Long-term allograft survival in renal transplantation from elderly donors

Increasing the donor and recipient pool-expanded criteria in living kidney donors

To increase the donor and recipient pool in living related renal transplantation, kidneys from expanded criteria living donors are used more frequently to reduce the general problem of organ shortage. This article presents an overview of the current literature concerning this topic to further improve donor selection and transplant decision making.

Living kidney donors: impact of age on long-term safety

The safety of older live kidney donors, especially the decline in glomerular filtration rate (GFR) after donation, has been debated. In this study we evaluated long-term renal outcome in older live kidney donors. From 1994 to 2006 follow-up data of 539 consecutive live kidney donations were prospectively collected, during yearly visits to the outpatient clinic. Donors were categorized into two groups, based on age: < 60 (n = 422) and ≥ 60 (n = 117). Elderly had lower GFR predonation (80 vs. 96 mL/min respectively, p < 0.001). During median follow-up of 5.5 years, maximum decline in eGFR was 38% ± 9% and the percentage maximum decline was not different in both groups. On long-term follow-up, significantly more elderly had an eGFR < 60 mL/min (131 (80%) vs. 94 (31%), p < 0.001). However, renal function was stable and no eGFR of less than 30 mL/min was seen. In multivariate analysis higher body mass index (HR 1.09, 95%CI 1.03-1.14) and more HLA mismatches (HR 1.17, 95%CI 1.03-1.34) were significantly correlated with worse graft survival. Donor age did not influence graft survival. After kidney donation decline in eGFR is similar in younger and older donors. As kidney function does not progressively decline, live kidney donation by elderly is considered safe.

Recipient outcomes for expanded criteria living kidney donors: the disconnect between current evidence and practice

Older individuals or those with medical complexities are undergoing living donor nephrectomy more than ever before. Transplant outcomes for recipients of kidneys from these living expanded criteria donors are largely uncertain. We systematically reviewed studies from 1980 to June 2008 that described transplant outcomes for recipients of kidneys from expanded criteria living donors. Results were organized by the following criteria: older age, obesity, hypertension, reduced glomerular filtration rate (GFR), proteinuria and hematuria. Pairs of reviewers independently evaluated each citation and abstracted data on study and donor characteristics, recipient survival, graft survival, serum creatinine and GFR. Transplant outcomes for recipients of kidneys from older donors (> or =60 years) were described in 31 studies. Recipients of kidneys from older donors had poorer 5-year patient and graft survival than recipients of kidneys from younger donors [meta-analysis of 12 studies, 72% vs. 80%, unadjusted relative risk (RR) of survival 0.89, 95% confidence interval (CI) 0.83-0.95]. In meta-regression, this association diminished over time (1980s RR 0.79, 95% CI 0.65-0.96 vs. 1990s RR 0.91, 95% CI 0.85-0.99). Few transplant outcomes were described for other expanded criteria. This disconnect between donor selection and a lack of knowledge of recipient outcomes should give transplant decision-makers pause and sets an agenda for future research.

Grandparent donors in paediatric renal transplantation

The outcome of transplantation from grandparent donors in comparison with parental donors in paediatric renal transplantation was evaluated in 53 living related donor (LRD) transplantations performed between January 1996 and August 2003. The donor in 13 cases (25%) was a grandparent (Gpar group), and the remaining donors formed the parent group (Par group). The median age of recipients in the Gpar group was 2.75 (1.7-10.6) years and in the Par group was 12.75 (2.4-22) years (P<0.0001). There was no evidence of a difference in patient and graft survival, glomerular filtration rate (GFR) after transplantation, or the number of biopsy proven episodes of rejection between the groups. Doses of prednisolone in the first year following transplantation were greater in recipients from Gpar donors, but the other immunosuppression doses were similar. The median age of donors in the Gpar group was 56 (50-67) years and in the Par group was 41 (27-58) years (P<0.0001). There was no evidence of a difference between the two donor groups in mean creatinine clearance at last follow-up. There were two major donor complications in the Gpar group and one in the Par group. There was no evidence that the length of stay differed between the two groups in either the donors or recipients. These results support the use of carefully selected healthy grandparents as LRDs in children. This option potentially allows for the use of parent donors for a subsequent transplantation.

Acute rejection in the elderly recipient: influence of age in the outcome of kidney transplantation

Since the immune response in older recipients is weaker they should be less likely to reject a transplanted organ and should need less aggressive immunosuppressive treatment. Our aim was to record the incidence and severity of episodes of acute rejection (AR), estimate the influence of these events on graft survival of elderly recipients (> or = 60) and to compare these with that in younger ones. We performed 363 kidney transplants between 1/94 and 12/98, and recorded clinical and immunological data, incidence-severity of AR and cause of graft loss. Patients were divided into two groups, according to the age at transplantation: A (<60, n = 281/77.4%) and B (> 60, n = 82/22.6%). The percentage of aging recipients and mean age of donors and recipients increased throughout the period. Although the incidence of ATN was higher in the older group (29% vs.19%, p < 0.0001) the number of graft biopsies was equal in both groups. The incidence of AR was similar, 33.4% vs. 26.8%, pNS. The number of AR episodes per patient was 0.44 and 0.41 respectively. The severity of AR was: Banff grade I: A (40.3%)/B (45.7%) pNS; grade II: A (44.1%)/B (48.57) pNS; grade III: A (15.5%)/B (5.7%) pNS. Younger recipients presented a higher level of panel-reactive antibodies (PRA) (4.3% vs. 2.07%, p = 0.01). One-yearpatient survival was 96%/91% (p < 0.05) and graft survival was 81%/78% (pNS) respectively. The age of recipient does not seem to have influenced the incidence-severity of AR or the graft survival. Thus immunosuppression should be individualized for each patient and should not depend on the age at transplantation.

The use of expanded criteria cadaver and live donor kidneys for transplantation

The use of expanded criteria donors (non-traditional donors) can help lessen the current shortage of kidneys available for transplantation. The use of older donors has accounted for a large measure of the increase in the organ donation rate; however, the most significant factors found to impact on transplant success negatively traditionally have been shown to be extremes of donor age and last-hour urine output. Less significant variables affecting success rates are average systolic blood pressure, terminal serum creatinine, and days of hospitalization. With the appropriate selection of organs from expanded donors, acceptable outcomes can be obtained. When living donors are selected properly, kidneys with anatomic variants without pathologic significance can be used safely. Kidneys with a heightened potential for the development of progressive disease should not be transplanted. Efforts to decrease the cold ischemia time by increasing the use of kidneys from expanded criteria donors may improve the outcome of transplantation further. Advances in surgical techniques, preservation solutions, and methods for predicting eventual long-term renal function in kidneys from expanded donors will be critical in allowing precise selection criteria for kidneys for transplantation, resulting in the optimum use of a scarce and precious resource. Until options such as xenotransplantation become clinically feasible, the challenge will be to identify which donor organs previously considered suboptimal can be used safely to expand the organ donor pool.