Mortality and renal outcome of primary glomerulonephritis in Korea: observation in 1,943 biopsied cases

Background: Previous epidemiological studies have focused on the prevalence of primary glomerulonephritis (GN), but few have explored long-term patient outcomes. This study was conducted to investigate the long-term patient and renal outcomes of primary GN.

Methods: A total of 1,943 biopsy-proven primary GN patients were included. The outcomes were mortality and end-stage renal disease (ESRD) progression. The relative mortality rate was expressed by the standardized mortality ratio (SMR) and the 95% confidence interval (CI).

Results: During the median follow-up of 90 months, 325 (16.7%) patients progressed to ESRD and 164 (8.4%) patients died. Patients with minimal change disease exhibited the best renal and patient outcomes, whereas those with membranoproliferative GN had the worst. IgA nephropathy patients appeared to have a good survival rate in spite of their considerable progression to ESRD, and focal segmental glomerulosclerosis patients showed poor renal and patient outcomes. Mortality was 67% higher in primary GN patients than in the age- and sex-matched general population (SMR, 1.67; 95% CI, 1.42-1.95). The difference was more prominent in women (SMR, 2.95; 95% CI, 2.27-3.77) than in men (SMR, 1.31; 95% CI, 1.07-1.60). Renal risk factors, e.g. hypertension, proteinuria and initial renal dysfunction, were all associated with higher mortality, and the relative mortality rate increased with the number of risk factors.

Conclusions: In patients with primary GN, mortality is significantly higher than in the age-/sex-matched general population, especially in women. Moreover, the presence of renal risk factors is positively associated with both relative mortality and progression to ESRD.