Evaluation of the older cadaveric kidney donor: the impact of donor hypertension and creatinine clearance on graft performance and survival

Predicting long-term outcomes of kidney transplantation in the era of artificial intelligence

The ability to accurately predict long-term kidney transplant survival can assist nephrologists in making therapeutic decisions. However, predicting kidney transplantation (KT) outcomes is challenging due to the complexity of the factors involved. Artificial intelligence (AI) has become an increasingly important tool in the prediction of medical outcomes. Our goal was to utilize both conventional and AI-based methods to predict long-term kidney transplant survival. Our study included 407 KTs divided into two groups (group A: with a graft lifespan greater than 5 years and group B: with poor graft survival). We first performed a traditional statistical analysis and then developed predictive models using machine learning (ML) techniques. Donors in group A were significantly younger. The use of Mycophenolate Mofetil (MMF) was the only immunosuppressive drug that was significantly associated with improved graft survival. The average estimated glomerular filtration rate (eGFR) in the 3rd month post-KT was significantly higher in group A. The number of hospital readmissions during the 1st year post-KT was a predictor of graft survival. In terms of early post-transplant complications, delayed graft function (DGF), acute kidney injury (AKI), and acute rejection (AR) were significantly associated with poor graft survival. Among the 35 AI models developed, the best model had an AUC of 89.7% (Se: 91.9%; Sp: 87.5%). It was based on ten variables selected by an ML algorithm, with the most important being hypertension and a history of red-blood-cell transfusion. The use of AI provided us with a robust model enabling fast and precise prediction of 5-year graft survival using early and easily collectible variables. Our model can be used as a decision-support tool to early detect graft status.

Ipsilateral dual kidney transplantation in an elderly patient with severe atherosclerosis: a case report

Dual Kidney Transplantation (DKT) has been developed to improve outcomes from transplantation based on extended criteria of donors (ECD) and demonstrated excellent short-term outcomes. We performed DKT at Samsung Medical Center in March 2021. The donor was a 74-year-old male with no history of known underlying diseases but died from traumatic subarachnoid hemorrhage. The recipient was a 72-year-old male who had been undergoing nephrological observation for 4 years prior to the kidney transplant. The patient had been on hemodialysis since July 2017 and had been suffering from type 2 diabetes since 2003. On non-contrast computed tomography, diffuse calcific atherosclerosis was observed in the abdominal aorta and left iliac artery. As a result, ipsilateral DKT was performed. Because of this diffuse calcific atherosclerosis, we planned ipsilateral DKT on the right side. Postoperative healing was uneventful without complications. In conclusion, DKT is an option for improving survival in the ECD pool, and ipsilateral DKT can be helpful option for preventing organ discard in ECDs.

A prediction model of delayed graft function in deceased donor for renal transplant: a multi-center study from China

Background

Kidneys obtained from deceased donors increase the incidence of delayed graft function (DGF) after renal transplantation. Here we investigated the influence of the risk factors of donors with DGF, and developed a donor risk scoring system for DGF prediction.

Methods

This retrospective study was conducted in 1807 deceased kidney donors and 3599 recipients who received donor kidneys via transplants in 29 centers in China. We quantified DGF associations with donor clinical characteristics. A donor risk scoring system was developed and validated using an independent sample set.

Results

The incidence of DGF from donors was 19.0%. Six of the donor characteristics analyzed, i.e., age, cause of death, history of hypertension, terminal serum creatinine, persistence of hypotension, and cardiopulmonary resuscitation (CPR) time were risk factors for DGF. A 49-point scoring system of donor risk was established for DGF prediction and exhibited a superior degree of discrimination. External validation of DGF prediction revealed area under the receiver-operating characteristic (AUC) curves of 0.7552.

Conclusions

Our study determined the deceased donor risk factors related to DGF after renal transplantation pertinent to the Chinese cohort. The scoring system developed here had superior diagnostic significance and consistency and can be used by clinicians to make evidence-based decisions on the quality of kidneys from deceased donors and guide renal transplantation therapy.

Pancreas grafts for transplantation from donors with hypertension: an analysis of the scientific registry of transplant recipients database

BACKGROUND

With the rising demands for pancreas transplantation, surgeons are trying to extend the donors pool and set up a more appropriate assessment system. We aim to evaluate the effect of donor hypertension on recipient overall and graft survival rates.

METHODS

Twenty-four thousand one hundred ninety-two pancreas transplantation patients from the Scientific Registry of Transplant Recipients database were subdivided into hypertension group (HTN, n = 1531) and non-hypertension group (non-HTN, n = 22,661) according to the hypertension status of donors. Recipient overall and graft survival were analyzed and compared by log rank test, and hazard ratios of predictors were estimated using Cox proportional hazard models.

RESULTS

Patient overall and graft survival of non-HTN group were higher than that of the HTN group (both p < 0.001). The duration of hypertension negatively influenced both overall and graft survival rates (both p < 0.001). Multivariate analyses demonstrated that hypertension was an independent factor for reduced survival (hazard ratio [HR], 1.10; 95% confidence interval [CI], 1.01-1.18; p < 0.001). Other independent factors included recipient body mass index (HR, 1.02; 95% CI, 1.01-1.05; p < 0.001) and transplant type (pancreas after kidney transplants / pancreas transplant alone vs. simultaneous pancreas-kidney transplants; HR, 1.41; 95% CI, 134-1.55; p < 0.001).

CONCLUSIONS

Donor hypertension is an independent factor for recipient survival after pancreas transplantation and could be considered in donor selection as well as post-transplant surveillance in clinical practice.

Systemic Expression of Oxidative DNA Damage and Apoptosis Markers in Acute Renal Graft Dysfunction

Background: Acute renal graft dysfunction (AGD) is one of the primary complications after kidney transplantation. The aim of this study was to identify the systemic oxidative DNA damage and apoptosis markers in patients with AGD, which will aid the understanding of the underlying processes of the complication. Methods: A cross-sectional analytical study was conducted in renal transplant (RT) recipients with and without AGD. The follow-up time of patients was <1 year. Using the ELISA technique, the markers of oxidative DNA damage (8-hydroxy-2-deoxyguanosine and 8-oxoguanine-DNA-N-glycosylase-1) and apoptosis (caspase-3, caspase-8, soluble TNF receptor 1, and cytochrome C) were determined. Results: Donor age was significantly higher in patients with AGD versus those without AGD (43±11 years versus 34.1±10.6 years, respectively; p<0.001). Levels of 8-hydroxy-2-deoxyguanosine were also significantly higher in AGD patients than those without AGD (624.1±15.3 ng/mL and 563.02± 17.4 ng/mL, respectively; p=0.039) and the DNA repair enzyme 8-oxoguanine-DNA-N-glycosylase-1 was significantly diminished in AGD patients versus non-AGD patients (7.60±1.8 ng/mL versus 8.13±1.70 ng/mL, respectively; p=0.031). A significant elevation of soluble TNF receptor levels in AGD patients was also found versus those without AGD (1178.6±25.2 ng/mL versus 142.6±39 ng/mL, respectively; p=0.03). Caspase-3 levels were higher in patients with AGD (1.19±0.21 ng/mL) versus those without AGD (0.79±0.11 ng/mL; p=0.121) and was also significantly augmented in AGD versus healthy control subjects (0.24±0.1 ng/mL; p=0.036). Cytochrome c in AGD patients was 0.32±0.09 ng/mL and 0.16±0.03 ng/mL in those without AGD versus 0.08±0.01 ng/mL in healthy controls (p=0.130 and p=0.184, respectively). Conclusion: These findings suggest that oxidative DNA damage with insufficient DNA repair and higher levels of caspase-3 compared to controls are markers of apoptosis protein dysregulation in AGD patients.

Living-Donor Kidney Transplantation: Donor-Recipient Function Correlation

BACKGROUND

With the rising prevalence of living-donor kidney transplantation, evaluation of factors correlated with renal function in the donor-recipient pair constitutes a main goal for kidney transplantation clinicians. Our objective was to analyze the more relevant donor characteristics that contribute to donor and recipient estimated glomerular filtration rates (eGFR) after 1 year.

METHODS

We evaluated 48 consecutive donor-recipient pairs from our unit.

RESULTS

Mean donor age was 46 ± 11 years, with 71% being women. Mean recipient age was 35 ± 12 years, with 54% being men. Mean duration of donor hospitalization was 7 ± 2 days. Donor eGFR was 104 ± 11 mL/min/1.73 m² before donation and 70 ± 14 mL/min/1.73 m² at discharge. After 1 year, donor eGFR was 71 ± 12 mL/min/1.73 m² and recipient eGFR was 69 ± 10 mL/min/1.73 m². Donor eGFR <100 mL/min/1.73 m² before donation and age >50 years correlated with 17.7- and 8.9-fold increased risks, respectively, of recipient eGFR <60 mL/min/1.73 m² after 1 year. Donor being female, although statistically associated with worse graft function, compared with a male donor (P = .020), did not represent a significantly increased risk of recipient eGFR <60 mL/min/1.73 m². Higher donor body mass index (BMI) also associated with a lower kidney function for donors (P = .048). In multivariate linear regression to predict pairs' eGFRs after 1 year, only donor eGFR before donation and at discharge retained statistical significance (P ≤ .001 and P = .045, respectively).

CONCLUSIONS

Excluding unpredictable complications in the post-transplantation period, donor eGFR before donation, eGFR at discharge, and age were the best parameters to predict recipient and donor eGFRs after 1 year and can be used as a tool for managing expectations regarding the post-transplantation period.

Donation and Transplantation of Kidneys Harvested From Deceased Donors Over the Age of 60 Years in the Upper Silesia Region

BACKGROUND

Population aging and shortage of organs for transplantation result in increasing numbers of kidneys retrieved from elderly donors. The aim of this study was to analyze donation of kidneys from donors after brain death (DBD) over the age of 60 years (≥60), comorbidities that affect decisions on retrieval, and early results of kidney transplantation.

METHODS

Ninety-six potential DBD ≥60 and 309 aged 40-59 years (40-59) reported in Upper Silesia, Poland, from 2004 to 2013 were enrolled in the study.

RESULTS

DBD >60 presented a higher rate of coexisting hypertension (53% vs 34%), limb ischemia (10% vs 1%), and past stroke (6% vs 1%) compared with DBD 40-59 (P < .05), but no differences were observed in serum creatinine concentration (85 vs 84 μmol/L), coexisting coronary disease (14% vs 6%), or diabetes (10% vs 4%). The decision of withdrawal from retrieval was more frequent in DBD ≥60 (16% vs 7%; P < .05). Twelve months after kidney transplantation, serum creatinine concentration was higher in recipients of kidneys from DBD ≥60 compared with DBD 40-59 (169 vs 138 μmol/L; P < .001). The survivals of recipients (93% vs 95%) and kidney grafts (90% vs 93%) as well as rates of proteinuria >1.0 g/24 h (6% vs 2%) did not differ between the groups.

CONCLUSIONS

A higher rate of comorbidities in potential kidney DBD ≥60 results in a lower retrieval rate in these donors. The function of kidneys harvested from DBD ≥60 12 months after transplantation is worse than those from DBD 40-59, but still acceptable.

Donor Characteristics of Pancreas Transplantation in Australia and New Zealand: A Cohort Study 1984-2014

Background

The aim of this study was to audit the characteristics of pancreas donors over time in Australia and New Zealand. Pancreas transplantation was introduced in Australian and New Zealand in 1984.

Methods

We analyzed data from the Australia and New Zealand Islet and Pancreas Transplant Registry, 1984 to 2014. We investigated the variation of donor characteristics of sex, age, body mass index, smoking status, blood group, multiple organ donation, cytomegalovirus status, terminal creatinine, hypertension, and cause of death for pancreas transplantation over time. We used χ² test (Fisher test when necessary) or analysis of variance to test difference for categorical or continuous characteristics, respectively.

Results

There were 628 pancreas donors from 1984 to 2014. Donor body mass index (from 21.9 to 24.0, P < 0.001) and age (from 23.9 to 28.5, P = 0.02) have both increased while terminal creatinine has decreased (86.3 to 73.3, P = 0.01) from 1995 to 2014. In the meantime, the proportions of donors with hypertension (from 19% to 1%, P < 0.001) and who were smokers (from 54% to 15%, P < 0.001) have decreased. Profile of cause of donor death has also changed over time (P = 0.06) with increase in cerebral hypoxia/ischemia (from 3% to 17%) and reductions in intracranial hemorrhage (27% to 13%).

Conclusions

Many donor characteristics have changed over time. The most significant changes appear to reflect changes in the general population, rather than changes in donor selection.

Successful Use of Kidneys from Deceased Donors with Acute Renal Failure

Background

Kidneys from deceased donors with acute renal failure are not widely used.

Objective

To compare outcomes for recipients of kidneys from donors with acute renal failure at organ recovery with outcomes for recipients of kidneys from donors with normal serum levels of creatinine.

Methods

Records of deceased donors and recipients of their organs at the Saudi Center for Organ Transplantation from 2003 to 2005 were reviewed. A total of 33 donors (donating 65 kidneys to 65 recipients) with elevated serum levels of creatinine (>1.7 mg/dL) and 94 donors (donating 188 kidneys to 188 recipients) with normal (<1.1 mg/dL) serum levels of creatinine at organ recovery and their respective recipients were compared. Both groups had normal creatinine levels at admission.

Results

Recipients in both groups had similar renal function at discharge and follow-up. Delayed graft function occurred more often ( P= .009) in the recipients of kidneys from donors with acute renal failure (47.7%) than in recipients of kidneys from donors with normal creatinine levels (29.8%). Elevation of serum level of creatinine at organ recovery did not correlate significantly with kidney function at discharge or last follow-up or with graft survival.

Conclusions

Survival of patients or grafts at 1, 2, and 3 years did not differ significantly between the recipients in the 2 groups. Only the frequency of delayed graft function differed between the 2 groups.

Geographic Variation in Cold Ischemia Time: Kidney vs. Liver Transplantation in the United States, 2003-2011

Background

Regional variations in kidney and liver transplant outcomes have been reported, but their causes remain largely unknown. This study investigated variations in kidney and liver cold ischemia times (CITs) across organ procurement organizations (OPO) as potential causes of variations in transplant outcomes.

Methods

This retrospective study analyzed the Standard Transplant Analysis and Research data of deceased donor kidney (n = 61,335) and liver (n = 39,285) transplants performed between 2003 and 2011. The CIT variations between the 2 types of organs were examined and compared. Factors associated with CIT were explored using multivariable regressions. Spearman rank tests were used to associate CIT with graft failure at the OPO level.

Results

Significant CIT variations were found across OPOs for both organs (P < 0.05). The variation was particularly large for kidney CIT. Those OPOs with longer average kidney CIT were likely to have a lower graft survival rate (P = 0.01). For liver, this association was insignificant (P = 0.23). The regression analysis revealed sharp contrasts between the factors associated with kidney and liver CITs. High-risk kidney transplant recipients and marginal kidneys were associated with longer average CIT. The reverse was true for liver transplants.

Conclusions

Large variations in kidney CIT compared to liver CIT may indicate that there is a room to reduce kidney CIT. Reducing kidney CIT through managerial improvements could be a cost-effective way to improve the current transplant system.

Surgical complications following 1670 consecutive adult renal transplantations: A single center study

BACKGROUND AND AIMS

The aim of the study was to clarify the frequency and the sequel of surgical complications occurring within 1 year after renal transplantation.

PATIENTS AND METHODS

Surgical complications after 1670 consecutive adult kidney transplantations performed between 2000 and 2009 were retrospectively analyzed. In 2%, a living-related allograft was used, and 10% were retransplantations. An intravesical technique without stenting was used for the ureteric implantation.

RESULTS

There were 282 surgical complications occurring in 259 (15.5%) transplantations. Ureteral obstruction occurred in 53 (3.1%), lymphoceles in 39 (1.5%), postoperative hemorrhage in 36 (2.1%), and renal vein thrombosis in 22 (1.3%) patients, respectively. Out of the 17 lung emboli, 4 were fatal. Male recipients had twice as much ureteral stenosis as female (2.4 vs 1.2%, p < 0.05), and the opposite was true of urinary leakage (1.8% vs 4.0%, p < 0.025). Five-year patient and graft survival was impaired in patients with complications compared with patients without complications. Five-year patient survival was 92% versus 88% and graft survival 87% versus 74%.

CONCLUSION

Surgical complications impair patient and graft survival after kidney transplantation.

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

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

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.

Monolateral dual kidney transplantation from marginal donors

BACKGROUND

Dual kidney transplantation (DKT) offers a safe way to face the organ shortage with good short-term and medium-term renal function. However, its application is limited by the longer operating time and the risk of surgical complication. This study reviews our results with DKT performed with an ipsilateral technique in terms of graft loss, graft and patient survival rates, and surgical complications.

PATIENTS AND METHODS

From January 2002 to March 2006, 23 patients underwent DKT through a monolateral Gibson incision with placement of both kidneys.

RESULTS

One primary nonfunction occurred (4%). Delayed graft function was observed in 3 DKT (13.3%). Acute rejection rate was 4.3% (1 patient). All patients are alive at a mean follow-up of 28 months. One-year and 2-year graft survival rates were 100% and 96%, respectively. Mean serum creatinine level at 1-year posttransplantation was 1.3 mg/dL (range, 0.8-2.1 mg/dL). One DKG recipient lost 1 graft, retaining the second normal functioning graft due to ureteral necrosis. The mean hospital stay after transplantation was 15 days (range, 12-34 days).

CONCLUSIONS

Monolateral placement in DKT offers the advantage of a single incision, minimizing the surgical risk. Tailored immunosuppression and careful selection of potential recipients, by excluding those with severe cardiopulmonary pathologies, could significantly improve both patient and graft survival in this group of patients.

Living donor renal transplantation: recent developments and perspectives

Renal transplantation is the optimal treatment for patients of all ages with end-stage renal disease. Life expectancy of the population in general is increasing consistently, as is the age of the dialysis population. Consequently, the average ages of kidney donors and recipients are rising. The combination of a growing number of patients with end-stage renal disease and a shortage of organs poses a significant challenge to the transplant community. Donor shortage is associated with unfavorable consequences (e.g. prolonged waiting time, and compromised graft and patient survival). As such, multidirectional efforts are required to expand the donor pool. Increasing the frequency of living donation seems to be an efficient solution. Living donation is associated with superior results for the recipient, and relatively benign long-term outcomes for donors. Reluctance to use organs from living donors whose eligibility was previously considered marginal (e.g. elderly donors) is declining. Although increased donor age is associated with reduced graft survival rates, this should not preclude use of older living donors; transplantation is definitely superior to remaining on dialysis. Thorough, standardized evaluation and careful screening for premorbid conditions in both elderly donors and elderly recipients are essential. Here, we present various options for expanding the living donor pool, with emphasis on the utilization of elderly living donors and transplantation in elderly recipients.

Medical management to optimize donor organ potential: review of the literature

PURPOSE

Over the past two decades, the demand for donor organs continues to outpace the number of organs available for transplantation. Parallel with this has been a change in the demographics of organ donors with an increase in older donors and donors with marginal organs as a proportion of the total organ donor pool. Consequently, efforts have been made to improve the medical care delivered to potential organ donors to improve the conversion rate and graft survival of available organs. The purpose of this literature review is to provide updated recommendations for the contemporary management of organ donors after the neurological determination of death in order to maximize the probability of recipient graft survival.

SOURCES

A comprehensive review of the literature obtained through searches of MEDLINE/PubMed, and personal reference files.

PRINCIPAL FINDINGS

Contemporary management of the organ donor after neurological determination of death includes therapies to prevent the detrimental effects of the autonomic storm, the use of invasive hemodynamic monitoring and aggressive respiratory therapy including therapeutic bronchoscopy in marginal heart and lung donors, and the use of hormonal therapy including vasopressin, corticosteroids, triiodothyronine or thyroxine, and insulin for the pituitary failure and inflammation seen in brain dead organ donors. The importance of normalizing donor physiology to optimize all available organs is stressed.

CONCLUSION

Aggressive hemodynamic and respiratory management of solid organ donors, coupled with the use of hormonal therapy improves the rate of conversion and graft survival in solid organ recipients.

Optimizing Living Donor Kidney Graft Function by Donor-Recipient Pair Selection

BACKGROUND

With the rising prevalence of living donor kidney transplantations (LDKT), we increasingly encounter transplant candidates who present with multiple potential living donors. For a given candidate, it can be unclear which donor offers the best opportunity for optimal posttransplant graft function. This study was undertaken to determine the relative contributions of individual donor demographic factors on graft function following LDKT.

METHODS

All LDKT donor-recipient pairs between January 1, 1999 and December 31, 2002 entered into the Scientific Registry of Transplant Recipients (SRTR) were reviewed. Suboptimal one year graft function was defined as a serum creatinine (Cr) greater than 1.5 mg/dL.

RESULTS

Of 20,528 adult LDKTs performed, 8,603 donor-recipient pairs had complete donor, recipient, and one year graft function data. Over one third (36%) of all LDKTs had suboptimal one year graft function. Logistic regression identified simple recipient and donor characteristics associated with suboptimal one year graft function. Four recipient factors (age, gender, race, and size), three donor factors (age, gender, and size) and recipient-donor relatedness were used to derive an equation that predicts the risk of suboptimal one year graft function posed by each potential living donor for a given transplant candidate.

CONCLUSIONS

In the setting of multiple potential living kidney donors, this quantitative tool may facilitate the choice of the optimal donor.

Retrospective follow-up of transplantation of kidneys from 'marginal' donors

The organ shortage has led to extend the procurement to kidneys from 'marginal' donors. As a result, an increasing number of kidneys are discarded, but an extended analysis of the validity of the clinical decision to accept or decline a marginal graft remains to be determined. We have retrospectively analyzed the outcome of 170 kidney transplantations, performed in eight renal transplantation centers between 1992 and 1998. Study group included transplantation from donors accepted after refusal for poor donor or graft quality by at least two centers. Control group included 170 paired recipients from kidneys unanimously accepted by all centers. Main causes of kidney refusal included impaired donor hemodynamics (28%), abnormal pre-harvesting serum creatinine (22%), advanced age in donors (15%), and donor atheroma (14%). The 5-year patient survival (88.2% in the study group and 88.9% in controls) and graft survival (70.4% in the study group and 76.7% in controls, P=0.129) were not significantly different. Delayed graft function occurred significantly more often in the study group patients than in controls patients (63 vs 32%, P<0.0001). Primary non-functioning kidneys were significantly more frequently observed in study patients than in controls (7.7 vs 1.8%, P=0.01). Mean creatinine clearance was significantly lower in the study group patients compared with controls during the post-transplant course. Our results suggest that these initially discarded kidneys provide satisfactory survival rates despite their impaired early functional recovery and poorer long-term renal function, and therefore might be considered acceptable for transplantation in the context of organ shortage.

Monolateral placement of both kidneys in dual kidney transplantation: low surgical complication rate and short operating time*

Dual kidney transplantation (DKT) from marginal donors is increasingly used at many centers to help cope with the organ shortage problem. The disadvantages of DKT consist in longer operating times and the risk of surgical complications. DKT can be performed in two ways, i.e. using monolateral or bilateral procedures. From October 1999 to June 2005, 58 DKTs were performed at our unit. In 29 cases (group I), the kidneys were extraperitoneally placed bilaterally in the iliac fossae via two separate incisions; as of June 2003, monolateral kidney placement was preferred in 29 cases, whenever compatible with the recipient's morphological status (group II). After a mean follow-up of 51 +/- 19 months for group I and 15 +/- 7 months for group II, all patients are alive with 1-year graft survival rates of 93% and 96%, respectively. Mean operating times were 351 +/- 76 min in group I and 261 +/- 31 min in group II (P = 0.0001). The mean S-creatinine levels in groups I and II were 132 +/- 47 and 119 +/- 36 mumol/l, respectively, at 1 year. We observed eight surgical complications in group I and seven in group II. Both techniques proved safe, with no differences in surgical complication rates. The monolateral procedure has the advantage of a shorter operating time and the contralateral iliac fossa remains available for further retransplantation procedures.

Clinical operational tolerance after kidney transplantation

Induction of allograft-specific tolerance and the detection of a "tolerance" state in recipients under immunosuppression with long-term stable graft function are major challenges in transplantation. Clinical "operational tolerance," defined as stable and acceptable graft function without immunosuppression for years, is a rare event. There is no report on the clinical history of such patients. In this article, we report on the medical history of 10 kidney recipients who display an immunosuppressive drug-free "operational tolerance" for 9.4 +/- 5.2 years. Clinical factors that may favor such a tolerant state are underlined. Firstly, most of the patients interrupted immunosuppression over a long time period (until 4 years), which mimics the procedure of intentional immunosuppression weaning following liver transplantation. Secondly, donor age was younger (median 25 years) than the one of the general transplanted population, suggesting that graft quality is one of the conditions favoring "operational tolerance." Moreover, the "operationally tolerant" recipients may be 'low responders' to blood transfusions (PRA 6 +/- 5.4%, six blood transfusions). We also show that "operational tolerance" occurs in the presence of anti-donor class II antibodies, as assessed in two patients. Finally, two patients degraded their renal function 9 to 13 years after treatment withdrawal, however only one presented histological lesions of chronic rejection.

Advantages of short-time ureteric stenting for prevention of urological complications in kidney transplantation: an 18-year experience

We retrospectively studied the incidence of urological complications in a consecutive series of 590 patients (group B) who received a kidney transplant (KT) with a ureteral stent from January 1994 to December 2002. The ureteral stent was sewn to the bladder catheter during the surgical procedure and left in situ for a mean time of 10 days (range 8 to 12 days). The results were compared to a consecutive series of 414 patients who received a KT from March 1986 to December 1993 without a ureteral stent (group A). The two groups were comparable in terms of donor and recipient gender, ischemia time, delayed graft function, and chronic rejection incidence, but differed in mean donor age (44.1 vs 36.0 years), mean recipient age (45.4 vs 39.1 years), living/cadaveric donor rate (19.8% vs 11.9%), arterial lesions and bench reconstruction rate (11.1 vs 3.5%), as well as acute rejection episodes (11.7% vs 29.2%). Complications were seen in nine patients in group B (1.5%) and 17 patients in group A (4.1%) (P < .0001). Urinary leaks presented in two patients in group B (0.3%) and 11 patients in Group A (2.6%; P < .0001), while stenosis was present in six patients in group B (1.5%) and 7 in group A (1.2%) (P = NS). Urological complications such as urinary tract infection and macroscopic hematuria were similar in both groups. Time to presentation of a leak was within 2 weeks from KT in 10 patients (92.3%), while stenosis presented early in four patients (one in group B and four in group A). Of the stenoses, 69.3% presented late (beyond 12 weeks) in five patients in group B and three in Group A. In conclusion, our data suggest that routine use of double pigtail ureteral stent significantly decreased the incidence of leaks and early stenoses, but it did not modify late stenosis incidence. In the last decade, risk factors for urological complications have been increasing over time, namely, older donors and older recipients, living donation, length of dialysis, and the use of grafts with arterial lesions. Therefore we believe that a ureteral stent should be routinely considered to afford the advantage to protect the urinary anastomosis in the early postoperative period when the incidence of complications is highest, without the need of cystoscopy for its removal.

Evaluation of the cost effectiveness of sirolimus versus tacrolimus for immunosuppression following renal transplantation in the UK

INTRODUCTION

Immunosuppressive therapy is required to prevent graft rejection. Calcineurin inhibitors such as tacrolimus are paradoxically toxic to the kidney, whereas sirolimus (rapamycin; Rapamune) is not generally associated with the nephrotoxicity of CNIs. The purpose of this study was to evaluate the relative cost utility of sirolimus versus tacrolimus for the primary prevention of graft rejection in renal transplant recipients in the UK.

METHODS

A stochastic simulation model was constructed using clinical trial and observational data comparing the two treatments. Time duration was up to 20 years. Costs were from a UK NHS perspective, valued at 2003 prices and discounted at 6%. Benefits were discounted at 1.5%. Simulated events included patient and graft survival, haemodialysis, peritoneal dialysis, re-transplants and acute rejection. Costs were summed for events and various maintenance therapies. Utility was differentially accredited depending upon survival and using the alternative renal replacement therapies. Outcome was predicted using post-transplant creatinine levels up to 3 years. Extensive statistical economic and sensitivity analyses were undertaken.

RESULTS

Over the 10-year horizon, sirolimus gained 0.72 years (discounted) of functioning graft over tacrolimus, resulting in an incremental cost per year of functioning graft that was dominant. Over a 20-year time horizon, the cost effectiveness of sirolimus over tacrolimus further improved with an average discounted gain in years of a functioning graft of 1.8 years, resulting in an incremental cost-utility ratio that was also dominant. The number of haemodialysis events was 48,243 for sirolimus recipients versus 127,829 for those receiving tacrolimus and peritoneal dialysis events 40,872 versus 105,249, respectively. Similar values were obtained when real-life observational data on tacrolimus use in Cardiff, Wales were entered into the model. Using data from Cardiff, sirolimus remained dominant over tacrolimus under all scenarios.

CONCLUSION

Our study suggests that sirolimus may be more cost effective than tacrolimus for the primary prevention of graft rejection in renal transplant recipients in the UK. Sirolimus was economically 'dominant' under almost all scenarios investigated. This finding was robust using statistical economic analysis and univariate sensitivity analysis.

Biopsy of potential cadaveric renal allografts at the time of retrieval

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Evaluation of the cost-effectiveness of Sirolimus versus cyclosporin for immunosuppression after renal transplantation in the United Kingdom

OBJECTIVE

The purpose of this study was to evaluate the cost-effectiveness of sirolimus compared with cyclosporin for the postsurgical management of renal transplant recipients, from the perspective of the UK National Health Service and the Personal Social Service.

METHODS

A discrete event stochastic simulation model was developed to evaluate both cost-effectiveness and cost utility over 10 and 20 years after transplant using historical data on 937 renal transplant recipients from the University Hospital of Wales in Cardiff, United Kingdom. The simulation was designed to forecast the incidence of acute rejection events, graft failure, retransplant, frequency of hemodialysis (HD) and peritoneal dialysis (PD), and death. Cox proportional hazard models were derived from historical transplant data, in which 1-, 2-, and 3-year post-transplant serum creatinine levels were used as the key drivers for predicting graft success and survival. Costs were reported as year-2003 UK pounds sterling (1 UK pound = US $1.76). Probabilistic sensitivity analysis was conducted and results reported with particular attention to 2 threshold values, 30,000/QALY and 20,000/QALY RESULTS: Over a 10-year time horizon, treatment with sirolimus was projected to produce a gain of 0.60 discounted year of functioning graft with a cost savings of 276 UK pounds per patient. Over a 20-year time horizon these benefits increased to 1.59 discounted years of functioning graft and a cost savings of 7405 UK pounds per patient. Using sensitivity analysis of the 10-year model, the only factors found to cause the probability of exceeding a 30,000 ceiling to be >5% were the proportion of subjects maintaining continuous graft function and the use of low-dose cyclosporin. With the 20-year model, sirolimus maintained cost-effectiveness across most scenarios in sensitivity analysis.

CONCLUSIONS

In this model analysis, sirolimus was cost-effective compared with cyclosporin for 10 to 20 years after renal transplantation in the United Kingdom, from the perspective of the UK National Health Service and Personal Social Service.

Kidney Transplantation From 1119 Deceased Donors in Finland, 1991 to 2003: Impact of Donor Factors

We assessed the effect of donor factors on the recovery and quality of cadaveric kidney transplant function. During 1991 to 2003, 2006 kidney grafts were derived from 1119 heart-beating donors in Finland. The annual mean age of donors increased from 33 to 46 years, with a significant decrease in the proportion of high-energy trauma and gunshot wounds and with an increased proportion of donors with coronary disease, hypertension, or cardiopulmonary resuscitation and surgical/radiological interventions before death. The transplant team's share of kidney retrievals increased from 50% to nearly 100%. In uni- and multivariate analyses all these factors had significant effects on the onset and quality of early graft function; however, this effect practically vanished by 1 year posttransplant. Of all studied donor factors, only donor cytomegalovirus (CMV) status significantly affected long-term survival, with donor CMV-positive grafts having 5% worse survival at 5 years. The 1-year graft survival improved from 90.9% to 96.2% and mean 1-year creatinine decreased from 121 micromol/L to 109 micromol/L during these 13 years, showing that the worsening trends in donors quality were compensated by improvements in other aspects of the process.

Reasons for non-use of recovered kidneys: the effect of donor glomerulosclerosis and creatinine clearance on graft survival

BACKGROUND

In 2000, the United Network for Organ Sharing/Organ Procurement and Transplantation Network Registry reported 540 recovered kidneys were discarded because of biopsy results, and 210 were discarded because of poor organ function. We compared the percentage of glomerulosclerosis (GS) and creatinine clearance (CrCl) of both discarded and transplanted cadaveric kidneys and examined their effect on graft survival and function.

METHODS

The cohort consisted of all cadaveric kidneys (n= 3,444) with reported biopsy results between October 25, 1999 and December 31, 2001. Graft survival was calculated by univariate and multivariate models.

RESULTS

Fifty-one percent of discarded kidneys had GS of less than 20%, 27% had a CrCl greater than 80 mL/min, and 15% (129 kidneys) had both GS less than 20% and a CrCl of greater than 80 mL/min. Univariate analyses of kidneys with less than or equal to 20% GS revealed no difference in 1-year graft survival when the CrCl was greater than or less than or equal to 80 mL/min. When GS was greater than 20%, 1-year graft survival of kidneys with a CrCl of greater than 80 mL/min was significantly greater than that of kidneys with a CrCl of less than or equal to 80 mL/min. Multivariate results showed no significant difference in relative risk of graft loss with GS greater than 20% versus less than or equal to 20% when the CrCl was either 50 or 80 mL/min. With both GS less than or equal to 20% and greater than 20%, serum creatinine at 1 year was significantly lower in kidneys with CrCl greater 80 mL/min.

CONCLUSIONS

Calculated donor CrCl does, and percentage GS on donor kidney biopsies does not, correlate well with 1-year graft survival and function, and percentage GS should not be used as the sole criterion for discarding recovered cadaveric kidneys.

Laparoscopic kidney donation from patients older than 60 years1 1No competing interests declared

BACKGROUND

The current study seeks to determine if the efficacy and safety of laparoscopic donor nephrectomy holds true when performed in patients older than 60 years of age.

STUDY DESIGN

Medical records of 42 renal donors older than 60 years were reviewed compared with younger controls carefully matched for gender, race, nephrectomy side, auxiliary recipient procedures, and date of surgery.

RESULTS

Preoperative baseline serum creatinine was identical in both groups (0.9 +/- 0.2 mg/dL) although controls had a slightly higher (NS) creatinine clearance (106.9 +/- 19.1 versus 100.0 +/- 35.5 mL/m). Operatively, there was no substantial difference between groups in operative time, warm ischemia time, estimated blood loss, number or size of ports used, and length of incision needed for removal of kidney. Intraoperative and postoperative complication rates were also equivalent between old and young donors. Postnephrectomy serum creatinine was identical. There was no increased length of hospitalization for older donors and they tended to require less morphine sulfate patient-controlled anesthesia. Recipient renal function was slightly better in the younger kidneys early and the difference became statistically significant at 6 to 12 months, but the magnitude of the improvement is not clinically important.

CONCLUSIONS

Laparoscopic donor nephrectomy may be performed safely in patients older than 60 years of age. There was no increase in complication rates or length of hospital stay. Older donors did not have a greater increase in serum creatinine after donation compared with donors younger than 40 years of age, nor did recipients of these older kidneys have clinically significantly higher serum creatinine than recipients of kidneys from donors less than 40 years old.

Increased kidney transplantation utilizing expanded criteria deceased organ donors with results comparable to standard criteria donor transplant

OBJECTIVE

To compare outcomes in recipients of expanded criteria donor (ECD) versus standard criteria donor (SCD) kidneys at a single center using a standardized approach with similar immunosuppression.

SUMMARY BACKGROUND DATA

Expanded criteria deceased organ donors (ECD) are a source of kidneys that permit more patients to benefit from transplantation. ECD is defined as all deceased donors older than 60 years and donors older than 50 years with 2 of the following: hypertension, stroke as the cause of death, or pre-retrieval serum creatinine (SCr) greater than 1.5 mg/dl.

METHODS

We retrospectively studied 90 recipients of adult deceased donor kidneys transplanted from October 1, 2001 to February 17, 2003, including 37 (41%) from ECDs and 53 (59%) from SCDs. ECD kidneys were used by matching estimated renal functional mass to recipient need, including the use of dual kidney transplants (n = 7). ECD kidney recipients were further selected on the basis of older age, HLA-matching, low allosensitization, and low body mass index. All patients received a similar immunosuppressive regimen. Minimum follow up was 9 months.

RESULTS

There were significant differences in donor and recipient characteristics between ECD and SCD transplants. Patient (99%) and kidney graft survival (88%) rates and morbidity were similar between the 2 groups, with a mean follow-up of 16 months. Initial graft function and the mean 1-week and 1-, 3-, 6-, 12-, and 18-month SCr levels were similar among groups.

CONCLUSIONS

The use of ECD kidneys at our center effectively doubled our transplant volume within 1 year. A systematic approach to ECD kidneys based on nephron mass matching and nephron sparing measures may provide optimal utilization with short-term outcomes and renal function comparable to SCD kidneys.

Drug Therapy in Transplant Recipients

Elderly patients with end-stage organ failure are now more frequently undergoing transplantation. Medication management in this population is challenging because of the combination of multiple comorbidities, polypharmacy, and immunological, pharmacokinetic and pharmacodynamic changes attributable to the aging process. Immunosuppressive medications can exacerbate pre-existing medical conditions and promote the development of disease processes. Cardiovascular disorders, such as hypertension, coronary artery disease, congestive heart failure and arrhythmias are common in elderly transplant recipients, and account for most of the deaths in this population. Blood pressure, blood glucose and cholesterol control is of particular concern because elderly transplant recipients frequently have or develop these complications. Elderly transplant recipients are commonly receiving anticoagulation therapy with warfarin and are at a higher risk of bleeding, especially if they have renal dysfunction. Infectious complications occur frequently in the transplanted population, with pneumonia being the most common infection seen in hospitalised patients. Attention to vaccination for the prevention of influenza and pneumococcal infections is important because of the increased risk of these diseases in this population. Depression itself has been associated with decreased survival in older individuals, and depression in elderly transplant recipients may be reversible with the administration of pharmacological agents. Effective long-term care of transplant recipients demands an understanding of how particular medications affect clinical evaluation and treatment. This article addresses some of the practical issues surrounding medication management and prevention of these particular problems in elderly transplant recipients.

Blood pressure evaluation among older living kidney donors

With more patients reaching end-stage renal disease, the demand for living kidney donation is increasing rapidly. Many potential donors are now in older age groups. The effects of increasing BP with age and the measurement criteria for hypertension in this group are not well defined. A total of 238 potential donors between 18 and 72 yr of age were prospectively studied, with a comparison of "clinic" BP values measured in the outpatient clinic with an oscillometric recorder (Dinamap; Critikon), ambulatory BP monitoring (ABPM) findings, and standardized BP values determined by nurses using American Heart Association criteria. Renal function was evaluated on the basis of iothalamate clearance (GFR) and urinary protein and microalbumin excretion. Ninety-six percent of subjects were Caucasian. All subjects exhibited normal GFR and urinary protein excretion. Three age groups were defined (group I, </=35 yr, n = 64; group II, 36 to 49 yr, n = 109; group III, >/= 50 yr, n = 65). BP increased with age, as determined with all methods. Subjects >/= 50 yr of age exhibited the highest clinic readings (145 +/- 2/83 +/- 1 mmHg, compared with 129 +/- 2/76 +/- 1 mmHg for group I, P < 0.01). Awake ABPM and nurse-determined BP measurements were lower than clinic readings, including those for group III (131 +/- 2/80 +/- 1 mmHg, compared with 145 +/- 2/83 +/- 1 mmHg in the clinic, P < 0.001). With the use of systolic BP values of >140 mmHg and/or diastolic BP values of >90 mmHg, 36.7% of subjects were initially considered hypertensive; this proportion decreased to 11% overall with awake ABPM findings (>135/85 mmHg). Measurement variability (SD in ABPM) and the effects of misclassification were greatest for donors >/= 50 yr of age. Multivariate regression indicated that GFR of both donors and recipients decreased with age, but regression identified no independent effect of BP. Recipient outcomes for up to 2 yr were equally good for donor kidneys considered normotensive or hypertensive on the basis of clinic BP measurements. These data indicate that higher arterial BP with age can lead to misclassification of many older living kidney donors. Sixty-two subjects with excellent kidney function were misclassified as hypertensive with clinic oscillometric measurements alone. Detailed evaluations of ABPM findings, GFR, and urinary protein levels are warranted for Caucasian subjects with high clinic BP readings who are otherwise suitable potential donors.

Increased expression of p16(INK4a) and p27(Kip1) cyclin-dependent kinase inhibitor genes in aging human kidney and chronic allograft nephropathy

BACKGROUND

The goal of the current study was to examine the potential value of p16(INK4a) and p27(Kip1) cyclin-dependent kinase inhibitor (CDKI) genes in the process of human kidney aging in vivo, and in the development of chronic allograft nephropathy (CAN).

METHODS

Expression of p16(INK4a) and p27(Kip1) CDKI genes was evaluated and compared in 20 normal human kidney tissues of different ages (range, 21 to 80 years) and in 9 chronically rejected kidney grafts. Age dependency of marker expression was analyzed by the Pearson correlation and linear regression.

RESULTS

Expression of p16 in cortical tubular (CTS) and interstitial (CIS) cells of normal kidney was age dependent (correlation coefficients: 0.608 and 0.726, 95% confidence interval [CI]: 0.227 to 0.828 and 0.417 to 0.884, respectively). Cortical tubular expression of p27 was also correlated with increasing age (0.672, 95% CI: 0.327 to 0.859). Linear regression analyses confirmed the linearity of marker relationship with age (coefficient of determination R(2):0.370, 0.452, and 0.527 for CIS p16, CTS p27, and CTS p16, respectively). The mean chronological and predicted graft ages (53 +/- 21 and 76 +/- 8.9 years, respectively) were significantly different (P = 0.0126). The glomeruli, tubules, and interstitial cells of rejected grafts expressed significantly higher levels of p16 and p27 than normal kidneys. Expression of p16 in glomerular and cortical interstitial cells was higher in grade 3 of CAN than in grade 2 (P = 0.013 and 0.004, respectively).

CONCLUSION

The results of the current study show that expression of p16(INK4a) and p27(Kip1) CDKI genes is increased in cortical cells of the aging human kidney and in chronic allograft rejection, supporting the senescence theory of CAN.

Dual-kidney transplants: long-term results

BACKGROUND

Dual-kidney transplantation, where two usually aged adult kidneys are placed into an adult recipient, is one way to help alleviate the continuing disparity between the number of patients on the kidney transplant waiting list and those who receive kidney transplants each year. The Dual Kidney Registry was developed to analyze donor and recipient data and outcomes at several centers.

METHODS

Two hundred eighty-seven patients who have undergone transplantation since 1994 have been entered into the relational database. The patients were followed yearly after initial entry into the database.

RESULTS

The mean donor age was 58+/-13 years and the mean terminal creatinine clearance was 77+/-40 mL/min. The mean glomerular sclerosis on procurement biopsy was 16+/-13%. Delayed graft function (DGF), defined as dialysis in the first 7 days after transplantation, was a predictor of poor outcome, and increased cold storage time was a predictor of DGF. The overall incidence of DGF was 27%. In recipients with prompt graft function (PGF), the mean cold storage time was 22+/-9 hr versus 29+/-10 hr in recipients with DGF (P<0.001). The overall 1- and 5-year graft survival was 86% and 69%, respectively. The 1- and 5-year graft survival rates were significantly better in recipients with PGF (90% and 74%) versus DGF (79% and 54%) (P<0.002).

CONCLUSIONS

Cold storage time and DGF have a significant impact on the 1- and 5-year graft survival in recipients of dual-kidney transplants. The 5-year graft survival in recipients of dual-kidney transplants is excellent.

Ischemia times and donor serum creatinine in relation to renal graft failure

BACKGROUND

The results of renal transplantation are dependent on many variables. To simplify the decision process related to a kidney offer, the authors wondered which variables had the most important influence on the graft failure risk.

METHODS

All transplant patients (n=1,124) between January 1981 and July 2000 were included in the analysis (2.6% had missing values). The variables included were donor and recipient age and gender, recipient original disease, race, donor origin, current smoking, cardiovascular disease, body weight, peak and current panel reactive antibody (PRA), number of preceding transplants, type and duration of renal replacement therapy, and time since failure of native kidneys. Also, human leukocyte antigen (HLA) identity or not, first and second warm and cold ischemia times, left or right kidney and fossa, donor kidney anatomy, donor serum creatinine and proteinuria, and transplantation year were included.

RESULTS

In a multivariate model, cold ischemia time and its time-dependent variable significantly influenced the graft failure risk censored for death (P<0.0001) independent of any of the other risk factors. The influence primarily affected the risk in the first week after transplantation; thereafter, it gradually disappeared during the first year after transplantation. Donor serum creatinine also significantly influenced the graft failure risk in a time-dependent manner (P<0.0001). The risk of a high donor serum creatinine is already enlarged in the immediate postoperative phase and increases thereafter; the curve is closely related to the degree of the elevation. The other variables with a significant influence on the graft failure rate were, in order of decreasing significance, recipient age, donor gender, donor age, HLA identity, transplantation year, preceding transplantations, donor origin, and peak PRA.

CONCLUSIONS

Donor serum creatinine and cold ischemia time are important time-dependent variables independently influencing the risk of graft failure censored for death. The best strategy for improving the results of cadaveric transplantations is to decrease the cold ischemia time and to allocate kidneys from donors with an elevated serum creatinine to low-risk recipients.

The relationship between donor age and cadaveric renal allograft survival is modified by the recipient's blood pressure

Increasing donor age correlates with reduced renal allograft survival. In this study we analyzed variables that may modify this relationship. The study included 1285 cadaveric kidney allograft recipients followed for 7.2 + 4.5 years. By Cox, increasing donor age beyond 30 years was associated with significant increases in the hazard ratio for graft loss [age 31-46, hazard ratio (HR) = 1.4, p = 0.02; 46-60, HR = 1.55, p = 0.008; > 60, HR = 1.68, p = 0.03]. Increasing donor age was significantly associated with: older and heavier recipients; higher creatinine and blood pressure (BP) 6 months post-transplant; and lower total cyclosporine dose during the first year. Of interest, the 6-month serum creatinine and the BP level modified significantly the relationship between age and survival. Thus, increasing donor age was significantly related to reduced graft survival only in patients with a 6-month creatinine < 2 mg/dL. Furthermore, donor age related significantly to graft survival only among patients with higher BP levels 6 month post transplant. It is concluded that increasing donor age is associated with reduced cadaveric graft survival, but that relationship is significantly modified by graft function and BP. These data suggest that poorly functioning kidneys have reduced survival irrespective of age. Furthermore, elevated BP levels may have a particularly negative effect on the survival of older grafts.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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