Inflammation in exhaled breath condensate from children with prematurity-associated lung disease

<bold>Introduction:</bold> We recently described several phenotypes of prematurity-associated lung disease (PLD) but the underlying mechanisms of each are unknown. <bold>Objective:</bold> We, therefore, compared cytokines measured in exhaled breath condensate (EBC) for the different phenotypes of PLD compared to Preterm and Term controls <bold>Methods:</bold> School-aged (7-12 years) children, stratified by spirometry into those with prematurity-associated obstructive lung disease (POLD; FEV1<LLN, FEV1/FVC<LLN), prematurity-associated preserved ratio of impaired spirometry (pPRISm; FEV1<LLN, FEV1/FVC≥LLN), Preterm controls (PTc, FEV1≥LLN) and Term controls (Tc), performed EBC as part of the Respiratory Health Outcomes in Neonates (RHiNO) study. Cytokines were measured in EBC using immunoassay (MSD platform). Data were compared using one-way ANOVA, with post-hoc Tukey correction. <bold>Results:</bold> 174 preterm-born children (mean age 10.8 years; POLD n=21, pPRISm n=10, PTc n=92, and Tc n=51) had cytokines measured from EBC. Differences were found between the POLD group and Preterm controls for IFN-γ, IL-12/IL-23p40, IL-12p70, IL-13, IL-15, IL-16, IL-17A, IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-7, IL-8, MCP-1, TNF-α and VEGF, with significantly higher concentrations of these cytokines identified. Greater concentrations of IL-10 and IL-1α were also noted in the POLD group when compared with the Term controls. Generally, no differences were noted between the pPRISm and the Preterm and Term control groups. <bold>Conclusion:</bold> Preterm-born children with obstructive lung disease phenotype have evidence of ongoing inflammatory processes as evidenced by greater cytokine levels in their EBC.