Surfactant protein B and A concentrations are increased in neonatal pneumonia (original) (raw)

Translational Investigation nature publishing group Background: Term newborns with pneumonia show a reduced pulmonary compliance due to multiple and illdefined factors. Surfactant proteins' (SPs) changes could have a role in the reduced compliance but the matter is still unsettled. The aim of this study was to clarify the meaning of SPs changes during pneumonia in term newborns. Methods: In 28 term ventilated newborns, 13 with pneumonia and 15 with no lung disease, we measured SP-B, SPA , disaturated-phosphatidylcholine (DSPC), and total phospholipids (PL) concentrations in tracheal aspirates at intubation and close to extubation. We also measured DSPC kinetics using (U-13 C-PA)dipalmitoyl-phosphatidylcholine. results: At baseline, SP-B, expressed as % of PL, was significantly different between the groups, being 3.5-fold higher in pneumonia than controls. Conversely, SPA did not vary between the groups. At extubation, SP-B and SPA concentrations had decreased significantly in newborns with pneumonia, while there was no significant change in controls. DSPC t 1/2 was significantly shorter in the pneumonia group (11.8 (5.5-19.8) h vs. 26.6 (19.3-63.6) h, P = 0.011). conclusion: In term newborns with pneumonia, SP-B increases with respect to PL, and DSPC is turned over at a faster rate. Disease's resolution is associated with the restoration of the normal ratio between SP-B and PL. a lveolar surfactant is essential for lung stability and its composition and functional state are altered during pneumonia and acute respiratory distress syndrome (1,2). Pulmonary surfactant also plays an important role on the innate immune system by enhancing pathogen clearance and by regulating immune-cell functions (3). Surfactant proteins (SPs) represent less than 10% of total surfactant weight but they play a pivotal role on its function. SP-B is a hydrophobic protein that is considered to be the most important protein for sustaining respiratory physiology (4). SP-B enhances lipid insertion into the monolayer at the air/liquid interface (5), it is involved in the formation of tubular myelin (6), and it may also be part of the host defense mechanisms (7). SPA , a pulmonary