Age-Related Differences in Graft Outcomes Among Deceased-Donor Kidney Transplant Recipients

Background: As the number of elderly patients with end-stage kidney disease (ESKD) increases, the importance of understanding how age affects post-transplant success grows. We sought to quantify the association of age with key outcomes in deceased donor kidney transplant recipients (DDKTs). Methods: We analyzed all adult kidney transplant recipients who received kidneys between 01/2001-06/2021 at our transplant center, stratified by age into four groups (18-49, 50-59, 60-69, ≥70). Outcomes of interest included death-censored graft failure (DCGF) and death with a functioning graft (DWFG) within 5 years of transplant and acute rejection (AR) within 1 year of transplant. Results: Of 3119 recipients, 1192 (38.2%) were 18-49 yrs old (control group), 947 (30.4%) were 50-59, 795 (25.5%) were 60-69, and 185 (5.9%) were ≥70. Incidence rates of DCGF per 100 person-years (100PY) were 3.30, 3.31, 4.21, and 6.00 (p-trend <0.001) for each age group respectively. The adjusted hazard ratio (aHR) was 0.88 (95% CI: 0.68-1.13) for 50-59 years; 1.11 (95% CI: 0.85-1.44) for 60-69 years; and 1.73 (95% CI: 1.16-2.96) for ≥ 70 yrs. [Figure 1a.] The incidence rates of DWFG per 100PY were 1.45, 3.17, 5.04, and 7.45 (p-trend <0.001) for each age group respectively. The aHR was 2.00 (95% CI: 1.47-2.73) for 50-59 yrs; 3.36 (95% CI: 2.47-4.58) for 60-69 yrs; and 5.45 (95% CI: 3.95-8.26) ≥70 yrs. [Figure 1b.] The incidence rates of AR per 100PY were 9.04, 6.95, 6.88, and 5.03 (p-trend<0.001) for each age group respectively. The aHR was 0.73 (95% CI: 0.61-0.88) for 50-59 yrs; 0.69 (95% CI: 0.56-0.84) for 60-69 yrs; and 0.47 (95% CI: 0.31-0.72) for ≥70 yrs. [Figure 1c.] Conclusion: Older patients are at substantially higher risk of DCGF and DWFG but have lower risk of AR than their younger counterparts. Understanding these differences is valuable for decision making when caring for elderly patients with ESKD.