Proinflammatory cytokines as predictors of bronchopulmonary dysplasia in preterm infants

Bronchopulmonary dysplasia (BPD) is an actual problem in pediatrics due to significant morbidity and high disability. Currently, there is no doubt that the immune system plays a leading role in the pathogenesis, clinical course and outcome of respiratory disorders and the development of BPD in children. The aim of this study was to determine the level of inflammatory indicator (CRP), pro- [interleukin-1-beta (IL-1β), IL-6 and tumor necrosis factor-alpha (TNF-α)] and anti-inflammatory (IL-10) cytokines in blood and tracheal aspirates to predict the subsequent development of BPD in premature babies. Material and methods. The cytokine status in blood serum and tracheal aspirate (TA) was studied in 47 children with respiratory distress syndrome (RDS), congenital pneumonia, and infection specific to the perinatal period with predominant lung involvement. All children with respiratory disorders were premature with a gestational age of 28–35 weeks, and weigh 890–2180 grams at birth. Of the 47 preterm infants initially enrolled in the study, 18 developed BPD and 29 did not. Results. Infants who developed BPD had significantly lower gestational age and birth weight than infants without BPD at follow-up. In newborns, there was an imbalance between the pools of cytokines in the peripheral blood and tracheal aspirate (TA). The levels of proinflammatory cytokines on the third day (TNF-α, IL-1β, IL-6) and CRP were significantly higher, and the levels of anti-inflammatory cytokines (IL-10) were significantly lower in the BPD group compared with those who did not develop BPD. Our study also determined the threshold levels of cytokines in blood samples and TA for predicting BPD. The most significant indicators were determined for the levels of IL-6 (≥926 pg/ml) in serum and IL-6 (≥763.5 pg/ml) and TNF-α (≥195.9 pg/ml) in TA samples. We propose to use these thresholds to predict the development of BPD.