Decreased Expression of Transforming Growth Factor-beta1 in Bronchoalveolar Lavage Cells of Preterm Infants with Maternal Chorioamnionitis

Maternal chorioamnionitis has been associated with abnormal lung development. We examined the effect of maternal chorioamnionitis on the expression of transforming growth factor-beta1 (TGF-β1) in the lungs of preterm infants. A total of 63 preterm (≤34 weeks) infants who were intubated in the delivery room were prospectively enrolled. Their placentas were examined for the presence of chorioamnionitis. Bronchoalveolar lavage (BAL) fluid and cells were obtained shortly after birth. TGF-β1 was measured in BAL fluid and TGF-β1 mRNA expression was determined by reverse transcription polymerase chain reaction (RT-PCR) in BAL cells. TGF-β1 mRNA expression in BAL cells showed a positive correlation with gestational age (r=0.414, p=0.002). TGF-β1 mRNA expression was significantly decreased in the presence of maternal chorioamnionitis (0.70±0.12 vs. 0.81±0.15, p=0.007). Adjustment for gestational age, birth weight, and delivery mode did not nullify the significance. TGF-β1 mRNA expression was marginally significantly decreased in preterm infants who developed bronchopulmonary dysplasia (BPD) later (0.75±0.11 vs. 0.82±0.15, p=0.055). However, adjustment for gestational age, patent ductus arteriosus (PDA), and maternal chorioamnionitis nullified the significance. These results might be an indirect evidence that maternal chorioamnionitis may inhibit normal lung development of fetus.