The effect of pre-transplant dialysis duration on the relationship between delayed graft function and recipient death.

The aim of this study was to evaluate the effect of delayed graft function (DGF) on recipient death after kidney transplant from donors after brain death (DBD) stratified by pre-transplant dialysis duration. Using a retrospective database, this study collected clinical data from 1,311 patients who underwent DBD kidney transplantation. Univariate and multivariate Cox regression analyses were performed to assess the relationship between the DGF and recipient death. We applied a competing risk analysis model to explore the risk factors associated with DGF. The interaction between DGF and pre-transplant dialysis duration on recipient death was then further determined and analysed in subgroups. In addition, an individualised prediction model for recipient death was developed in the group with an extended pre-transplant dialysis duration. Overall, 53 patients (4.0%) died after kidney transplantation. DGF was independently associated with recipient death (HR: 2.672, 95% CI: 1.441-4.954, P = 0.002). A significant interaction was found between DGF and pre-transplant dialysis duration on recipient death (P = 0.037). In the extended pre-transplant dialysis duration (> 24.7 months), recipient age (HR: 1.059, 95% CI: 1.019-1.102, P = 0.004), donor age (HR: 1.050, 95% CI: 1.005-1.096, P = 0.027), and DGF level (HR: 4.311, 95% CI: 2.003-9.279, P < 0.001) were independent risk factors for recipient death. Furthermore, in the group of patients with extended pre-transplant dialysis duration, a predictive model based on DGF, recipient age, and donor age showed good predictive accuracy, calibration, and clinical utility. DGF was associated with recipient death within 3 years after DBD kidney transplantation only in patients with an extended pre-transplant dialysis duration, suggesting that pre-transplant dialysis duration is associated with whether DGF is an independent risk factor for recipient death.