Abstract 1198 Poster Session IV, Tuesday, 5/4 (poster 332)

Objective: To examine the effects of surfactant therapy on levels of proinflammatory cytokines IL-6 and IL-1B in tracheal fluid and blood of premature infants with RDS and to corrolate the findings with the infant's respiratory status. Design: We measured levels of IL-6 and IL-1B in tracheal aspirate samples (TAS) and blood specimen of 33 premature infants (BW ≤ 1250 g) with RDS requiring ventilatory support and surfactant therapy on day one before initiation of surfactant therapy and at five to seven days of age. The infants' ventilatory parameters were recorded concommittantly. Results: Mean (± SD) birthweight and gestational age of infants were 843±161 grams and 27±2 weeks, respectively. There was a significant reduction in median (range) levels of IL-6 in tracheal fluid [1565 (0-130,800) vs 1038 (0-53,117) pg/ml, p < 0.05] and blood [0 (0-79,110) vs 0 (0-7) pg/ml, p < 0.05] and in median (range) levels of IL-1B in blood [4 (0-598) vs 0 (0-27) pg/ml, p < 0.05] following surfactant therapy. However, median (range) levels of IL-1B in TAS rose significantly by five to seven days of age following surfactant therapy [17 (0-5,030) vs 109 (0-3,000) pg/ml, p < 0.05]. A significant reduction in mean (± SD) ventilatory parameters (PiP: 22±4 vs 17±4 cmH2O; FiO2: 0.91±0.11 vs 0.32±0.15; IMV: 51±12 vs 22±13 bpm, p < 0.05, respectively) was observed concurrently. Conclusion: The beneficial effects of surfactant therapy in preterm infants with RDS may not be limited to providing a substance that is deficient in their lungs but also to its ability to modulate levels of inflammatory cytokines involved in the inflammatory process.