'Old-for-old'--new strategies for renal transplantation

Over the past decade, there has been a dramatic increase in the number of patients awaiting kidney transplantation, resulting in a progressive increase in the time spent on waiting list and in the length of time patients are receiving dialysis [1]. Patient survival is lower in patients receiving dialysis than in those who receive a transplant. Furthermore, the duration of pre-transplant dialysis is an important risk factor for both graft and patient survival post-transplantation. Indeed, 10-year graft survival of cadaveric kidney transplantation for patients undergoing pre-emptive transplantation is significantly higher than for patients transplanted when receiving dialysis (69% vs 39% for 24 months on dialysis, respectively) [2]. Reducing the waiting list time improves all aspects of chronic kidney failure, therefore, it is of utmost importance that the transplant community assesses measures to increase donor availability. Age-matching of donors and recipients is one way of expanding the donor pool, and maximizing the use of donated renal allografts through such ‘old-for-old’ transplantation has shown promising results with good graft survival. Over the last decade, there has been a substantial improvement in graft survival rates following renal transplantation. However, maintaining long-term graft and patient survival remains a challenge, with post-transplant malignancies, cardiovascular disease and infections commonly resulting in death with a functioning graft. In fact, patients with pre-existing morbidities such as malignancies, cardiovascular disease, infections and coagulopathies may not benefit as greatly from transplantation [3]. Older recipients receiving a kidney from an older donor have an increased risk of calcineurin inhibitor (CNI) induced nephrotoxicity as well as being at an increased risk of post-transplant infections, malignancy and cardiovascular disease, all of which impact on the patients’ quality of life and long-term patient survival. The newly developed proliferation signal inhibitors, PSIs (also known as mTOR inhibitors) are a class of drugs including the two agents everolimus (Certican®, Novartis Pharma AG, Basel, Switzerland) and sirolimus (Rapamune®, Wyeth Pharmaceuticals, Collegeville, PA, USA). They have both immunosuppressive and anti-proliferative actions and may be beneficial in this population. This editorial reviews the expanding use of ‘old-for-old’ renal transplantation and discusses the potential of PSIs in prolonging graft and patient survival.