Renal biopsy findings among Indigenous Australians: a nationwide review

Australia's Indigenous people have high rates of chronic kidney disease and kidney failure. To define renal disease among these people, we reviewed 643 renal biopsies on Indigenous people across Australia, and compared them with 249 biopsies of non-Indigenous patients. The intent was to reach a consensus on pathological findings and terminology, quantify glomerular size, and establish and compare regional biopsy profiles. The relative population-adjusted biopsy frequencies were 16.9, 6.6, and 1, respectively, for Aboriginal people living remotely/very remotely, for Torres Strait Islander people, and for non-remote-living Aboriginal people. Indigenous people more often had heavy proteinuria and renal failure at biopsy. No single condition defined the Indigenous biopsies and, where biopsy rates were high, all common conditions were in absolute excess. Indigenous people were more often diabetic than non-Indigenous people, but diabetic changes were still present in fewer than half their biopsies. Their biopsies also had higher rates of segmental sclerosis, post-infectious glomerulonephritis, and mixed morphologies. Among the great excess of biopsies in remote/very remote Aborigines, females predominated, with younger age at biopsy and larger mean glomerular volumes. Glomerulomegaly characterized biopsies with mesangiopathic changes only, with IgA deposition, or with diabetic change, and with focal segmental glomerulosclerosis (FSGS). This review reveals great variations in biopsy rates and findings among Indigenous Australians, and findings refute the prevailing dogma that most indigenous renal disease is due to diabetes. Glomerulomegaly in remote/very remote Aboriginal people is probably due to nephron deficiency, in part related to low birth weight, and probably contributes to the increased susceptibility to kidney disease and the predisposition to FSGS.