Renal transplantation is a safe treatment for eligible elderly patients with end stage renal disease. When there is a lack of organs it is challenging to prioritize between older and younger patients on the waiting list. Often young patients, who potentially have many years to live ahead of them, will be selected. Consequently very few transplants are carried out internationally in which elderly patients receive a kidney from a deceased donor, even though there is no formal upper age limit (3).
It is essential that good routines are established for the selection of patients who are eligible for renal transplantation. There is no scientific documentation that supports the introduction of an upper age limit (27). An American study found that comorbidity described using CCI assessment at the time of the transplantation was associated with post-transplant survival in patients over the age of 60 (28), but there were no corresponding findings for patients in Norway over the age of 70 (25). The probable explanation is that the oldest patients accepted for transplantation are selected, eligible patients with low comorbidity.
There are no randomized studies in which survival on dialysis is compared with survival following transplantation in elderly patients. Therefore comparisons must be carried out using epidemiological methods. Such a comparison is only described in two of the studies identified (12, 26). To ensure the validity of these analyses, it is essential that the groups compared are as similar as possible.
In the Norwegian material no great differences in patient characteristics were found between those who received transplants and those who remained on the waiting list. Certainly there was a somewhat greater incidence of diabetic nephropathy among those who did not receive a transplant (9 % as against 3 %, p < 0.05), but apart from this, the groups were comparable (26). A large proportion had also received a transplant (81 %). As a result of the method adopted in which a Cox regression analysis with a time-dependent covariate was carried out, transplant recipients were also included in the waiting list group up to the time of the transplantation, so that they also contributed to the survival time of this group.
The American data have been obtained from many centres across the whole of the US and thus reflect a number of different treatment protocols. Only 43 % of the patients in this material finally received a transplant, and due to the long waiting time we must assume that those who received a transplant were a selected group with particularly good health. This complicates the interpretation of the results and the transfer value to Norwegian patients may be limited.
A special programme has been initiated as part of the Eurotransplant collaboration – Eurotransplant Senior Program (ESP) – in which kidneys from elderly donors are allocated to elderly recipients (16). This is described as giving very satisfactory results. In this way increased waiting times for younger patients on the waiting list can be avoided (29). An American register study also describes a similar system (30). However, the use of kidneys from older donors also increases the risk of rejection. This may be attributed to a stronger immune response because of tissue damage in the older organ, which in turn can trigger the immune system of the recipient (31). Increased rejection also has a negative impact on survival in the oldest patients (25). Nonetheless, an analysis of data from patients who received transplants at a period of time when there was a low frequency of rejection showed that kidneys from elderly donors did not present an increased risk of death (32). Adequate immunosuppressive treatment and better understanding of pharmacokinetic principles in elderly recipients can thus reduce the risk of using a kidney from elderly donors.
The optimal immunosuppressive treatment for elderly patients following renal transplantation is not as yet clarified. Since there is a lower incidence of rejection in elderly patients, it has been asserted that they may derive benefit from a milder immunosuppressive regime (33). On the other hand, a clearly higher survival rate and reduction of rejection frequency following intensification of treatment have been described (26). The decisive factor is the provision of sufficient immunosuppressive treatment to avoid rejection while ensuring that the treatment is not so intense as to increase the danger of infection. Often it is the anti-rejection treatment itself that leads to serious infections.
Since 2007, everyone over the age of 50 who has received a kidney transplant at Oslo University Hospital, Rikshospitalet has received induction therapy with interleukin 2-receptor antagonist in addition to prednisolone, cyclosporine A and mycophenolate mofetil. An assessment is now underway to determine whether this change causes a higher survival rate as a result of fewer rejections, or whether it will lead to higher mortality because of more infections.
The Norwegian results show that reduced time on dialysis is associated with improved survival after renal transplantation in patients over the age of 70 (Table 2), while this has not been consistently found in younger patients (25). It is therefore very important to identify and start assessment of elderly patients who are potential candidates for renal transplantation at an early stage. Ideally, the patient should receive a transplant before the need for dialysis is established or shortly after starting dialysis. The use of living donors gives a greater opportunity to achieve this, since in practice there is no waiting time when a living donor is accepted as a donor.