal blood samples in two neonatal intensive care units at onset and after 24 and 48 hours. The analysis included 15 neonates with late-onset sepsis, eight non-septic controls, and ten in vitro stimulation samples.

Sixty-six proteins showed altered expression during sepsis. Upregulated proteins were predominantly cytokines and chemokines, whereas downregulated proteins were associated with development, growth, and metabolism. Most alterations normalized within 48 hours. In parallel experiments, whole blood from preterm neonates without sepsis was stimulated with E. coli and S. epidermidis. This reproduced expression changes in a subset of proteins, suggesting direct pathogen-induced immune responses.

The findings identify potential targets for future diagnostic and monitoring research, rather than clinically validated biomarkers. The small, exploratory study requires replication in larger, independent cohorts before clinical use. The supplied report does not provide diagnostic accuracy estimates or establish whether these protein measurements improve early diagnosis or clinical outcomes.