Waiting time between failure of first graft and second kidney transplant and graft and patient survival

Background. The number of patients with end-stage renal disease being relisted for a second kidney transplant is increasing worldwide. The aim of this study was to determine the relationship between waiting time for a second transplant and outcomes after that second transplant. Methods. Using Australia and New Zealand Dialysis and Transplant registry, patients who have received second kidney transplants between 1997 and 2009 were included. The associations between waiting time, defined as duration of dialysis between first allograft failure and second transplantation, and clinical outcomes including acute rejection, graft and patient survival were examined using adjusted logistic and Cox regression models. Results. Of the 911 recipients, the median follow-up time was 4.7 years resulting in 4825 person-years of follow-up. Increasing waiting time before second transplants was associated with an increased risk of early acute rejection occurring within the first 6 months after transplant (adjusted odds ratio, 1.11; 95%confidence interval [95%CI], 1.06-1.16; P < 0.001), severe vascular and/or humoral rejection (adjusted odds ratio, 1.06; 95%CI, 1.01-1.11; P = 0.011), overall graft failure (adjusted hazard ratio [HR], 1.06; 95% CI, 1.02-1.10; P = 0.001), all-cause mortality (adjusted HR, 1.13; 95% CI, 1.07-1.19; P < 0.001), and death with a functioning graft (adjusted HR, 1.12; 95% CI, 1.06-1.18; P < 0.001), independent of donor, recipient, and immunological factors. Conclusions. Prolonged waiting time for a second transplant was associated with inferior patient and graft outcomes.