title: Angiogenic molecule Tie-2 and VEGF in the pathogenesis of pleural effusions.
abstract: BACKGROUND
  The role of angiogenesis in the pathogenesis of pleural effusion (PE) has not been determined. The expression of angiogenic factors may represent useful markers for the diagnosis and prediction of disease outcome. To measure the pleural fluid (PF) and serum levels of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and Tie receptor tyrosine kinase (Tie-2) in order to investigate their role in the pathogenesis of PEs.
  
  
  METHODS
  Sixty-seven, 17 with transudative PEs due to heart failure and 50 with exudative PEs (malignant, 22; inflammatory, 15; undiagnosed, 13) were included in the study. PF and serum levels of the growth factors (VEGF, bFGF and Tie-2) were measured using enzyme-linked immunosorbent assays.
  
  
  RESULTS
  PF and serum VEGF levels but not bFGF and Tie-2 levels were higher (p<0.005) in exudates than in transudates. PF VEGF levels were significantly higher in malignant than inflammatory and undiagnosed PEs (p=0.03). In addition, PF Tie-2 levels were not found different in malignant or in parapneumonic PEs.
  
  
  CONCLUSIONS
  Our results showed that VEGF is one of the main mediators in exudative PEs, but this effect is not mediated through the angiogenetic pathway Ang-1/Tie-2. However, the role of angiogenesis and its pathways in the pathogenesis of exudative PEs needs further exploration.
authors.affiliation: Department of Thoracic Medicine, University Hospital, Medical School, University of Crete, Heraklion 71110 Crete, Greece.
authors.forename: Foteini
authors.initials: F
authors.lastname: Economidou
authors.forename: Katerina M
authors.initials: KM
authors.lastname: Antoniou
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Tzanakis
authors.forename: Katerina
authors.initials: K
authors.lastname: Sfiridaki
authors.forename: Nikolaos M
authors.initials: NM
authors.lastname: Siafakas
authors.forename: Sofia E
authors.initials: SE
authors.lastname: Schiza
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000032:analysis / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005122:Exudates and Transudates / Q000737:chemistry; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000032:analysis / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic; D010996:Pleural Effusion / Q000097:blood / Q000378:metabolism* / Q000503:physiopathology; D016066:Pleural Effusion, Malignant / Q000097:blood / Q000378:metabolism / Q000503:physiopathology; D011446:Prospective Studies; D042787:Receptor, TIE-2 / Q000032:analysis* / Q000097:blood; D018709:Statistics, Nonparametric; D042461:Vascular Endothelial Growth Factor A / Q000032:analysis* / Q000097:blood
chemical_list: D015415:Biomarkers; D042461:Vascular Endothelial Growth Factor A; D016222:Fibroblast Growth Factor 2; D042787:Receptor, TIE-2