Epigenome-wide association study on peripheral blood DNA of bronchopulmonary dysplasia in preterm infants

Bronchopulmonary dysplasia (BPD) is a lung disease in premature infants characterized by impaired pulmonary development which persists into later life. While advances in neonatal care have improved survival rates of premature infants, cases of BPD haves been increased. Therapeutic options are limited for prevention and treatment. This study was designed to explore the relationship between gestational age (GA), birth weight and estímate blood cell-type composition in premature infants and to elucidate early epigenetic biomarkers associated with BPD. Peripheral blood DNA (at days 14 and 28) from preterm neonates that went on to develop BPD (n = 14) or not (nonBPD, n = 93) was applied to Illumina EPIC methylation arrays. Using DNA methylation analysis of cord blood DNA, we investigated association of GA and birth weight with the estimated distribution of cord blood cell types, particularly the nucleated red blood cell (NRBC) in a pilot-size cohort of preterm infants with or without BPD. We describe changes in methylation-based estimates of blood cell-type composition in relation to GA and birth weight. After adjusting for covariates (GA, birth weight, cell type proportions, etc.) we identify differentially methylated CpGs and genes associated with BPD at different time points. Peripheral blood DNA at days 14 and 28 from preterm neonates that went on to develop BPD (n = 12) or not (nonBPD, n = 84) was applied to Illumina EPIC methylation arrays. We identify differentially methylated CpGs associated with BPD.