O10
Deceased donor renal transplants from older donors; does the age of the recipient
influence transplant outcomes?
Maria Pippias1, Anna Casula2, Chris G. Winearls3, Rommel Ravanan4
1, ERA-EDTA Registry, Department of Medical Informatics, Academic Medical Center,
University of Amsterdam, Amsterdam, The Netherlands 2, UK Renal Registry, Bristol,
United Kingdom 3, Oxford Kidney Unit, Churchill Hospital, Oxford, United Kingdom,
4, Richard Bright Renal Unit, Southmead Hospital, Bristol, United Kingdom
Introduction: Animal experiments indicate that grafted organs from older animals can work
well in younger recipients (YR) with preserved cell repair machinery, more active
management of senescence, stem cell participation in tissue preservation and healing all
proposed as feasible explanations for these phenomena. It is possible such protective
mechanisms may only be active and/or sufficiently robust to protect isografts but may not
have meaningful translation to allograft transplantation. This is contrary to traditional clinical
practice which encourages the view that kidneys from older deceased donors (ODD) should
be selectively allocated to age matched recipients as younger recipients of these kidneys may
have inferior outcomes. Currently over 50% of deceased donor kidney transplants within the
UK are from donors aged over 50 years. As the age of deceased donors continues to rise, YR
on the transplant waiting list will be increasingly dependant on kidneys from ODD or
disadvantaged if the current practice of avoiding large donor-recipient age gradients
continues. The aim of this study was to identify whether YR have inferior outcomes
compared to older recipients (OR) with grafts from ODD.
Methods: Using UK Renal Registry and NHSBT data we performed a cohort study of
incident renal transplants between 2000 and 2007 from deceased donors aged between 55 and
70 years. Transplants where one kidney was transplanted in a recipient of less than 5 years
age difference to the donor (control group) and the paired kidney was transplanted in a
recipient more than 6 years younger (YR) than the donor were included. Outcomes were
overall graft failure and death-censored graft failure at 1 and 5 years and eGFR at 1 year.
Survival analysis was performed using the Kaplan Meier method and Cox regression model
stratified by donor with adjustments for recipient group (young vs old recipient), ethnicity,
primary renal disease, cold ischaemic time, HLA mismatch, sex and dialysis vintage.
Results: Of the 333 pairs included, median age for the YR and OR were 45 (Interquartile
range, IQR 38-50) and 60 (IQR 56-64) years respectively, median donor age was 60 (IQR 5764) years. The median follow up time was 7 (IQR 4.3-9.1) years. 5 year unadjusted graft
survival probability was 76% in the YR and 68% in the OR. The unadjusted 5 year death
censored graft failure was 80% in both recipient groups. The adjusted death-censored graft
survival was similar between the 2 groups at 1 and 5 years (HR 1.24, 95%CI 0.66-2.32,
P=0.51 and HR 1.05, 95%CI 0.68-1.61, P=0.83, respectively). The adjusted overall graft
survival showed a trend towards an improved outcome in the YR group at 1 year (HR 0.82,
95%CI 0.48-1.39, P=0.46), however by 5 years, graft survival was significantly better in the
YR group (HR 0.65, 95%CI 0.45-0.93, P=0.02). At 1 year the median eGFR was no different
between the 2 groups (YR; 41.6, IQR 32.1-51.8, OR; 39.3, IQR 29.3-49.8, P=0.09).
Discussion: This is the first study comparing transplant outcomes in old and young recipients
of ODD by means of a ‘paired kidney analysis’. In the adjusted analyses, we found YR of
ODD kidneys did not have a worse 5 year graft outcome compared to OR, in fact there was a
trend towards better graft survival. The study result raises the possibility that similar to animal
studies, currently poorly understood inherent recipient factors that may promote better
‘healing’ of ODD kidney in a YR as compared to a OR. The traditionaly held scepticism
regarding use of ODD kidneys in YR needs to be reviewed.