The role of pretransplant dialysis modality on renal allograft outcome

Background and objectives. The pretransplant dialysis modality might influence renal allograft and patient survival after transplantation. Studies published to date yielded conflicting results. Methods. Deceased-donor allograft recipients reported to the 'Collaborative Transplant Study' were analysed, using multivariate Cox regression analysis, considering potential confounders which included pretransplant patient cardiovascular risk evaluation as well as immunological and treatment parameters. Primary end points were all-cause graft survival, death-censored graft survival and patient survival. Results. In total, 60 008 recipients were analysed. Patients who were on peritoneal dialysis (PD) (n = 11 664) prior to transplantation demonstrated a 10% lower all-cause mortality (P = 0.014) but similar death-censored graft survival (P = 0.39) as recipients treated with haemodialysis (n 45 651). This lower all-cause mortality in PD patients was primarily a consequence of a significantly lower rate of cardiovascular death with a functioning graft (P < 0.013) in a subcohort of patients defined as at increased risk. Conclusions. Pretransplant dialysis modality per se has no significant impact on allograft outcome. Superior all-cause survival of PD patients is primarily due to a lower rate of cardiovascular death in a subcohort of high-risk recipients. This might explain the conflicting results published to date.