Dialysis

Abstract. Transplantation is the preferred method of renal replacement therapy in end-stage renal failure. Short- and medium-term graft survival is good but, in the longer term, grafts are lost due to vascular oblitera-tion, i.e. chronic vascular rejection. The pathogenesis of these changes is unclear. We carried out a histopathological and immunocyto-chemical study of 31 vessels from 20 graft nephrec-tomies. Four patterns of arterial pathology were identified: (1) subendothelial inflammation ('endot-helialitis') with little intimal thickening; (2) 'Endothelialitis ' with intimal thickening; (3) Intimal thickening without 'endothelialitis'; and (4) Intimal thickening with calcification and cholesterol clefts ('natural atherosclerosis'). We suggest that the lesions of chronic vascular rejection evolve, at varying rates, from an early 'endo-thelialitis ' to a later stage with pronounced intimal thickening but no subendothelial inflammation. These changes probably reflect a delayed type hypersensitivity response involving activated macrophages and T lymphocytes and smooth muscle cell proliferation. Key words: vascular rejection; morphology; immuno-cytochemistr