Hepcidin, an Iron Regulatory Hormone of Innate Immunity, is Differentially Expressed in Premature Fetuses with Early-Onset Neonatal Sepsis.

OBJECTIVE

Hepcidin, a mediator of innate immunity, binds the iron exporter ferroportin, leading to functional hypoferremia through intracellular iron sequestration. We explored hepcidin-ferroportin interactions in neonates clinically diagnosed with early-onset neonatal sepsis (EONS).

STUDY DESIGN

Hepcidin and interleukin (IL)-6 were quantified by enzyme-linked immunosorbent assay (ELISA) in 92 paired cord blood-maternal blood samples in the following groups: "Yes" EONS ( = 41, gestational age [GA] 29 ± 1 weeks) and "No" EONS ( = 51, GA 26 ± 1 weeks). Placental hepcidin and ferroportin expression were evaluated by immunohistochemistry and real-time-polymerase chain reaction (RT-PCR). Liver hepcidin and ferroportin expression patterns were ascertained in autopsy specimens of neonates ( = 8) who died secondary to culture-proven sepsis.

RESULTS

Cord blood hepcidin was significantly elevated (GA corrected,  = 0.018) and was positively correlated with IL-6 ( = 0.379,  = 0.001) in EONS. Hepcidin localized at syncytiotrophoblast and fetal vascular endothelium. Placental ferroportin, but not hepcidin mRNA correlated with cord blood hepcidin levels ( = 0.46,  = 0.039) and funisitis severity ( = 0.50,  = 0.018). Newborns who died from sepsis ( = 4) had higher hepatic hepcidin and iron sequestration, but lower ferroportin staining than those who died of nonsepsis causes ( = 4).

CONCLUSION

Premature fetuses with EONS have elevated circulating hepcidin, likely related to lower placenta and liver ferroportin expression. Fetal hepcidin-ferroportin interaction appears to play a role in EONS pathophysiology independent of maternal response to intrauterine inflammation.