Robust Early Immune Function in Preterm Infants

Abstract

Aims: To detail the systemic inflammatory response in the preterm infant by examining functional neutrophil activation over the first week of life. Method: We prospectively collected serial blood samples from premature infants (n=51; < 32 weeks gestation) on day 0, 1, 2 and 7 of life and from adult controls (n=12). Whole blood CD11b and Toll-like Receptor 4 (TLR4) expression as well as reactive oxygen intermediate (ROI) production were evaluated using appropriate antibodies and fluorescent substrates via flow cytometry at baseline. Premature infants were divided into normal and abnormal outcome groups according to Cranial USS findings [Normal (n=41): Grade 0-2 intraventricular haemorrhage (IVH); Abnormal (n=10): Grade 3-4 IVH, Periventricular Leukomalacia or death]. Results: Preterm infants in both outcome groups have elevated baseline CD11b, TLR4 expression, and ROI production compared with adults over the first week of life. These results were not associated with the presence or absence of chorioamnionitis. Figure Conclusions: Preterm infants have robust baseline immune responses irrespective of outcome. These results are comparable to the adult immune response.