Brainstem respiratory chemosensitivity: New insights and clinical implications

Abstract

<h3>Abstract</h3> <h3>Objective</h3> To 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. <h3>Design</h3> Descriptive, observational cohort study. <h3>Setting</h3> Edinburgh, UK. <h3>Population</h3> 118 preterm infants (mean gestational age 29⁺⁰ weeks, range 23⁺² to 32⁺⁰) and 59 term-born controls. <h3>Methods</h3> Placental 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. <h3>Results</h3> The 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. <h3>Conclusion</h3> Preterm 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.