Objective: To measure the impact of the Share-35 policy on the allocation of ideal deceased donor kidneys and to examine the impact of age on outcomes after kidney transplantation using ideal donor kidneys.
Background: In the United States, through Share-35, transplant candidates aged 18 years or younger receive priority for the highest-quality deceased donor kidneys. Adolescent (15-18 years) kidney transplant recipients (KTRs), however, may be more susceptible to allograft loss due to elevated rates of acute rejection and a possible increased risk of primary renal disease recurrence.
Methods: We used registry data to perform a retrospective cohort study of 39,136 KTRs from January 1, 1994, to December 31, 2008. Ideal donors were defined as 2 to 34 years old with creatinine <1.5 mg/dL and absence of hypertension, diabetes, and hepatitis C.
Results: After Share-35, the percentage of ideal donor kidneys allocated to pediatric recipients increased from 7% to 16%. In multivariable Cox regression, compared with adolescent KTRs, all age strata except recipients older than 70 years had a lower risk of allograft failure (P < 0.01 for each comparison); results were similar after excluding KTRs with diseases at high risk of recurrence. Adolescent recipients had higher mortality rates than KTRs younger than 14 years, similar mortality compared with that of KTRs older than 18 and younger than 40 years, and lower mortality than KTRs older than 40 years.
Conclusions: The allocation of "ideal donors" to adolescent recipients may not maximize graft utility. Reevaluation of pediatric allocation priority may offer opportunities to optimize ideal renal allograft survival.