Long-term outcomes of end-stage kidney disease for patients with IgA nephropathy: a multi-centre registry study

Abstract

Background: Clinical outcomes of patients with end-stage kidney disease (ESKD) receiving renal replacement therapy (RRT) secondary to IgA nephropathy (IgAN) have not been well described. Aim: To investigate the characteristics, treatments and outcomes of ESKD because of kidney-limited IgAN and Henoch-Schönlein purpura nephritis (HSPN) in the Australian and New Zealand RRT populations. Methods: All ESKD patients who commenced RRT in Australia and New Zealand between 1971 and 2012 were included. Dialysis and transplant outcomes were evaluated in both a contemporary cohort (1998-2012) and the entire cohort (1971-2012). Results: Of 63 297 ESKD patients, 3721 had kidney-limited IgAN, and 131 had HSPN. For the contemporary cohort of IgAN patients on dialysis (n = 2194), 10-year patient survival was 65%. Of 1368 contemporary IgAN patients who received their first renal allograft, 10-year patient, overall renal allograft and death-censored renal allograft survival were 93%, 82% and 88%, respectively. Using multivariable Cox regression analysis, patients with IgAN had favourable dialysis patient survival (adjusted hazard ratio (HR) 0.63, 95% confidence interval (CI) 0.57-0.69), overall renal allograft survival (HR 0.67, 95% CI 0.57-0.79) and renal transplant patient survival (HR 0.58, 95% CI 0.45-0.74) compared with ESKD controls. Similar results were found in the entire cohort and when using competing-risks models. Compared with kidney-limited IgAN patients, those with HSPN had worse dialysis patient survival (HR 1.94, 95% CI 1.02-3.69), overall renal allograft survival (HR 3.40, 95% CI 1.00-11.55) and renal transplant patient survival (HR 3.50, 95% CI 1.03-11.92). Conclusion: IgAN ESKD was associated with better dialysis and renal transplant outcomes compared with other forms of ESKD. The survival outcomes of ESKD patients with HSPN were worse than kidney-limited IgAN.