Recipient age as a determinant factor of patient and graft survival

Abstract

Background. Age of renal transplants has been related to death, alloimmune response and graft outcome. We reviewed the influence of patient age on transplant outcome in three cohorts of patients transplanted in Spain during the 1990s. Methods. Patient age was categorized into four groups (I, 18–40; II, 41–50; III, 51–60; and IV, > 60 years). Risks factors for acute rejection were evaluated by logistic regression adjusting for transplant centre and transplantation year, while a Cox proportional hazard model was employed for analysing patient and graft survival. Results. Older patients had a higher death rate (I, 3.5%; II, 7.7%; III, 13.2%; and IV, 16.9%; P<0.001), but a lower standardized mortality index (I, 7.6; II, 7.0; III, 5.8; and IV, 4.1; P = 0.0019). Older patients had the lowest risk of acute rejection [odds ratio (OR) 0.79 and 95% confidence interval (CI) 0.66–0.97 for group II; OR 0.75 and 95% CI 0.62–0.91 for group III; OR 0.43 and 95% CI 0.33–0.56 for group IV). Death-censored graft survival was poorer in patients older than 60 years (relative risk 1.40; 95% CI 1.09–1.80), but this result was not explained by any combination of patient age with donor age, delayed graft function or immunosuppression. Conclusions. Patient age is a main determinant of transplant outcome. Although death rate is higher for older patients, standardized mortality was not. Thus, the efforts to reduce mortality should be also implemented in younger patients. Old patients have a low risk of acute rejection but a poorer death-censored graft survival. This last result was not explained by any controlled variable in our study.