Diagnostic value of interleukine-6, transforming growth factor-beta 1 and vascular endothelial growth factor in malignant pleural effusions.

STUDY OBJECTIVES: 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. PATIENTS AND 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