Preterm birth is associated with immune dysregulation which persists in infants exposed to histologic chorioamnionitis: a descriptive study

AbstractObjectiveTo characterise the umbilical cord blood immune profile in preterm infants compared to term-born controls and the postnatal immune response following exposure to histologic chorioamnionitis (HCA) in preterm infants.DesignDescriptive, observational cohort study.SettingEdinburgh, UK.Population118 preterm infants (mean gestational age 29+0 weeks, range 23+2 to 32+0) and 59 term-born controls.MethodsPlacental histopathology was used to identify reaction patterns indicative of HCA, and a customised immunoassay of 24 inflammatory markers and trophic proteins selected to reflect the perinatal immune response was performed on umbilical cord blood in term and preterm participants and postnatal day 5 blood in the preterm group.ResultsThe umbilical cord blood immune profile classified gestational age category with 86% accuracy (95% CI 0.78-0.92), p-value=1.242×10−14. Pro-inflammatory proteins IL-6, MCP-1 and CRP were elevated in the cord blood of preterm infants whilst BDNF, C3, C9, IL-18, MMP-9 and RANTES were decreased, compared to infants born at term. In preterm infants, exposure to HCA was associated with elevations in 5 immune proteins on postnatal day 5 (BDNF, C3, IL-8, MIP-1β and MMP-9) when compared to preterm infants who were not exposed.ConclusionPreterm birth is associated with a distinct immune profile in umbilical cord blood and infants exposed to HCA experience specific alterations in immune function that persist to day 5 of postnatal life.