Renal transplantation with limit donors: to what should the good results obtained be attributed?

Donor Kidney Evaluation

In patients with end-stage renal disease, kidney transplantation is the best means to extend survival and offer a better quality of life. The current shortage of organs available for transplantation has led to an effort to expand the kidney donor pool, including the use of nonideal donor kidneys. Assessment of the quality of the donated kidney is essential, and would facilitate the decision to transplant a potential organ or discard it. Multiple clinical and histologic parameters have been examined to evaluate the donor kidney and relate the findings to the graft outcome, but clear-cut criteria are yet to be defined.

Significance of preimplantation analysis of kidney biopsies from expanded criteria donors in long-term outcome

BACKGROUND

The shortage of organs has led to expanding the criteria for donors. Histologic evaluations before transplantation may enable the identification of organs unsuitable for single implantation. The aim of this study was to evaluate the histologic findings as prognostic factors of allograft survival from expanded criteria donors (ECDs).

METHODS

We included a cohort of 136 single transplantations with kidneys from ECD and correlated the preimplantation pathologic findings with graft failure. Renal structures from ECD older (n=104) or younger (n=32) than 60 years were evaluated histologically for renal senescence and rated with a total histologic score. A multivariate Cox analysis was performed to identify predictors of graft failure.

RESULTS

Glomerulosclerosis was the most prevalent lesion in biopsies from donors older and younger than 60 years (P=0.002); interstitial fibrosis was more severe in biopsies from older donors (P=0.001); older donors showed a higher prevalence of tubular atrophy (P=0.022), and vascular compartment showed no significant differences. Kidney biopsy-based scoring system ranged from 0 to 15 points, indicating the presence of changes in the renal parenchyma. Biopsies with total histologic scores less than or equal to 5 showed significantly better 5-year graft survival than those with scores more than 5 (P<0.001). A preimplantation score more than 5 points remained an independent predictor of graft failure (hazard ratio 6.95; 95% confidence interval 1.57-30).

CONCLUSIONS

Histologic analysis of kidney biopsies before transplantation is a valuable tool for facilitating the selection of viable grafts from ECD donors. When the total score is more than 5, single kidney transplantation from ECD should not be recommended for patients similar to this study population.

A simple clinico-histopathological composite scoring system is highly predictive of graft outcomes in marginal donors

The predictive value of pre-implantation biopsies versus clinical scores has not been studied extensively in marginal donors. Pre-implantation biopsies were performed in 313 kidneys from donors that were > or = 50 years of age (training set, n = 191; validation set, n = 122). The value of the donor clinical parameters and histological results in predicting 1-year estimated glomerular filtration rate (eGFR) <25 mL/min/1.73 m(2) was retrospectively evaluated. In multivariate analysis, the only clinical parameters associated with low eGFR were donor hypertension and a serum creatinine level > or =150 micromol/L before organ recovery. Clinical scores (Nyberg and Pessione) were not significantly associated with graft function. Regarding histological parameters, univariate analysis showed that glomerulosclerosis (GS) (p = 0.02), arteriolar hyalinosis (p = 0.03) and the Pirani (p = 0.02) and chronic allograft damage index (CADI) (p = 0.04) histological scores were associated with low eGFR. The highest performance in predicting low eGFR was achieved using a composite score that included donor serum creatinine (> or =150 micromol/L or <150 micromol/L), donor hypertension and GS (> or =10% or <10%). The validation set confirmed the critical importance of taking into account biopsy and clinical parameters during marginal donor evaluation. In conclusion, clinical scores are weak predictors of graft outcomes with marginal donors. Instead, a simple and convenient composite score strongly predicts graft function and survival and may facilitate optimal allocation of marginal donors.

Histological assessment of preimplantation biopsies may improve selection of kidneys from old donors after cardiac death

Kidneys from old donors after cardiac death (DCD) may increase the donor pool but the prognosis of these kidneys is unsatisfactory. To improve these results, we retrospectively evaluated the diagnostic utility of published selection algorithms for old donor kidneys. We studied all DCD kidney transplantations between January 1, 1994 and July 1, 2005 at our institution (n = 199). Selection algorithms were evaluated in the subset of kidney transplantations from donors aged 60 years or older (n = 52). For histological assessment of kidney biopsies, glomerulosclerosis, tubular atrophy, interstitial fibrosis and vascular narrowing were blindly scored. Functional kidney weight was calculated as renal mass multiplied by the fraction of nonsclerosed glomeruli. Graft function and survival of kidneys from DCD aged 60 years or older were inferior to those from younger DCD. Histological scores were associated with kidney function and graft survival of old DCD kidney transplantations. Functional kidney weight was associated with kidney function but not graft survival, while donor glomerular filtration rate (GFR), donor age and machine perfusion characteristics were associated with neither of the clinical outcomes of interest. We conclude that histological assessment of preimplantation biopsies may improve the selection of kidneys from old DCD and may therefore contribute to expansion of the donor pool.

Transplantation rénale du sujet âgé

For ten years, an increase in the number of elderly patients on renal transplant waiting lists has occured. In an attempt to close the widening gap between supply and demand and because the demand for kidneys for younger patients already surpasses the supply, transplant physicians nowadays accept organs from older donors that might have been deemed inappropriate in the past. Programs of age matching between donors and recipients and of dual-kidneys transplantation have emerged. The initial results of these programs are encouraging with excellent patient and graft survival at one and three years.

Biopsy of potential cadaveric renal allografts at the time of retrieval

Biopsy of cadaver renal allografts may aid in the assessment of marginal allografts. However, the use of this approach is not clear. This study presents the outcome of institution of a protocol for back table biopsy of renal allografts during organ procurement.

METHODS

Data from Lifelink Organ Donation Network records and the ANZDATA registry were analysed.

RESULTS

The biopsy rate of renal allografts increased from 0.8% to 15.6% (P=0.01). The discardment rate of potential renal allografts increased slightly with 1.9% being discarded based on the biopsy result and 3.8% being discarded for other reasons. Under the biopsy protocol, 28/40 (70%) of donors with renal allograft biopsies had <20% glomerulosclerosis. The incidence of both delayed graft function and non-function was higher (P=0.014 and P=0.033, respectively) for the protocol biopsied allografts compared with the other non-biopsied allografts. One-year renal allograft survival was not significantly different between the protocol biopsied allografts versus the other non-biopsied allografts.

CONCLUSIONS

A biopsy protocol for marginal potential renal allografts leads to acceptable allograft outcomes without significantly increasing allograft discardment.

Relationship between duration of brain death and hemodynamic (in)stability on progressive dysfunction and increased immunologic activation of donor kidneys

BACKGROUND

Consistent difference in graft survival after renal transplantation has been shown when cadaveric transplants are compared to the living related donor situation, in favor of the latter. Recently, evidence has been put forward that brain death has significant effects on the donor organ quality. In this study, we aimed to assess the relation between brain death-induced hemodynamic instability in combination with the duration of brain death on the function and immunogenicity status of potential donor kidneys.

METHODS

In Wistar rats, short-term (1 hour) or long-term (6 hours) brain death in the presence or absence of hemodynamic stability was applied. Sham-operated rats served as controls (1 hour and 6 hours). Organ function was studied by monitoring serum creatinine, lactate dehydrogenase (LDH), lactate, and total protein content. Expression of cell adhesion molecules [intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1)] and the influx of leukocytes in the kidney assessed the immunologic status of the kidney.

RESULTS

Progressive organ dysfunction was most pronounced in hemodynamically unstable brain-dead donors reflected by increased serum creatinine levels. Regardless of hemodynamic status, a progressive inflammatory activation by cell adhesion molecule expression and an influx of leukocytes could be observed in kidneys of brain-dead rats compared with nonbrain-dead controls.

CONCLUSION

Brain death causes progressive kidney dysfunction. Also, inflammatory responses reflecting tissue injury are caused by brain death. When hemodynamic instability in the brain-dead donor is not corrected, kidney dysfunction is enhanced and immune activation occurs faster and is more profound. The observed changes may predispose the graft for additional ischemia/reperfusion injury during the transplant process and hence accelerate rejection of the graft after transplantation.

Extended criteria for organ acceptance. Strategies for achieving organ safety and for increasing organ pool

The terms extended donor or expanded donor mean changes in donor acceptability criteria. In almost all cases, the negative connotations of these terms cannot be justified. Factors considered to affect donor or organ acceptability have changed with time, after showing that they did not negatively affect graft or patient survival per se or when the adequate measures had been adopted. There is no age limit to be an organ donor. Kidney and liver transplantation from donors older than 65 years can have excellent graft and patient actuarial survival and graft function. Using these donors can be from an epidemiological point of view the most important factor to esablish the final number of cadaveric liver and kidney transplantations. Organs with broad structural parenchyma lesion with preserved functional reserve and organs with reversible functional impairment can be safely transplanted. Bacterial and fungal donor infection with the adequate antibiotic treatment of donor and/or recipient prevents infection in the latter. The organs, including the liver, from donors with infection by the hepatitis B and C viruses can be safely transplanted to recipients with infection by the same viruses, respectively. Poisoned donors and non-heart-beating donors, grafts from transplant recipients, reuse of grafts, domino transplant and splitting of one liver for two recipients can be an important and safe source of organs for transplantation.

Multivariate analysis of donor risk factors for graft survival in kidney transplantation

BACKGROUND

The results of the transplantation of marginal donor kidneys remain controversial. This study aimed to investigate the impact of donor risk factors as predictors of kidney-graft outcome.

METHODS

Allograft failure risk factors were studied in 7,209 cadaveric kidney-transplant recipients reporting to the Etablissement français des Greffes (EfG) from 1996 to 2000, of which 544 (7.6%) were from donors aged over 60. Both univariate and multivariate analysis were used to assess the effect of donor risk factors and were stratified according to recipient age.

RESULTS

Overall graft survival was 91.1% (95% confidence interval [CI] 90.5-91.8) at 1 year, 88.6% (95% CI 87.8-89.4) at 2 years, and 85.6% (95% CI 84.6-86.6) at 3 years posttransplant. Univariate analysis of risk factors showed a significant reduction of graft survival in recipients transplanted with kidneys coming from donors older than 60 years, donors with a history of hypertension, a cerebrovascular cause of death, and a preharvesting serum creatinine greater than 150 micromol/L. Multivariate analysis revealed significantly higher failure rate associated with cerebrovascular cause of death (RR=1.2, P=0.02), history of hypertension (RR=1.2, P=0.04), and elevated serum creatinine (RR=1.3, P=0.03), whereas donor age greater than 60 years was not found as an independent risk factor.

CONCLUSIONS

Our results suggest that cerebrovascular cause of death, history of hypertension, and elevated creatinine are significant independent donor risk factors for graft survival, whereas donor age is a statistically significant, but dependent, risk factor. This result is important for the design of allocation and transplantation strategies for kidneys procured in elderly donors.

Elderly donor kidney grafts into young recipients: results at 5 years

BACKGROUND

To date, few data are available on older donor renal grafts transplanted into young recipients. We compare 63 kidneys grafts from donors older than 60 years transplanted into recipients younger than 60 years (group 1) with a control group of 235 patients in whom both recipients and donors were younger than 60 years (group 2).

RESULTS

Patient survival rates at 1 and 5 years, respectively, were 98% and 95% (group 1) and 95% and 84% (group 2) (P=0.01). Graft survival rates were 95% and 83% in group 1 versus 94% and 81% in group 2, although death censoring was significant (100% and 98% group 1 vs. 96% and 86% group 2, P=0.04). In group 1, plasmatic creatinemia was significantly higher. The aged donor, female donor-male recipient combination, and the presence of acute rejection alone or together with acute tubular necrosis, were determinants for worse renal functioning at 1 year after transplantation. Seven patients had chronic nephropathy not related to any clinical parameter.

CONCLUSION

We conclude that kidneys from older donors can be successfully transplanted to younger patients.

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.

Protective effect of UR-12670 on chronic nephropathy induced by warm ischaemia in ageing uninephrectomized rats

BACKGROUND

In young animals, renal ischaemia/reperfusion injury and mass reduction are associated with chronic lesions that mimic those found in chronic rejection. We have shown that the phospholipid platelet-activating factor (PAF) participates in young animals in such chronic nephropathy. Here we examine the long-term effects of the orally active PAF antagonist, UR-12670 in ageing uninephrectomized rats exposed to prolonged warm ischaemia.

METHODS

Fifteen- to eighteen-month-old uninephrectomized male Sprague-Dawley rats were allocated into three groups and followed for 16 weeks: UNx, rats without ischaemia; UNxISC, ischaemic kidney (60 min), and UNxISC+UR, ischaemic kidney and UR-12670 from day 0 to the 16th week. Serum creatinine and proteinuria were monitored every 4 weeks. At the end of the study, conventional histology was performed and monocyte-macrophages were identified with the specific monoclonal antibody ED-1.

RESULTS

The UNxISC group had severe acute renal failure with a high mortality rate, which was associated with incomplete restoration of renal function. Renal insufficiency in this group was sustained throughout the follow-up. Both UNx and UNxISC groups developed progressive proteinuria from the 12th week. Though UNxISC+UR group showed similar acute renal failure and mortality rate to the ischaemic non-treated group, serum creatinine decreased to levels similar to UNx group, which were maintained until the end of the study. Treatment of ischaemic kidneys with UR-12670 produced a slight decrease in 24-h proteinuria and a reduction in glomerulosclerosis, the mean tubulointerstitial score and number of monocyte-macrophages to values similar to UNx group.

CONCLUSIONS

The chronic administration of the PAF antagonist UR-12670 attenuates the long-term effects of ischaemia-reperfusion injury in uninephrectomized ageing rats. The beneficial effect of this agent suggests that PAF contributes to the progression to late renal damage in this model.

Eurotransplant Senior Program 'old for old': results from 10 patients

More frequently there is the need for renal transplantation of older patients. Against the background of an increasing number of old donors and recipients, Eurotransplant Leiden started the Eurotransplant Senior Program (ESP) 'old for old' in 1999. The ESP works with donors and recipients both over 65 yr. The kidneys are transplanted with short cold ischaemia time regardless of the human leukocyte antigen (HLA) compatibility. Compatibility of blood groups, negative crossmatch and less than 5% cytotoxic antibodies are required. First experiences from 10 patients at Heinrich Heine University hospital are reported here. The course of 10 transplanted patients is described from January 1999 until November 1999 (28.4+/-15.8 wk). Age of donor and recipient, cause of dialysis and concomitant diseases from recipients, function of the transplanted kidney and complications are analysed. Immunosuppression consisted initially of cyclosporin A, mycophenolic acid and steroids. The results of these 10 patients were compared to 14 patients who were transplanted according to the ordinary Eurotransplant criteria (Eurotransplant Kidney Allocation System) in the same period of time. Kidneys from six donors (70.5+/-3.3 yr) were transplanted to 10 different recipients (66.9+/-2.2 yr). The control group consisted of 14 patients (47.6+/-14.4 yr) who received kidneys from 14 donors (48.3+/-10.1 yr). One double kidney transplantation was performed in the senior group, i.e. two kidneys from a marginal donor were transplanted to one recipient ('two in one'). In the ESP group, cold ischaemia time was reduced by 5 h and mean of HLA mismatches was more than doubled. Mean length of hospitalisation of ESP and control groups was 47.2+/-28.2 and 34.2+/-11.6 d, respectively. Intraoperatively, no complications were seen, post-operative care was performed on a normal ward. ESP patients suffered more often from delayed graft function, which led to further need for haemodialysis for 11.2 d. Finally, 9 of 10 patients acquired a satisfactory renal graft function. A total of 13 biopsies were performed in eight cases. Altogether seven acute rejections in 6 patients were found (four interstitial, one vascular, one interstitial+vascular, one clinical). The 9 patients with sufficient renal graft function were discharged with a mean serum creatinine level of 2.3+/-0.5 mg/dL (control: 1.9+/-0.8 mg/dL). Comparing these 10 recipients to a control group consisting of 14 patients, the results are comparable and encouraging. In conclusion, the short-term results of the ESP are promising. Nevertheless, the post-operative care requires more attention due to several complications. Though the HLA compatibility was not considered, all rejections were coped with effectively. Quality of life was improved.

Early experience with dual kidney transplantation in adults using expanded donor criteria. Double Kidney Transplant Group (DKG)

Dual transplant of marginal kidneys otherwise not considered for single transplant may give access to an expanded pool of cadaveric organs without exposing recipients to the drawbacks of a limited nephron mass supply. This prospective, case-control study compares adverse events and graft outcome in 24 recipients of two marginal kidneys from donors who were >60 yr old or who had diabetes, hypertension, or non-nephrotic proteinuria (cases), with that of 48 age- and gender-matched control subjects who received single ideal grafts at the same center and were given the same immunosuppressive therapy. Marginal kidneys with no macroscopic abnormalities were selected for the double transplant on the basis of a predefined score of histologic damage. Six-month patient and kidney survival was 100% with both of the procedures. Incidence (20.8% versus 20.8%) and median (range) duration of posttransplant anuria (5 [2 to 12] versus 7 [2 to 13] days) were comparable in cases and control subjects, respectively. Time to normal serum creatinine and mean serum creatinine values at each time visit were comparable as well, but with significantly lower levels in cases compared with control subjects from month 2 to last follow-up (1.56 +/- 0.65 versus 1.74 +/- 0.73 mg/dl, P = 0.04). Diastolic BP values averaged during the entire posttransplant period were significantly lower in cases than in control subjects (83.2 +/- 11.5 versus 85.1 +/- 12.5 mmHg, respectively, P = 0.008). Donor/recipient body weight ratio was the only covariate significantly associated at univariate (P = 0.002) and multivariate (P = 0.001) analysis with last available serum creatinine concentrations. Incidence of acute allograft rejections (20.8% versus 18.8%) and of major surgical complications was comparable in the two groups. No renal artery or vein thrombosis was reported in either group. Dual transplants of marginal kidneys are as safe and tolerated as single transplants, and possibly offer an improved filtration power without exposing the recipient to enhanced risk of delayed renal function recovery, acute allograft rejection, or major surgical complications.