Age-specific impact of different immunosuppressive regimens on kidney transplant outcomes: clinical evidence from the scientific registry of transplant recipients.

BACKGROUND: Although older kidney transplant recipients have a higher risk of side effects leading to infection and malignancies, the impact of different immunosuppressive regimens on clinical outcomes in this group remains unclear. METHODS: Retrospective cohort study analyzing data from the Scientific Registry of Transplant Recipients database. Kidney transplant recipients were categorized according to age categories (18-64 and >65 years) and immunosuppressive maintenance regimens: tacrolimus/mycophenolate mofetil (Tac-MMF), Tac/mTOR-inhibitor (Tac-mTORi), cyclosporin/MMF (CsA-MMF) and mTORi-MMF. The primary endpoint was overall survival. RESULTS: Among the 112, 952 patients analyzed, overall survival rates at 2-, 3- and 5-years post-transplant were 95.6%, 93.7% and 87.6% respectively. No significant differences in the risk of mortality, graft loss or acute rejection were observed between patients treated with Tac-mTORi and those receiving Tac-MMF. Furthermore, no significant interactions were found between the maintenance immunosuppressive regimens and recipient age groups. Regarding kidney function, younger patients on the Tac-mTORi compared with Tac-MMF regimen exhibited a lower mean eGFR throughout the follow-up period compared to those on Tac-MMF. In contrast to this younger cohort, older patients treated with Tac-mTORi did not experience a significant additional decline in renal function. CONCLUSION: In this study, Tac-mTORi and Tac-MMF showed comparable results regarding patient survival, graft survival and rejection rates. Because older patients remain at higher risk for drug-related side effects, including infections, metabolic disorders and malignancies, these results highlight the critical need for individually immunosuppressive regimens in older transplant recipients and warrant further prospective validation.