EARLY INCREASE IN ENDOTHELIN-1 IN TRACHEAL ASPIRATES OF PRETERM INFANTS - CORRELATION WITH BRONCHOPULMONARY DYSPLASIA

Objectives: To determine whether endothelin-1 (ET-1) in tracheal aspir ates (TA) is a specific marker for acute lung injury in preterm infant s with respiratory distress syndrome (RDS) who progress to bronchopulm onary dysplasia (BPD); and to investigate the relationship between TA ET-1 and the proinflammatory cytokines, interleukin-6 (IL-6) and IL-8, as early mediators of BPD. Study design: We measured TA ET-1, IL-6, a nd IL-8 levels in preterm infants whose lungs were mechanically ventil ated for RDS, categorized into two groups, BPD or non-BPD, on the basi s of oxygen requirement at 36 weeks' postconceptional age. Results: A total of 106 TA samples were obtained from 34 infants with gestational ages ranging from 24 to 28 weeks on days 1, 3, 5, and 7 of life. Ther e was a wide range of ET-1 concentration. TA ET-1 levels were signific antly elevated on days 1, 3, and 7 in infants in whom BPD developed, i n comparison with the non-BPD group (Mann-Whitney U test: p < 0.01). T A IL-8 levels were elevated on days 1, 3, 5, and 7 in the BPD group (p < 0.01); TA IL-6 levels were elevated (p < 0.05) only on day 5. There was a similarity in pattern of increase of TA ET-1 and TA IL-8 levels in the BPD group, with both being elevated in the first 24 hours of l ife and through the first week. There was no correlation between ET-1 and IL-8 values. Conclusion: Early significant increase in the TA ET-1 and IL-8 concentrations in preterm infants with acute lung injury cor relates with subsequent progression to BPD.