Ischemia-reperfusion edema is a common early complication after lung transplantation where the hypoxia-induced vascular endothelial growth factor (VEGF)-A plays a pivotal role. It remains unclear whether a VEGF blockade is beneficial in lung transplantation.Methods
VEGF-A blockade was investigated in an orthotopic rat model of lung transplantation. VEGF-A antibody was added into the preservation solution alone (α-VEGF D/−), in the preservation solution and systemically to the recipient before reperfusion (α-VEGF D/R), or applied to the recipient alone before reperfusion (α-VEGF −/R). Forty-eight hours after lung transplantation, left lungs were collected and wet-to-dry ratio, Western blotting, RT-PCR, and immunohistology were performed.Results
VEGF-A blockade in α-VEGF D/−, α-VEGF D/R, and α-VEGF −/R resulted in neutralization of tissue VEGF-A. Reperfusion edema was only reduced in α-VEGF D/R and α-VEGF D/− groups versus Perfadex controls. Some α-VEGF −/R rats showed a hyperinflammation leading to increased pro-inflammatory cytokine expressions as well as increased edema. Whereas generally the α-VEGF D/− group showed decreased inflammation, the combination with anti-VEGF treatment to the recipient resulted in a pro-inflammatory and a pro-apoptotic phenotype. Short-term survival, however, was not significantly different in all groups as compared to the controls. In the α-VEGF (D/R) or (D/−) groups, animals mainly died from arterial thromboembolisms and in the α-VEGF (−/R) group, hyperinflammation was the main cause of death.Conclusion
VEGF-A directly contributes to the formation of a reperfusion edema, which might be reduced by its blockade. However, the α-VEGF effect on the endothelial integrity might also favor arterial thrombosis formation.