Cord blood T-Cell imbalances as early predictors of bronchopulmonary dysplasia in extremely preterm neonates

Bronchopulmonary dysplasia (BPD) is a major morbidity among extremely preterm neonates and has been increasingly linked to dysregulated early-life immune responses. whether cord blood T-cell subset profiles can identify neonates at increased risk of BPD remains unclear. We examined the association between cord blood immune cell subsets and the subsequent BPD and explore immunological measures could improve early risk prediction when combined with clinical variables. In this prospective cohort study, 75 extremely preterm infants born before 32 weeks of gestation were enrolled at birth. High-parameter flow cytometry was used to quantify innate and adaptive immune cell populations from umbilical cord arterial blood. Clinical data were collected, and BPD was diagnosed at 36 weeks’ postmenstrual age. Multivariable regression and least absolute shrinkage and selection operator regression were conducted to identify cord immune features associated with BPD and to develop an exploratory prediction model. Among 75 infants, 31 developed BPD and 44 did not. After adjustment for gestational age, birth weight, duration of mechanical ventilation and amniotic inflammatory syndrome, infants who developed BPD had lower cord blood proportions of CD3⁺ T cells, CD4⁺ T cells, and regulatory T cells, as well as a lower CD4⁺/CD8⁺ T-cell ratio. Least absolute shrinkage and selection operator regression retained pulmonary hemorrhage, regulatory T-cell proportion, duration of oxygen therapy, and intraventricular hemorrhage for the final prediction model. The resulting nomogram showed high apparent discrimination, with an area under the receiver operating characteristic curve of 0.959. Decision curve analysis suggested potential clinical utility across a range of threshold probabilities. Extremely preterm infants who developed BPD showed altered cord blood T-cell profiles at birth, particularly reduced regulatory T-cell proportions. A nomogram incorporating regulatory T-cell proportion and selected clinical risk factors may support early identification of infants at increased risk of BPD.