Changes in phospholipid composition of tracheal aspirates from newborns with hyaline membrane disease or transient tachypnoea.

Phospholipid analysis of tracheal aspirates obtained from 37 newborn infants, all intubated for respiratory diseases, was performed in order to compare infants having hyaline membrane disease (HMD) (n = 11), to those presenting with transient tachypnoea (TT) (n = 16) or another respiratory disorder (n = 10) and to determine if distinguishing features could be discovered for HMD or TT. In the HMD group, a significantly lower amount (about 20%) of recoverable phospholipid material was observed. Furthermore, the groups differed in their phospholipid profile: infants with HMD presented with a deficiency in saturated phosphatidylcholine, but had a related increase in unsaturated phosphatidylcholine, and an increased proportion of phosphatidylethanolamine (about 2.5 times more) as compared with both other groups. In infants suffering HMD and TT, phosphatidylglycerol was lower and phosphatidylinositol was higher than in infants with other diseases. This change was the only one displayed in infants with TT. We speculate that the observed changes reflect changes in amount and composition of surfactant and are involved in the etiology of HMD and TT.