Abstract 1885

Purpose: Lung inflammation is believed to play a role in the pathogenesis of lung injury and development of chronic lung disease. However, the relationship between pro- and anti-inflammatory cytokines in the neonatal period is not clear. The current study was undertaken to delineate the 'balance' between pro- [IL-6, TNF-α] and anti-[IL-10] inflammatory cytokines in BAL of preterm [25-32 weeks] infants with respiratory distress.

Methods: Serial BAL samples were obtained from day 2 of life in 7 infants [at least 3 × week] until 2 weeks of life or extubation. BAL, obtained by standardized technique, were analyzed for IL-6, IL-10, TNF-α [competitive enzyme immunoassay] and secretory piece of IgA [immunodiffusion]. Fraction of inspired oxygen and mean airway pressure at time of BAL, birthweight, additional diagnoses and treatments were also documented.

Results: Forty-one samples were obtained from 7 infants. Data for the cytokines adjusted for secretory piece of IgA are shown in the Table [Mean (SD)]: TNF-α, IL-6, and IL-10 appear to 'parallel' each other over the two week period. Significant correlations were present between IL-10 and TNF-α [r2=0.43, p<0.001], TNF-α and IL-6 [r2=0.74, p<0.001], IL-10 and IL-6 [r2=0.57, p<0.001], TNF-α/IL-10 and FiO2 X mean airway pressure [p<0.001]. Five of 7 infants received systemic steroids by day 8 of life and the decrease in all three cytokine concentrations in BAL is apparent by day 10.

Table 1 No caption available
Full size table

Conclusions: These data demonstrate a significant correlation between the pro- and anti-inflammatory cytokines in BAL in the first two weeks of life. It is possible that the imbalance between the pro- and anti-inflammatory cytokines and the resultant changes in ventilatory parameters may be related to the development of chronic lung disease. The alteration in the "balance" between these groups of cytokines needs further investigation.