Decreased long-term survival with antithymocyte globulin induction in elderly kidney transplant recipients

Purpose: Long-term consequences of immunosuppression on the elderly is still unclear. This data to evaluates long-term outcomes for younger (Y) versus elderly (E) kidney transplant recipients (KTR). Methods: A single-center retrospective analysis of 318 medical records from 2003-10 for KTR on mycophenolate, tacrolimus, and steroid regimen was performed. KTR received antithymocyte globulin (Thy: 4.5mg/kg), basiliximab (Sim: 20mg x2), or no induction based on immunological risk. KTR were divided into two cohorts: (Y: ≤59 yrs; n=172; E: ≥65 yrs; n=146). KTR aged 60-64 were excluded to distinguish groups. Graft and patient survival were demonstrated by Kaplan-Meier plots and reliability was tested using a multivariate Cox proportional-hazards model and log-rank test, controlled for induction, type of transplant, gender, and race. Death events were plotted along the follow-up (FU) period by COD. Results: There was no statistical difference between groups\u27 baseline characteristics, induction therapy, graft failure, or median FU days [Y, 2132 (1770, 2729); E, 2048 (1540, 2538); p\u3e0.05]. Y KTR have better survival than E (figure 1) (p\u3c0.001), especially those who received Thy (p\u3c0.001). In the CoxPH model, risk of mortality increased with age [2.169 (1.287, 3.656), p=0.004]. No difference in mortality was observed for Sim or No (p\u3e0.05). When stratified by COD, cancer and infection (Inf) tended to occur early, within the first 5 yrs of transplant. Cardiovascular events (CV) were more evenly distributed during the long-term FU. Conclusions: Despite similar long-term graft survival, patient survival significantly decreased among the elderly patients. Mortality strongly correlated with patients who received Thymo. These findings suggest a survival benefit with less severe immunosuppressive regimen, particularly induction therapy among the elderly