The effect of age and prolonged cold ischemia times on the national allocation of cadaveric renal allografts

Subnormothermic Ex Vivo Porcine Kidney Perfusion Improves Energy Metabolism: Analysis Using 31P Magnetic Resonance Spectroscopic Imaging

The ideal preservation temperature for donation after circulatory death kidney grafts is unknown. We investigated whether subnormothermic (22 °C) ex vivo kidney machine perfusion could improve kidney metabolism and reduce ischemia-reperfusion injury.

Donor Age, Cold Ischemia Time, and Delayed Graft Function

BACKGROUND AND OBJECTIVES

Increased donor age is one of the most important risk factors for delayed graft function (DGF), and previous studies suggest that the harmful effect of cold ischemia time is increased in kidneys from older donors. Our aim was to study the association of increased donor age and cold ischemia time with the risk of delayed graft function in a large cohort kidney transplants from the current era.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The Scientific Registry of Transplant Recipients was used for this observational, retrospective registry analysis to identify all deceased donor kidney transplantations in the United States between 2010 and September 2018, who were on dialysis pretransplantation (n=90,810). The association of donor age and cold ischemia time with the risk of DGF was analyzed in multivariable models adjusted for recipient characteristics (age, race, sex, diabetes, calculated panel-reactive antibodies, pretransplant dialysis duration) and donor characteristics (cause of death, sex, race, body mass index, creatinine, donation after circulatory death status, history of hypertension, and HLA mismatch).

RESULTS

Cold ischemia time and donor age were independently associated with the risk of DGF, but the risk of DGF was not statistically significantly lower in donor age categories between 50 and 64 years, compared with donors ≥65 years. The harmful association of cold ischemia time was not higher in kidneys from older donors in any age category, not even among donation after circulatory death donors. When donor risk was assessed with kidney donor profile index, although a statistically significant interaction with cold ischemia time was found, no practically meaningful increase in cold-ischemia susceptibility of kidneys with a high kidney donor profile index was found.

CONCLUSIONS

We were unable to demonstrate an association between donor age and DGF. The association of longer cold ischemia time with the risk of DGF was not magnified in older or more marginal donors.

Time of Cold Ischemia and Delayed Graft Function in a Cohort of Renal Transplant Patients in a Reference Center

There are many factors involved in the delayed graft function of a renal graft, with prolonged cold ischemia time being one of the most relevant. The aim of this study is to evaluate the relationship between the time of cold ischemia and the delayed graft function, and acute rejection and graft loss at 1 year of follow-up. A retrospective cohort of 347 renal transplant patients were evaluated during the years 2009-2013. The incidence of delayed graft function was 18.4% (n = 65). The cold ischemia time was an independent risk factor for delayed graft function (odds ratio [OR] 1.10, 95% confidence interval [CI] 1.04-1.16). By grouping the time of cold ischemia by intervals, the risk of delayed graft function was greater in the 12-18 hours group (OR 2.06, 95% CI 1.02-4.15) and in the >18 hours group (OR 3.38, 95% CI 1.57-7.27). The risk of acute rejection did not increase with longer cold ischemia (p = 0.69), and cold ischemia time was not a risk factor for renal graft loss at 1-year follow-up (hazard ratio 0.97, 95% CI 0.88-1.06). In conclusion the time of cold ischemia (>12 hours) in renal transplant recipients of optimal deceased donors increases the risk of delayed graft function; however, this does not negatively impact the results in acute rejection or graft loss in the first year of the transplant.

Are Octogenarians With End-Stage Renal Disease Candidates for Renal Transplantation?

Background

Elderly patients are the fastest-growing group in need of renal transplantation. This study puts focus on renal transplant recipients in their 80th year or longer at time of engraftment. Is there evidence to support an absolute upper age limit for renal transplantation?

Methods

Recipients in their 80th year or longer, transplanted between 1983 and 2015, were included. Data were retrieved from the Norwegian Renal Registry in the end of October 2015. Graft and patient survivals were compared with recipients aged 70 to 79 years at transplantation.

Results

Forty-seven patients older than 79 years were transplanted in the defined period. Median age 80.1 years, 81% were men. Median time on dialysis before transplantation was 18.5 months. All patients received an allograft from a deceased donor (median donor age, 61.8 years). In the death-censored graft survival model, there was no statistical difference between the groups. We found improved patient and graft survivals after introduction of mycophenolate mofetil and induction with basiliximab. Patients transplanted before 2000 had increased risk of death compared with those transplanted after 2000 (hazard ratio, 3.2; 95% confidence interval, 1.2-8.7). Median uncensored graft survival for patients transplanted after the year 2000 was 5.0 year (95% confidence interval, 2.4-7.6). Median patient survival was 5.0 years (3.1-6.9) and 5-year patient survival was 55%.

Conclusions

Age by itself should not be an absolute contraindication against renal transplantation. An estimated 5-year survival rate of 55% post-engraftment for an 80-year-old patient is in our opinion more than acceptable.

The authors reveal an estimated 5 years survival rate of 55% postengraftment for an 80 years old patient with end-stage renal disease. In carefully selected octogenarians, kidney transplantation has an acceptable estimated 5 years survival rate in their opinion.

ECD kidney transplantation outcomes are improved when matching donors to recipients using a novel creatinine clearance match ratio (CCMR)

Improved outcomes have been associated with various methods of size matching between expanded criteria (ECD) donors and recipients. A novel method for improved functional based matching was developed utilizing manipulation of Cockcroft-Gault estimated creatinine clearances for donor and recipient. We hypothesized that optimal clearance-based matches would have superior outcomes for both immediate graft function and long-term graft survival. For the analysis, recipients of ECD kidneys in the Scientific Registry of Transplant Recipients (SRTR) transplanted between October 1, 1987 and August 31, 2011 were included. Univariate and multivariate analyses predicted the hazard ratio of graft failure and the odds ratio of requiring dialysis within the first week. A total of 25,640 ECD kidney transplants were analyzed. On multivariate analysis, higher creatinine clearance match ratio (CCMR) was associated with increased graft failure and odds of requiring dialysis within the first week (comparing highest ratio quintile versus lowest ratio quintile: HR 1.43, p < 0.001; OR 2.08, p < 0.001). This study suggests that ECD kidneys have improved outcomes when the recipient/donor CCMR is optimized.

Does kidney transplantation with deceased or living donor affect graft survival?

Background:

There are growing numbers of patients with end-stage renal disease globally at an unexpected rate. Today, the most serious challenge in transplantation is organ shortage; hence, using deceased donor is increasingly encouraged.

Objectives:

The aim of the study was to investigate the differences in survival rates between kidney transplant recipients with deceased donor and living donor.

Patients and Methods:

In a retrospective cohort study, 218 patients who had undergone kidney transplantation in our institute from April 2008 to September 2010 were recruited. Demographics and post-transplantation follow-up data including immunosuppression regimens, rejection episodes, and survival rates were evaluated. The patients were assigned to two groups according to the donor kidney transplantation: group I, living donor kidney transplants; and group II, deceased donor kidney transplants.

Results:

Although there were no significant differences in one-year survival rates of patient and graft between study groups, three-years survival rates of patient and graft were significantly longer in living donor kidney transplants in comparison with the deceased donor kidney recipients (P = 0.006 and P = 0.004, respectively). In Cox-regression model after adjusting for other confounding factors such as age, sex, diabetes mellitus, and first- or second-time transplantation, overall patient and graft survivals were also significantly shorter in deceased kidney transplantation than those who received kidney from a living donor (HR, 3.5; 95% CI, 1.2-10.4; and P = 0.02 for patient survival; and HR, 5.4; 95% CI, 1.5-19.5; and P = 0.009 for graft survival).

Conclusions:

We found acceptable short-term survival in both groups; however, living donor recipients continue to have better long-term patient and graft survival rates.

Bayesian modeling of pretransplant variables accurately predicts kidney graft survival

INTRODUCTION

Machine learning can enable the development of predictive models that incorporate multiple variables for a systems approach to organ allocation. We explored the principle of Bayesian Belief Network (BBN) to determine whether a predictive model of graft survival can be derived using pretransplant variables. Our hypothesis was that pretransplant donor and recipient variables, when considered together as a network, add incremental value to the classification of graft survival.

METHODS

We performed a retrospective analysis of 5,144 randomly selected patients (age ≥18, deceased donor kidney only, first-time recipients) from the United States Renal Data System database between 2000 and 2001. Using this dataset, we developed a machine-learned BBN that functions as a pretransplant organ-matching tool.

RESULTS

A network of 48 clinical variables was constructed and externally validated using an additional 2,204 patients of matching demographic characteristics. This model was able to predict graft failure within the first year or within 3 years (sensitivity 40%; specificity 80%; area under the curve, AUC, 0.63). Recipient BMI, gender, race, and donor age were amongst the pretransplant variables with strongest association to outcome. A 10-fold internal cross-validation showed similar results for 1-year (sensitivity 24%; specificity 80%; AUC 0.59) and 3-year (sensitivity 31%; specificity 80%; AUC 0.60) graft failure.

CONCLUSION

We found recipient BMI, gender, race, and donor age to be influential predictors of outcome, while wait time and human leukocyte antigen matching were much less associated with outcome. BBN enabled us to examine variables from a large database to develop a robust predictive model.

Influence of donor and recipient gender as well as selected factors on the five-year survival of kidney graft

The aim of the study was to determine the impact of the gender of renal allograft donor and recipient on the graft function over a 5-year follow-up period.

MATERIAL AND METHODS

The 154 kidney grafts from 77 donors transplanted into recipients of both genders. Two study groups were formed: one group consisted of male donors, while the other consisted of female donors. The recipients in each of the groups consisted of a pair, one male and one female.

RESULTS

71% of grafts survived the five-year period in the group of male and female recipients when the donor was male; in case of female donors, the rate was 62.5%. Depending on the gender of the donor and the recipient, the rates of grafts with five-year survival were as follows: 79.2% for male donors and female recipients (MF); 62.5% for male donors and male recipients (MM). The difference between both groups was not statistically significant. In the case of female donors and male recipients (FM), the five-year survival rate was 58.3%, while in female donors and female recipients, the five-year survival rate was 64.1%.

CONCLUSIONS

Grafts from male donors show a trend towards better five-year survival compared to grafts from female donors. The highest five-year survival rate was observed when the donor was male and the recipient was female; the lowest rate was observed for female donors and male recipients.

Are some kidneys better than others? Clinical goals and the challenging ethical landscape

The increasing shortage of donor kidneys available for transplantation combined with an ageing population has resulted in the use of expanded-criteria donor (ECD) kidneys. These kidneys are associated with an increased risk of delayed graft function, acute rejection and reduced graft survival. This paper will cover the use of ECDs and the presentation of risk to patients receiving these organs.

Clinical analysis of living related renal transplantation with donors older than 50 years in China

OBJECTIVE

The objective of this study was to investigate whether kidney grafts from living related donors older than 50 years were safe for the donors and recipients in the long term.

METHODS

One hundred seven living related donor kidney transplantations were performed in our center from April 1994 to December 2007. No prisoners or organs from prisoners were used in the collection of these data. Donors were divided into 2 groups: >50 years of age (range, 51-78 years), designated as the study group, and ≤50 years of age (range, 21-50 years), designated as the control groups. The mean time of follow-up was 49 months (range, 12-180 months). Clinical data were compared, including donor serum creatinine (Scr) levels, glomerular filtration rates (GFR) before and after the procedures operative complications, and postoperative short-term and long-term recovery of renal function in recipients as well as their complications and recipient and kidney survivals.

RESULTS

All operations were successfully performed. Before the operation, the mean Scr and GFR were 82.16 ± 10.86 umol/L and 85.82 ± 6.26 mL/min, respectively, in the study group versus 78.66 ± 10.41 umol/L and 88.74 ± 9.44 mL/min, respectively, in the control group. There were no significant differences in mean Scr or GFR values between the groups at various preoperative or postoperative times (P > .05). No severe perioperative complications occurred, and no subsequent renal function failure was observed upon long-term follow-up of donors in the 2 groups. Comparisons of recipient age, gender ratio, duration on dialysis, HLA matches, cold/warm ischemia times, and immunosuppression therapy showed a correlations between the 2 groups. Mean Scr levels of recipients, which were compared from 1 week to 3 years following surgery, were slightly higher among the control than the study group, but the difference was not significant (P > .05). There were no significant differences between the study and control groups in 1-,3-,5-, and 8-year recipient/graft survival rates (P > .05).

CONCLUSIONS

Long-term follow-up showed that transplantations using grafts from donors older than 50 years of age yielded similar results to those with younger donors.

Favorable outcomes with machine perfusion and longer pump times in kidney transplantation: a single-center, observational study

BACKGROUND

Hypothermic machine perfusion (MP) preservation is used for all deceased donor kidney transplants at our center. Kidneys are placed in cold storage at retrieval, then transferred to MP on arrival. Because a lack of consensus regarding optimal use of MP still exists, we evaluated the overall impact of using MP at our center and the prognostic value of MP (Pump) time.

METHODS

We retrospectively analyzed 339 adult, primary deceased donor kidney transplant recipients who were pooled across three prospective, randomized immunosuppression trials (since 2000) at our center. In addition to providing overall results for delayed graft function (DGF) (requirement for dialysis in the first week), slow graft function (SGF), first biopsy-proven acute rejection (BPAR), and graft failure, stepwise logistic and Cox regression analyses were used to determine the prognostic value of pump time, particularly after controlling for other significant prognosticators.

RESULTS

Mean cold storage and pump times were 6.6 and 26.7 hr, consistent across immunosuppression protocols. Overall DGF and SGF rates were 4.4% (15/339) and 12.1% (41/339). DGF was equally low for pump time less than 24 vs. more than or equal to 24 hr, 5.2% (6/116) vs. 4.0% (9/223) (P=0.63), with similar results after adjusting for known DGF predictors. A significantly lower first BPAR rate was observed for longer pump time (as a continuous variable) among more immunologically active recipients (those having more risk factors: DGF, age <50 yr, and non-white) (univariable P=0.005; multivariable P=0.009), with an estimated hazard ratio of 0.43 (P=0.006) favoring pump time more than or equal to 24 hr among those with more than or equal to two risk factors. CONCLUSIONS.: In this single-center, observational study, MP with prolonged pump times was associated with low DGF/SGF and first BPAR rates, supporting continued use of MP.

Trends in HLA antibody screening and identification and their role in transplantation

HLA testing has been a staple in transplantation since the recognition that antibodies, directed against lymphocytes, were associated with allograft failure. This seminal finding led to the discovery of the MHC and the appreciation of the importance of HLA testing in transplantation. Early approaches focused on the importance of HLA matching, and were an important aspect of deceased organ donor allocation. More recently, and as a direct result of improvements in immunosuppression, there has been a movement away from 'matching' as the driving force in organ allocation. By contrast, we are now challenged with selecting donor-recipient pairs based on acceptable mismatches. For patients devoid of HLA antibodies, this is not an issue. However, for patients with HLA alloantibodies, that is, the sensitized patient, we face significant challenges in assessing the repertoire of the HLA antibody reactivity they possess. Over the past several years, significant advances in HLA antibody detection have occurred. Solid-phase, multiplex testing platforms have replaced traditional cell-based assays, and have provided better sensitivity and specificity in antibody detection. As a direct result of improved antibody identification, many programs are moving into the realm of the 'virtual crossmatch'. The virtual crossmatch has proven to be successful in renal, cardiac and lung transplantation, and has resulted in a greater percentage of sensitized patients gaining access to transplantation. This review will be devoted to highlighting the latest developments in antibody assessments and discussing their utilization in transplant testing.

Deceased donor organ transplantation with expanded criteria donors: a single-center experience from India

INTRODUCTION

Deceased donor organ transplantation (DDOT) accounts for <4% of renal transplants in India. Many volunteers come forth for organ donation with increasing awareness; unfortunately, the majority are marginal donors, but their rejection would hamper the DDOT program. Judicious use of marginal organs is a challenge for developing countries.

PATIENTS AND METHODS

We performed 29 renal transplants from 21 expanded criteria donors (ECD) out of 115 DDOT between January 2006 to April 2009-10 dual (DKT) and 19 single (SKT). Fourteen donors had hypertension, a cerebrovascular accident as the cause of death, 9 had both, and 4 had diabetes. Mean donor age was 70.3 +/- 8.9 years. Decisions on the procedure were based upon frozen section biopsy in 13 of 21 donors. Mean DKT donor age was 76 +/- 9.7 years versu 64 +/- 5.7 years of SKT donors. The native kidney diseases were chronic glomerulonephritis (n = 14), diabetic nephropathy (n = 7), tubulointerstitial nephritis (n = 4) and polycystic kidney disease, focal segmental glomerulosclerosis, lupus nephritis and patchy cortical necrosis, (n = 1 each). Mean recipient age of DKT versus SKT was 43.5 versus 42.3 years. All recipients received rabbit anti-thymocyte globulin, followed by steroid, mycophenolate mofetil/calcinueurin inhibitor.

RESULTS

Over a mean follow-up of 341 days, the mean serum creatinine (SCr) of 25/29 patients was 1.60 mg/dL (range, 1.0-2.6). The mean SCr of SKT patients was 1.59 +/- 0.63 mg/dL and of DKT, 1.62 +/- 0.48 mg/dL. Ten patients had delayed graft function and 11 had biopsy proven acute tubular necrosis. Seven (24%) patients had rejection (grade 3 Banff update '05, type IA; 4, type 2A); 6 responded to antirejection; 1 graft was lost at 7 months due to chronic rejection. Three (10.3%) patients were lost, 1 each due to AMI, sepsis, and CMV disease.

CONCLUSION

In the circumstances of organ shortage, DDOT with expanded criteria donor is a feasible option.

Ten-yr results of the trans-Atlantic kidney transplant airlift between the Dutch Caribbean and the Netherlands

The prevalence of end-stage renal failure in Curaçao (Dutch Caribbean) is one of the highest in the world. In 1998, the St. Elisabeth Hospital started a unique trans-Atlantic collaboration with the Academic Medical Center in Amsterdam, the Netherlands, and the Eurotransplant Foundation. The partnership aimed to achieve a structured transplantation program for patients in the Dutch Caribbean, who otherwise would need lifelong dialysis. This study is an analysis of the 10-yr transplantation results of this trans-Atlantic program. In 41 consecutive transplantations performed between January 1998 and April 2007, one-yr graft survival and complication rates were retrospectively studied. Twenty-four men and 17 women with a median age of 54 were transplanted. The median dialysis period prior to transplantation was 6.8 yr. The one-yr graft survival rate was 69% (95% confidence interval: 52-80%). Initially 28 grafts functioned (68%); four grafts showed primary non-function (10%) and delayed graft function developed in nine patients (22%). Ten recipients had 16 post-operative complications. Our trans-Atlantic program affords patients with end-stage renal failure, who otherwise would need lifelong dialysis, a chance to be transplanted.

The relationship of donor source and age on short- and long-term allograft survival in pediatric renal transplantation

Limited pediatric data on allograft survival from advanced aged kidney donors exist. To determine the influence of donor source and age on allograft survival in pediatric renal transplant recipients, we analyzed the OPTN database. Allograft survival for 7291 pediatric renal transplants was evaluated. Up to five yr post-transplantation, graft survival was higher for LD vs. DD recipients. At seven yr, allograft survival was 71% in 18-54 yr-old LD recipients, 59.1% in >or=55 yr-old LD, and 45.1% in >or=50 yr-old DD recipients. An approximate 35% improvement in allograft survival in 18-54 yr-old LD recipients was observed. Multivariate results showed that recipients of LD 35-49 (aRR 0.66, 95% CI 0.55-0.80) and LD 50-54 (aRR 0.65, 95% CI 0.45-0.94) have a graft survival advantage over the ideal DD. In LD >or=55 yr, no improvement in graft survival was observed when compared with the 18-34 yr-old DD. In summary, we observed in a pediatric population, <55 yr-old LD kidneys afford improved long-term allograft survival when compared with DD kidney recipients. Increasing awareness of the long-term graft survival advantage for children receiving an LD kidney, even from older donors, should be a priority.

Growth of follicles of various animals following ovarian grafting under the kidney capsules of immunodeficient mice

Aim:  Various researchers have studied xenografting ovarian tissues into immunodeficient mice to accelerate the follicular growth of several mammalian species. In this study, the authors focused on the following three points in growing follicles in transplanted ovarian tissues under kidney capsules: the effects of the storage conditions of the donor ovarian tissues, the effects of donor age on the survival rates of grafted mouse ovaries, and the methods used to grow the follicles of xenografted bovine ovaries. Methods and Results:  When ovaries stored for 0, 6, 12 or 24 h at 4°C and at room temperature were transplanted under the kidney capsules of immunodeficient mice, fewer mouse and rabbit grafts survived following 24 h storage. The survival rates of bovine grafts were relatively low for all storage times. When mouse ovaries were held for 24 h at 4°C or at room temperature, low-temperature storage effectively improved the survival rates of the grafts. Although the survival rates of grafted genital ridges containing premeiotic germ cells from fetuses and grafted ovaries from mice 0, 10, 20, 40 and 80 days after birth were similar among donors of different ages, the cleavage rate of oocytes following insemination was significantly lower in the grafts from the ovaries of 80-day-old mice. Antral follicles formed in surviving bovine ovarian grafts. Cumulus-oocyte complexes were collected from the grafted ovaries of fetuses and calves, and the oocytes reached the metaphase II stage following culture, but they did not develop to the pronuclear stage after in vitro fertilization. Conclusion:  Our findings provide basic data on xenografting ovarian tissues into immunodeficient mice to accelerate the growth of follicles. (Reprod Med Biol 2008; 7: 45-54).

Prospective age-matching in elderly kidney transplant recipients--a 5-year analysis of the Eurotransplant Senior Program

Renal transplantation faces challenges: the organ shortage resulting in extended waiting times and an aging population resulting in death with a functioning graft. The Eurotransplant Senior Program (ESP) allocates kidneys within a narrow geographic area from donors aged >/=65 years to recipients >/=65 years regardless of HLA. This analysis investigates the impact of the ESP on waiting time, graft and patient survival. The ESP group (n = 1406, old to old) was compared to two groups allocated via the Eurotransplant Kidney Allocation System (ETKAS) with either similar donor age (old to any [O/A], donor age >/=65, n = 446) or recipient age (any to old, [A/O], recipient age 60-64, n = 1687). All patients were transplanted between 1999 and 2004. Since initiation of the ESP (1999), availability of elderly donors doubled and waiting time for ESP patients decreased. Local allocation led to shorter cold ischemia time (11.9 vs. >17.0 h, p < 0.001) and less delayed graft function (DGF, ESP 29.7% vs. O/A 36.2%, p = 0.047) but 5-10% higher rejection rates. Graft and patient survival were not negatively affected by the ESP allocation when compared to the standard allocation. The ESP age matching of elderly donors and recipients is an effective allocation system for organs from elderly donors.

Sequential quadruple immunosuppression including sirolimus in extended criteria and nonheartbeating donor kidney transplantation

The aim was to evaluate feasibility and safety of calcineurin inhibitor-free immunosuppression in high-risk donor kidney transplantation with sequential sirolimus introduction. Kidney transplant patients (n=76) with a donor aged >60 years, donor with acute renal failure, or a nonheartbeating donor were included. Immunosuppression consisted of antithymocyte globulin or basiliximab, mycophenolate mofetil, prednisone, and sequential introduction of sirolimus. One-year patient survival was 96.2% and 95.8%; graft survival was 94.2% and 91.7%; acute rejection rates were 21.2% and 12.4%; delayed graft function was 21.2% and 66.7%; and creatinine clearance was 58+/-20 mL/min and 56+/-21 mL/min for the brain-dead donor group and the nonheartbeating donor group, respectively. Most adverse events were infections, but also three lymphoceles, three urinary fistulas, three wound seromas. Sequential sirolimus introduction in high-risk donor kidney transplantation was found to lead to good patient and graft survival and incidence of acute rejection and delayed graft function.

The advantage of allocating kidneys from old cadaveric donors to old recipients: a single-center experience

BACKGROUND

In January 1999 a new kidney allocation program was launched by the Eurotransplant Foundation, the 'Eurotransplant Senior Program' (ESP). Cadaveric donors above the age of 65 yr are allocated to kidney transplant recipients of the same age group.

METHODS

Using a single-center database, 91 patients who underwent first renal transplantation at the age of 65 yr and older in the years 1999-2002 were identified. Fifty-six patients were transplanted through ESP allocation (study group) and 35 patients (control group) via normal Eurotransplant Kidney Allocation System (ETKAS) procedure.

RESULTS

Age, sex and comorbid conditions did not differ by group. The rate of acute rejection episodes, primary non-function, delayed graft function, perioperative mortality did not differ by group. Serum creatinine was significantly lower in the ETKAS group (1.3 vs. 1.9 mg/dL; p=0.015) from six months after the transplantation on. Overall graft survival at six yr was 56% in the ETKAS group and 52% in the ESP group. With 73% in the ETKAS group and 71% in the ESP group, cumulative patient survival according to the Kaplan-Meier estimation was not statistically different at five yr.

CONCLUSIONS

We did not find a relevant difference in the outcome between young and old kidney transplants in old recipients after this long observation period.

Growth and histology of ovarian follicles after cold storage in the tammar wallaby

Cold storage is a simple method for storing and transporting tissues and organs. The reliability of this method for maintaining structure and function of marsupial ovarian tissue was assessed using histological techniques and follicle culture. Tammar wallaby ovaries were placed in cold storage (phosphate-buffered saline at 4°C) for 24 or 48 h. Although necrotic changes were evident in the germinal epithelium, cortex and interstitial tissue after cold storage, there was little evidence of necrotic changes in ovarian follicles and oocytes appeared normal. Secondary follicles isolated from ovarian tissue after cold storage grew by a similar amount to non-stored follicles when cultured for 4 days in vitro, but no follicles from any group developed to tertiary follicles. Cold storage for up to 24 h had little obvious effect on the structure of ovarian tissue and follicles isolated from this tissue maintained their structure during culture. However, degeneration in culture increased with storage time and was significantly higher after cold storage for 48 h. As demonstrated in the tammar wallaby, cold storage has potential as a method for storage and transport of marsupial ovaries up to 24 h.

Expanded criteria donor kidney allocation: marked decrease in cold ischemia and delayed graft function at a single center

Expanded criteria donor (ECD) kidney allocation aims to increase utilization and facilitate placement. We implemented an ECD program for pre-consented candidates and studied whether ECD allocation decreased cold ischemia time and delayed graft function (DGF). We compared donor, recipient and transplant data for ECD transplants performed during the first year of our program to those performed in the preceding 5 1/2 years. Logistic regression identified risk factors for DGF. Of 356 candidates, 107 (30%) consented, 32 (9%) completed evaluation and 20 (6%) underwent ECD transplantation during the program's first year. The recent and historical ECD cohorts had similar donor and recipient characteristics, except that recent ECD recipients were older. The rate of donor kidney biopsy dropped from 85% to 24% (p < 0.001). Cold ischemia time decreased from 16.4 to 7.4 h (p < 0.001), as did the incidence of DGF from 43% to 15% (p = 0.031). Three independent risk factors for DGF emerged: recipient height (OR 1.21/10 cm; p = 0.008), >4 HLA mismatches (OR 20.46; p = 0.0033) and cold ischemia time (OR 1.24/h; p = 0.0036). We conclude the ECD designation provides a description of kidney quality that may obviate biopsy. ECD allocation decreased cold ischemia time and DGF, which may improve graft survival.

UW solution for hypothermic machine perfusion of warm ischemic kidneys

BACKGROUND

Donation of kidneys from non-heart beating donors (NHBD) is increasingly being used to expand the donor pool. Warm ischemic injury of these kidneys suffered at harvest results in DGF at transplantation. In this study, we used hypothermic continuous machine perfusion preservation to mitigate this injury using two available solutions.

METHODS

Dog kidneys (beagles) were exposed to 0, 60, or 75 min of in situ warm ischemia (37 degrees C), followed by 24 to 72 hr preservation by machine perfusion with Belzer MPS solution or the UW-solution (Viaspan). Auto-transplantation was performed with immediate contralateral nephrectomy. Survival and renal function (serum creatinine) were evaluated for up to 10 days posttransplant.

RESULTS

Both solutions were equally effective for 72 hr machine perfusion preservation of dog kidneys giving 100% survival with only minor renal injury. Both solutions were also equally effective for preservation of kidneys exposed to 60 min of warm ischemia. However, only the UW solution gave reliable preservation (86% survival vs. 25% survival) in kidneys exposed to 75 min of warm ischemia and 24 hr machine perfusion.

CONCLUSION

UW solution used with continuous hypothermic machine perfusion preservation can rescue canine kidneys from severe warm ischemic injury.

Impact of the Expanded Criteria Donor Allocation System on the Use of Expanded Criteria Donor Kidneys

BACKGROUND

The U.S. Organ Procurement and Transplantation Network recently implemented a policy allocating expanded criteria donor (ECD) kidneys by waiting time alone. ECD kidneys were defined as having a risk of graft failure > or = 1.7 times that of ideal donors. ECDs include any donor > or = 60 years old and donors 50 to 59 years old with at least two of the following: terminal creatinine >1.5 mg/dL, history of hypertension, or death by cerebrovascular accident. The impact of this policy on use of ECD kidneys is assessed.

METHODS

The authors compared use of ECD kidneys recovered in the 18 months immediately before and after policy implementation. Differences were tested using t test and chi2 analyses.

RESULTS

There was an 18.3% increase in ECD kidney recoveries and a 15.0% increase in ECD kidney transplants in the first 18 months after policy implementation. ECD kidneys made up 22.1% of all recovered kidneys and 16.8% of all transplants, compared with 18.8% (P<0.001) and 14.5% (P<0.001), respectively, in the prior period. The discard rate was unchanged. The median relative risk (RR) for graft failure for transplanted ECD kidneys was 2.07 versus 1.99 in the prepolicy period (P=not significant); the median RR for procured ECD kidneys was unchanged at 2.16. The percentage of transplanted ECD kidneys with cold ischemia times (CIT) <12 hr increased significantly; the corresponding percentage for CIT > or = 24 hr decreased significantly.

CONCLUSIONS

The recent increase in ECD kidney recoveries and transplants appears to be related to implementation of the ECD allocation system.

How old is old for transplantation?

Elderly patients are the fastest growing group requiring renal transplantation. This study investigates whether transplantation is worthwhile in the elderly and whether there is evidence supporting an age limit for transplantation. One thousand ninety-five adults transplanted in Scotland between 1 January 1989 and 31 December 1999 were followed up to 11 years. Sociodemographic, comorbidity and transplant data were obtained from the national databases and patient's notes. Patient and graft survival, risk and causes of graft failure and patient death were compared between four age groups (18-49, 50-59, 60-64 and >65). All groups had similar gender, social deprivation and renal disease distribution. The incidence of comorbidity increased with age. The groups had comparable HLA matching, but patients aged 18-49 years received transplants from younger donors and with shorter cold ischaemic times. Younger patients had more acute rejection and less delayed graft function. Older patients had a higher incidence of death with functioning graft. Patients over 65 years had an almost dialysis-free remaining life, while the graft half-life was significantly shorter than patient half-life in the youngest group. Transplantation in elderly recipients is worthwhile despite a higher comorbidity. Careful selection rather than a fixed age limit should be used to ensure a satisfactory graft and patient survival.

20-year experience with elderly donors in living renal transplantation

PURPOSE

This study evaluates the impact of living renal donors (LD) aged 60 years and older on graft performance and patient survival in an old-for-young constellation.

PATIENTS AND METHODS

We analyzed 144 consecutive LDs between January 1983 and December 2002 (19 patients 60+/125 controls).

RESULTS

Mean donor age in the 60+ group was 63.7 (+/- 2.6) years and 43.7 (+/- 9.0) years for the <60 group. Mean recipient age was 42.4 (+/- 15.2) years versus 32.6 (+/- 15.3) years HLA-A, -B, and DR-mismatches were 3.16 (+/- 1.3) for the 60+ group and 3.13 (+/- 1.7) for the controls (P = NS). Rejection episodes in the first year following LD did not differ (53% versus 33%, P =.25). Mean serum creatinine for 65+ versus <65 after 1, 3, and 12 months was 1.91 +/- 1.2 versus 1.48 +/- 0.85 mg/dL (P =.16), 1.82 +/- 0.89 versus 1.29 +/- 0.35 mg/dL (P <.05) and 1.80 +/- 0.31 versus 1.37 +/- 0.38 mg/dL (P <.05) and mean creatinine clearance at 12 months 62 versus 82 mL/min (P =.06). Censored 1-, 3-, and 5-year graft survival was 100% versus 95% (P = NS), 100% versus 93% (P = NS) and 100% versus 83% (P = NS) with no significant difference in the log-rank test for Kaplan Meier.

CONCLUSION

No impact of donor age was found for graft survival but function of the 65+ kidneys at 3 and 12 months was reduced. Living renal donors 60+ are acceptable for carefully allocated recipients.

“Old-for-Old” Cadaveric Renal Transplantation: Surgical Findings, Perioperative Complications and Outcome

OBJECTIVE

To evaluate the surgical findings and outcome of locally allocated, blood-group-compatible but HLA-unmatched cadaveric kidneys in first renal transplantation of donor/recipient pairs aged 65 years and above (Eurotransplant Senior Program=ESP).

METHODS

26 patients of the study group (donor age 70.4 +/- 3.6/recipient age 67.7 +/- 2.8) were compared to 30 controls aged 60 and above (mean recipient age 62.6 +/- 2.3/mean donor age 43.8 +/- 15.3). For controls kidney allocation included HLA matching.

RESULTS

Cold ischemic time (ESP vs. controls 501 vs. 883 min; p<0.05) and mean number of HLA mismatches (4.2 +/- 1.36 vs. 1.6 +/- 1.62; p<0.05) differed significantly. Delayed graft function was lower in the study group (12% vs. 43%; p<0.05), rejection episodes in the ESP group were numerous but did not differ significantly from the controls (46% vs. 30%; p=0.21). More intraoperative complications and a higher incidence of donor organ arteriosclerosis (p<0.05) were seen in the ESP group. Three-year graft survival uncensored and censored for death with functioning graft did not differ, even though mean creatinine and creatinine clearance differed significantly beginning at month three. Three-year patient survival (55% vs. 81%) differed in favour of the control group, even though the difference was not significant due to small number of patients.

CONCLUSION

"Old-for-old" kidney transplantation with local allocation yields graft survival rates comparable to HLA-matched young grafts and is a good approach to extend the donor and recipient pool. Careful patient selection is advised.

Impact of selected factors on early graft function in patients after renal transplantation

Transplantation is the best treatment for end-stage renal diseases. For transplantologists, it is most important to know the factors that worsen graft survival prognosis. The aim of the study was to investigate factors predictive of graft loss and shortened graft survival. We retrospectively reviewed 442 renal transplant patients between 1990 and 1995 in two Szczecin units, all of whom received a triple-drug immunosuppressive regimen. One hundred thirty patients showed graft disorders such as delayed graft function or primary nonfunction. The occurrence of these disorders was examined as a function of donor and recipient age and sex, cause of ESRD, HLA compatibility, ABO and Rh compatibility, cold ischemia time, warm ischemia time, antileukocyte antibody level (PRA), and period of dialysis therapy before transplantation. The study showed that a high maximal PRA level, incompatibility for ABO group, and a longer warm ischemia time increase the probability of early graft function disorders.

Basiliximab plus low-dose cyclosporin vs. OKT3 for induction immunosuppression following renal transplantation

BACKGROUND

Current immunosuppressive therapies are very effective in preventing acute rejection (AR) and graft loss following renal transplantation. Newer agents now make it possible to develop equally efficacious but better tolerated and less toxic strategies. This is especially relevant for our ageing recipients. We now compare the efficacy of basiliximab combined with early low-dose cyclosporin therapy to standard OKT3 induction therapy.

METHODS

In this single-centre study, 100 consecutive recipients of cadaveric kidney transplants from November 1998 to August 2000 were treated with basiliximab combined with early low-dose cyclosporin, reduced steroids and mycophenolate mofetil (MMF). Clinical outcomes at 100 d and 1 yr were compared with a group of 26 patients transplanted from March 1995 to November 1998 who received OKT3, delayed full-dose cyclosporin, high-dose steroids and MMF. Amongst basiliximab treated patients, we compared clinical outcomes in those older and younger than 60 yr.

RESULTS

Both groups were similar except for a shorter cold ischaemic time in the basiliximab group. Length of stay, number of readmissions, total hospitalization days and cytomegalovirus infections were lower in the basiliximab group. Despite a 40% reduction in steroids, basiliximab-treated patients had fewer biopsy-proven episodes of AR (basiliximab 14% vs. OKT3 35%) and required less antilymphocyte antibody therapy. Clinical outcomes including patient and graft survival were no different between groups. Long-term graft survival for patients over 60 yr was limited primarily by mortality.

CONCLUSIONS

Compared with OKT3 induction therapy, the combination of early low-dose cyclosporin and basiliximab is steroid sparing, effective, well tolerated and relatively safe.

Tackling the shortage of donor kidneys: how to use the best that we have

Shortage of kidney donor is still a major limitation for renal transplantation programs. This review focuses on the emerging practices, adopted to increase transplant activities, of expanding the criteria for donor and recipient selection without exposing the recipient to the drawbacks of a graft with inadequate nephron mass. Expanding the donor pool inevitably led to consideration for kidney transplantation of organs from older donors or from donors with hypertension, diabetes or other renal diseases. To fit the reduced performance of these suboptimal organs with the renal requirement of the recipient, selection of recipients with reduced metabolic requirements or increase of nephron mass by simultaneous transplantation of two suboptimal kidneys in the same recipient have been pursued. However, a critical aspect of both approaches is to quantify functioning nephron mass provided to the recipient by pre-transplant kidney biopsies. Morphological parameters assessed on kidney biopsies at the time of donor evaluation may serve to quantify the preserved tissue and to discriminate chronic irreversible lesions from acute changes that may account for a transiently impaired renal function in the donor, but that may recover after transplant.

Factors contributing to long graft survival in non-heart-beating cadaveric renal transplantation in Japan: a single-center study at Kitasato University

A total of 107 cadaveric kidneys from non-heart-beating donors (NHBDs) have been transplanted between 1974 and 2000 at Kitasato University Hospital, Sagamihara, Japan. The patient survival of the 107 recipients of cadaveric renal transplants at 1, 5 and 10 yr was 0.857, 0.770 and 0.746, respectively. The 50% graft survival was 3.8 yr. The 5 and 10-yr graft survival was 0.457 and 0.337, respectively. Twenty of the 107 recipients of non-heart-beating cadaveric renal transplantation had graft survival longer than 10 yr. Of these 20 patients, 14 survivors still maintain functioning renal grafts and two died with functioning graft, although the remaining four reverted to dialysis because of chronic rejection and nephropathy. The average graft survival of these 20 patients at the time of study was 13.3 yr and the longest was 21.4 yr. The average serum creatinine level at 10 yr after transplantation was 1.63 mg/dL, almost identical to that at 5 yr post-transplant. The donors aged on average 40.2 yr; 13 were male and seven were female. The youngest donor was 9-yr-old and the oldest was 66. The graft survival was significantly better in the group with donor age younger than 55 yr (Log-rank: p=0.007). The average weight of the renal graft was not different between the long and shorter graft survival groups. The average warm ischemic time and total ischemic time were 9.7 and 539.7 min, respectively. The duration of post-transplant acute tubular necrosis averaged 9.2 days. These parameters tended to be shorter than those in recipients with graft survival >10 yr, but with no statistical significance. The mean numbers of acute rejection (AR) episode within 3 months after transplantation were 0.25 +/- 0.66 and 0.92 +/- 0.90 (p=0.020) in long survival and shorter survival groups, respectively. Long survivors had a significantly lower incidence of AR. Two of 20 cases received conventional immunosuppression with prednisolone, azathioprine and mizoribin, and 18 had prednisolone and calcineurin inhibitor (CNI). Kaplan-Meier analysis showed a significant contribution of CNI to graft survival (p=0.036). However, the graft survival reduction rate after 1 yr post-transplant did not differ between conventional and CNI immunosuppression. These data suggest that renal grafts retrieved with proper organ procurement procedures from NHBDs may survive long-term and help to overcome donor shortage.

Attenuation of renal ischemia-reperfusion injury by FR167653 in dogs

BACKGROUND

Inflammatory cytokines are known to contribute to ischemia-reperfusion injury. We investigated the effect of FR167653 (FR), a suppressor of interleukin-1beta and tumor necrosis factor-alpha, on ischemia-reperfusion injury of the kidney in dogs.

METHODS

The left kidney was subjected to ischemia for 60 minutes followed by removal of the right kidney. A control group (n = 10) and an FR group (n = 8) were evaluated for tissue blood flow; resistive index, pulsatility index, arterial oxygen pressure, serum creatinine, blood urea nitrogen, aspartate transaminase, and alanine transaminase levels; interleukin-1beta messenger RNA expression in the peripheral blood; apoptotic index; and histopathology.

RESULTS

The FR group showed lower creatinine, serum urea nitrogen, aspartate transaminase, and alanine transaminase levels (P <.038 each) and lower interleukin-1beta mRNA expression and apoptotic index (P <.041 each) than did the control group. Arterial oxygen pressure during the 120 minutes after reperfusion in the FR group decreased but recovered quickly (P =.024). Renal tissue damage in the FR group was less than that in the control group (P =.036).

CONCLUSIONS

FR ameliorates ischemia-reperfusion injury of the kidney potentially by reduced production of inflammatory cytokines that may contribute to damage to the ischemic kidney and the distant organs.

Matching older kidneys with older patients does not improve allograft survival

Centers may restrict the use of some donor kidneys on the belief that overall graft survival is improved by giving older kidneys to older recipients and vice versa. The prevalence and the effect on graft survival (determined by death, return to dialysis, or retransplantation) of this practice among 74,297 first cadaver kidney transplantations in 1988 to 1998 was examined by using data from the United States Renal Data System. Giving older kidneys to older recipients is common; recipients > or =55 yr old received donor kidneys that were > or =55 yr old 46.2% more often than expected, but they received kidneys that were 18 to 29 yr old 33.6% less often than expected (chi(2) P < 0.0001). Both recipient and donor age have important effects on graft survival, although the effects of donor age are much stronger than those of recipient age. Compared with recipients 18 to 29 yr old, recipients > or =55 yr old were 25% (95% confidence interval, 15 to 35%, P < 0.0001) more likely to have graft failure (adjusted for donor age and other risk factors). On the other hand, donor kidneys > or =55 yr old were 78% (95% confidence interval, 58 to 99%, P < 0.0001) more likely to fail compared with kidneys 18 to 29 yr old. However, giving older kidneys to older recipients had little independent effect on graft survival, once the intrinsic effects of recipient and donor age were taken into account. For example, transplanting donor kidneys > or =55 yr old into recipients > or =55 yr old reduced the risk of graft failure only -6% (95% confidence interval, -18 to 8%, P = 0.3923) after the independent effects of donor and recipient age per se were taken into account. Thus, giving older kidneys to older recipients is a common practice that does not improve overall graft survival.

Different patterns of renal cell killing after warm and cold ischemia

Kidneys preserved for transplantation surgery sustain injuries caused by cold ischemia during storage. Additionally, kidneys harvested from non-heart-beating donors encounter the stress of warm ischemia. The aim of this study was to determine the specific cell types losing viability after warm and cold ischemia. In warm ischemia studies, the pedicles of left kidneys of Lewis rats were cross-clamped for up to 90 min. In cold ischemia studies, kidneys were flushed with cold University of Wisconsin solution and stored up to 48h at 0-1 degrees C. After warm or cold ischemia, kidneys were perfused via the renal arteries with Krebs-Henseleit bicarbonate (KHB) buffer at 37 degrees C, followed by trypan blue to label the nuclei of nonviable cells. Warm ischemia for 90 min caused renal failure and led to injury of proximal tubular cells, e.g., loss of brush borders, cast formation and trypan blue labeling. Cold ischemia for 48 h also caused renal failure but, unlike warm ischemia, caused trypan blue labeling of glomerular podocytes and peritubular endothelial cells. In warm ischemia-induced injury, electron microscopy showed shedding of microvilli and marked swelling of proximal tubular cells, microvilli and mitochondria. In cold ischemia-induced injury, podocytes were blebbed and swollen, and their pedicels were detached from the basement membrane, but disruption in proximal tubules was milder. In conclusion, warm ischemia triggers injury primarily to proximal tubular cells, whereas cold ischemia damages glomerular podocytes and peritubular endothelial cells in addition to proximal tubules.