A logical basis for age matching in organ transplantation: studies of recipient renal function in relation to donor age.

The ever rising demand for renal transplantation has led to an increased use of older (> 50 years) organ donors. Previous studies have shown that donor-to-recipient age difference is an independent risk factor for allograft survival. A recent multicentre study of 6397 first cadaver renal transplants showed that, where donors are more than 5 years older than the recipient, there is significantly impaired graft survival. The mechanism of this effect is unclear, but it has been suggested that age-related donor factors may influence subsequent graft function. Pathological studies have shown that native kidneys acquire specific histological (i.e. glomerulosclerosis, interstitial fibrosis) and functional defects in a linear fashion related to increasing age. Whilst graft loss may be seen as the worst outcome from using older donors, impaired function leading to shortened half-life may also occur. Recipients of kidneys from donors > 50 years of age also have a significantly higher creatinine than those from donors < 50 years of age. A study was therefore undertaken to investigate in greater detail the effect of age on the function of donor kidneys in their respective recipients.