Immunosuppression Regimen Use and Outcomes in Older and Younger Adult Kidney Transplant Recipients: A National Registry Analysis

Background. Although the population of older transplant recipients has increased dramatically, there are limited data describing the impact of immunosuppression regimen choice on outcomes in this recipient group. Methods. National data for US Medicare-insured adult kidney recipients (N = 67 362; 2005-2016) were examined to determine early immunosuppression regimen and associations with acute rejection, death-censored graft failure, and mortality using multivariable regression analysis in younger (18-64 y) and older (>65 y) adults. Results. The use of antithymocyte globulin (TMG) or alemtuzumab (ALEM) induction with triple maintenance immunosuppression (reference) was less common in older compared with younger (36.9% versus 47.0%) recipients, as was TMG/ALEM + steroid avoidance (19.2% versus 20.1%) and mammalian target of rapamycin inhibitor (mTORi)-based (6.7% versus 7.7%) treatments. Conversely, older patients were more likely to receive interleukin (IL)-2-receptor antibody (IL2rAb) + triple maintenance (21.1% versus 14.7%), IL2rAb + steroid avoidance (4.1% versus 1.8%), and cyclosporine-based (8.3% versus 6.6%) immunosuppression. Compared with older recipients treated with TMG/ALEM + triple maintenance (reference regimen), those managed with TMG/ALEM + steroid avoidance (adjusted odds ratio [aOR], (0.44)0.52(0.61)) and IL2rAb + steroid avoidance (aOR, (0.39)0.55(0.79)) had lower risk of acute rejection. Older patients experienced more death-censored graft failure when managed with Tac + antimetabolite avoidance (adjusted hazard [aHR], (1.41)1.78(2.25)), mTORi-based (aHR, (1.70)2.14(2.71)), and cyclosporine-based (aHR, (1.41)1.78(2.25)) regimens, versus the reference regimen. mTORi-based and cyclosporine-based regimens were associated with increased mortality in both older and younger patients. Conclusions. Lower-intensity immunosuppression regimens (eg, steroid-sparing) appear beneficial for older kidney transplant recipients, while mTORi and cyclosporine-based maintenance immunosuppression are associated with higher risk of adverse outcomes.

Automated summary

The study found that lower-intensity immunosuppression regimens, such as steroid-sparing, appear beneficial for older kidney transplant recipients, while mTORi and cyclosporine-based maintenance immunosuppression are associated with higher risk of adverse outcomes in both older and younger patients.