Introduction: Non-adherence is an important risk factor for acute rejections and premature allograft failures after kidney transplantation. Consideration for retransplantation in patients who have lost their first kidney allografts from non-adherence remains debatable, and it remains unknown whether patients who have experienced first allograft failure secondary to non-adherence are at an increased risk of allograft failure following retransplantation. The aim of this study was to determine the association between causes of first allograft failure and allograft outcomes following retransplantation.
Materials & Methods: Using data from the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry, patients who had received a second live or deceased donor kidney transplants between 1960-2014 were included. The association between causes of first allograft failure attributed to non-adherence or other causes, death censored graft failure (DCGF) and non-adherence-related DCGF following retransplantation were examined using Cox regression and competing risk analyses, respectively.
Results & Discussion: Of 2822 patients who have received second kidney allografts, 59 (2%) lost their first allografts from non-adherence. The overall median (IQR) allograft follow-up period was 5.8 (1.6-12.0) years, resulting in 22,527 graft years of exposure. Patients who had experienced non-adherence-related first allograft failure were younger at time of first allograft failure (median [IQR] of 25 [20-32] vs. 38 [27-46] years. p<0.001), compared to those who had experienced first allograft failure from other causes. Waiting time before retransplantation was significantly longer in patients who had experienced non-adherence-related first allograft failure (waiting time >5 years: 57% vs. 20%, p<0.001). Compared to patients who had lost their first allografts from causes other than non-adherence, the adjusted hazard ratio (HR) for DCGF was 0.76 (95%CI 0.44, 1.32; p=342) for those who had lost their first allograft from non-adherence. Following retransplantation, the adjusted subdistribution HR of second allograft failure attributed to non-adherence for patients who had experienced non-adherence-related first allograft failure was 2.84 (95%CI 0.83, 17.79; p=0.082).
Conclusion: In patients who had experienced non-adherence-related first allograft failure, the long-term risk of DCGF in the second allograft was similar to those who had lost their first allografts from other causes. Non-adherence-related allograft failure should not be considered an impediment to successful retransplantation, but careful patient selection and close monitoring post-transplant may be imperative to ensure optimal allograft outcome in this population.