Strategies for an Expanded Use of Kidneys From Elderly Donors

Abstract

The old-for-old allocation policy used for kidney transplantation (KT) has confirmed the survival benefit compared to remaining listed on dialysis. Shortage of standard donors has stimulated the development of strategies aimed to expand acceptance criteria, particularly of kidneys from elderly donors. We have systematically reviewed the literature on those different strategies. In addition to the review of outcomes of expanded criteria donor or advanced age kidneys, we assessed the value of the Kidney Donor Profile Index policy, preimplantation biopsy, dual KT, machine perfusion and special immunosuppressive protocols. Survival and functional outcomes achieved with expanded criteria donor, high Kidney Donor Profile Index or advanced age kidneys are poorer than those with standard ones. Outcomes using advanced age brain-dead or cardiac-dead donor kidneys are similar. Preimplantation biopsies and related scores have been useful to predict function, but their applicability to transplant or refuse a kidney graft has probably been overestimated. Machine perfusion techniques have decreased delayed graft function and could improve graft survival. Investing 2 kidneys in 1 recipient does not make sense when a single KT would be enough, particularly in elderly recipients. Tailored immunosuppression when transplanting an old kidney may be useful, but no formal trials are available.Old donors constitute an enormous source of useful kidneys, but their retrieval in many countries is infrequent. The assumption of limited but precious functional expectancy for an old kidney and substantial reduction of discard rates should be generalized to mitigate these limitations.

FIGURE 1.

Higher risk of graft loss using organs from ECD vs non-ECD after DCD.

FIGURE 2.

Outcomes using kidneys from very advanced age compared with classical ECDs.

FIGURE 3.

Comparison of mortality between patients undergoing kidney transplantation using ECDs and patients remaining on dialysis on the waiting list for kidney transplantation.

FIGURE 4.

Different criteria for allocating kidneys to dual KT. According to Remuzzi et al, the allocation of a dual KT may be based in histopathological criteria in preimplantation donor biopsy with the assessment of 4 compartments (glomerulosclerosis, tubular atrophy, interstitial fibrosis and vascular lesions). The score ascribes 0 to 3 points to each compartment according to the degree of lesions. If the overall score is 3 points or less, a single KT is carried out, between 4 and 6 points, a dual KT, and 7 points or more lead to kidney discard. Rigotti et al, in addition to the histological score, takes into account donor age and donor comorbidities. If the donor is 70 years or older, or is 60 to 69 years old with at least 1 comorbid condition such as creatinine clearance below 61 mL/min, AH controlled with 2 drugs or more, proteinuria, diabetes or any cardiovascular complication, the recipient receives 2 kidneys in a dual KT. Snanoudj et al proposal is based in donor kidney function and donor age: a donor 65 years or older and eGFR between 30 and 60 mL/min is allocated to dual KT, if >60 ml/min to a single KT and if <30 ml/min discarded. UNOS criteria to allocate kidneys for dual KT are based in donor age (>60 years old), creatinine clearance (lower to 65 ml/min at admission), creeping creatinine after admission (to 2.5 mg/dl or higher) and comorbidities such as AH or DM, with glomerulosclerosis between 15-50%. Tanriover proposal for dual KT is based in UNOS criteria for kidneys with a KDPI higher than 90%. HTA, arterial hypertension; DM, diabetes mellitus; GS, glomerulosclerosis; eGFR, estimated glomerular filtration rate; CV, cardiovascular; CrCl, creatinine clearance.

FIGURE 5.

Outcomes after dual KT versus single transplantation using an ECD kidney.