ABSTRACT
OBJECTIVES: We investigated the influence of the interaction between donor age and cold ischemia time on allograft survival in the absence of delayed graft function, early acute rejection, or the combination of both. MATERIALS AND METHODS: We conducted a retrospective analysis of a cohort of patients first transplanted with living-related and deceased-donor allografts between 2001 and 2016. Predictors included cold ischemia time, donor and recipient age and sex, body mass index, renal replacement therapy duration, cause of end-stage renal disease, HLA class I and II mismatches, panel of reactive antibodies score, donor creatinine concentration, development of delayed graft function, and biopsy-proven acute rejection. The response variable was time until return to renal replacement therapy. Patients who died with functioning allografts were censored at the time of death. Analyses included multivariate Cox proportional hazards regression. RESULTS: The study included 498 patients followed for median of 4.1 years with median cold ischemia time of 17.0 hours. On multivariate analysis, allograft survival was negatively affected by the cold ischemia time-donor age interaction (P = .026), acute rejection (P = .043), delayed graft function (P = .001), and acute rejection combined with delayed graft function (P = .002). Restricted mean allograft survival times in patients who developed neither delayed graft function nor acute rejection decreased from 13.6 to 8.6 years when cold ischemia time increased from 12 to 36 hours and donor age increased from 30 to 60 years. CONCLUSIONS: Allograft survival was negatively affected by donor age-cold ischemia time interaction independently of the development of delayed graft function, acute rejection, or their combination.