Vascular endothelial growth factor expression in human chronic renal allograft rejection

Background. Chronic renal allograft rejection is characterized by interstit ial fibrosis and vasculopathy, Vascular endothelial growth factor (VEGF) is an endothelial mitogen with increased expression in inflammation and vascu lopathy. Methods. Renal tissue from 17 patients with chronic rejection was examined for VEGF protein and the presence of CD 68-positive macrophages, and compar ed to biopsies from patients with temporary allograft dysfunction, acute re jection, and native kidneys with thin membrane disease. Results. In the chronic rejection group, there was markedly increased expre ssion of VEGF protein in the interstitium (P<0.0001), In serial sections, V EGF colocalized with the expression of CD 68-positive macrophages, Signific antly more macrophages were in the tubulointerstitium in tissue with chroni c rejection than in those with temporary allograft dysfunction (P<0.005). A dditionally, VEG;F protein expression in the glomeruli and the vascular com partment 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.