Decreased vascular endothelial growth factor expression in lung tissue during acute respiratory distress syndrome

Introduction

Endothelial injury is an important prognostic factor in acute respiratory distress syndrome (ARDS) [1, 2]. Vascular endothelial growth factor (VEGF) plays a critical role in endothelial destruction and angiogenesis [3]. The expression of VEGF in ARDS varies, depending on epithelial and endothelial damage [4, 5]. The objective of this study was to investigate the expression of VEGF in lung tissue from ARDS patients.

Methods

Lung specimens were obtained by autopsy from 10 patients with severe ARDS and were compared with a control group of 10 non-ARDS patients autopsied. All lung samples were stained for standard histopathological analysis and for immunohistochemical methods using a specific mouse monoclonal antibody.

Results

Compared with expression in non-ARDS control individuals, pulmonary expression of VEGF was significantly decreased (P < 0.001) in ARDS patients. Alveolar macrophages were similarly immunopositive in both groups. No differences were noted with regard to the individual patient's characteristics (age, gender, period of ARDS condition, number of ICU days).

Conclusion

A decrease in alveolar type II cellularity, due to apoptosis, has been observed during ARDS that may reduce the production of VEGF in the alveolar space and may participate in the decrease in lung perfusion.