title: Soluble Vascular Cell Adhesion Molecule-1 (sVCAM-1) Is Elevated in Bronchoalveolar Lavage Fluid of Patients with Acute Respiratory Distress Syndrome.
abstract: BACKGROUND
  Pulmonary vascular endothelial activation has been implicated in acute respiratory distress syndrome (ARDS), yet little is known about the presence and role of endothelial activation markers in the alveolar space in ARDS. We hypothesized that endothelial activation biomarkers would be differentially expressed in bronchoalveolar lavage fluid from patients with ARDS compared with healthy volunteers, and that biomarker concentrations would be associated with ARDS severity.
  
  
  METHODS
  We performed a cross-sectional analysis of data from 26 intubated patients with ARDS undergoing evaluation for clinically suspected ventilator-associated pneumonia and five healthy volunteers. Patients underwent bronchoalveolar lavage a median of five days after intubation. Healthy volunteers also underwent bronchoalveolar lavage. Endothelial activation biomarkers (soluble vascular cell adhesion molecule-1 [sVCAM-1], soluble endothelial selectin [sESEL], angiopoietin-1 [Ang-1] and angiopoietin-2 [Ang-2]) were measured in bronchoalveolar lavage fluid. Clinically suspected ventilator-associated pneumonia was confirmed with microbiologic culture data.
  
  
  RESULTS
  Patients with ARDS had significantly higher median sVCAM-1 concentrations in the bronchoalveolar lavage fluid compared with healthy volunteers (985 vs 119 pg/mL, p = 0.03). Additionally, there was a trend toward greater bronchoalveolar lavage fluid sVCAM-1 concentrations among patients with moderate/severe compared to mild ARDS (1395 vs 209 pg/mL, p = 0.06). We did not detect significant differences in bronchoalveolar lavage fluid levels of sESEL, Ang-1 or Ang-2 between patients with ARDS and healthy volunteers. Median bronchoalveolar lavage fluid biomarker levels did not differ between patients with and without microbiologically-confirmed ventilator-associated pneumonia.
  
  
  CONCLUSIONS
  sVCAM-1 concentrations were significantly higher in the bronchoalveolar lavage fluid of patients with ARDS compared to healthy controls, and tended to be higher in moderate/severe ARDS compared to mild ARDS. Our findings add to the growing evidence supporting the concept that endothelial activation plays an important mechanistic role in the pathogenesis of ARDS. Further studies are necessary to characterize the role and/or clinical significance of sVCAM-1 and other endothelial activation markers present in the alveolar space in ARDS.
authors.affiliation: Department of Medicine, Division of Pulmonary and Critical Care Medicine, University of Washington, Seattle, Washington, United States of America.
authors.forename: Engi F
authors.initials: EF
authors.lastname: Attia
authors.affiliation: Department of Medicine, Section of Pulmonary/Critical Care and Allergy/Immunology, Louisiana State University Health Sciences Center, New Orleans, Louisiana, United States of America.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Jolley
authors.affiliation: Department of Medicine, Division of Pulmonary and Critical Care Medicine, University of Washington, Seattle, Washington, United States of America.
authors.forename: Kristina
authors.initials: K
authors.lastname: Crothers
authors.affiliation: Department of Medicine, Division of Pulmonary, Critical Care, Allergy and Sleep Medicine, Medical University of South Carolina, Charleston, South Carolina, United States of America.
authors.forename: Lynn M
authors.initials: LM
authors.lastname: Schnapp
authors.affiliation: Departments of Medicine, Pathology, Pharmacology, and Global Health, Center for Lung Biology, University of Washington, Seattle, Washington, United States of America.
authors.forename: W Conrad
authors.initials: WC
authors.lastname: Liles
mesh_terms: D000368:Aged; D042683:Angiopoietin-1 / Q000032:analysis; D042702:Angiopoietin-2 / Q000032:analysis; D018893:Bronchoalveolar Lavage; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012128:Respiratory Distress Syndrome / Q000175:diagnosis / Q000378:metabolism*; D019087:Selectins / Q000032:analysis; D012720:Severity of Illness Index; D019010:Vascular Cell Adhesion Molecule-1 / Q000032:analysis*
chemical_list: D042683:Angiopoietin-1; D042702:Angiopoietin-2; D019087:Selectins; D019010:Vascular Cell Adhesion Molecule-1