Assessing Long-Term Adverse Outcomes in Older Kidney Transplant Recipients: A Propensity Score-Matched Comparison of Early Steroid Withdrawal Versus Continuous Steroid Immunosuppression Using a Large Real-World Database.

Background: Steroids are widely used in maintenance immunosuppression treatment in kidney transplant recipients. Older individuals undergo age-related immunosenescence that consequently decreases their ability to process and evoke a response to foreign antigens. Thus, steroids may not be necessary in preventing allograft rejection and may consequently increase older recipients' risk of long-term steroid-related adverse effects.

Objective: The objective of this study was to analyze the adverse outcomes of long-term steroid immunosuppression in older kidney transplant recipients using real-world electronic medical record data.

Methods: The TriNetX database "US Collaborative Network" was utilized to perform a propensity score-matched case-control study comparing 1-year, 3-year, and 5-year adverse effects of steroid immunosuppression in older adults (aged ≥ 65 years) kidney transplant recipients who underwent either an early-steroid withdrawal (ESW) maintenance regimen or a steroid continuous immunosuppression (SCI) regimen between 31 December, 2010 and 31 December, 2020. Early-steroid withdrawal was defined as tacrolimus plus mycophenolate mofetil maintenance with no prednisone after the seventh day post-transplant. Steroid continuous immunosuppression was defined as tacrolimus plus mycophenolate mofetil plus prednisone maintenance. Cohorts were matched on age, race/ethnicity, and risk factors for adverse steroid-related outcomes and rejection. Outcomes included post-transplant diabetes mellitus, dyslipidemia osteoporosis/fractures, myocardial infarction, glaucoma/cataract, stroke, pulmonary embolism, and malignancy. Secondary outcomes analyzed incidences of infection-related outcomes, graft-related outcomes, and recipient mortality.

Results: After matching, there were 304 recipients in each group (ESW, SCI). Mean age at the time of transplant was 69.2 ± 3.7 years (ESW) and 69.2 ± 3.4 years (SCI, p = 0.96). The Kaplan-Meier analysis showed recipients who underwent SCI had increased incidences of post-transplant diabetes mellitus at 1 year (22.36% vs 30.37%, p = 0.01) and 3 years (34.89% vs 44.29%, p = 0.01), but this became non-significant at 5 years post-transplant (41.97% vs 42.6%, p = 0.34). Incidences of acute pancreatitis were higher for the SCI cohort at 3 years (p = 0.02) as well as incidences of acute myocardial infarction at 5 years post-kidney transplant (6.75% vs 14.39%, p < 0.01). No difference was found for other adverse outcomes. Early-steroid withdrawal recipients experienced significantly fewer infection-related outcomes, such as cytomegalovirus, BK virus, sepsis/bacteremia, and fungal infections, compared with SCI recipients. Last, recipients who underwent ESW experienced fewer incidences of rejection and death-censored graft failure at 5 years post-transplant.

Conclusions: There is currently no standard maintenance immunosuppression protocol for older kidney transplant recipients. Death-censored graft survival, rejection, and patient survival were improved with ESW. Steroid minimization may be beneficial in this population given that it lowers the risk of drug-induced adverse effects.