OBJECTIVETo study the expression profile and significance of serum transforming growth factor-beta 1 (TGF-β1) and bone morphogenetic protein-7 (BMP-7) in preterm infants with respiratory distress syndrome (RDS).

METHODSThirty-two preterm infants with RDS who were given pulmonary surfactant (PS) within 12 hours after birth were enrolled as the PS group. Twenty-eight preterm infants with RDS who were not given PS were selected as the non-PS group. Another 30 preterm infants without RDS were used as the control group. Serum levels of TGF-β1 and BMP-7 in the three groups were measured using enzyme-linked immunosorbent assay at 0, 1, 3, and 7 days after birth.

RESULTSThe PS group had higher serum levels of TGF-β1 than the control group at 1 and 3 days after birth (P<0.05). The non-PS group had significantly higher serum levels of TGF-β1 than the control group at 1, 3, and 7 days after birth (P<0.05), and serum levels of TGF-β1 in the non-PS group were significantly higher than the PS group at 3 and 7 days after birth (P<0.05). The PS group had higher serum levels of BMP-7 than the control group at 1 and 3 days after birth (P<0.05). The non-PS group had higher serum levels of BMP-7 than the control group at 1, 3, and 7 days after birth (P<0.05). The levels of BMP-7 in the non-PS group at 7 days after birth were reduced than before, but were still higher than in the PS group (P<0.05).

CONCLUSIONSBoth serum TGF-β1 and BMP-7 levels increase in the early stage in preterm infants with RDS, however, in the late stage, the expression of BMP-7 decreases with the increase in TGF-β1 expression, suggesting that administration of exogenous BMP-7 may reduce the expression of TGF-β1, which might be a therapeutic approach for RDS in preterm infants.