Donor-recipient age difference and graft survival in living donor kidney transplantation

In paired living kidney exchange donation from an old donor to a young recipient, it may be argued that elderly donors provide an inferior quality kidney. However, the impact of donors older than recipients on transplant outcomes remains unclear.

We retrospectively reviewed the charts of primary living kidney transplantation patients who were divided into two groups based on the age difference between donor and recipient (recipient age subtracted from donor age, donor-recipient < 20 vs ≥ 20). The donor-recipient age difference < 20 group comprised 75 and donor-recipient age difference ≥ 20 group, 25 subjects. Outcome measures included serum creatinine, acute rejection episodes as well as graft and patient survivals at 1 and 5 years after transplantation.

The mean donor age difference cohorts of < 20 and ≥ 20 years showed donor ages of 33 ± 8 and 54 ± 8 years, respectively. The mean recipient age in both groups averaged under 40 years. The acute rejection rate within the first year posttransplantation was greater among age difference ≥ 20 years. The mean serum creatinine values of the donor-recipient age difference < 20 group was lower than the ≥20 years group at 1 and 5 years posttransplant. The 1-year difference was associated with an increased creatinine value at 5 years. However, death-censored graft survival of the age difference of the ≥ 20 years group was not different (hazard ratio [HR] = 0.1, 95% confidence interval [CI] = 0.01-1.37, P = .08). Patient survival of the age difference ≥ 20 years group showed no difference compared with the age difference < 20 years group (HR = 0.25, 95% CI = 0.01-6.35, P = .4).

Although the cohort of a donor-young recipient age difference ≥ 20 years showed a greater risk of an acute rejection episode early posttransplantation, it did not affect graft or patient survivals. When considering paired kidney donation, older age donors should not necessarily be limited.