Long-term outcomes for primary glomerulonephritis: New Zealand Glomerulonephritis Study

Abstract

Aims: Due to the paucity of studies focusing on primary glomerulonephritis, the second commonest cause of end-stage-kidney-disease in most of the developed world, we sought to review outcomes of these renal pathologies.

Methods: We reviewed renal outcomes and mortality for primary glomerulonephritis patients enrolled in the New Zealand Glomerulonephritis Study between 1972 and 1983.

Results: There were 765 patients with median follow-up of 30 years (range 0.1-42 years). They were predominantly New Zealand European, male and hypertensive. Poor renal outcomes and increased mortality were associated with hypertension, heavy proteinuria, impaired renal function and older age at diagnosis. Ethnicity was not significantly associated with progression to end-stage-kidney-disease although NZ Maori patients were at significantly increased risk of death. Patients with rapidly progressive glomerulonephritis had the highest risk of reaching end-stage-kidney-disease while the cumulative incidence of end-stage-kidney-disease was 20% and 30% for those with immunoglobulin-A nephropathy and membranous nephropathy respectively. Mortality risk was high for patients with rapidly progressive glomerulonephritis and anti-glomerular basement membrane disease. The era of diagnosis did not have much effect on outcomes except for patients with focal segmental glomerulosclerosis or immunoglobulin A nephropathy but this could be type II error.

Conclusion: We report one of the longest follow-up studies on biopsy-proven glomerulonephritides. Age, hypertension, and severity of chronic kidney disease at diagnosis were strong predictors of the development of end-stage-kidney-disease and death. The specific renal pathology had a profound impact upon prognosis and therefore should continue to drive efforts to find targeted therapeutic options for these glomerulonephritides.

Keywords: competing risks; end-stage kidney disease; long-term outcomes; mortality risk primary glomerulonephritis.