title: Clinical and biological role of secretory phospholipase A2 in acute respiratory distress syndrome infants.
abstract: BACKGROUND
  Secretory phospholipase A2 is supposed to play a role in acute lung injury but no data are available for pediatric acute respiratory distress syndrome (ARDS). It is not clear which enzyme subtypes are secreted and what the relationships are between enzyme activity, biophysical and biochemical parameters, and clinical outcomes. We aimed to measure the enzyme and identify its subtypes and to study its biochemical and biophysical effect. The secondary aim was to correlate enzyme activity with clinical outcome.
  
  
  METHODS
  Bronchoalveolar lavage was performed in 24 infants with ARDS and 14 controls with no lung disease. Samples were assayed for secretory phospholipase A2 and molecules related to its activity and expression. Western blotting and captive bubble surfactometry were also performed. Clinical data were real time downloaded.
  
  
  RESULTS
  Tumor necrosis factor-α (814 (506-2,499) vs. 287 (111-1,315) pg/mL; P = 0.04), enzyme activity (430 (253-600) vs. 149 (61-387) IU/mL; P = 0.01), free fatty acids (4.3 (2.8-8.6) vs. 2 (0.8-4.6) mM; P = 0.026), and minimum surface tension (25.6 ± 6.1 vs. 18 ± 1.8 mN/m; P = 0.006) were higher in ARDS than in controls. Phospholipids are lower in ARDS than in controls (76.5 (54-100) vs. 1,094 (536-2,907) μg/mL; P = 0.0001). Three enzyme subtypes were identified (-IIA, -V, -X), although in lower quantities in controls; another subtype (-IB) was mainly detected in ARDS. Significant correlations exist between enzyme activity, free fatty acids (ρ = 0.823; P < 0.001), and surface tension (ρ = 0.55; P < 0.028). Correlations also exist with intensive care stay (ρ = 0.54; P = 0.001), PRISM-III24 (ρ = 0.79; P< 0.001), duration of ventilation (ρ = 0.53; P = 0.002), and oxygen therapy (ρ = 0.54; P = 0.001).
  
  
  CONCLUSIONS
  Secretory phospholipase A2 activity is raised in pediatric ARDS and constituted of four subtypes. Enzyme correlates with some inflammatory mediators, surface tension, and major clinical outcomes. Secretory phospholipase A2 may be a clinically relevant target in pediatric ARDS.
authors.forename: Daniele
authors.initials: D
authors.lastname: De Luca
authors.forename: Elena
authors.initials: E
authors.lastname: Lopez-Rodriguez
authors.forename: Angelo
authors.initials: A
authors.lastname: Minucci
authors.forename: Francesca
authors.initials: F
authors.lastname: Vendittelli
authors.forename: Leonarda
authors.initials: L
authors.lastname: Gentile
authors.forename: Eleonora
authors.initials: E
authors.lastname: Stival
authors.forename: Giorgio
authors.initials: G
authors.lastname: Conti
authors.forename: Marco
authors.initials: M
authors.lastname: Piastra
authors.forename: Massimo
authors.initials: M
authors.lastname: Antonelli
authors.forename: Mercedes
authors.initials: M
authors.lastname: Echaide
authors.forename: Jesus
authors.initials: J
authors.lastname: Perez-Gil
authors.forename: Ettore D
authors.initials: ED
authors.lastname: Capoluongo
mesh_terms: D018893:Bronchoalveolar Lavage / Q000379:methods; D004789:Enzyme Activation / Q000502:physiology; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D054497:Phospholipases A2, Secretory / Q000502:physiology*; D012121:Respiration, Artificial / Q000379:methods; D012127:Respiratory Distress Syndrome, Newborn / Q000201:enzymology*; D013500:Surface Tension
chemical_list: D054497:Phospholipases A2, Secretory