ARTERIAL ENDOTHELIALITIS IN CHRONIC RENAL-ALLOGRAFT REJECTION - A HISTOPATHOLOGICAL AND IMMUNOCYTOCHEMICAL STUDY

Transplantation is the preferred method of renal replacement therapy i n end-stage renal failure. Short- and medium-term graft survival is go od but, in the longer term, grafts are lost due to vascular obliterati on, i.e. chronic vascular rejection. The pathogenesis of these changes is unclear. We carried out a histopathological and immunocytochemical study of 31 vessels from 20 graft nephrectomies. Four patterns of art erial pathology were identified: (1) subendothelial inflammation ('end othelialitis') with little intimal thickening; (2) 'Endothelialitis' w ith intimal thickening; (3) Intimal thickening without 'endothelialiti s'; and (4) Intimal thickening with calcification and cholesterol clef ts ('natural atherosclerosis'). We suggest that the lesions of chronic vascular rejection evolve, at varying rates, from an early 'endotheli alitis' to a later stage with pronounced intimal thickening but no sub endothelial inflammation. These changes probably reflect a delayed typ e hypersensitivity response involving activated macrophages and T lymp hocytes and smooth muscle cell proliferation.