LAUSR

INTRODUCTION AND OBJECTIVE: For patients who have undergone primary kidney transplant(PKT) and returned to dialysis, second kidney transplantation(SKT) offers improved quality of life and survival advantages. However, SKT is associated with increased immunologic and non-immunologic risk. Despite these challenges, reported outcomes and 5 year allograft survival rates following SKT are acceptable. There are few studies that investigate significant perioperative predictors for long-term renal allograft survival after SKT. We aimed to compare long term survival following SKT with primary kidney transplant at a single centre. We also investigated donor and recipient perioperative predictors for renal allograft failure after SKT. METHODS: An institutional review-board approved study was performed on outcomes of all patients who received a primary or second kidney transplant at a national kidney transplant center between 1993 and 2017. The primary outcomes measurements were renal allograft survival for both first and second kidney transplants and overall patient and graft survival. Secondary outcome measurements were incidence of delayed graft function (DGF), incidence of allograft rejection and predictors for renal allograft survival in SKT recipients. RESULTS: In total, there were 392 SKT and 2,748 PKT recipients. The duration between first and SKT was 10.5 7.4 years and the median follow-up after SKT was 155 (13-309) months. The 1-,5and 10-year death censored renal allograft survival rates after SKT were 94.1%, 87.0% and 75.1% respectively compared to 95.4%, 89.1% and 78.7% for PKT recipients (p[0.0174). Overall 1-, 5and 10-year patient and graft survival rates after SKT were 93.4%, 82.0% and 66.7% respectively compared to 93.7%, 81.9% and 65.2% for PKT recipients (p[0.822). Survival of primary renal allograft 6 years (HR0.6, p[0.017), episodes of acute rejection (AR) (HR1.6, p[0.031), delayed graft function (DGF) (HR 2.0, p[0.005) and HLA-DR MM (HR 1.8, p[0.018) were independent predictors of long-term renal allograft failure after SKT. There was no significant difference in rates of acute rejection(15.4% vs 15.8%, p[0.843) and delayed graft function (14.1% vs 16.3%, p[0.228) when PKT and SKT were compared. CONCLUSIONS: We report the largest single centre series of patients to undergo SKT. These findings may provide important information on long-term survival outcomes after SKT and for identifying patients at risk for long-term renal allograft failure after SKT.