Background: Information to guide the timing of a second kidney transplantation is limited.
Methods: We compared outcomes of 3509 preemptive and 14,075 nonpreemptive second kidney transplant recipients in the U.S. Renal Data System between 1995 and 2007.
Results: Preemptive recipients had less acute rejection (12% vs. 16%; P<0.0001) and delayed graft function (8% vs. 23%; P<0.0001). Preemptive transplantation was associated with a lower multivariate adjusted risk of allograft failure from any cause including death (hazard ratio [HR], 0.88; 95% confidence interval [95% CI], 0.81-0.96) and death with a functioning graft (HR [95% CI], 0.76 [0.66-0.87]) but a similar risk of death-censored graft loss (HR [95% CI], 0.98 [0.88-1.08]). The benefits of preemptive transplantation were evident in all patients groups with first transplant survival equal to or more than 1 year; however, a 34% increased risk of death-censored graft loss was observed in preemptive recipients when first transplant survival was less than 1 year.
Conclusions: Benefits and risks of preemptive transplantation vary between primary and second transplant recipients. Benefits in second transplant recipients are primarily due to decreased death with a functioning graft, with no difference in death-censored graft survival. Preemptive transplantation was beneficial when first transplant survival was equal to or more than 1 year but associated with increased risk when graft survival was less than 1 year.