Outcomes Following Kidney Failure From IgA Nephropathy Compared to Diabetic Kidney Disease and Other Glomerular Diseases.

RATIONALE &

OBJECTIVE

IgA nephropathy (IgAN) is a major cause of kidney disease worldwide, yet contemporary comparative outcome data following kidney failure are limited. We compared trends in access to kidney transplantation and mortality among patients with kidney failure due to IgAN, to those with diabetic kidney disease (DKD) or other glomerular diseases (GD).

STUDY

DESIGN

Longitudinal cohort study.

SETTING &

PARTICIPANTS

Patients with kidney failure initiating maintenance dialysis (1965-2023) due to IgAN, DKD, or other GD in Australia.

EXPOSURE: Kidney failure etiology.

OUTCOMES: All-cause death, death from cardiovascular disease and cancer, and entry onto the deceased donor kidney transplant waitlist.

ANALYTICAL APPROACH: Age-standardized incidence, prevalence, and mortality rates and temporal trends assessed using log-linear regression-derived estimated annual percentage change (EAPC). Associations between kidney failure etiology and outcomes estimated using inverse probability treatment-weight (IPTW)- adjusted Cox proportional hazards models.

RESULTS

44,659 patients (4,925 with IgAN; 15,079 with other GD; 24,655 with DKD) were studied with a median follow-up of 53 months (IQR 23.3-109.8). The age-standardized incidence of IgAN remained stable over the past two decades (EAPC -0.01%, 95% CI - 0.80 to 0.78). Compared with other GD, patients with IgAN experienced lower all-cause (HR 0.69, 95% CI 0.65-0.73; p < 0.001) and cardiovascular (HR 0.67, 95% CI 0.60-0.74; p < 0.001) mortality, and increased rates of being placed on the transplant waitlist (HR 1.55, 95% CI 1.39-1.73; p < 0.001). Compared with IgAN, patients with DKD had higher all-cause (HR 1.58, 95% CI 1.53-1.64, p<0.001) and cardiovascular mortality (HR 1.81, 95% CI 1.71-1.91, p<0.001), lower cancer-related mortality (HR 0.82, 95% CI 0.70-0.95, p=0.009), and lower rates of being placed on the transplant waitlist (HR 0.64, 95% CI 0.60-0.69, p<0.001).

LIMITATIONS: Residual confounding, diagnostic misclassification due to variation in biopsy practices.

CONCLUSION

Differences in survival and placement onto the kidney transplant waitlist exist across patients with different etiologies of kidney failure. Individuals with IgAN have longer survival and enter the transplant waitlist more often than those with DKD or other GD.