title: Diagnostic value of interleukine-6, transforming growth factor-beta 1 and vascular endothelial growth factor in malignant pleural effusions.
abstract: OBJECTIVE
  We evaluate the accuracy of pleural interleukine-6 (IL-6), transforming growth factor-beta 1 (TGF-beta1), and vascular endothelial growth factor (VEGF) levels for differentiating benign from malignant pleural exudates.
  
  
  METHODS
  Levels of IL-6, TGF-beta1, and VEGF were measured by ELISA in 103 patients with non neutrophilic (<50%) exudative pleurisy including both benign and malignant effusions. Pleurisies were split into benign and malignant according to the pathological diagnosis.
  
  
  RESULTS
  Thirty-nine benign (seven infections; 32 inflammatory diseases) and 64 malignant (34 extrathoracic tumors; 25 lung cancers; five mesotheliomas) pleural exudates were diagnosed by thoracoscopy. Pleural reticulo-monocyte count, protein Light's ratio and lactic dehydrogenase Light's ratio were significantly higher in malignant than in benign effusions (p<0.05, p<0.001 and p<0.001, respectively). The median (range) level of VEGF was significantly higher in malignant than in benign effusions (664.50 pg/ml [10-40,143] vs 349 pg/ml [10-8888]) (p<0.05). VEGF levels correlated with pleural LDH (r=0.41, p<0.0001), glucose (r=-0.30, p<0.01) and red cell count (r=0.57, p<0.0001). No significant difference was found between malignant and benign effusions with respect to IL-6 (26.8 ng/ml [1.8-421] vs 18.4 ng/ml [0.45-400], respectively) and TGF-beta1 (1079 pg/ml [18-6206] vs 1123 pg/ml [34-5447]) levels. ROC analysis between benign and malignant pleurisies for VEGF showed an area under the curve of 619 (p=0.03) with a value of 382 pg/ml as the best threshold for distinguishing benign from malignant effusions.
  
  
  CONCLUSIONS
  Malignant effusions may enhance the release of VEGF in pleural space and its measurement may help in the diagnosis of malignant effusion.
authors.affiliation: Division of Pulmonary Medicine, University of Liège, CHU Sart-Tilman B35, B-4000 Liège, Belgium. bduysinx@swing.be
authors.forename: Bernard C
authors.initials: BC
authors.lastname: Duysinx
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Corhay
authors.forename: Laurent
authors.initials: L
authors.lastname: Hubin
authors.forename: Delphine
authors.initials: D
authors.lastname: Nguyen
authors.forename: Monique
authors.initials: M
authors.lastname: Henket
authors.forename: Renaud
authors.initials: R
authors.lastname: Louis