The value of vascular endothelial growth factor in the differantial diagnosis of pleural effusions and its correlation with radiologic and biochemical parameters

Pleural effusion is a common clinical problem in which the differentialdiagnosis sometimes can be challenging. Previous studies demonstrated thatvascular endothelial growth factor (VEGF) is increased in malignant andinflammatory etiologies and may contribute to the formation of exudativeeffusions. The aim of this study is to determine the levels of VEGF in thedifferential diagnosis of pleural effusions, and determine any correlationbetween VEGF, and the radiological findings and the biochemical features ofthe pleural fluid.The study included 97 patients. The patients had exudative pleural effusionrelated to lung cancer (17), nonpulmonary malignancies (25), mesothelioma (9),pneumonia (14), tuberculosis (8) miscellaneous causes (6) and transudativeeffusion (18). VEGF levels in pleural fluid were measured by ELISA (Enzyme-linked immunosorbent assay).VEGF levels were higher in exudative effusions with respect to transudativeeffusions (p<0.001), in effusions related to malignancies vs benign causes(p<0.001). VEGF was inversely correlated with pleural fluid glucose and pHlevels and had positive correlation with LDH, protein, cholesterol levels(p<0.001), hematocrit and eosinophil values (p<0.05). VEGF levels were alsohigher in patients with massive effusions and pleural thickening (both p<0.001).In conclusion, the overlap of the VEGF levels between the groups may limitthe value of using VEGF alone in differential diagnosis of pleural effusions,however it may be useful discriminating between malignant vs benign andexudative vs transudative effusions in addition to various methods. The VEGFlevels in pleural fluid seem to be related to the degree of inflammation andpleural invasion.Key words: Pleural effusion, VEGF, Pleural thickening, Pleural fluid amount