Vascular endothelial growth factor expression in human chronic renal allograft rejection

Background. Chronic renal allograft rejection is characterized by interstitial fibrosis and vasculopathy, Vascular endothelial growth factor (VEGF) is an endothelial mitogen with increased expression in inflammation and vasculopathy. Methods. Renal tissue from 17 patients with chronic rejection was examined for VEGF protein and the presence of CD 68-positive macrophages, and compared to biopsies from patients with temporary allograft dysfunction, acute rejection, and native kidneys with thin membrane disease. Results. In the chronic rejection group, there was markedly increased expression of VEGF protein in the interstitium (P<0.0001), In serial sections, VEGF colocalized with the expression of CD 68-positive macrophages, Significantly more macrophages were in the tubulointerstitium in tissue with chronic rejection than in those with temporary allograft dysfunction (P<0.005). Additionally, VEG;F protein expression in the glomeruli and the vascular compartment of patients with chronic rejection was increased. Conclusion. The up-regulation of VEGF in chronic renal allograft rejection may be important in inflammation and development of fibrosis.