Living donors > 55 years - To use or not to use?

Background. Kidney transplants using older donors are becoming increasingly accepted as a strategy for alleviating the growing donor organ shortage. M ost studies to date have shown decreased graft survival associated with the use of older cadaver donors; however, studies on the effect of living dono r age on graft survival are less clear-cut. Methods. We studied the effect of donor age on patient and graft survival a fter 1126 consecutive cyclosporine-treated primary kidney transplants perfo rmed between January 1, 1985 and December 31, 1995. Of these grafts, 598 we re from living donors (74 from donors >55 years old) and 528 from cadaver d onors (54 from donors >55 years). We calculated actuarial patient survival, graft survival, and death-censored graft survival for recipients of both l iving donor and cadaver kidneys. Living donors were then further divided by HLA mismatch (0 vs. 1 - 6) and the presence or absence of an acute rejecti on episode. Multivariate analysis of factors associated with decreased graf t survival was performed for recipients of both living and cadaver donor ki dneys, Factors included for analysis were donor age >55 years, recipient ag e >50 years, the presence of diabetes mellitus, HLA mismatch (6 vs. 1 - 6), and the presence of an acute rejection episode. Results. For cadaver kidneys, univariate analysis indicates that both overa ll (P=0.004) and death-censored (P=0.001) graft survival was significantly better with younger cadaver kidneys. This is supported by our multivariate analysis, which shows that cadaver donor age >55 years is an independent pr edictor of poor actuarial graft survival (P=0.0003). For living donor kidneys, univariate analysis also indicates that both over all (P=0.045) and death-censored (P=0.005) graft survival was significantly better with younger living donor kidneys, However, in the absence of acute rejection, 10-year death-censored graft survival for patients with older v s. younger living donor kidneys was 93% vs. 94%, whereas in the presence of one or more acute rejection episodes, 10-year death-censored graft surviva l dropped markedly to 39% with older and 54% with younger living donors. Ki dneys from living donors >55 years had significantly better long-term graft survival than cadaver donors >55 years (P=0.012) and had comparable graft survival to younger cadaver donors. In contrast to our univariate analysis, multivariate analysis of our living donor data shows that decreased actuarial living donor death-censored graf t survival was significantly associated only with the presence of one or mo re acute rejection episodes (P<0.0001). Living donor age >55 years was not independently associated with decreased graft survival. Conclusions. Ours is the largest single-center study of outcome for recipie nts of kidneys from living donors >55 years. Using univariate analysis, we have shown that graft survival of kidneys from older living donors is signi ficantly better than that of kidneys from older cadaver donors and is compa rable to that of kidneys from younger cadaver donors, Using multivariate an alysis, we have shown that the presence of one or more acute rejection epis odes significantly shortens both cadaver and living donor long-term graft s urvival, Most significantly, we have shown that, although the use of kidney s from cadaver donors >55 years is associated with significantly decreased longterm graft survival, no such association exists for recipients of kidne ys from living donors >55 years. We feel that our data support the continue d use of kidneys from older living donors.