Pulmonary secretory phospholipase A2 in infants with respiratory distress syndrome stimulates in vitro neutrophil migration.

Background: The massive pulmonary neutrophil influx in respiratory distress syndrome (RDS) in preterm infants has been ascribed to the effect of leukotriene B(4) (LTB(4)).

Objectives: To investigate whether secretory phospholipase A(2) (sPLA(2)), the rate-limiting enzyme in LTB(4) production, is present in lungs of RDS infants and stimulates neutrophil migration.

Methods: sPLA(2) was measured in tracheal aspirates from 15 preterm infants with RDS.

Cord blood Clara cell protein CC16 predicts the development of bronchopulmonary dysplasia.

Clara cell protein (CC16) is an anti-inflammatory protein and a biomarker of pulmonary epithelial cells and alveolocapillary membrane injury in adults. We investigated whether low cord blood concentrations of CC16 are associated with the development of respiratory distress syndrome (RDS) and bronchopulmonary dysplasia (BPD) in preterm infants and the relationship between CC16 and its pro-inflammatory counterpart, the secretory phospholipase A(2) (sPLA(2)) enzyme. CC16 concentration, sPLA(2) activity and IL-6 concentration were measured in cord blood plasma from 79 preterm infants (25 controls, 37 infants who developed RDS and 17 infants who developed BPD).

Meconium is a source of pro-inflammatory substances and can induce cytokine production in cultured A549 epithelial cells.

Inflammation plays an important role in the pathogenesis of meconium aspiration syndrome, and pneumonitis is one of the major characteristics. We have previously shown that meconium has chemotactic properties because of the presence of IL-8. We hypothesize that IL-8 and other proinflammatory substances in meconium may amplify inflammation in meconium aspiration syndrome, inducing endogenous cytokine production by lung epithelial cells.