Vascular endothelial growth factor (VEGF) in inflammatory and malignant pleural effusions

BACKGROUND Investigation and management of pleural effusions is an important clinical problem yet the pathogenesis of pleural fluid accumulation is poorly understood. Vascular endothelial growth factor (VEGF) is a potent inducer of capillary permeability that is produced by both malignant and inflammatory cells. A study was undertaken to determine whether VEGF has a potential pathogenic role in the development of pleural effusions and whether VEGF receptors are present on human pleural mesothelial cells. METHODS Normal and inflamed pleura were examined immunohistochemically for the presence of FLT-1 (the fms-like tyrosine kinase receptor of VEGF). VEGF levels were measured by ELISA in 78 consecutive patients presenting with undiagnosed unilateral pleural effusions and the levels were correlated with the aetiology of the effusions. RESULTS Immunohistochemical staining of normal and diseased pleura demonstrated the presence of the FLT-1 VEGF receptor on human mesothelial cells. Median VEGF levels were 2500 pg/ml in the malignant group and 305 pg/ml in the non-malignant group (median difference 1397.5 pg/ml (95% CI 851 to 2693), p