Glomerular fine structure in mixed membranous and proliferative glomerulonephritis.

A case of mixed membranous and proliferative glomerulonephritis has been studied by light and electron microscopy. Electron microscopy has shown that the cellular proliferation is mesangial in origin and that there are qualitative and quantitative alterations in the filtration basement membrane. In addition there are numerous examples of direct contact between filtration basement membrane and neutrophil polymorphonuclear leucocytes. This latter phenomenon is good direct evidence that interaction of glomerular-bound antigen-antibody complex and complement has taken place. The light and electron microscopic evidence is thus in favour of the histopathological entity, mixed membranous and proliferative glomerulonephritis, being fundamentally a proliferative glomerular lesion initiated by complement-induced basement membrane injury.