2222 kidney transplantations at the University Hospital Basel: a story of success and new challenges.

Questions Under Study: The aim was to investigate changes in kidney allograft donor/recipient characteristics and outcomes at our centre.

Methods: We retrospectively reviewed all 2222 kidney transplantations performed between 1967 and 2015. The population was divided into four eras on the basis of time intervals corresponding to major changes in immunosuppression and pretransplant risk stratification: (i.) 1967-1980 (n = 231), (ii.) 1981-1997 (n = 883), (iii.) 1998-2004 (n = 437), (iv.) 2005-2015 (n = 671).

Results: In deceased donor transplants, we observed a continuous increase of the median recipient (45, 51, 56 and 58 years; p <0.0001) and donor (26, 36, 49 and 54 years; p <0.0001) age. Notably, the frequency of expanded criteria donors increased dramatically (1%, 10%, 28%, 40%, p <0.0001). Graft survival at 1 year (63%, 82%, 89%, 95%), 5 years (46%, 66%, 72%, 78%) and 10 years (27%, 46%, 48%, 61%) significantly improved (p <0.0001). Patient survival also significantly improved and remained stable at a high level within the last three eras (1 year: 97%; 5 years: 87%; 10 years: 71%). Similar trends along with slightly better outcomes were noticed in living donor transplantations. In the most recent era, graft losses in elderly patients were in 81% of cases related to the patient's death, whereas in young patients 83% of graft losses were caused by transplant failure (mainly rejection). Allograft function at the time of patients' deaths would have allowed for calculated 10 additional years with an estimated glomerular filtration rate >15 ml/min.

Conclusion: Despite increasing donor and recipient age, outcomes improved, illustrating ongoing progress in kidney transplantation. A major new challenge is to match the functional capacity of the donor organ with the anticipated lifespan of the recipient.