Vascular Endothelial Growth Factor Level Correlates With Transforming Growth Factor-β Isoform Levels in Pleural Effusions

Recent studies have demonstrated highlevels of vascular endothelial growth factor (VEGF) in exudativepleural effusions and a possible etiologic role. The factors regulating, VEGF accumulation in the pleural space are unknown. Transforming growthfactor (TGF)-β is a potent stimulator of VEGF expression invitro. We hypothesized that TGF-β induces VEGF production inpleural tissues, and, hence, the pleural fluid VEGF levels shouldcorrelate with the levels of TGF-β in pleural fluid of differentetiologies. Seventy pleural fluid sampleswere analyzed. These included 20 malignant, 13 post-coronaryartery bypass grafting (CABG), 8 parapneumonic, 11 miscellaneousexudative, and 18 congestive heart failure (CHF) pleuraleffusions. Pleural fluid VEGF levels showedgood correlation with those of TGF-β1(r = 0.58; p < 0.0001), TGF-β2(r = 0.43; p < 0.001), and lactate dehydrogenase(r = 0.65; p < 0.001). The levels of, TGF-β1 and TGF-β2 also were correlated(r = 0.60; p < 0.0001). The median levels of, TGF-β1 (2,480 pg/mL) and TGF-β2 (266pg/mL) in the CHF group were significantly lower than those in themalignant (TGF-β1, 4,902 pg/mL; TGF-β2, 428pg/mL), post-CABG (TGF-β1, 5,456 pg/mL; TGF-β2, 377 pg/mL), parapneumonic (TGF-β1,5,024 pg/mL; TGF-β2, 464 pg/mL), and miscellaneousexudate groups (TGF-β1, 7,690 pg/mL; TGF-β2, 369 pg/mL). There was no significant differencein TGF-β1 and TGF-β2 levels among the fourexudate groups. VEGF levels in pleuraleffusions are significantly correlated with the levels of, TGF-β1 and β2 isoforms. VEGF,TGF-β1, and TGF-β2 levels were all higherin exudative effusions than in effusions secondary to, CHF.