Rapid immune perturbations during sepsis and necrotising enterocolitis in preterm babies

Abstract Deaths complicated by infection are a major cause of mortality in preterm babies. Here we study the influence of bacterial sepsis and the gut inflammatory disorder necrotising enterocolitis (NEC), frequently associated with bacterial complications, on host immune dysregulation in extremely preterm babies. We identify a peripheral blood immune signature that distinguishes sepsis and NEC from other cases of suspected, though microbiologically unconfirmed, sepsis. Some signature traits could even make this distinction in babies with low or undetectable C-reactive protein, a common clinical test to alert infection. Our analysis incorporates longitudinal single-cell genomic evaluation of peripheral blood immune cells, elucidating amphiregulin as a key differentially expressed gene during sepsis and NEC, which was validated as a plasma analyte that correlated with disease-associated clinical signs. Collectively, signature immune traits provide insight into dysregulated sepsis and NEC-associated pathways and highlight candidate markers, pending validation, that could improve diagnostic-led, targeted antibiotic prescribing.