Membranoproliferative glomerulonephritis in the aged and its possible causal relationship with CD8+CD57+ lymphocytes.

Membranoproliferative glomerulonephritis (MPGN) is a chronic progressive glomerulonephritis that occurs primarily in patients under the age of 30, and is rare in the elderly. We report eight aged patients with MPGN associated with CD8+CD57+ lymphocytosis. All eight patients showed a significant increase in CD8+CD57+ lymphocytes with a significant decrease in the ratio of CD4+ cells to CD8+ cells. Infiltration of CD8+CD57+ lymphocytes was observed within capillary lumens to various degrees according to the severity of endocapillary proliferation in each case. Expression of endothelial-leukocyte adhesion molecule-1 was observed in a focal and segmental manner on glomerular endothelial cells and on the endothelium of arterioles and arteries in kidney tissue in four cases in which a pronounced endocapillary proliferation was simultaneously seen. These findings suggest that cell-mediated cytotoxic mechanisms against glomerular endothelial cells may be involved in the pathogenesis of MPGN in the aged.