Donor age and delayed graft function as predictors of renal allograft survival in rejection-free patients

Sequential transplant of paired kidneys following donation after cardiac death: impact of longer cold ischemia time on the second kidney on graft and patient outcome

The United Kingdom has no national sharing scheme for kidneys received from donation after cardiac death (DCD). Therefore, both kidneys retrieved by a transplant team are implanted at a single unit, often sequentially. This study analyzes the impact of a prolonged cold ischaemia time on the second transplanted kidney and the effects on short-term and long-term outcomes in all our DCD renal implants from 2002 to 2009. Cold ischaemia time was significantly longer with the second kidney (P = .04) as was delayed graft function (P = .02). Acute rejection was increased in the first transplanted kidney (P < .001). Five-year patient survival was comparable between groups, but 5-year graft survival was higher in the second transplanted group (P = .04). The results confirm that, provided recipient centers are willing to accept higher initial rates of delayed graft function, it is acceptable to transplant DCD grafts sequentially without jeopardizing long-term graft or recipient outcome.

Identification of a gene expression profile associated with operational tolerance among a selected group of stable kidney transplant patients

Despite their utility, immunosuppressive treatments have numerous side effects, including infectious complications, malignancies and metabolic disorders, all of which contribute to long-term graft loss. In addition to the development of new pharmaceutical products with reduced toxicity and more comfortable modes of administration, tailoring immunosuppression according to the immune status of each patient would represent a significant breakthrough. Gene expression profiling has been shown to be a clinically relevant monitoring tool. In this paper, we have assessed the overall long-term kidney transplant outcome and attempted to identify operationally tolerant-like patients among recipients with stable clinical status at least 5 years post-transplantation. We thus measured a combination of noninvasive blood biomarkers of operational tolerance in a cohort of 144 stable patients and showed that only 3.5% exhibited a gene expression profile of operational tolerance, suggesting that such a profile can be detected under immunosuppressive therapy but that its frequency is low in kidney transplant recipients when compared with liver transplant recipients. We suggest that a rational approach to patient selection, based on a combination of clinical and biological characteristics, may help to provide a safer method for identification of patients potentially suitable for immunosuppressive drug weaning procedures.

Post-transplant nuclear renal scans correlate with renal injury biomarkers and early allograft outcomes

BACKGROUND

Clinical- and histopathology-based scores are limited predictors of allograft outcome. In addition, more objective markers of early transplant function are needed to identify and validate biomarkers and predictive scores. We evaluated existing scores and transcriptome biomarkers of kidney injury as predictors of early transplant function measured by renal scan.

METHODS

Clinical, histopathologic and transcriptome data were collected in 143 consecutive kidney transplant recipients. A post-operative renal scan was performed within 48 h. Prediction scores for early outcomes were calculated.

RESULTS

Patients were stratified into three groups by renal scan: normal, mild-to-moderate or severe dysfunction. Kidneys with severe dysfunction were more often from deceased donors (P < 0.001), had greater HLA antigen mismatches (P < 0.001), were transplanted into older recipients (P = 0.040), had lower urine output during the first 8 h (P < 0.001), higher Day 7 serum creatinine (P < 0.001) and higher incidence of delayed graft function (P < 0.001). Clinical- and pathology-based scores did not discriminate between scan groups. In contrast, the overall transcriptome (P < 0.001) and transcripts of preselected acute kidney injury (AKI) genes were significantly different between the groups, with kidney injury molecule 1 (P = 0.001) and neutrophil gelatinase-associated lipocalin (P = 0.002) being most highly expressed and genes associated with glutathione metabolism (GSTA1, 3 and 4) most down-regulated in kidneys with subsequent severe dysfunction.

CONCLUSIONS

Renal scans reflect early transplant function and allow for a more objective assessment of scores predicting early outcome and for identification of biomarkers. The study shows that transcript levels of AKI genes correlate better with renal scans than clinical- or histopathology-based scores.

Analysis of factors that affect outcome after transplantation of kidneys donated after cardiac death in the UK: a cohort study

BACKGROUND

A third of all kidneys from deceased donors in the UK are donated after cardiac death, but concerns have been raised about the long-term outcome of such transplants. We aimed to establish these outcomes for kidneys donated after controlled cardiac death versus brain death, and to identify the factors that affect graft survival and function.

METHODS

We used data from the UK transplant registry to select a cohort of deceased kidney donors and the corresponding transplant recipients (aged ≥18 years) for transplantations done between Jan 1, 2000, and Dec 31, 2007. Kaplan-Meier estimates were used to assess graft survival, and multivariate analyses were used to identify factors associated with graft survival and with long-term renal function, which was measured from estimated glomerular filtration rate (eGFR).

FINDINGS

9134 kidney transplants were done in 23 centres; 8289 kidneys were donated after brain death and 845 after controlled cardiac death. First-time recipients of kidneys from cardiac-death donors (n=739) or brain-death donors (n=6759) showed no difference in graft survival up to 5 years (hazard ratio 1·01, 95% CI 0·83 to 1·19, p=0·97), or in eGFR at 1-5 years after transplantation (at 12 months -0·36 mL/min per 1·73 m(2), 95% CI -2·00 to 1·27, p=0·66). For recipients of kidneys from cardiac-death donors, increasing age of donor and recipient, repeat transplantation, and cold ischaemic time of more than 12 h were associated with worse graft survival; grafts from cardiac-death donors that were poorly matched for HLA had an association with inferior outcome that was not significant, and delayed graft function and warm ischaemic time had no effect on outcome.

INTERPRETATION

Kidneys from controlled cardiac-death donors provide good graft survival and function up to 5 years in first-time recipients, and are equivalent to kidneys from brain-death donors. Allocation policy for kidneys from cardiac-death donors should reduce cold ischaemic time, avoid large age mismatches between donors and recipients, and restrict use of kidneys poorly matched for HLA in young recipients.

FUNDING

UK National Health Service Blood and Transplant, and Cambridge National Institute for Health Research Biomedical Research Centre.

Short-term and long-term effects of slow graft function on graft survival in pediatric live donor renal transplantation

SGF generally has early and long-term consequences for allograft survival. Limited studies have been performed on SGF and its complications in pediatric renal transplantation. Therefore, 230 children who received transplants between 1985 and 2005 in Labafi Nejad hospital were included in this study. SGF was defined if the serum creatinine level increased, remained unchanged, or decreased by <10% per day immediately after surgery during three consecutive days in the first week after transplantation. The children were divided into two groups: 183 children in group A (non-SGF) and 47 patients in group B (SGF). The impact of SGF on renal function within the first year, long-term graft survival and post-transplantation complications were analyzed and compared using logistic regression model and Kaplan-Meier survival analysis. The incidence of graft failure at the end of follow-up period was significantly more common in SGF group (53.2% vs. 22.4%, p < 0.001). The median survival time was 140.25 (s.e.m. = 19.35) months in group A (non-SGF) and 60 (s.e.m. = 17.90) months in group B (SGF) (p < 0.001). The graft survival rate was 94.9%, 91.9%, 83.9%, 79.2%, and 72% at one, three, five, seven, and twelve yr after transplantation in children without SGF vs. 75.6%, 53.2%, 47.2%, 40% at one, three, five, and seven yr after transplantation in patients with SGF. The results of our study showed that slow graft function could remarkably affect graft survival and worsen both short-term and long-term transplantation outcomes. Thus, the prevention of SGF is one of the most important issues in graft survival improvement.

Influence of donor age on renal graft function in first seven post transplant days

Increasing gap between demand and availability of human kidneys for transplantation has forced a re-evaluation of the limits on donor age acceptability. The present study included 74 patients who underwent kidney transplantation in University Clinical Centre Tuzla. In an observational cohort study we assessed impact of donor age on post transplant renal function by analyzing following parameters: 24 hour urine output, creatinine clearance (Cr Cl) and glomerular filtration rate (GFR). Depending on donor age recipients were allocated in to two groups. Group I included patients who received renal graft from donors age up to 55 years, and Group II encountered recipients who received renal graft from donors older than 55 years. Our goal was to determine whether donor age over 55 years significantly diminishes renal graft function in first seven post transplant days. No statistically significant difference was found between Group I and II regarding 24 hour urine output. From second to fifth postoperative day creatinine clearance values were higher in the group of patients who received kidney from donors older than 55 years (47+/-19, 1 vs. 44, 4+/-20, 8). On the fifth, sixth and seventh post operative day GFR was significantly higher in patients who received renal graft from donors age up to 55 years (p<0, 0161). Our data showed no significant difference in observed variables between the two groups, thus indicating that utilization of renal grafts from donors' age > 55 years is acceptable and may considerably expand the donor pool.

Single versus dual renal transplantation from donors with significant arteriosclerosis on pre-implant biopsy

BACKGROUND

Transplantation of kidneys from donor with arteriosclerosis seen on pre-implantation biopsy has not been well studied.

METHODS

We retrospectively evaluated 20 dual kidney transplant (DKT) and 28 single (SKT) kidney transplant recipients with >or=12 months follow-up from donors with moderate arteriosclerosis (>or=25% luminal diameter narrowing).

RESULTS

Death censored graft survival was 100% and 79%, respectively (p = 0.0339). DKT recipients had significantly lower mean creatinine levels at one, three, six, and nine months and spent somewhat less time on the waiting list (181 +/- 160 vs. 318 +/- 306 d, p = 0.1429). DKT patients received kidneys from significantly older donors (64 +/- 7 vs. 54 +/- 11 yr; p = 0.0012), proportionately more expanded criteria donors (95% vs. 54%; p = 0.0029), and more donors with hypertension (81% vs. 48%, p = 0.0344) and death related to cerebrovascular accident (100% vs. 71%, p = 0.0143); however, more DKT kidneys underwent machine perfusion (95% vs. 57%, p = 0.0068). Baseline recipient variables were comparable between the two groups including age, race, gender, retransplantation, and HLA mismatch. Pre-implant biopsy was notable for similar frequencies of moderate interstitial fibrosis (10% vs. 14%, respectively) and glomerulosclerosis.

CONCLUSION

Among recipients of deceased-donor kidneys with >25% arteriosclerosis, short-term outcomes after DKT were superior to that of SKT grafts. This approach may help to expand the donor-organ pool while optimizing outcomes.

Donor age and renal P-glycoprotein expression associate with chronic histological damage in renal allografts

The contributions of donor kidney quality (partially determined by donor age), allograft rejection, and calcineurin inhibitor nephrotoxicity on the progression of histologic damage of renal allografts are not completely defined. Moreover, the determinants of individual susceptibility to calcineurin inhibitor nephrotoxicity are not known but may include variability in drug transport and metabolism. In a prospective cohort of 252 adult renal allograft recipients treated with a combination of tacrolimus, mycophenolate mofetil, and corticosteroids, we studied 744 renal allograft biopsies obtained regularly from time of transplantation for 3 yr. We assessed determinants of histologic evolution, including tacrolimus exposure, renal P-glycoprotein (ABCB1) expression, and polymorphisms in the CYP3A4, CYP3A5, and ABCB1 genes. Within the first 3 yr after transplantation, we noted a progressive increase in interstitial fibrosis, tubular atrophy, glomerulosclerosis, and vascular intimal thickening. Older donor age, absence of P-glycoprotein expression at the apical membrane of tubular epithelial cells, and combined donor-recipient homozygosity for the C3435T variant in ABCB1 significantly associated with increased susceptibility to chronic allograft damage independent of graft quality at implantation. Changes in graft function over time reflected these associations with donor age and ABCB1 polymorphisms, but it was acute T cell-mediated and antibody-mediated rejection that determined early graft survival. In conclusion, the effects of older donor age reach beyond the quality of the allograft at implantation and continue to be important for histologic evolution in the posttransplantation period. In addition, ABCB1 genotype and expression of P-glycoprotein in renal tubular epithelial cells determine susceptibility to chronic tubulointerstitial damage of transplanted kidneys.

Fate of the mate: the influence of delayed graft function in renal transplantation on the mate recipient

Delayed graft function (DGF) in a deceased-donor renal recipient is associated with allograft dysfunction 1-year posttransplant. There is limited research about the influence to allograft function on the mate of a DGF recipient over time. Using a retrospective cohort design, we studied 55 recipients from a single center. The primary outcome was the change in glomerular filtration rate (GFR) 1-year posttransplant. The secondary outcome was the GFR at baseline. We found that mates to DGF recipients had a mean change in GFR 1-year posttransplant of -11.2 mL/min, while the control group had a mean change of -0.4 mL/min. The difference in the primary outcome was significant (p = 0.025) in a multivariate analysis, adjusting for cold ischemic time, panel reactive antibody level, allograft loss, human leukocyte antibody (HLA)-B mismatches and HLA-DR mismatches. No significant difference between groups was found in baseline GFR. In conclusion, mates to DGF recipients had a significantly larger decline in allograft function 1-year posttransplant compared to controls with similar renal function at baseline. We believe strategies that may preserve allograft function in these'at-risk'recipients should be developed and tested.

Acute rejection and chronic nephropathy: a systematic review of the literature

BACKGROUND

The risk of graft failure is the pivotal measure of effectiveness when evaluating immunosuppressive regimens for renal transplantation. However, to date most randomized trials of immunosuppressive therapy have had acute rejection as the primary endpoint for treatment comparisons. The objective here was to review the evidence relating acute rejection to renal graft function and graft survival.

METHODS

A systematic review of the published literature was undertaken. Studies were reviewed if they included the following: study populations of adults undergoing renal transplantation, endpoints of graft loss or survival, and quantitative data on the associations between acute rejection and graft function and survival.

RESULTS

Overall, 31 observational studies were included. The definition of acute rejection varied, and there was substantial heterogeneity in study design and methodology. In all but two studies, acute rejection was associated with an increased risk of graft loss-risk ratios ranged from 1.2 (no definition reported) to 10.5 (confirmed by biopsy and grade I Banff criteria). In addition, there was fairly strong evidence linking timing of acute rejection and graft survival and weaker evidence linking the number of episodes and graft survival. The heterogeneity between studies invalidated pooling of quantitative studies.

CONCLUSIONS

The weight of the evidence indicates that occurrence, timing, and number of acute rejection episodes are associated with increased risk of graft loss. Less is known about the severity of rejection, which is important because many immunosuppressive regimens lessen severity. Quantifying these relationships is a priority if acute rejection continues to be a surrogate trial endpoint.

Changes in the expression of the immunoglobulin-like transcript 3 (ILT3) and ILT4 receptors in renal allograft recipients: effect of donor and recipient aging

INTRODUCTION

The aim of the present study was to investigate the number and phenotype of pre- and posttransplant peripheral blood dendritic cells (DCs) in kidney graft recipients to correlate with CD4(+)CD25(high) Treg and CD8(+)CD28(-) cells. Data were analyzed according to the age of the donor-recipient pairs.

MATERIALS AND METHODS

A cohort of 49 cadaveric kidney transplant recipients was prospectively studied pretransplant and 6 months posttransplant by three-color flow cytometry with specific monoclonal antibodies. Patients were subgrouped according to age (elderly were considered above 60 years old and young below 55 years old) in the following donor-recipient pairs: aged/aged, young/aged, aged/young, young/young.

RESULTS

At 6 months posttransplant, the proportion of cells tended to increase when the donor was young, regardless of the recipient. Importantly, there was a significant correlation between the numbers of immunoglobulin-like transcript 4(+) DCs and CD4(+)CD25(high) Treg cells before transplantation (r = .476, P = .004) and at 6 months (r = .408, P = .013). A significant association was also observed between ILT4(+) DCs and CD8(+)CD28(-) pretransplant (r = .540, P = .001) and at 12 months posttransplant (r = .609, P = .012).

CONCLUSIONS

Renal grafts from young but not from aged donors seem to induce DC of a tolerogenic phenotype, both in aged and young recipients. These preliminary results suggested that donor age may have consequences in terms of tolerance induction.

Similar outcomes with different rates of delayed graft function may reflect center practice, not center performance

To better understand the implications for considering delayed graft function (DGF) as a performance measure, we compared outcomes associated with a 2- to 3-fold difference in the incidence of DGF at two transplant centers. We analyzed 5072 kidney transplantations between 1984 and 2006 at the University of Minnesota Medical Center (UMMC) and Hennepin County Medical Center (HCMC). In logistic regression the adjusted odds ratio for DGF at HCMC versus UMMC was 3.11 (95% Confidence Interval [CI]= 2.49-3.89) for deceased donors and 2.24 (CI = 1.45-3.47) for living donors. In Cox analysis of 4957 transplantations, slow graft function (SGF; creatinine >or=3.0 mg/dL [230 micromol/L] on day 5 without dialysis) was associated with graft failure at UMMC (Relative Risk [RR]= 1.43, CI = 1.25-1.64), but not HCMC (RR = 0.99, CI = 0.77-1.28). RR's of DGF were similar at both centers. Thus, the lower incidence of DGF at UMMC likely resulted in a higher incidence and higher risk of SGF compared to HCMC. Indeed, graft survival for recipients with DGF at HCMC was similar (p = 0.3741) to that of recipients with SGF at UMMC. We conclude that dialysis per se is likely not a cause of worse graft outcomes. A better definition is needed to measure early graft dysfunction and its effects across transplant programs.

Identification of the optimal donor quality scoring system and measure of early renal function in kidney transplantation

BACKGROUND

The early identification of kidney allografts at risk of later dysfunction has implications for clinical practice. Donor quality scoring systems (preoperative) and measures of early allograft function (first week postoperative) have previously shown practical utility. This study aimed to determine the optimal parameter(s) (preoperative and postoperative) with greatest predictive power for the development of subsequent allograft dysfunction.

METHODS

Consecutive deceased donor renal transplants (n=217) were studied. In each, the following measures were assessed: Preoperative donor quality scores: expanded criteria donor status; Deceased Donor Score (Nyberg et al., Am J Transplant 2003;3:715); Donor Risk Score (Schold et al., Am J Transplant 2005; 5(4 pt 1): 757); and delayed graft function (DGF) Nomogram (Irish et al., J Am Soc Nephrol 2003; 14: 2967). Postoperative early function measures: dialysis requirement and duration; extended DGF definition (Boom et al., Kidney Int 2000; 58: 859); creatinine at day 5 and day 7; creatinine reduction ratios at day 2 and day 7; and urine output posttransplantation. Primary outcome measures were creatinine at 12 months and the development of chronic kidney disease stage 4T.

RESULTS

Of donor scoring systems, Donor Risk Score was best associated with subsequent allograft function. Of early function measures: the extended definition of DGF, creatinine at day 5, and dialysis duration showed greatest predictive power in the patient population overall, those not requiring postoperative dialysis, and those requiring dialysis, respectively. No scores or early function measures were associated with change in creatinine between 6 and 12 months.

CONCLUSIONS

This study validates and identifies the optimal early predictive parameter available for kidney transplant recipients, with implications for refining early postoperative management and potential utility in organ allocation policy.

"Nature versus nurture" study of deceased-donor pairs in kidney transplantation

Donor characteristics such as age and cause of death influence the incidence of delayed graft function (DGF) and graft survival; however, the relative influence of donor characteristics ("nature") versus transplant center characteristics ("nurture") on deceased-donor kidney transplant outcomes is unknown. We examined the risks for DGF and allograft failure within 19,461 recipient pairs of the same donor's kidneys using data from the US Renal Data System. For the 11,894 common-donor pairs transplanted at different centers, a recipient was twice as likely to develop DGF when the recipient of the contralateral kidney developed DGF (odds ratio [OR] 2.05; 95% confidence interval [CI] 1.82 to 2.30). Similarly, for 7567 common-donor pairs transplanted at the same center, the OR for DGF was 3.02 (95% CI 2.62 to 3.48). For pairs transplanted at the same center, there was an additional 42% risk for DGF compared with pairs transplanted at different centers. After adjustment for DGF, the within-pair ORs for allograft failure by 1 yr were 1.92 (95% CI 1.33 to 2.77) and 1.77 (95% CI 1.25 to 2.52) for recipients who underwent transplantation at the same center and different centers, respectively. These data suggest that both unmeasured donor characteristics and transplant center characteristics contribute to the risk for DGF and that the former also contribute significantly to allograft failure.

Association between delayed graft function and allograft and patient survival: a systematic review and meta-analysis

BACKGROUND

Delayed graft function (DGF) is a common complication of renal transplantation. The short-term consequences of DGF are well known, but the long-term relationship between DGF and patient and graft survival is controversial in the published literature. We conducted a systematic review and meta-analysis to precisely estimate these relationships.

METHODS

We performed a literature search for original studies published through March 2007 pertaining to long-term (>6 months) outcomes of DGF. The primary outcome was graft survival. Secondary outcomes were patient survival, acute rejection and kidney function.

RESULTS

When compared to patients without DGF, patients with DGF had a 41% increased risk of graft loss (RR 1.41, 95% CI 1.27-1.56) at 3.2 years of follow-up. There was no significant relationship between DGF and patient survival at 5 years (RR 1.14, 95% CI 0.94-1.39). The mean creatinine in the non-DGF group was 1.6 mg/dl. Patients with DGF had a higher mean serum creatinine (0.66 mg/dl, 95% CI 0.57-0.74) compared to patients without DGF at 3.5 years of follow-up. DGF was associated with a 38% relative increase in the risk of acute rejection (RR 1.38, 95% CI 1.29-1.47).

CONCLUSION

The results of this meta-analysis emphasize and quantify the long-term detrimental association between DGF and important graft outcomes like graft survival, acute rejection and renal function. Efforts to prevent and treat DGF should be aggressively investigated in order to improve graft survival given the deficit in the number of kidney 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.

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

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

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.

Marked variation in the definition and diagnosis of delayed graft function: a systematic review

BACKGROUND

The term delayed graft function (DGF) is commonly used to describe the need for dialysis after receiving a kidney transplant. DGF increases morbidity after transplantation, prolongs hospitalization and may lead to premature graft failure. Various definitions of DGF are used in the literature without a uniformly accepted technique to identify DGF.

METHODS

We performed a systematic review of the literature to identify all of the different definitions and diagnostic techniques to identify DGF.

RESULTS

We identified 18 unique definitions for DGF and 10 diagnostic techniques to identify DGF.

CONCLUSIONS

The utilization of heterogeneous clinical criteria to define DGF has certain limitations. It will lead to delayed and sometimes inaccurate diagnosis of DGF. Hence a diagnostic test that identifies DGF reliably and early is necessary. Heterogeneity, in the definitions used for DGF, hinders the evolution of a diagnostic technique to identify DGF, which requires a gold standard definition. We are in need of a new definition that is uniformly accepted across the kidney transplant community. The new definition will be helpful in promoting better communication among transplant professionals and aids in comparing clinical studies of diagnostic techniques to identify DGF and thus may facilitate clinical trials of interventions for the treatment of DGF.

Trends in kidney transplantation in Australia and New Zealand, 1993-2004

BACKGROUND

We hypothesize that transplant outcome in Australia and New Zealand has improved despite more unfavorable transplant characteristics. Data from the Australia and New Zealand Dialysis and Transplant registry was used to examine this hypothesis.

METHODS

All adult kidney-only transplants from January 1993 to December 2004 in Australia or New Zealand were followed-up until death or December 2005. Outcomes were adjusted for covariates in multivariate models, with transplant year modeled as a continuous variable.

RESULTS

Altogether 6764 patients were included. There were proportionately more live donor and primary transplants, older donors and recipients, and higher recipient body mass index, waiting time, and human leukocyte antigen mismatch in recent cohorts. Death-censored graft loss decreased (adjusted hazard ratio: 0.92 [0.90-0.95] per year, P<0.001). This trend was seen at both 0-1 and 1-5 years posttransplant, and was mainly for immune-mediated graft losses. Patient survival improved only in New Zealand, and only for the first posttransplant year (adjusted odds ratio: 0.88 [0.82-0.95] per year, P=0.001). Cardiovascular deaths decreased while infection or cancer deaths were unchanged. Adjusted delayed graft function rates were unchanged. The acute rejection incidence at 6 months decreased (adjusted odds ratio: 0.88 [0.85-0.90] per year, P<0.001). One and 3-year graft function significantly improved, even after adjusting for rejection. All outcomes did not vary by expanded donor criteria status.

CONCLUSIONS

Graft survival and function have improved in recent years, but long-term patient survival remains unchanged. With longer follow-up, the improvement in rejection rates and graft function may lead to further improvements in long-term graft survival and potentially better patient survival.

Reduction of ischemia-reperfusion injury in the rat kidney by FTY720, a synthetic derivative of sphingosine

BACKGROUND

The current shortage of organ donors has led many centers to use marginal and nonheart-beating donors (NHBDs). Recent research has implicated the infiltration of lymphocytes as an important mediator of ischemia-reperfusion injury (IRI). FTY720 is an immunosuppressant that promotes lymphocyte sequestration into lymph nodes. The purpose of this study was to examine the potential for FTY720 to abrogate IRI when subjected to increasing ischemic times.

METHODS

Male Sprague-Dawley rats underwent bilateral flank incision with removal of the right kidney and clamping of the left hilum. Groups were divided into ischemia times of 45, 55, and 65min; each group was further divided into a control group (IRI only), IRI+FTY720 (1 mg/kg/d), and IRI+cyclosporine (15 mg/kg/d), n=4 per group.

RESULTS

Thre days after 45 min of ischemia, serum creatinine in the ischemia only (477+/-37 micromol/L) and cyclosporine groups (698+/-32 micromol/L) was significantly increased compared with the FTY720-treated animals (194+/-66 micromol/L). The beneficial effect of FTY720 was also observed at 55 and 65 min; indeed, FTY720-treated animals demonstrated signs of recovery from 65 min of ischemia whereas control and cyclosporine-treated animals required sacrifice between days 3 and 5. Treatment with FTY720 reduced renal damage assessed histologically and also reduced apoptosis and increased cell proliferation.

CONCLUSION

Treatment with FTY720 reduced IRI and prevented unrecoverable acute renal failure after significant ischemic injury. This study suggests that FTY720 may help improve the quality of grafts from NHBD and marginal donors by abrogating the IRI insult.

Living donor kidney transplantation: the effects of donor age and gender on short- and long-term outcomes

BACKGROUND

The influence of donor age and sex on acute rejection episodes and short- and long-term graft survival in living donor (LD) kidney transplantation has not been well characterized.

METHODS

This prospective cohort study includes 739 first time LD transplantations with median follow-up time of 55.1 months. Death censored graft survival according to donor age and sex was compared with Kaplan-Meier plots. Cox regression was performed to estimate the association between different risk factors and graft survival and acute rejection episodes.

RESULTS

Graft survival was not affected by donor age above 50 years as long as these recipients did not experience an early acute rejection episode. Acute rejection episodes increased in recipients of grafts from donors > or =65 years (P=0.009). Donor age > or =65, recipient age less than 50 years, human leukocyte antigen (HLA)-DR matching, and female donor gender were risk factors for early acute rejection episodes. In multivariate analysis donor age > or =65 years was a risk factor for graft loss in all time periods after transplantation. During the first 5 years after transplantation a steroid resistant rejection episode was an additional risk factor. More than 5 years after transplantation male donor gender was the only additional risk factor for graft loss.

CONCLUSION

These results support the continued use of older male and female living donors who meet carefully constructed medical criteria and who are highly motivated to donate. Furthermore, donor age seems to be a more important predictor of graft loss than donor sex.

Impact of donors aged 60 years or more on outcome after lung transplantation: results of an 11-year single-center experience

OBJECTIVE

We examined the outcome of lung transplantation with the use of donors aged 60 years or more.

METHODS

From May 1994 to May 2005, 467 lung transplants were performed at our institution. A total of 60 recipients received lungs from donors aged 60 years or more (range 60-77 years, median 65 years), whereas 407 recipients received lungs from younger donors (range 9-59, median 39 years).

RESULTS

A total of 48 patients (10%) died within 30 days of surgery: 10 (17%) in the older donor group versus 38 (9%) in the younger donor group (P = .08). The operative mortality varied with the underlying lung disease and was higher in recipients presenting with pulmonary hypertension and pulmonary fibrosis than with emphysema or cystic fibrosis. A total of 210 patients died after a median follow-up of 25 months (range 0-136 months). The overall 5- and 10-year survivals were 57% and 38%, respectively. However, the 10-year survival tended to be worse in the older donor group (16% vs 39% in the younger donor group, P = .07). Bronchiolitis obliterans syndrome was the predominant cause of death in recipients of older donors who survived for more than 90 days after surgery (11/17, 65% vs 45/132, 34% in recipients of younger donors surviving for >90 days after surgery, P = .01).

CONCLUSIONS

Given the lack of organ donors, lungs from donors aged 60 years or more should be considered for transplantation. However, the use of donors aged 60 years or more is associated with a lower 10-year survival, and bronchiolitis obliterans syndrome plays a significant role as the cause of late death.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Evaluation of the Effects of Ischemic Injury and Ureteral Obstruction on Delayed Graft Function in Cats After Renal Autotransplantation

OBJECTIVE

To determine the relative importance of ischemic injury to delayed graft function (DGF) in cats.

STUDY DESIGN

Experimental study.

ANIMALS

Six intact female cats.

METHODS

Cats had renal autograft transplantation without ureteral transection and reimplantation and a contralateral nephrectomy. Serum creatinine and blood urea nitrogen (BUN) concentrations were measured regularly and abdominal ultrasound was performed before surgery, the day after surgery and twice weekly thereafter. Ultrasound-guided renal biopsy was performed on day 7. Cats were euthanatized on day 21. Histology of the autograft, ureter, bladder, vascular anastomoses sites, and contralateral kidney were performed. Observations were compared with those from an historic group of research cats that had extravesicular ureteroneocystostomy and contralateral nephrectomy.

RESULTS

Five cats completed the study. Serum creatinine and BUN concentrations increased after surgery, peaking at 3.2+/-0.8 and 77.6+/-15.9 mg/dL, respectively, 1-2 days after surgery. Serum creatinine concentration returned to the reference interval by 6 days after surgery. BUN gradually decreased in all cats but did not return to the reference interval by study end. Serum creatinine and BUN concentrations were consistently lower but not significantly so (P=.29 and .56, respectively) compared with the historic ureteroneocystostomy group. No ultrasonographic abnormalities or renal biopsy histologic abnormalities were observed. At necropsy, 1 autograft had generalized interstitial fibrosis.

CONCLUSION

Harvesting the renal graft and the ischemia before revascularization causes impaired renal function after engraftment.

CLINICAL RELEVANCE

The process of harvesting and reimplanting the renal graft can contribute to DGF in cats, independent of ureteral obstruction.

Long-term outcome of renal transplantation from older donors

BACKGROUND

Long-term survival of kidney grafts from older donors is inferior to that of grafts from younger donors. We sought to determine whether selecting older kidneys according to their histologic characteristics before implantation would positively influence long-term outcome.

METHODS

In a prospective cohort study, we assessed outcomes among 62 patients who received one or two histologically evaluated kidneys from donors older than 60 years of age. These outcomes were compared with outcomes among 248 matched recipients of single kidney grafts that had not been histologically evaluated and were either from donors 60 years of age or younger (124 positive-reference recipients who, according to available data, were expected to have an optimal outcome) or from those older than 60 years (124 negative-reference recipients, expected to have a worse outcome). The primary end point was graft survival.

RESULTS

During a median period of 23 months, 4 recipients (6 percent) of histologically evaluated kidneys progressed to dialysis, as compared with 7 positive-reference recipients (6 percent) and 29 negative-reference recipients (23 percent). Graft survival in recipients of histologically evaluated kidneys did not differ significantly from that of grafts in positive-reference recipients but was superior to that of grafts in negative-reference recipients (hazard ratio for graft failure in the negative-reference recipients relative to the recipients of histologically evaluated kidneys, 3.68; 95 percent confidence interval, 1.29 to 10.52; P=0.02). The performance of preimplantation histologic evaluation predicted better survival both in the whole study group (P=0.02) and among recipients of kidneys from older donors (P=0.01).

CONCLUSIONS

The long-term survival of single or dual kidney grafts from donors older than 60 years of age is excellent, provided that the grafts are evaluated histologically before implantation. This approach may help to expand the donor-organ pool for kidney transplantation.

Pediatric renal transplantation: comparative study with renal transplantation in the adult population

PURPOSE

To retrospectively review our experience with pediatric renal transplantation and to compare the results with the adult population.

PATIENTS AND METHODS

Between January 1981 and August 2003, 74 renal transplants were performed in patients < or =18 years at the time of the transplant--the pediatric group versus 1153 patients in the adult group. We analyzed various risk factors for actuarial kidney graft and patient survivals using the Kaplan-Meier method.

RESULTS

Median ages were 13.8 +/- 3.5 and 42.6 +/- 2.4 years, respectively. There was no statistically significant difference in the human leukocyte antigen matching or immunosuppression. There was, however, a younger donor age and shorter ischemia time in the pediatric group. Overall, kidney transplant survival rates for patients < or =18 years at 1, 2, 5, and 10 years were 94.4%, 91.3%, 70.6%, and 58.2%, respectively, with no significant difference for patients older than 18 (91.2%, 89.3%, 78.8%, 60.5%, P = .4325). There was a significantly decreased graft survival in the adult group at 10 years when the donor age was over 60 years and when the ischemia time was > or =20 hours. The incidence of delayed graft function and the creatinine levels of functioning grafts did not differ between the two groups. During the follow-up, acute rejections were more frequent in the younger group. Patient survival in the pediatric group at 1, 2, 5, and 10 years was 98.6%, 98.8%, 98.6%, and 90.3%, respectively, significantly lower in the adult group (95.3%, 94.0%, 87.9%, 76.8%, P < .02).

CONCLUSIONS

Renal transplantation may be successfully performed in the pediatric patients with end-stage renal disease. Overall graft survival at 10 years did not differ significantly between the two groups. There is a higher incidence of acute rejections but longer patient survival in the pediatric population.

Effect of donor age on the outcome of living-related kidney transplantation

The study compared the results of kidney transplantation from living-related donors older and younger than 60 years. The 273 kidney graft recipients were divided into group 1 (115 recipients of older grafts) and group 2 (158 recipients of younger grafts). The frequency of acute rejection (AR) episodes was similar in both groups but slow graft function occurred more frequently in group 1. The frequency of chronic renal allograft dysfunction in the first post-transplant year was significantly higher in group 1 than in group 2. Patient and graft survival was significantly worse in group 1. Risk factors for graft loss were the difference between donor and recipient age and AR. Donor age and graft function were risk factors for patient death. Although kidneys from older donors provide a statistically poorer transplant outcome, they are clinically acceptable, especially when waiting time is prolonged and access to dialysis limited.

The advanced age deceased kidney donor: current outcomes and future opportunities

BACKGROUND

Due to the aging general population, deceased donors > or =55 years will form an increasingly larger proportion of the deceased kidney donor pool.

METHODS

Using data from the United States Renal Data System, we determined the change in graft survival between 1996 and 2000 among 32,557 recipients of donors aged <55 years and > or =55 years in univariate and multivariate survival analyses. We identified donor risk factors for graft loss that might influence the decision to accept or reject donors <55 and > or =55 years. The initial glomerular filtration rate established 6 months after transplantation (initial GFR), and the stability of GFR in the first post-transplant year (GFR at 12 months post-transplantation-GFR at six months post-transplantation) were compared between recipients of donors <55 and > or =55 years and the association of these factors with graft survival was determined.

RESULTS

In 2000, one-year graft survival in donors > or =55 years was 86.7%. Between 1996 and 1999 the projected graft half life improved from 11.4 to 14.5 years for recipients of donors <55 years (P < 0.01); however, there was no improvement for recipients of donors > or =55 years (8.2 to 9.2 year, P= 0.46). Among donor factors studied, only cold ischemic time >24 hours identified recipients of donors > or =55 years at risk for graft loss. Compared to recipients of donors <55 years, recipients of donors > or =55 years established a lower initial GFR (42 vs. 56 mL/min/1.73 m(2), P < 0.0001), and had less stable GFR in the first post-transplant year (-1.5 vs. -0.6 mL/min/1.73 m(2), P <.0001). Recipients from donors > or =55 years with initial GFR > or =50 mL/min/1.73 m(2) and no drop GFR during the first post-transplant year had graft survival that was superior to that of donors <55 years with either initial GFR <50 mL/min/1.73 m(2) or a drop in GFR during the first post-transplant year.

CONCLUSION

Donors > or =55 years are a valuable resource. Despite improvements in immunosuppression, rejection, and delayed graft function, the projected increase in long-term graft survival among recipients of donors <55 years was not shared among recipients of donors > or =55 years. Recipients of donors > or =55 years had lower initial GFR, and less stable GFR during the first post-transplant year. Limiting cold ischemic time to <24 hours may improve outcomes among recipients of donors > or =55 years. Future studies to maximize initial GFR and minimize early loss of GFR in recipients of donors > or =55 years may lead to improved outcomes from deceased donors > or =55 years.

H-NMR-based metabolic signatures of mild and severe ischemia/reperfusion injury in rat kidney transplants

BACKGROUND

Severe ischemia/reperfusion (IR) injury is a risk factor for delayed graft function. Delayed graft function remains difficult to predict, and it currently relies primarily on serum creatinine (SCr), urine output, and occasionally on graft biopsy. (1)H-NMR (nuclear magnetic resonance spectroscopy) based metabolomics was used to establish IR-specific metabolic markers in both blood and kidney tissue. These markers were compared to SCr and graft histology.

METHODS

Male Lewis rats were used for kidney transplantation. Two cold ischemia (CI) groups (24- and 42-hour) and two transplantation groups [after 24 (TX24) and after 42 hours (TX42) of CI] were compared to a control group. Whole blood and kidney tissue were collected for further analysis.

RESULTS

SCr levels taken 24 hours after transplantation were 1.6 +/- 0.12 mg/dL (TX24) and 2.1 +/- 0.5 mg/dL (TX42), (P= n.s.). Histology samples revealed mild injury in the TX24 group and severe injury in the TX42 group. A significantly decreased level of polyunsaturated fatty acids (PUFA) and elevated levels of allantoin, a marker of oxidative stress, was found in the renal tissue. In the blood, both trimethylamine-N-oxide (TMAO), a marker of renal medullary injury, and allantoin were significantly increased. Allantoin levels were low in both the control and CI groups. Levels were significantly increased after reperfusion (control 0.02 +/- 0.03 micromol/mL, TX24 1.13 +/- 0.22, and TX42 1.89 +/- 0.38, P < 0.001), and correlated with cold ischemia time (r= 0.96) and TMAO (r= 0.94).

CONCLUSION

The (1)H-NMR metabolic profiles of both the mild and severe IR groups revealed significant changes consistent with graft histology, while the SCr did not.

Negative impact of 'old-to-old' donations on success of cadaveric renal transplants

The effect of 'old-to-old' cadaveric renal transplants on operative complications and graft survival was assessed in all 325 patients undergoing solitary cadaveric renal transplantations in Israel during a 3-yr period. Preoperative information and hospital course data were abstracted from the charts. Results were analyzed using Kaplan-Meyer survival curves, univariate and multivariate Cox models. Overall, 62 (19.1%) grafts failed within a year. Failure rate was 46.2% for 'old-to-old' transplants compared with 15.5% for all other donor/recipient age combinations (p < 0.0001). 'Old-to-old' transplants remained independently associated with graft failure in a multivariate Cox model after controlling the effect of other risk factors. 'Old-to-old' transplants were also associated with increased operative complications relative to other age combinations. The decision to use 'old-to-old' transplants, even when donors are scarce, is problematic and should be reconsidered.

A comparison of long-term graft survival rates between the first and second donor kidney transplanted--the effect of a longer cold ischaemic time for the second kidney

Prolonged cold ischaemic time (CIT) is associated with delayed initial graft function and may also have a negative impact on long-term graft outcome. We carried out a study comparing the long-term graft survival rates between those recipients who received the first of a pair of donor kidneys versus the recipient of the second graft. Adult kidney transplant recipients who received one of a pair of donor kidneys at our institution between 1989-1995 were included. All recipients received a cyclosporin based immunosupression regimen. Graft survival rates were compared between the 2 groups at 1-, 3-, 5- and 10-year intervals. A total of 520 renal transplant grafts were included in this study. Mean donor age was 35.4 years. Groups were similar for recipient age, gender, number of HLA mismatches, transplant number for that patient and percentage PRA. CIT was the only variable that was significantly different between the two groups; mean of 19.93 h in the first group compared to 25.65 h in the second group. Graft survival rates for the first kidney were significantly better than the second kidney-graft survival at 1 year 88.5% versus 84.7%, at 3 years 81.8% versus 76.7%, at 5 years 72.2% versus 64.9% and at 10 years 55.2% versus 40% (p = 0.012). Patient survival rates were similar in both groups. In our experience, the long-term graft survival rates are significantly better for the first kidney transplanted compared to the second kidney.

The Impact of Age on Rejection in Kidney Transplantation

The time to failure of a renal allograft is determined by the initial function achieved after transplantation, the number and severity of insults to the graft, and a number of tissue characteristics. The insults a graft usually encounters include ischaemia/reperfusion injury, acute rejection episodes, drug-related nephrotoxicity, hypertension and hyperlipidaemia. Important tissue characteristics include susceptibility to injury and the ability of the tissue to repair damage. Elderly transplant recipients are considered poor immune responders but if a single acute rejection episode occurs this is more likely to significantly shorten graft and patient survival in this age group. Two issues have been identified with the use of old (>50 years of age) donor kidneys. First, compared with kidneys from younger donors, they have an increased incidence of acute interstitial rejection. Secondly, once a rejection episode occurs, the ability to mount a tissue repair process seems impaired. An explanation for the increased loss of grafts from old donors that have experienced acute rejection episodes is that such kidneys have fewer nephrons that function adequately and that the cumulated effect of damage results in an earlier demise of the graft compared with younger donor kidneys. Alternatively, graft parenchymal cells may undergo premature senescence or aging as a result of multiple injuries and repair. If progressive loss of renal mass or senescence is the mechanism responsible for increased graft loss, then it is expected that grafts from older donors will show a progressive decrease in function over time and that the rate of decline of function will correlate with donor age. We have suggested that increased graft loss of older donor kidneys results from increased incidence of acute rejection episodes in the early post-transplantation months together with a partly impaired ability to repair the tissue. Drug pharmacokinetic parameters are generally little influenced by age. However, the degree to which drugs suppress the immune system, and the extent to which kidneys from older donors are susceptible to the nephrotoxic effects of certain drugs, are unpredictable. There appears to be a more delicate balance between adequate immunosuppression and excess nonimmune toxicity in patients receiving older kidneys. Outcome parameters in elderly renal transplant recipients are currently dominated by increased death from infectious disease and drug-related (cardiovascular) causes. Increased susceptibility to nephrotoxic drugs, and to calcineurin inhibitors in particular, may be related to the increased risk of allograft failure experienced by the elderly as a surrogate for chronic allograft nephropathy.

Delayed graft function: risk factors, consequences and parameters affecting outcome-results from MOST, A Multinational Observational Study

BACKGROUND

Delayed graft function (DGF) is a common complication after renal transplantation, and may affect graft function. The aim of this analysis was to evaluate risk factors for DGF, as well as parameters and events influencing graft function after DGF. We analyzed data collected in an ongoing international, prospective; observational study, the Neoral-MOST (Multinational Observational Study in renal Transplantation), and included in the analysis all patients with cadaveric kidney transplants for whom renal function at 1 year posttransplantation was documented (N = 8950). Logistic regression was used to evaluate the risk factors for DGF occurrence, and multifactorial analysis of variance (ANCOVA) to assess the relevance of different factors for GFR at 1 year.

RESULTS

Higher donor age, longer CIT, male recipients, Caucasian recipients, high recipients body mass index, and PRA were all associated with a higher risk for DGF. Renal function of former DGF kidneys at 1 year was lower in kidneys of elder donors, or which had experienced rejection or CMV infection. Variations of the maintenance regimen at 1 year posttransplantation were not associated with better graft function. Multifactorial analysis showed donor age and acute rejection as significant independent factors.

CONCLUSIONS

Most factors increasing the risk for DGF or having a negative impact on renal function at 1 year in grafts with DGF are predetermined. Additional posttransplant damage by acute rejection was associated with further reductions in GFR. Preventing acute rejection is an important step in achieving optimal function of DGF grafts.

Factors associated with primary and secondary graft failure following cadaveric kidney transplant*

The risk profile for primary renal graft failure is largely unknown because of its inclusion with secondary failures or its exclusion from analysis. This study compares characteristics of the cadaveric transplant recipients who experienced primary failure, secondary failures or survived with a functioning graft for at least 6 months. Medical records of all cadaveric kidney-transplant patients performed in Israel over a 3-yr period 1997-2000 were reviewed. Fisher's exact test and multinomial regression models were used to assess the association of demographic, pre-operative and operative risk factors with the two types of failure outcomes. Of 325 grafts, 54 (16.6%) failed of which half were primary failures. Univariate analysis demonstrated a significant trend of increasing proportion of patients with specific risk factors from the functioning grafts group to the secondary and to the primary graft failure groups. Independent risk factors for primary graft failure included 'surgical complications', 'donor's age > or =60 yr', 'waiting for transplant > or =6 yr', and 'human leukocyte antigen-DR (HLA-DR) mismatch', based on the multivariate model. These factors may reflect the scarcity of organ donations in Israel, which leads to a prolonged waiting time, higher tolerance for HLA-DR mismatches, and utilization of kidneys from elderly donors.

Patient and graft outcomes from older living kidney donors are similar to those from younger donors despite lower GFR

BACKGROUND

Donor age adversely affects deceased-donor kidney transplant outcomes, but its influence on living-donor transplantation is less well characterized.

METHODS

Living-donor kidney transplants at a single center between 1998 and 2000 were reviewed. Data were abstracted for 52 transplants from donors aged > or =50 years and for a matched group of 104 transplants from donors aged <50 years. Survival indices were compared during the first three years' post-transplantation. Functional indices, including serial iothalamate clearances, were compared at 1, 12, and 24 months.

RESULTS

Predonation glomerular filtration rate (GFR) was lower among older donors (94 +/- 12 vs. 108 +/- 17 mL/min/SA) but post-transplant compensatory hypertrophy was similar (11.7 +/- 26.3% vs. 7.7 +/- 31.4%). Recipients of older-donor grafts were older (52.8 +/- 16.5 vs. 46.1 +/- 15.1 years) and more frequently unrelated to the donor (54% vs. 39%). Trends toward higher frequency of slow graft function, cytomegalovirus (CMV) infection, and polyomavirus nephropathy were observed for older-donor grafts. Three-year recipient, graft, and death-censored graft survivals were > or =90% for both groups. At 1, 12, and 24 months, serum creatinine was higher and GFR was lower among recipients of older- compared with younger-donor grafts. Other functional indices (urine total protein, serum potassium and uric acid, hemoglobin, and number of antihypertensives) were not different. Donor age correlated with graft GFR at 1, 12, and 24 months for the entire study cohort by linear regression.

CONCLUSION

Older donor age does not preclude excellent results from living-donor kidney transplantation but should be appreciated as being associated with relatively lower GFR.

Impact of donor dopamine on immediate graft function after kidney transplantation

Optimizing medical donor management may have a considerable impact on transplantation outcome. This study investigated the effect of donor dopamine on initial graft function in renal allograft recipients, involving 254 consecutive recipients of a cadaver kidney, aged 18-74 years, transplanted between 1990 and 2003. Immunosuppression was based on cyclosporine. Patients were grouped according to donor use of dopamine during intensive care. Delayed graft function (DGF), and serial creatinine concentrations were compared between the groups. Dopamine-treated and -untreated donors were very similar regarding hemodynamics and renal function. Delayed graft function occurred in 47/158 treated and 48/96 untreated kidneys (p = 0.001). Donor dopamine was associated with a more rapid decrease of s-creatinine, which became obvious on the first postoperative day. Of patients in the treated and untreated group, respectively, 81.9% and 65.8% reached a s-creatinine level less than 2 mg/dL during the first month (p = 0.005). Donor dopamine remained predictive of a normalized s-creatinine level [HR 1.71; 95% CI 1.22-2.41] after controlling for confounding factors by multivariate Cox regression. Donor dopamine is associated with improvements of initial graft function after kidney transplantation. The beneficial effect of dopamine is achievable without side-effects for the recipients, and correlates with superior long-term graft survival.