For the millions of patients worldwide managing end-stage kidney disease, the timing of transplantation relative to dialysis initiation may be far more consequential than previously appreciated — even in healthcare systems with exemplary dialysis management. This multicenter Japanese analysis sharpens the clinical picture considerably, suggesting a critical two-year threshold that could inform transplant listing decisions globally.
Drawing on 805 living-donor kidney transplant recipients across three institutions between 2001 and 2021, the study quantified how pretransplant dialysis duration (PTDD) shapes long-term allograft survival. Preemptive kidney transplantation — performed before dialysis ever begins — already carried a known survival advantage (hazard ratio 1.67 for graft loss in the dialysis group versus preemptive recipients). More notably, multivariate modeling identified ≥2 years of pretransplant dialysis as a distinct risk factor for allograft loss, with a hazard ratio of 2.61 — a magnitude comparable to diabetic nephropathy (HR 2.94) and male recipient sex (HR 2.35). Recipients who spent fewer than two years on dialysis before transplantation showed ten-year allograft survival rates statistically indistinguishable from preemptive transplant recipients.
The finding carries layered significance. Most prior research on dialysis duration effects was conducted in contexts where dialysis quality was highly variable; the Japanese cohort is notable precisely because hemodialysis management was described as favorable, suggesting the two-year threshold holds even under near-optimal conditions. Mechanistically, prolonged dialysis is associated with cumulative uremic injury, systemic inflammation, cardiovascular remodeling, and sensitization — any of which could impair graft longevity. The study is observational and retrospective, limiting causal inference, and the living-donor-only design restricts generalizability to deceased-donor settings. Still, for transplant programs weighing listing urgency, this evidence adds meaningful weight to the case for minimizing dialysis exposure well below the two-year mark — an incremental but practically actionable finding.