Imbalance between vascular endothelial growth factor and endostatin in emphysema

Vascular endothelial growth factor (VEGF) stimulates endothelial cell proliferation, and endostatin directly antagonises the biological effects of VEGF. The maintenance of pulmonary endothelial cells is also thought to depend upon the local balance of VEGF and endostatin in the lung. Therefore, this study was designed to determine whether there is an imbalance between VEGF and endostatin levels in patients with pulmonary emphysema. VEGF and endostatin levels were simultaneously measured from 25 emphysema patients and 12 normal control subjects, and their correlation and balance in induced sputum was evaluated. VEGF levels in induced sputum were significantly lower in emphysema patients (854 +/- 307 pg x mL(-1)) than in normal controls (1,791 +/- 1,192 pg x mL(-1)). In contrast, there was no significant difference in endostatin levels among the two groups. Therefore, the ratio of VEGF to endostatin levels was markedly lower in emphysema patients (4.5 +/- 1.8) than in normal controls (8.1 +/- 2.6). Moreover, VEGF levels were correlated with endostatin levels in normal controls but not in emphysema patients. In addition, the ratio of VEGF to endostatin levels was correlated with forced expiratory volume in one second (FEV1), FEV1/forced vital capacity and carbon monoxide diffusing capacity of the lung in emphysema patients. The findings in this study suggest that there is an imbalance between vascular endothelial growth factor and endostatin levels in induced sputum from emphysema patients.