Survival benefit of living donor kidney transplantation in patients on hemodialysis.

Background: Donors bravely donate their kidneys because they expect that living donor kidney transplantation (LKT) confers benefits to recipients. However, the magnitude of the survival benefit of LKT is uncertain.

Methods: This prospective cohort study used two Japanese nationwide databases for dialysis and kidney transplantation and included 862 LKT recipients and 285,242 hemodialysis (HD) patients in the main model and 5299 LKT recipients and 151,074 HD patients in the supplementary model. We employed time-dependent model in the main model and assessed the hazard ratio and the difference in the restricted mean survival time (RMST) between LKT recipients and HD patients. In the main analysis of the main model (LKT, N = 675; HD, N = 675), we matched LKT recipients with HD patients by age, sex, dialysis vintage, and cause of renal failure and excluded HD patients with dementia or performance status grades 2, 3, or 4.

Results: The median observational period was 8.00 (IQR 3.58-8.00) years. LKT was significantly associated with a lower risk of mortality (hazard ratios (95% confidence interval (CI)), 0.50 (0.35-0.72)) and an increase in life expectancy (7-year RMST differences (95% CI), 0.48 (0.35-0.60) years) compared with HD. In subgroup analysis, the survival benefit of LKT was greater in female patients than in male patients in the Cox model; whereas older patients gained longer life expectancy compared with younger patients.

Conclusions: LKT was associated with better survival benefits than HD, and the estimated increase in life expectancy was 0.48 years for 7 years.