Influence of kidney transplant recipient age on the immunological responseto an alloantigen

Since the immune response in older recipients has been described as weaker they may have a lower risk of rejection of a transplanted organ. Therefore a less aggressive immunosuppressive regimen should be the best option. The aim of our study was to evaluate the incidence and severity of acute reject ion (AR) episodes on graft survival of older patients (greater than or equa l to 60 years) and to compare them with the younger ones (<60 years). A total of 439 kidney transplants were performed between 1/94 and 12/99 at our Transplant Unit. Clinical and immunological data, incidence and severit y of AR and cause of graft loss were recorded. Patients were divided into t wo groups, according to age at transplantation [A (<60, n=342/77.9%) and B (greater than or equal to 60, n=97/22.1%)]. The percentage of aging recipie nts and mean age of both donors and recipients increased through the period of study. Although the incidence of acute tubular necrosis was higher in t he older group (31% vs 22.8%, pNS), the incidence of AR was also similar (3 1.6% vs 29.8%, pNS). The number of AR episodes per patient was 0.44 and 0,4 1 respectively. The incidence of AR was higher in those patients who had AT N (50% vs 19.6%), p<0.01). The severity of AR was: Banff grade I A (40.3%)/ B (45.7%) pNS; grade II: A (44.1%)/B (48.5%) pNS; grade III: A (15.6%)/B (5 .8%) pNS. One-year patient survival was 96%/91% (p<0.001) and graft surviva l was 81%/78% (pNS) respectively. The age of recipient does not seem to have a significant influence on the i ncidence and severity of AR or on graft survival. So immunosuppression shou ld be individualised for each patient.