Survival in recipients of marginal cadaveric donor kidneys compared with other recipients and wait-listed transplant candidates

Earlier is not necessarily better in preemptive kidney transplantation

While preemptive (before chronic dialysis) transplantation is associated with improved graft survival, it is unclear whether higher versus lower pretransplant kidney function is associated with even better graft survival after preemptive transplantation. We examined 671 first, preemptive, kidney-only transplantations at Hennepin County Medical Center and the University of Minnesota Medical Center 1984-2006. We estimated pretransplant glomerular filtration rate (eGFR, mL/min/1.73 m(2)) using the Modification of Diet in Renal Disease (MDRD) equation with Group 1: <10.0 (7.3 +/- 1.7, N = 324), Group 2: 10.0-14.9 (12.0 +/- 1.4, N = 217) and Group 3: >or=15.0 (21.1 +/- 10.0, N = 130). The mean difference in eGFR for Group 1 versus 3 was 13.8 pretransplant, 16.3 on day 1 and 13.9 on day 2 posttransplant. By week 1 and year 1 posttransplant, the differences between Groups 1 and 3 reduced to 6.3 and 4.5 mL/min/1.73 m(2), respectively. The adjusted relative risk (RR; Cox analysis) for graft failure was not significantly lower with higher pretransplant eGFR (reference eGFR <10.0); RR = 0.99 (95% confidence interval = 0.68-1.44, p = 0.9432) for eGFR 10.0-14.9; RR = 1.35 (0.89-2.05, p = 0.1588) for eGFR >or=15. Thus, early preemptive transplantation with higher eGFR does not necessarily improve graft survival after kidney transplantation, compared to preemptive transplantation with lower pretransplant eGFR.

A systematic review of kidney transplantation from expanded criteria donors

BACKGROUND

During the past few years, there has been renewed interest in the use of expanded criteria donors (ECD) for kidney transplantation to increase the numbers of deceased donor kidneys available. More kidney transplants would result in shorter waiting times and limit the morbidity and mortality associated with long-term dialysis therapy.

STUDY DESIGN

Systematic review of the literature.

SETTING & POPULATION

Kidney transplantation population.

SELECTION CRITERIA FOR STUDIES

Studies were identified by using a comprehensive search through MEDLINE and EMBASE databases. Inclusion criteria were case series, cohort studies, and randomized controlled trials assessing kidney transplantation in adult recipients using ECDs.

PREDICTOR

A special focus was given to studies comparing the evolution of kidney transplantation between standard criteria donors (defined as a donor who does not meet criteria for donation after cardiac death or ECD) and ECDs (defined as any brain-dead donor aged > 60 years or a donor aged > 50 years with 2 of the following conditions: history of hypertension, terminal serum creatinine level >or= 1.5 mg/dL, or death resulting from a cerebrovascular accident).

OUTCOMES

Criteria used to define and select ECDs, practice patterns, long-term outcomes, early complications, and some patient issues, such as selection criteria and immunosuppressive management.

RESULTS

ECD kidneys have worse long-term survival than standard criteria donor kidneys. The optimal ECD kidney for donation depends on adequate glomerular filtration rate and acceptable donor kidney histological characteristics, albeit the usefulness of biopsy is debated.

LIMITATIONS

This review is based mainly on data from observational studies, and varying amounts of bias could be present. We did not attempt to quantitatively analyze the effect of ECD kidneys on kidney transplantation because of the huge heterogeneity found in study designs and definitions of ECD.

CONCLUSIONS

Based on the available evidence, we conclude that patients younger than 40 years or scheduled for kidney retransplantation should not receive an ECD kidney. Patients 40 years or older, especially with diabetic nephropathy or nondiabetic disease, but a long expected waiting time for kidney transplantation, show better survival receiving an ECD kidney than remaining on dialysis therapy.

Immunosuppression without calcineurin inhibition: optimization of renal function in expanded criteria donor renal transplantation

INTRODUCTION

To assess the efficacy of calcineurin inhibitor (CNI)-free immunosuppression vs. calcineurin-based immunosuppression in patients receiving expanded criteria donor (ECD) kidneys.

PATIENT AND METHODS

Thirteen recipients of ECD kidneys were enrolled in this pilot study and treated with induction therapy and maintained on sirolimus, mycophenolate mofetil (MMF) and prednisone. A contemporaneous control group was randomly selected comprised of 13 recipients of ECD kidneys who had been maintained on CNI plus MMF and prednisone.

RESULTS

For the study group vs. the control group, two-yr graft survival was 92.3% vs. 84.6% (p = NS), two-yr patient survival was 100% vs. 92.3% (p = NS) and the acute rejection rates were 23% vs. 31% (p = NS), respectively. Renal function was significantly better in the study group compared with control up to the six-month mark, after which, it remained numerically but not statistically significant. Complications were more common in the study group, but serious adverse events requiring discontinuation were rare.

CONCLUSION

This pilot study demonstrates that CNI-free regimens can be safely implemented in patients receiving ECD kidneys with excellent two-yr patient and graft survival and good renal allograft function. Longer follow-up in larger randomized controlled trials are necessary to establish these findings.

Outcomes of kidney transplantation from older living donors to older recipients

BACKGROUND

More than half the newly wait-listed patients for kidney transplantation in 2005 were older than 50 years, and 13% were older than 65 years. As waiting times for a deceased donor kidney increase, these older candidates are disadvantaged by rapidly deteriorating health, often resulting in death or removal from the wait list before transplantation.

STUDY DESIGN

An observational cohort study was conducted using data from the Organ Procurement Transplant Network/United Network for Organ Sharing.

SETTING & PARTICIPANTS

All adult kidney-only transplantations performed in recipients 60 years and older from 1996 to 2005 were included.

PREDICTOR

The recipient cohort was stratified into 4 groups based on donor source: older living donor (OLD: living donor age > 55 years), younger living donor (YLD: living donor age </= 55 years), standard criteria deceased donor (SCD), and expanded criteria deceased donor (ECD).

OUTCOMES & MEASUREMENTS

Early posttransplantation outcomes, graft survival, patient survival, renal function 1 year posttransplantation, and relative risk of graft loss and patient death were compared.

RESULTS

Of 23,754 kidney transplantations performed in recipients 60 years and older, 7,006 were living donor transplantations (1,133 were > 55 years [OLD] and 5,873 were <or= 55 years [YLD]), 12,197 from SCDs, and 4,551 from ECDs. Early posttransplantation outcomes were best in YLD transplantations, followed by SCD and OLD transplantations. OLD transplantations were associated with inferior 3-year graft survival rates (85.7%), but similar 3-year patient survival rates (88.4%) compared with YLD (3-year graft survival, 83.4%; patient survival, 87.4%) and had superior graft survival compared with all deceased donor options. Compared with OLD transplantations, ECD transplantations were associated with a greater risk of graft loss (hazard ratio, 2.36; 95% confidence interval, 1.18 to 4.74).

LIMITATIONS

Observational retrospective studies using registry data are subject to inherent limitations, including the possibility of selection bias.

CONCLUSIONS

With superior graft and patient survival in recipients of transplants from OLDs compared with SCDs and ECDs, OLDs may be an important option for elderly transplantation candidates and should be considered for older patients with a willing and suitable older donor.

Gene expression patterns in deceased donor kidneys developing delayed graft function after kidney transplantation

BACKGROUND

Delayed graft function (DGF) after kidney transplantation (KTx) ranges between 2% and 50%. The mechanisms leading to DGF deserve special interest because DGF exerts negative influences on long-term outcomes. We studied gene expression profiles in deceased donor kidney (DDK) biopsies with and without DGF.

METHODS

Gene expression profiling was performed on donor kidney tissues from 33 DDK with the use of microarrays. DDK were classified as grafts with immediate function (non-DGF; n=21) and grafts with DGF (n=12). DGF was defined as a dialysis requirement in the first week after transplantation. Demographic donor and recipient information was collected. The robust-multiarray average method was used to estimate probe set expression summaries. Logistic regression was used to identify genes significantly associated with DGF development.

RESULTS

Patients were followed for 3 months after KTx. Thirty-eight probe sets (n=36 genes) were univariably differentially expressed in DDK with DGF when compared with DDK with non-DGF (alpha=0.001). Sixty-nine probe sets (n=65 genes) were differentially expressed in DDK with DGF when compared with DDK with non-DGF after adjusting for cold ischemia time (alpha=0.001). Gene ontology terms classified the overexpressed genes in DDK with DGF as principally related to cell cycle/growth (e.g., IGFBP5, CSNK2A2), signal transduction (e.g., RASGRP3), immune response (e.g., CD83, BCL3, MX1), and metabolism (e.g., ENPP4, GBA3). TNFRSF1B was overexpressed in DDK with DGF.

CONCLUSIONS

Cold ischemia time was a predictor of DGF independently of the preservation method. We identified a set of 36 genes candidates of DGF in DDK, with genes involved in the inflammatory response being the more important.

Organ shortage crisis: problems and possible solutions

The demand for organ transplantation has rapidly increased all over the world during the past decade due to the increased incidence of vital organ failure, the rising success and greater improvement in posttransplant outcome. However, the unavailability of adequate organs for transplantation to meet the existing demand has resulted in major organ shortage crises. As a result there has been a major increase in the number of patients on transplant waiting lists as well as in the number of patients dying while on the waiting list. In the United States, for example, the number of patients on the waiting list in the year 2006 had risen to over 95,000, while the number of patient deaths was over 6,300. This organ shortage crisis has deprived thousands of patients of a new and better quality of life and has caused a substantial increase in the cost of alternative medical care such as dialysis. There are several procedures and pathways which have been shown to provide practical and effective solutions to this crisis. These include implementation of appropriate educational programs for the public and hospital staff regarding the need and benefits of organ donation, the appropriate utilization of marginal (extended criteria donors), acceptance of paired organ donation, the acceptance of the concept of "presumed consent," implementation of a system of "rewarded gifting" for the family of the diseased donor and also for the living donor, developing an altruistic system of donation from a living donor to an unknown recipient, and accepting the concept of a controlled system of financial payment for the donor. As is outlined in this presentation, we strongly believe that the implementation of these pathways for obtaining organs from the living and the dead donors, with appropriate consideration of the ethical, religious and social criteria of the society, the organ shortage crisis will be eliminated and many lives will be saved through the process of organ donation and transplantation.

Correlation of histologic findings on preimplant biopsy with kidney graft survival

Kidney biopsies are being used to evaluate marginal deceased donor organs, but, the literature on the utility of this practice remains conflicting. We re-examined this issue by performing a multivariate analysis of 597 kidney transplant recipients. The presence of moderate arteriosclerosis and/or moderate arteriolosclerosis (MA), defined as >or=25% luminal compromise, was a significant predictor of graft outcome in standard criteria donors (multivariate, P=0.01) and in expanded criteria donors (ECD) as defined by UNOS criteria (univariate P=0.02). One-, 3-, and 5-year overall allograft survival with MA was 71%, 58%, and 40%, respectively. Increasing degrees of glomerulosclerosis (GS) were associated with earlier graft failure on univariate (P=0.03) but not multivariate analysis (P=0.36). GS>20% and interstitial fibrosis>25% had a low frequency in the material reviewed, likely reflecting our organ utilization practices, and did not have a demonstrable effect on graft outcome. Clinical parameters independently associated with worse graft function were ECD status (P<0.05), retransplantation (P=0.004), recipient age (P<0.05), and delayed graft function (P<0.0001). Donor vascular disease is an independent risk factor for suboptimal graft survival. Great caution should be exercised in the decision to transplant kidneys with moderate arterial and/or arteriolar luminal narrowing.

[Comparative analysis of renal graft function after open vs. laparoscopic nephrectomy: experimental model]

INTRODUCTION

Living donor renal transplant reports a higher patient and graft survival in comparison to cadaver donor and represents a good alternative facing the current lack of organs for transplant.

GOALS

To analyze comparatively in an experimental model (pig) the influence of ischemia-reperfusion and functional outcome of renal graft retrieved by open Vs laparoscopic nephrectomy.

MATERIAL AND METHODS

30 lab pigs were nephrectomized (left kidney): 15 by laparoscopy and 15 by open surgery, as living donors, in a model of renal autotransplant. Renal blood flow (RBF) was measured by means of an electromagnetic probe and creatinine levels during the first week after the implant.

RESULTS

Comparative analysis of RBF during the immediate 60 min after unclamping showed a significant reduction of average RBF in laparoscopic group in comparison to open group (p < 0.001), with a more evident reduction of RBF in the laparoscopic group during the 5-min period after unclamping (p < 0.001) and a progressive recuperation of RBF during the 1st hour, slowest in laparoscopic group. Creatinine levels in the first week after the transplant decreased progressively from 1.3 to 0.8 mgrs/dl in the open group and from 2 to 1.1 mg/dl in laparoscopic group (p < 0.001).

CONCLUSIONS

Renal grafts retrieved by laparoscopy presents a more evident ischemia-reperfusion syndrome shown by a lower average RBF after unclamping and a significant deterioration of renal function during the first week after transplant.

Determinants of discard of expanded criteria donor kidneys: impact of biopsy and machine perfusion

We examined factors associated with expanded criteria donor (ECD) kidney discard. Scientific Registry of Transplant Recipients (SRTR)/Organ Procurement and Transplantation Network (OPTN) data were examined for donor factors using logistic regression to determine the adjusted odds ratio (AOR) of discard of kidneys recovered between October 1999 and June 2005. Logistic and Cox regression models were used to determine associations with delayed graft function (DGF) and graft failure. Of the 12,536 recovered ECD kidneys, 5139 (41%) were discarded. Both the performance of a biopsy (AOR = 1.21, p = 0.02) and the degree of glomerulosclerosis (GS) on biopsy were significantly associated with increased odds of discard. GS was not consistently associated with DGF or graft failure. The discard rate of pumped ECD kidneys was 29.7% versus 43.6% for unpumped (AOR = 0.52, p < 0.0001). Among pumped kidneys, those with resistances of 0.26-0.38 and >0.38 mmHg/mL/min were discarded more than those with resistances of 0.18-0.25 mmHg/mL/min (AOR = 2.5 and 7.9, respectively). Among ECD kidneys, pumped kidneys were less likely to have DGF (AOR = 0.59, p < 0.0001) but not graft failure (RR = 0.9, p = 0.27). Biopsy findings and machine perfusion are important correlates of ECD kidney discard; corresponding associations with graft failure require further study.

Aortic stiffness of kidney transplant recipients correlates with donor age

Increased aortic stiffness is a major factor responsible for the high cardiovascular mortality in patients with end-stage renal disease, but the impact of kidney transplantation on recipient aortic stiffness remains poorly defined. The use of expanded-criteria kidney donors is associated with decreased recipient survival compared with the use of standard-criteria donors, although the underlying mechanisms are incompletely understood. It was hypothesized that donor characteristics may affect recipient aortic stiffness, which may contribute to cardiovascular mortality in these patients. Aortic stiffness was evaluated by measurement of carotid-femoral pulse wave velocity in 74 cadaveric kidney recipients at 3 and 12 mo after transplantation. At 3 mo, aortic stiffness was associated exclusively with recipient-related factors: Age, gender, and mean BP. At 12 mo, age of the donor kidney emerged as an additional determinant. The change in aortic stiffness between 3 and 12 mo strongly correlated with donor age; stiffness improved in recipients of young kidneys (first tertile of donor age) and worsened in recipients of older kidneys (upper tertile of donor age). At 12 mo, the carotid-femoral pulse wave velocity was >1 m/s higher in recipients of the oldest kidneys than in the recipients of younger kidneys. The association between donor age and aortic stiffness was independent of recipient age, gender, mean BP, pretransplantation dialysis duration, conventional cardiovascular risk factors, medication, posttransplantation events, and GFR. These results demonstrate that the impact of kidney transplantation on recipient aortic stiffness is dependent on donor age and suggest that ongoing damage to large arteries might contribute to the mechanism underlying the association of old-donor kidneys and increased cardiovascular mortality.

The overlapping risk profile between dialysis patients listed and not listed for renal transplantation

The survival advantage of kidney transplantation extends to many high-risk ESRD patients; however, numerous factors ultimately determine which patients are evaluated and listed for the procedure. Broad goals of patient evaluation comprise identifying patients who will benefit from transplantation and excluding patients who might be placed at risk. There is limited data detailing whether current access limitations and screening strategies have achieved the goal of listing the most appropriate patients. The study estimated the life expectancy of adult patients in the United States prior to transplantation with ESRD onset from 1995 to 2003. Factors associated with transplant listing were examined based on patient prognosis after ESRD. Approximately one-third of patients listed for transplantation within 1 year of ESRD had </=5-year life expectancy on dialysis. In contrast, one-third of patients not listed had >5-year life expectancy. The number of patients not listed with 'good' prognosis was significantly higher than those listed with 'poor' prognosis (134 382 vs. 16 807, respectively). Age, race, gender, insurance coverage and body mass index (BMI) were associated with likelihood for listing with 'poor' prognosis and not listing with 'good' prognosis. Over the past decade, many ESRD patients viable for transplantation have not listed for transplantation while higher-risk patients have listed rapidly.

Outcome of kidney transplantation using expanded criteria donors and donation after cardiac death kidneys: realities and costs

Expanded criteria donors (ECDs) and donation after cardiac death (DCD) provide more kidneys in the donor pool. However, the financial impact and the long-term benefits of these kidneys have been questioned. From 1998 to 2005, we performed 271 deceased donor kidney transplants into adult recipients. There were 163 (60.1%) SCDs, 44 (16.2%) ECDs, 53 (19.6%) DCDs and 11 (4.1%) ECD/DCDs. The mean follow-up was 50 months. ECD and DCD kidneys had a significantly higher incidence of delayed graft function, longer time to reach serum creatinine below 3 (mg/dL), longer length of stay and more readmissions compared to SCDs. The hospital charge was also higher for ECD, ECD/DCD and DCD kidneys compared to SCDs, primarily due to the longer length of stay and increased requirement for dialysis (70,030 dollars, 72,438 dollars, 72,789 dollars and 47,462 dollars, respectively, p < 0.001). Early graft survival rates were comparable among all groups. However, after a mean follow-up of 50 months, graft survival was significantly less in the ECD group compared to other groups. Although our observations support the utilization of ECD and DCD kidneys, these transplants are associated with increased costs and resource utilization. Revised reimbursement guidelines will be required for centers that utilize these organs.

Preemptive kidney transplantation in patients with diabetes mellitus

Kidney transplantation is the most preferred treatment for end-stage renal disease because it improves not only the patient's survival compared with dialysis, but also the quality of life. Preemptive transplantation is transplantation performed prior to the initiation of renal dialysis. Recent observational studies have shown increased patient and graft survival with preemptive transplantation, compared to patients receiving transplantation after the initiation of dialysis. Preemptive simultaneous pancreas and kidney transplantation in type 1 diabetic recipients has also been shown to improve patient survival. These results indicate the importance of early referral of patients who have chronic kidney disease to nephrologists and transplant centers.

Anaesthesia for renal transplant surgery

Renal transplantation is the preferred therapeutic option for patients with end-stage renal disease. Survival rates are much higher in patients who receive a transplant. Patients with renal failure have significant concomitant medical conditions, such as cardiovascular disease. This article provides an overview of the important issues to be considered in patients undergoing renal transplant, and discusses the anaesthetic management of these patients.

Living Kidney Donors Requiring Transplantation: Focus on African Americans

Risks of kidney donation include a poorly characterized risk of late kidney failure. We hypothesized that African Americans (AA) kidney donors were at greater risk for kidney failure. The United Network for Organ Sharing/Organ Procurement Transplantation Network database was searched for patients who previously donated a kidney and were subsequently placed on the kidney transplant waiting list. We then compared the race of donors listed for kidney transplant to the race of all living donors during the same time period. Between 1993 and 2005, 8889 donors (14.3%) were AA and 42,419 (68.1%) were Caucasian. During this same time period, 102 previous kidney donors developed kidney failure and were listed for kidney transplantation. Although AAs comprised 14.3% of all living kidney donors, they constituted 44% of donors reaching the waiting list (P<0.001). These data provide indirect evidence that the risk of kidney failure may be exaggerated in AA donors.

Renal transplantation from extended criteria cadaveric donors: problems and perspectives overview

The critical shortage of organs available for renal transplantation has led to the consideration of alternative strategies for increasing the donor pool. Recently, the cadaveric kidney donor pool extended to donors who might have been deemed unsuitable in early times, leading to the concept of marginal donors and more recently to the notion of expanded criteria donors. Such organs are eligible for organ donation but, because of extreme age and other clinical characteristics, are expected to produce allograft at risk for diminished post-transplant function. Thus, the challenge is now to reduce the difference between graft outcome from patients grafted with marginal and 'optimal' donors. This implies appropriate transplantation strategies during pre-, peri- and post-transplantation phases including reduction of cold ischemia time, recipient selection, adaptation of immunosuppressive drug regimens, increase in nephron mass by dual kidney transplantation, and improvement in the graft selection process using histological criteria. This review summarizes current definition of a marginal donor and provides some guidance for clinical management of such transplant.

Predicting Kidney Transplant Survival Using Tree-Based Modeling

Predicting the outcome of kidney transplantation is clinically important and computationally challenging. The goal of this project was to develop the models predicting probability of kidney allograft survival at 1, 3, 5, 7, and 10 years. Kidney transplant data from the United States Renal Data System (January 1, 1990, to December 31, 1999, with the follow-up through December 31, 2000) were used (n = 92,844). Independent variables included recipient demographic and anthropometric data, end-stage renal disease course, comorbidity information, donor data, and transplant procedure variables. Tree-based models predicting the probability of the allograft survival were generated using roughly two-thirds of the data (training set), with the remaining one-third left aside to be used for models validation (testing set). The prediction of the probability of graft survival in the independent testing dataset achieved a good correlation with the observed survival (r = 0.94, r = 0.98, r = 0.99, r = 0.93, and r = 0.98) and relatively high areas under the receiving operator characteristic curve (0.63, 0.64, 0.71, 0.82, and 0.90) for 1-, 3-, 5-, 7-, and 10-year survival prediction, respectively. The models predicting the probability of 1-, 3-, 5-, 7-, and 10-year allograft survival have been validated on the independent dataset and demonstrated performance that may suggest implementation in clinical decision support system.

Kidney grafts from brain dead donors: Inferior quality or opportunity for improvement?

Major improvements in immunosuppressive treatment, surgical techniques, and treatment of post-transplant complications have contributed considerably to improved outcome in renal transplantation over the past decades. Yet, these accomplishments have not led to similar improvements in transplant outcome when the results of living and deceased donors are compared. The enormous demand for donor kidneys has allowed for the increase in acceptance of suboptimal donors. The use of brain dead patients as organ donors has had a tremendous positive influence on the number of renal transplants. Unfortunately, the physiologically abnormal state of brain death has a negative effect on transplant outcome. The fact that transplanted kidneys derived from brain dead donors have a decreased viability indicates that potential grafts are already damaged before retrieval and preservation. In this review, we present an overview of the current knowledge of (patho)-physiological effects of brain death and its relevance for renal transplant outcome. In addition, several options for therapeutic intervention during brain death in the donor with the goal to improve organ viability and transplant outcome are discussed.

Outcomes of kidneys from donors after cardiac death: implications for allocation and preservation

Although donation after cardiac death (DCD) kidneys have a high incidence of delayed graft function (DGF) and have been considered marginal, no tool for stratifying risk of graft loss nor a specific policy governing their allocation exist. We compared outcomes of 2562 DCD, 62,800 standard criteria donor (SCD) and 12,812 expanded criteria donor (ECD) transplants reported between 1993 and 2005, and evaluated factors associated with risk of graft loss and DGF in DCD kidneys. Donor age was the only criterion used in the definition of ECD kidneys that independently predicted graft loss among DCD kidneys. Kidneys from DCD donors <50 had similar long-term graft survival to those from SCD (RR 1.1, p = NS). While DGF was higher among DCD compared to SCD and ECD, limiting cold ischemia (CIT) to <12 h decreased the rate of DGF 15% among DCD <50 kidneys. These findings suggest that DCD <50 kidneys function like SCD kidneys and should not be viewed as marginal or ECD, and further, limiting CIT <12 h markedly reduces DGF.

Marginal kidney donor

Renal transplantation is the treatment of choice for a medically eligible patient with end stage renal disease. The number of renal transplants has increased rapidly over the last two decades. However, the demand for organs has increased even more. This disparity between the availability of organs and waitlisted patients for transplants has forced many transplant centers across the world to use marginal kidneys and donors. We performed a Medline search to establish the current status of marginal kidney donors in the world. Transplant programs using marginal deceased renal grafts is well established. The focus is now on efforts to improve their results. Utilization of non-heart-beating donors is still in a plateau phase and comprises a minor percentage of deceased donations. The main concern is primary non-function of the renal graft apart from legal and ethical issues. Transplants with living donors outnumbered cadaveric transplants at many centers in the last decade. There has been an increased use of marginal living kidney donors with some acceptable medical risks. Our primary concern is the safety of the living donor. There is not enough scientific data available to quantify the risks involved for such donation. The definition of marginal living donor is still not clear and there are no uniform recommendations. The decision must be tailored to each donor who in turn should be actively involved at all levels of the decision-making process. In the current circumstances, our responsibility is very crucial in making decisions for either accepting or rejecting a marginal living donor.

Restricting Cadaveric Kidney Transplantation Based on Age: The Impact on Efficiency and Equity

BACKGROUND

Caring for patients with end-stage renal disease (ESRD) is resource intense, and health care costs for this small segment of the population continue to rise. When compared to long-term dialysis as a therapy for ESRD, kidney transplantation increases survival, improves quality of life, and is cost saving.

METHODS

We used decision analytic techniques to determine if cadaveric kidney transplantation is cost-effective in all age groups. We then looked at the impact of a strategy of restricting access to transplantation to those under 60 years of age to determine the impact on overall clinical outcomes and costs, as well as the outcomes and costs within each age group.

RESULTS

Equal access to cadaveric kidney transplantation resulted in an increase in expected life years (7.4 vs 6.7 years) and a significant cost savings ($376,577 vs $568,670 per patient) compared to a strategy of long-term dialysis therapy over a 25-year time horizon. This pattern was seen for the overall cohort, and for all four age groups individually. Restricting access to transplantation to patients under the age of 60 resulted in only a very small improvement in expected life years and small cost savings under base-case assumptions. As expected, older patients were adversely impacted by this strategy.

CONCLUSION

We have shown that transplantation is cost-effective for all age groups. A strategy of restricting access to transplantation to younger patients does not result in large cost savings and provides only small improvements in expected life-years at the expense of significantly worse outcomes in older patients.

Effect of population aging on the international organ donation rates and the effectiveness of the donation process

This study analyzed the effect of population aging on organ donation for transplants in 43 countries and on the effectiveness of the donation process by comparing the results between Spain and the United States. The percentage of the population aged 65 or over accounted for 33% of the difference in the donation rates between the countries and for 91% of the variation in the rates after age adjustment. However, the level of aging of the Spanish (16.5%) and American (12.3%) populations failed to account for the percentages of deceased donors 65 or over (28% vs. 10%), due to the different age-specific donation rates, much higher in Spain above 50 years. These differences lead to a higher effectiveness of the process in the United States (3.1 transplanted organs per donor vs. 2.5 in Spain), though at lower rates of transplant per million population (73 vs. 87). We conclude that older populations have a greater donation potential as donation rates are strongly associated with population aging. It should therefore be mandatory to adjust donation rates for age before making comparisons. Additionally, effectiveness decreases with older donors, so age should be considered when establishing standards relating to organ donation and effectiveness of the process.

Estimated benefits of transplantation of kidneys from donors at increased risk for HIV or hepatitis C infection

Kidneys from organ donors who have behaviors that place them at increased risk for infection with human immunodeficiency virus (HIV) or hepatitis C virus (HCV) are often discarded, even if viral screening tests are negative. This study compared policies that would either 'Discard' or 'Transplant' kidneys from Centers for Disease Control classified increased-risk donors (CDC-IRDs) using a decision analytic Markov model of renal failure treatment modalities. Base-case CDC-IRDs were current injection drug users (IDUs) with negative antibody and nucleic acid testing (NAT) for HIV and HCV, comprising 5% of kidney donors. Compared to a CDC-IRD kidney 'Discard' policy, the 'Transplant' policy resulted in higher patient survival, a greater number of quality-adjusted life-years (QALYs) (5.6 vs. 5.1 years per patient), more kidney transplants (990 vs. 740 transplants per 1000 patients) and lower cost of care ($60 000 vs. $71 000 per QALY). The total number of viral infections was lower with the 'Transplant' policy (13.1 vs. 14.8 infections per 1000 patients over 20 years), because the 'Discard' policy led to more time on hemodialysis, with a higher HCV incidence. We recommend that kidneys from NAT-negative CDC-IRDs be considered for transplantation since the practice is estimated to be beneficial from both the societal and individual patient perspective.

Mortality experience in recipients undergoing repeat transplantation with expanded criteria donor and non-ECD deceased-donor kidneys

Nearly one-quarter of the kidney transplant waiting list is composed of repeat transplantation candidates. Survival following retransplantation using expanded criteria donor (ECD) kidneys has not been adequately studied. Using data from the Scientific Registry of Transplant Recipients, we analyzed mortality after retransplantation with ECD and non-ECD deceased-donor kidneys. Adult patients who experienced graft failure and were relisted for transplantation between 1995 and 2004 were studied (n=9641). Follow-up began at the date of relisting and continued until death or the end of the observation period (December 31, 2004), with censoring at living-donor transplantation. Sequential stratification (an extension of Cox regression) was used to compare mortality between patients receiving an ECD retransplant and those remaining on the waiting list or receiving a non-ECD retransplant (conventional therapy). Of 2908 retransplantations, 292 used ECD kidneys. Survival after ECD retransplantation was approximately equal to that of conventional therapy, with an adjusted hazard ratio of 0.98 (p=0.88). In contrast, non-ECD retransplant recipients experienced a significant reduction in mortality (HR=0.44; p<0.0001). Based on these national data, recipients of ECD retransplantation do not have a survival advantage relative to conventional therapy, whereas non-ECD retransplantation is associated with a significant survival advantage.

Influence of Pulsatile Perfusion Preservation on Outcomes in Kidney Transplantation from Expanded Criteria Donors

BACKGROUND

Expanded criteria donors (ECDs) increase the donor organ pool, but the value of transplanting these kidneys has been questioned because of concerns about diminished survival, poorer renal function, and higher rates of delayed graft function.

STUDY DESIGN

Retrospective analysis of intermediate-term outcomes in ECD kidney transplantations according to method of preservation at a single center using a standardized approach.

RESULTS

Over a 5-year period, we performed 141 donations-after-brain-death ECD kidney transplantations into adult recipients. A total of 114 kidneys (81%) were managed with combined cold-storage and pulsatile perfusion preservation (PPP), and the remaining 27 (19%) were preserved with cold storage (CS). The PPP group had a higher proportion of kidneys preserved for longer than 30 hours (28% versus 0, p < 0.001) and a longer mean cold ischemia time (24.5 hours PPP versus 19 hours CS, p < 0.01). Other donor and recipient characteristics were similar between groups. Incidence of delayed graft function was 11% in PPP-stored kidneys versus 37% in CS kidneys (p = 0.002). With a mean followup of 27 months, patient (91% PPP versus 96% CS) and kidney graft survival (81% PPP versus 81.5% CS) rates were comparable. Mean 12-month serum creatinine (1.9 mg/dL) and calculated Modification of Diet in Renal Disease glomerular filtration rate (41 mL/min) values were similar between groups.

CONCLUSIONS

Despite longer cold ischemia times, recipients of ECD kidneys managed with PPP had similar survival and functional outcomes, but experienced a marked reduction in the rate of delayed graft function.

Results of a calcineurin-inhibitor-free immunosuppressive protocol in renal transplant recipients of expanded criteria deceased donors

The increasing number of patients on waiting lists and the relatively stable organ procurement rate provide the groundwork for the use of expanded criteria deceased donors. While calcineurin-inhibitors (CNI) are excellent immunosuppressive drugs, their nephrotoxicity is largely responsible for the lack of improvement in long-term graft survival. The objective of this study was to analyze the results obtained with the use of a calcineurin inhibitor-free immunosuppressive protocol (polyclonal antibody induction, plus sirolimus, mycophenolate mofetil, and low doses of steroids) in terms of graft and patient survival as well as posttransplant clinical complications over 2 years. Under this immunosuppressive protocol, 78.04% of the patients completed the follow-up. A protocol biopsy was performed on 17 patients (53.1%) within 2 years posttransplant of which 82.31% were diagnosed as chronic allograph nephropathy grade I. The incidence of clinical complications was low and not significantly different from that reported with other immunosuppressive schemes. Death-censored graft survival was 95.12%. In conclusion, the use of a calcineurin inhibitor-free protocol in renal-transplant recipients of expanded criteria deceased donors was associated with excellent graft and patient survival rates and a low incidence of adverse events.

Early mortality rates in older kidney recipients with comorbid risk factors

BACKGROUND

There are over 60,000 candidates on the deceased donor kidney wait-list and the percentage of candidates over age 50 years continues to grow each year. National data have not previously been used to evaluate the association of comorbidities with mortality in older patients.

METHODS

A multivariate analysis of 30,262 deceased donor primary kidney recipients aged 18-59 years and 8,895 aged >or=60 years evaluated the association of six recipient comorbidities on 90- and 365-day patient mortality rates. The additional effects of expanded criteria donors (ECD) and development of delayed graft function (DGF) were also evaluated.

RESULTS

The 365-day mortality rate for recipients aged >or=60 years (10.5%) was more than twice that of recipients aged 18-59 years (4.4%) and comorbidities significantly increased mortality rates even higher (10.6-21.4%). The 365-day mortality rate for recipients aged >or=60 years who received an ECD kidney was 14.4% and who developed DGF was 15.9% while recipients with comorbidities but no DGF and no ECD ranged from 16.0 to 42.3%. The 365-day transplant mortality rate of recipients aged >or=60 years with comorbidities is higher than the 365-day wait-list mortality for patients with the same comorbidities, suggesting a lack of survival benefit from transplantation.

CONCLUSIONS

Mortality rates for patients aged >or=60 years with comorbidities are higher than for those without comorbidities, significantly higher than for younger patients, and higher than for wait-listed patients. Thus, utility may be poorly served by allocating kidneys to older patients with comorbidities, and perhaps discussion of exclusionary listing criteria is warranted.

The impact of human leukocyte antigen matching on transplant complications and immunosuppression dosage

Administrative claims data facilitate ascertainment of outcomes not collected by the transplant registry and provide the opportunity to examine prescribed doses of immunosuppressive medications. Here, we examine the impact of human leukocyte antigen (HLA) matching on traditional outcomes, rejection and survival, and use novel methods to examine immunosuppresion doses and complication rates. The central hypothesis tested in this analysis is that HLA-matched recipients receive lower doses of immunosuppression and have fewer posttransplant complications. We break from tradition by examining HLA matching in both living and deceased donor kidney transplants. As secondary aims, we compare the relative impact of class I and II mismatches and describe outcomes achieved with older donors. Medicare claims linked to the United States Renal Data System database for 23,443 kidney transplants were included in the study. A total of 15,793 transplants were DR mismatched (DRMM), 5,340 manifested no DR mismatches (NODRMM), and 2,310 manifested no ABDR mismatches (NOABDRMM). Patients with NOABDRMM experienced lower adjusted risk of rejection (0.66, 95% confidence interval 0.59-0.74, P < 0.001) and lower hazard of graft loss (0.69, 0.61-0.77, P < 0.001) and death (0.76, 0.63-0.92, P < 0.001) compared with those with DRMM. The hazard of cardiac and diabetic complications was similar between recipients of NOADRMM and DRMM transplants, but the hazard of diarrhea was significantly lower (0.82, 0.73-0.92, P < 0.001) in patients with NOABDRMM. The 6-month dose of mycophenolate mofetil was lower in patients with NOABDRMM. This study validates previous studies that indicated significantly lower risks of rejection, graft loss, and death among patients with 0 HLA-A,B,DR mismatches. Use of administrative claims revealed similar rates of cardiovascular complications. However, HLA-matched deceased donor recipients received lower dosages of mycophenolate mofetil and manifested a lower risk of developing posttransplant diarrhea.

Role of pre-transplant marital status in renal transplant outcome

BACKGROUND

End-stage renal disease is associated with illness-induced disruptions that challenge patients and their families to accommodate and adapt. However, the impact of patients' marital status on kidney transplant outcome has never been studied. This project, based on data from United States Renal Data System (USRDS), helps to answer how marriage affects renal transplant outcome.

METHODS

Data have been collected from USRDS on all kidney/kidney-pancreas allograft recipients between January 1, 1995 and June 30, 2002, who were 18 yr old or older and had information about their marital status prior to the kidney transplantation (n = 2061). Survival analysis was performed using Kaplan-Meier methods and Cox proportional hazards modeling to control for confounding variables.

RESULTS

Overall findings of this study suggest that being married has a significant protective effect on death-censored graft survival [Hazard Ratio (HR) 0.80, p < 0.05] but a non-significant effect on recipient survival (HR 0.85, p = 0.122). When stratified by gender, the effect was still present in males for death-censored graft survival (HR 0.75, p < 0.05), but not for recipient survival (HR 0.86, p = 0.24). The effect was not observed in females, where neither graft (HR 0.90, p = 0.55) nor recipient (HR 0.8, p = 0.198) survival had an association with marital status. In subgroup analysis similar association was found in the recipients of a single transplant.

CONCLUSION

Based on our analysis, being married in the pre-transplant period is associated with positive outcome for the graft, but not for the recipient survival. When analyzed separately, the effect is present in male, but not in female recipients.