Adverse effect of donor arteriolosclerosis on graft outcome after renal transplantation

Arteriolar hyalinization at 0-hour biopsy predicts long-term graft function in deceased kidney transplantation

OBJECTIVES

Regarding the relationship between donor kidney quality and renal graft function after deceased kidney transplantation (KTx) following donation after cardiac death (DCD), the evaluation timing varies depending on the study. Evaluation of histology and changes in long-term renal graft function is limited.

METHODS

A retrospective single-center study included 71 recipients who underwent 0-hour biopsy for KTx from DCD. The recipients were divided into two groups to evaluate factors related to renal graft function (study1). The two groups were categorized as stable graft function and poor graft function with the change of estimated glomerular filtration rate (eGFR) after KTx. The recipients were then divided into four groups to assess whether the factors identified in study1 were related to the change in long-term renal graft function (study2). They were categorized as follows: Improved, Stable, Deteriorated, and Primary non-function with the change of eGFR after KTx.

RESULTS

In study1, donor age ≥ 50 years (29.5% vs. 65.2%; p = 0.09), banff arteriolar hyalinosis (ah) score (0.66 ± 0.78 vs. 1.2 ± 1.0; p = 0.018), and presence of glomerulosclerosis (43.2% vs. 76.2%; p = 0.017) were significant risk factors for poor long-term graft function. When the recipients were divided into four groups, the severity of ah correlated well with changes in long-term renal function.

CONCLUSIONS

We can predict the shift in long-term renal graft function after KTx from DCD according to the severity of ah by 0-hour biopsy.

Abnormal time-zero histology is predictive of kidney transplant outcomes

Time-zero biopsies can detect donor-derived lesions at the time of kidney transplantation, but their utility in predicting long-term outcomes is unclear under the updated Kidney Allocation System. We conducted a single-center retrospective cohort study of 272 consecutive post-reperfusion time-zero biopsies. We tested the hypothesis that abnormal time-zero histology is a strong indicator of donor quality that increases the precision of the kidney donor profile index (KDPI) score to predict long-term outcomes. We detected abnormal biopsies in 42% of the cohort, which were independently associated with a 1.2-fold increased hazard for a composite of acute rejection, allograft failure, and death after adjusting for clinical characteristics including KDPI. By Kaplan-Meier analysis, the relationship between abnormal time-zero histology and the composite endpoint was only significant in the subgroup of deceased donor kidney transplants with KDPI scores > 35. Abnormal time-zero histology, particularly vascular intimal fibrosis and arteriolar hyalinosis scores, was independently associated with lower 12-month estimated GFR. In conclusion, abnormal time-zero histology is relatively common and identifies a group of kidney recipients at increased risk for worse long-term outcomes. Further studies are needed to determine the optimal patient population in which to deploy time-zero biopsies as an additional surveillance tool. This article is protected by copyright. All rights reserved.

Impact of the explanting surgeon's impression of donor arteriosclerosis on outcome of kidney transplantations from donors aged ≥65 years

PURPOSE

Careful donor selection is important for kidney transplantations (KT) from suboptimal donors aged ≥65 years. Several tools such as histopathological assessment of preimplant biopsies have been shown to predict allograft survival and can be applied for selection. Whether the explanting surgeon's appraisal is associated with outcomes of KTs from suboptimal donors is unknown.

METHODS

We compared outcomes of KTs from ≥65-year-old deceased donors performed at our centre between 1999 and 2018 for which grading of macroscopic 'donor arteriosclerosis' (n=104) and 'organ quality' (n=208) as judged by the explanting surgeon and documented on the Eurotransplant kidney organ report was available.

RESULTS

No association was observed between degree of macroscopic donor arteriosclerosis and death-censored graft survival in univariable or multivariable regression analyses. Compared to KTs from donors with no/mild arteriosclerosis, KTs from donors with moderate/severe arteriosclerosis were associated with a significantly impaired allograft function 3 months, 1 year and 3 years after transplantation (e.g. at 3 years: 176.8 µmol/l vs 137.0 µmol/l, P=0.003). Following multivariable regression analysis, these differences remained significant at 3 months and 3 years after KT. No association was observed between degree of macroscopic arteriosclerosis and mortality or primary non-function as well as no consistent association with delayed graft function and histological arteriosclerosis. Assessment of 'organ quality' was not associated with outcomes.

CONCLUSION

Our data suggest that the explanting surgeon's assessment of donor arteriosclerosis is associated with allograft function. Larger studies and better standardization of kidney inspection after explantation are required to further explore the impact of surgeon's appraisal in KT.

Arterial Intimal Fibrosis in Reperfusion Biopsy Correlates with Graft Function after Kidney Transplant

INTRODUCTION

Alterations to the procurement biopsy are one of the main reasons that kidneys are not suitable for transplant and are discarded. The literature on procurement and reperfusion biopsy is inconsistent and heterogeneous. The objective of this study is to describe the correlation of the different histological characteristics detected by the procurement and reperfusion biopsies in relation to graft function.

METHODS

This is a retrospective cohort study of deceased donor kidney transplants performed from 2013 to 2017. All of the different histological components of procurement and reperfusion biopsies were analyzed with nonparametric tests and multivariate regressions. Graft function was expressed as glomerular filtration rate (GFR) at 1, 3, 6, and 12 months after transplant. All tests were based on a level of significance of α = 0.05.

RESULTS

A comparison of procurement and reperfusion biopsies revealed that 60.4% of the grafts exhibited more arterial intimal fibrosis and 55.6% more arteriolar hyalinosis in the reperfusion biopsy than in the procurement biopsy. Arterial intimal fibrosis in reperfusion biopsy correlated with GFR at all time points, and it was the only histological characteristic of the reperfusion biopsy that remained significant in multivariate analysis. Glomerulosclerosis in the procurement biopsy correlated with graft function and remained significant in multivariate analysis, but only at 6 months. Arterial intimal fibrosis in the reperfusion biopsy is significantly associated with graft function independently of clinical characteristics.

CONCLUSION

Our study highlights the importance of arterial intimal fibrosis in predicting kidney function after transplant. Because arterial intimal fibrosis is a chronic change not related to ischemia-reperfusion injury, the differences between the 2 biopsies may be due to the biopsy technique. In order to increase the prognostic accuracy of the procurement biopsy, the technique should be improved to better evaluate the vasculature.

Human kidney graft survival correlates with structural parameters in baseline biopsies: a quantitative observational cohort study with more than 14 years' follow-up

This prospective cohort study evaluates associations between structural and ultrastructural parameters in baseline biopsies from human kidney transplants and long-term graft survival after more than 14 years' follow-up. Baseline kidney graft biopsies were obtained prospectively from 54 consecutive patients receiving a kidney transplant at a single institution. Quantitative measurements were performed on the baseline biopsies by computer-assisted light microscopy and electron microscopy. Stereology-based techniques estimated the fraction of interstitial tissue, the volume of glomeruli, mesangial fraction, and basement membrane thickness of glomerular capillaries. The fraction of occluded glomeruli and scores according to the Banff classification were achieved. Kidney graft survival was analyzed by Kaplan-Meier estimates and Cox regression. Association to long-term kidney function was also analyzed. The long-term surviving kidney transplants were characterized at implantation by less arteriolar hyaline thickening (P < 0.001) and less interstitial fibrosis (P = 0.001), as well as a lower fraction of occluded glomeruli (P = 0.004) and lower glomerular volume (P = 0.03). At the latest follow-up, eGFR was decreased by 12 ml/min/1.73 m² per unit increase in the score for arteriolar hyalinosis at implantation (P = 0.02), and eGFR was decreased by 19 ml/min/1.73 m² per 10⁶ μm³ increase in glomerular volume at baseline (P = 0.03). The unbiased Cavalieri estimate of glomerular volume and the ultrastructural parameters are the first to be evaluated in a cohort study with prospective follow-up for more than 14 years. The study shows that baseline biopsies from human kidney grafts contain extraordinary long-term prognostic information, and it highlights the importance of these intrinsic graft factors.

Strategies for an Expanded Use of Kidneys From Elderly Donors

The old-for-old allocation policy used for kidney transplantation (KT) has confirmed the survival benefit compared to remaining listed on dialysis. Shortage of standard donors has stimulated the development of strategies aimed to expand acceptance criteria, particularly of kidneys from elderly donors. We have systematically reviewed the literature on those different strategies. In addition to the review of outcomes of expanded criteria donor or advanced age kidneys, we assessed the value of the Kidney Donor Profile Index policy, preimplantation biopsy, dual KT, machine perfusion and special immunosuppressive protocols. Survival and functional outcomes achieved with expanded criteria donor, high Kidney Donor Profile Index or advanced age kidneys are poorer than those with standard ones. Outcomes using advanced age brain-dead or cardiac-dead donor kidneys are similar. Preimplantation biopsies and related scores have been useful to predict function, but their applicability to transplant or refuse a kidney graft has probably been overestimated. Machine perfusion techniques have decreased delayed graft function and could improve graft survival. Investing 2 kidneys in 1 recipient does not make sense when a single KT would be enough, particularly in elderly recipients. Tailored immunosuppression when transplanting an old kidney may be useful, but no formal trials are available.Old donors constitute an enormous source of useful kidneys, but their retrieval in many countries is infrequent. The assumption of limited but precious functional expectancy for an old kidney and substantial reduction of discard rates should be generalized to mitigate these limitations.

Banff Histopathological Consensus Criteria for Preimplantation Kidney Biopsies

The Banff working group on preimplantation biopsy was established to develop consensus criteria (best practice guidelines) for the interpretation of preimplantation kidney biopsies. Digitally scanned slides were used (i) to evaluate interobserver variability of histopathologic findings, comparing frozen sections with formalin-fixed, paraffin-embedded tissue of wedge and needle core biopsies, and (ii) to correlate consensus histopathologic findings with graft outcome in a cohort of biopsies from international medical centers. Intraclass correlations (ICCs) and univariable and multivariable statistical analyses were performed. Good to fair reproducibility was observed in semiquantitative scores for percentage of glomerulosclerosis, arterial intimal fibrosis and interstitial fibrosis on frozen wedge biopsies. Evaluation of frozen wedge and core biopsies was comparable for number of glomeruli, but needle biopsies showed worse ICCs for glomerulosclerosis, interstitial fibrosis and tubular atrophy. A consensus evaluation form is provided to help standardize the reporting of histopathologic lesions in donor biopsies. It should be recognized that histologic parameters may not correlate with graft outcome in studies based on organs deemed to be acceptable after careful clinical assessment. Significant limitations remain in the assessment of implantation biopsies.

Wedge Versus Core Biopsy at Time Zero: Which Provides Better Predictive Value for Delayed Graft Function With the Remuzzi Histological Scoring System?

BACKGROUND

Histopathological features on time-zero renal biopsies correlate with graft outcome after renal transplantation. With increasing numbers of marginal donors, assessment of pre-implantation graft quality is essential. The clinician's choice of wedge or core biopsy is performed without evidence of efficacy or safety. This study aims to compare the information derived from wedge biopsy versus core biopsy.

METHODS

Prospective evaluation of 37 wedge biopsies and 30 core biopsies was performed. Histopathological data were collected on number of glomeruli and arterioles observed, and Remuzzi scoring for glomerulosclerosis, tubular atrophy, interstitial fibrosis, and arteriolar narrowing was performed. Clinical data on delayed graft function (DGF) were also collated. Sensitivity, specificity, and positive and negative predictive values for DGF were compared.

RESULTS

Patient demographics between the two cohorts were comparable. No complications of biopsies occurred; 81% of wedge biopsies versus 50% of core biopsies had >10 glomeruli (P = .01), whereas 32% of wedge biopsies and 57% of core biopsies had >2 arterioles (P = .02). Wedge biopsies were more likely to identify pathology with more glomerulosclerosis, tubular atrophy (P < .01), and interstitial fibrosis (P < .01). There was a non-significant trend toward high Remuzzi scores in wedge biopsy (22% versus 7% with Remuzzi ≥ 4; P = .12). The sensitivity and positive predictive value of Remuzzi ≥ 4 for predicting DGF was better on wedge biopsy (45.5% versus 0%; P < .01 and 62.5% versus 0%; P < .01, respectively).

CONCLUSIONS

Wedge biopsies were safe and superior to core biopsies for identifying clinically significant histopathological findings on pre-implantation renal biopsy. We believe that the wedge biopsy is the method of choice for time-zero biopsies.

Donor Kidney Evaluation

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

Donor acute kidney injury and short-term graft outcome in renal transplantation

BACKGROUND

With increased waiting times for kidney transplantation, marginal organs from expanded criteria donors (ECD) are increasingly offered for allocation. In addition to ECD status, donors may have suffered from acute kidney injury (AKI) prior to organ procurement.

METHODS

In this retrospective cohort study, we studied short-term allograft function in 517 kidney transplants performed between the years 2008-2014. Recipients of allografts from deceased organ donors were categorized as standard criteria donors (SCD) or ECD with or without AKI defined by RIFLE criteria.

RESULTS

Of 382 deceased donations, 174 (45.5%) were classified as ECD and 63 (16.5%) fulfilled AKI criteria. Donor creatinine on hospital admission was similar, whereas creatinine before organ procurement differed (p < 0.001). Despite these differences, serum creatinine and eGFR at discharge and after one yr showed only minor differences between kidneys with or without AKI. In multivariate linear regression analyses, donor AKI was not a predictor of one-yr allograft function.

CONCLUSIONS

Given the poor prognosis of dialysis patients and the increase in waiting time, kidneys from SCD and ECD donors with AKI should be allocated for transplantation. In case of ECD donors with AKI, recipients should be informed about the possibility of permanent non-function or early graft loss.

Correlation between dual kidney biopsy in expanded-criteria donors and transplant survival

OBJECTIVE

The aim was to study the relation between same-donor renal biopsies and analyze whether the score influences graft survival.

METHODS

We retrospectively reviewed histologic results of expanded-criteria donors and the graft survival in patients followed at Reina Sofia Hospital (Cordoba, Spain) from January 2004 to October 2012. We analyzed clinical and demographic variables from the donors, as well the association between the scores of same-donor biopsies who had different scores for each kidney and the graft survival with a t test for paired data. A Kaplan-Meier with log-rank test was performed between the higher-score and the lower-score groups. We excluded retransplantation and those who received a combined transplantation (liver or pancreas).

RESULTS

We analyzed 168 kidneys that had been biopsied, from 84 donors. Of the whole sample, 35.7% (n = 30) had the same score for each kidney, whereas 64.3% (n = 54) had discrepancies. In this second group, 81.8% (n = 44) had a difference of 1 point, and the remaining 18.2% (n = 10) had a larger difference. Both kidneys were suitable for transplantation in 72.7% of cases (n = 40), only 1 in 14.5% (n = 8), and none in 12.7% (n = 7). For analyzing the survival of the paired kidneys there were 48 kidneys from 24 donors with a different score for each kidney. We observed a difference in favor of the better scores, with a difference of 11 months up to the time of the analysis (P = .045). We found no significant differences in the log-rank test between the survival rate for the group with a less favorable score (95% confidence interval [CI], 61.26-95.67) versus those with a more favorable score (95% CI, 66.76-93.03).

CONCLUSIONS

A high percentage of biopsies had a different score for the 2 kidneys from the same donor. This difference was important for graft survival. We therefore recommend doing a biopsy of both kidneys.

Pre-implant biopsy predicts outcome of single-kidney transplantation independent of clinical donor variables

BACKGROUND

Pre-implant biopsy findings account for the discard of many donor kidneys although their clinical value is not fully understood. We retrospectively investigated the predictive value of pre-implant histology, which in our center was obtained for protocol purposes, not for transplant decisions, on long-term allograft and recipient outcome after single-kidney transplantation.

METHODS

This single-center study included 628 consecutive adult recipients of 174 Expanded Criteria Donor (ECD) and 454 Standard Criteria Donor kidneys. Chronic donor organ injury was assessed applying a chronic lesion score differentiating between mild, moderate, and severe histologic organ injury based on the integration of glomerular, vascular, tubular, and interstitial lesions. Recipients were followed over a median time of 7.8 years.

RESULTS

Donor kidneys exhibiting mild or moderate chronic lesions yielded almost identical graft and recipient survival independent of ECD status or other clinical covariables (HR 1.20, 95% CI 0.83-1.74, P=0.326, and HR 1.27, 95% CI 0.83-1.95, P=0.274, respectively). However, if allograft injury was severe, occurring in 3% of transplanted kidneys, graft and recipient survival was significantly reduced (HR 3.13, 95% CI 1.61-6.07, P<0.001 and HR 2.42, 95% CI 1.16-5.04, P=0.005, respectively).

CONCLUSION

The results suggest that donor kidneys displaying moderate chronic injury can safely be transplanted as single kidneys, while organs displaying severe injury should be discarded. Thus, pre-implant biopsy might offer an effective approach to increase the utilization of renal donor organs, especially from ECD and donors with cerebrovascular accident as cause of death, and to improve overall graft outcome.

Predictive model for the optimal glomerular filtration rate in living kidney transplant recipients

BACKGROUND

Recipient glomerular filtration rate (GFR) after living kidney transplantation (KT) is influenced by many factors. Defining the appropriate level of recipient GFR post-KT is helpful. The aim of this study was to establish a predictive model to estimate the optimal recipient GFR at 1 week post-KT.

METHODS

We retrospectively analyzed 211 living KTs without delayed or slow graft function. Estimated GFR was calculated using the Cockcroft-Gault (CG) formula. Donor kidney volume was obtained from routine computed tomographic angiography (CTA) by work station GE (AW 4.20) program. Multivariate analysis was carried out with automated backward selection to establish the predictive model. The bias, precision, and accuracy of our model were also determined by application of the model to another 37 living KTs.

RESULTS

In multivariate analysis, the significant parameters to predict recipient GFR were donor age (P = .025) and kidney volume (P < .0001) and both were incorporated in the predictive model; predicted CG recipient GFR = 28.325 + (donor kidney volume x 0.282) - (0.297 x donor age). The correlation coefficient (R) is 0.5. Application to another group revealed that our model had high precision (14.45 mL/min), small positive bias (0.24 mL/min), and high percentage (81%) of predicted value, which was within 30% of the observed recipient GFR post-KT.

CONCLUSION

Our predictive model included donor age and donor kidney volume and could be used to estimate the optimal recipient GFR post-KT. This could be helpful to identify early graft dysfunction and to make a decision if further invasive investigation such as allograft biopsy is necessary.

Peritransplant kidney biopsies: comparison of pathologic interpretations and practice patterns of organ procurement organizations

The preimplantation kidney biopsy affects utilization by diagnosing glomerulosclerosis, interstitial fibrosis (IF), arteriosclerosis, and arteriolar hyalinosis. Organ procurement organizations (OPOs) determine whether a donor warrants this biopsy and the donor hospital pathologists (DHPs) report on an OPO-specific pathology interpretation form. Biopsy slides from 40 deceased donor kidneys transplanted at our institution were used to compare interpretations between our transplant pathologist and the DHPs. Thirty-three of these kidneys also had post-perfusion biopsies (PPB). All 58 OPOs were queried for criteria used to request a preimplantation biopsy, and their pathology interpretation forms were also analyzed. The transplant and DHPs had substantial agreement for percent glomerulosclerosis with 75% of biopsies being interpreted within five percentage points. Concordance for IF was poor. The DHP rarely reported arterial pathology. Seventy percent of preimplantation and PPB were read similarly for glomerulosclerosis; concordance for other lesions was weaker. There were no cues for arterial disease on our OPO's pathology interpretation form. Criteria for obtaining a preimplantation biopsy lacked uniformity for the 21 OPOs with a self-generated policy. The pathology interpretation forms varied widely among the OPOs. Current OPO practices with regard to the preimplantation biopsy should be improved.

Pre-existing arteriosclerotic intimal thickening in living-donor kidneys reflects allograft function

BACKGROUND

Donor shortage is a serious problem worldwide and it is now debated whether kidneys from marginal donors are suitable for renal transplantation. Recent studies have shown that the findings of preimplantation kidney biopsy are useful to evaluate vasculopathy in the donated kidney, and may predict transplant outcomes in deceased- donor kidney transplantation. However, few studies have focused on the pathological findings of preimplantation biopsy in living-donor kidney transplantation. Therefore, we investigated whether arteriosclerotic vasculopathy in living-donor kidneys at the time of transplantation predicts the recipient's kidney function (allograft function) later in life.

METHODS

We retrospectively analyzed 75 consecutive adult living-donor kidney transplants performed at Kagawa University Hospital. Renal arteriosclerotic vasculopathy was defined according to the presence of fibrous intimal thickening in the interlobular artery.

RESULTS

Forty-one kidneys exhibited mild arteriosclerotic vasculopathy on preimplantation kidney biopsies. The decreases in estimated glomerular filtration rate after donation were similar in donors with or without renal arteriosclerotic vasculopathy. Pre-existing arteriosclerotic vasculopathy did not affect graft survival rate, patient survival rate or the incidence of complications. Recipients of kidneys with arteriosclerotic vasculopathy had lower allograft function at 1 and 3 years after transplantation than the recipients of arteriosclerosis-free kidneys with or without donor hypertension. In multivariate analysis, fibrous intimal thickening on preimplantation biopsy was predictive of reduced allograft function at 1 year after transplantation.

CONCLUSIONS

The present study demonstrated that mild arteriosclerotic vasculopathy in the donated kidney is an important pathological factor that reflects future impaired function of renal allografts from marginal donors.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Outcomes and utilization of kidneys from deceased donors with acute kidney injury

Utilization and long-term outcomes of kidneys from donors with elevated terminal serum creatinine (sCr) levels have not been reported. Using data from the Scientific Registry of Transplant Recipients from 1995 to 2007, recipient outcomes of kidneys from adult donors were evaluated stratified by standard criteria (SCD; n = 82 262) and expanded criteria (ECD; n = 16 978) donor type and by sCr </=1.5, 1.6-2.0 and >2.0 mg/dL. Discard rates for SCDs were ascertained. The relative risk of graft loss was similar for recipients of SCD kidneys with sCr of 1.6-2.0 and >2.0 mg/dL, compared to </=1.5 mg/dL. For ECD recipients, the relative risk of graft failure significantly increased with increasing sCr. Of potential SCDs, the adjusted risk of discard was higher with sCr >2.0 mg/dL (adjusted odds ratio [AOR] 7.04, 95% confidence interval [CI] 6.5-7.6) and 1.6-2.0 mg/dL (AOR 2.7; CI 2.5-2.9) relative to sCr </=1.5 mg/dL. Among potential SCDs, elevated terminal creatinine is a strong independent risk factor for kidney discard; yet, when kidney transplantation is performed elevated donor terminal creatinine is not a risk factor for graft loss. Further research is needed to identify safe practices for the optimal utilization of SCD kidneys from donors with acute kidney injury.

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.

The Maryland aggregate pathology index: a deceased donor kidney biopsy scoring system for predicting graft failure

Despite the common use of diagnostic pretransplant deceased donor kidney biopsy, there is no consensus on the prognostic significance of the pathologic findings. In order to assist clinicians with interpretation we analyzed 371 pretransplant biopsies and correlated the findings with graft failure. Glomerular pathology was assessed with percent glomerulosclerosis (GS), glomerular size and periglomerular fibrosis (PGF); vascular pathology with arterial wall-to-lumen ratio (WLR) and arteriolar hyalinosis and interstitial pathology with measurement of cumulative fibrosis and presence of scar. Using two-thirds of the study population as a model-development cohort, we found that biopsy features independently associated with an increased risk of graft failure were GS > or =15%, interlobular arterial WLR > or =0.5 and the presence of PGF, arteriolar hyalinosis or scar. The Maryland Aggregate Pathology Index (MAPI), was developed from these parameters and validated on the remaining one-third of the population. Five-year actuarial graft survival was 90% for kidneys with MAPI scores between 0 and 7, 63% for scores from 8 to 11 and 53% for scores from 12 to 15 (p < 0.001). We conclude MAPI may help transplant physicians estimate graft survival from the preimplantation biopsy findings, in clinical situations similar to this study population (cold ischemia over 24 h, GS < 25%).

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.

Donor biopsy and kidney transplant outcomes: an analysis using the Organ Procurement and Transplantation Network/United Network for Organ Sharing (OPTN/UNOS) database

BACKGROUND

Although the degree of glomerulosclerosis on pretransplant donor biopsy is one criterion used in the decision to accept a deceased donor kidney, its relationship with graft survival remains controversial. This study compared graft survival with the degree of glomerulosclerosis found on donor biopsy. We also examined the agreement in degree of glomerulosclerosis between paired kidneys.

METHODS

Biopsy results from 12,129 adult deceased donor transplants between January 1, 2000 and December 31, 2005 were identified in the Organ Procurement and Transplantation Network/United Network for Organ Sharing data, as of September 11, 2006. Of these, 2696 donors had both kidneys biopsied and subsequently transplanted.

RESULTS

Among the groups with greater than 5% glomerulosclerosis, there was no statistically significant difference in graft survival rates (log-rank, P=0.44). The overall graft survival rates of the 0-5% group were significantly superior to those of the >5% groups (1-, 3-, and 5-year rates: 85.9%, 72.4%, and 59.0% for 0-5% group vs. 81.6%, 68.1%, and 53.6% for >5% group, log-rank P<0.001). Agreement between paired kidneys from the same donor was highest for the 0-5% glomerulosclerosis groups (90.6% for pairs with 0-5% glomerulosclerosis in the left kidney vs. 42.5% for pairs with >5% glomerulosclerosis in the left kidney).

CONCLUSION

Donor kidneys with less than 6% glomerulosclerosis were associated with better graft outcomes and intrapair agreement in the degree of glomerulosclerosis. Among kidneys with greater than 5% glomerulosclerosis, the degree of glomerulosclerosis did not help predict graft outcomes. Sampling error may contribute to the lack of outcome differences seen among these kidneys, given the low intrapair agreement.

Donor Structural and Functional Parameters Are Independent Predictors of Renal Function at 3 Months

INTRODUCTION

Epidemiological studies have shown that demographic, clinical, and histological donor characteristics influence renal function after transplantation, but whether these variables are independent predictors has not been established. The aim of this study was to evaluate the relative contribution of different donor variables on glomerular filtration rates (GFRs) at 3 months.

PATIENTS AND METHODS

We analyzed single renal transplants performed at our center from January 2000 to July 2004. Donor variables included age, gender, weight and height, cause of death, duration of brain death, serum creatinine at admission and preprocurement, history of arterial hypertension or diabetes mellitus, and smoking habit. Donor chronic damage score was calculated in preimplantation biopsies as was the addition of interstitial fibrosis, fibrous intimal thickening, and glomerulosclerosis (<10% = 0, >10% = 1). Donor and recipient GFRs were calculated according to the Cockroft-Gault formula.

RESULTS

We analyzed 202 transplants obtained from 113 deceased donors. A renal biopsy was available in 111 transplants. Recipient GFR at 3 months correlated negatively with donor age (R = -0.32, P < .01) and donor chronic damage score (R = 0.32, P < .01). GFR was lower among recipients of female versus male donors (50 +/- 15 vs 60 +/- 20 mL/min; P < .01). Donor cerebrovascular accident death (53 +/- 19 vs 63 +/- 19 mL/min; P < .01) and hypertension (48 +/- 16 vs 59 +/- 20 mL/min; P < .01) were also associated with lower GFR at 3 months. There was a positive correlation between GFR at admission, GFR preprocurement, and GFR at 3 months (R = 0.32 and R = 0.18 respectively; P < .01). Stepwise regression analysis included chronic damage score, GFR at admission, and donor gender but not donor age as independent predictors of GFR at 3 months (R = 0.50; P < .01).

CONCLUSION

Donor structural and functional parameters are independent predictors of renal function at 3 months.

Outcomes after transplantation of deceased-donor kidneys with rising serum creatinine

The increasing number of candidates for kidney transplantation and relatively unchanged deceased-donor pool has led to expansion in the criteria for donor acceptability. Outcomes of kidneys from donors with progressively rising creatinine values have not been reported. Patients transplanted between September 2003 and August 2006 with kidneys from donors with peak creatinine levels >2.0 mg/dL were stratified into two groups based on the terminal creatinine and evaluated for outcome: (1) falling creatinine (FC)(n= 27), terminal creatinine at least 0.2mg/dL less than peak, and (2) rising creatinine (RC)(n=24), terminal creatinine = peak. The mean terminal creatinine was significantly higher in the RC group (3.2 +/- 1.3 mg/dL) compared to the FC group (1.9 +/- 0.9 mg/dL)(p<0.0001). Peak creatinine values were similar (RC, 3.2 +/- 1.3; FC, 3.1 +/- 1.3; p=0.6521) between the two groups. Rates of delayed graft function (RC, 24%; FC 32%; p=0.7881) and mean creatinine at follow-up (RC, 1.6 +/- 0.6, FC 1.6 +/- 0.4; p=0.3533) were not significantly different. With a mean follow-up of 287 +/- 274 days, allograft survival was 92% in the RC recipients and 89% in the FC recipients. Under certain conditions, kidneys from donors with rising serum creatinine can be used safely with reasonable early outcomes.

Can donor implantation renal biopsy predict long-term renal allograft outcome?

BACKGROUND

Donor kidney implantation biopsy (IB) is performed on a regular basis, particularly as part of clinical studies.

OBJECTIVE

To determine the utility of donor implantation renal biopsy to predict the long-term renal allograft outcome.

METHODS

A Medline search for studies in English was performed with the following key words: implantation biopsy, renal transplantation and long-term outcome.

RESULTS

Sixteen trials involving 8,122 kidney transplants were identified, of which 6 were prospective studies. The histological abnormalities were scored mainly by the Banff schema and the graft outcome was defined either by delineating the delta changes in the pathology score or glomerular filtration rate. Normal histology with a well-functioning renal allograft had a favorable outcome. The extent to which the baseline tubular atrophy, interstitial fibrosis, glomerulosclerosis and vascular changes had on the long-term outcome varied from one study to another.

CONCLUSION

Abnormal IB has a better chance of predicting early graft outcome. The review questions the current wisdom for routine IB on all donors. In some donor kidneys, a biopsy provides significant prognostic information, such as older donor kidney, those with history of hypertension, diabetes, cardiovascular disease, and kidneys with abnormal creatinine. Future research on IB is necessary to find a more useful method to predict the long-term transplant outcome.

Assessment of renal graft function depending on pre-transplant morphology

BACKGROUND

Histopathological assessment of kidney prior to transplantation is a part of the comprehensive information gathered on the transplanted organ. In our study we monitor the influence of individual morphological findings (glomeruli, arteries, arterioles, interstitium, tubules) and degree of histopathological changes in the kidney function after transplantation.

METHODS

From 1994 to 1997, 117 cadaveric kidneys were histopathologically examined and subsequently transplanted. Biopsy in a form of wedge excision was obtained during the organ procurement after in situ kidney perfusion and its removal from donor's body. Evaluated were glomerulosclerosis, intimal fibrosis of arteries, arteriolar hyalinization, interstitial fibrosis and tubular changes (vacuolar dystrophy of tubular epithelium, desquamation of tubular epithelium, brush border of proximal tubules, tubular dilatation, haemoglobin cylinders in distal tubules). Kidney recipients were monitored both for immediate function of transplanted organ and long-term kidney function for a period of five years following.

RESULTS

In our group of patients, no unambiguously negative influence of histopathological change in individual morphologies was found either in the immediate or in the long-term function of the transplanted kidney.

CONCLUSION

It is possible to transplant kidneys and attain satisfactory results even with these types of histopathological changes: glomerulosclerosis greater or equal to 20 %, mild degree of arterial lesion, moderate arteriolar lesions, moderate lesions of interstitial fibrosis and tubular lesions. The degree of arterial lesions, arteriolar lesions and the degree of interstitial fibrosis closely correlate to the donor's age, hypertension and nontraumatic cerebrovascular accident as the cause of death. Same outcomes were also confirmed with glomerulosclerosis, with the exception of the influence of the donor's age.

Correlation Between the Biopsies in Marginal Donor Kidneys for Transplantation: Is It Necessary to Biopsy Both Kidneys?

OBJECTIVES

The objective of this study was to analyze the correlation between histological findings in both transplanted kidneys from marginal donors.

METHODS

We retrospectively reviewed the histological information on 92 kidneys obtained between January 2001 and January 2004, corresponding to 46 marginal donors. Criteria for biopsy were age greater than 55 years, hypertension, diabetes, and proteinuria. Scores were established by the pathologist including glomerulosclerosis, tubular atrophy, interstitial fibrosis, and arteriosclerosis. The score for each lesion was classified as 0 if absent; 1 if <20%; 2 if >20% and <50%; and 3 if >50%. Finally, we defined an index of renal severity damage (RSD) in order to classify the kidneys for single transplantation (0), double transplantation (1), and unsuitable for transplantation (2).

RESULTS

Of the kidneys studied, 82.6% of both kidneys showed similar degrees of glomerulosclerosis (<20% in 71.7% and >20% in 10.9%), while 17.4% showed discrepancies (> vs <20%; P=.008). On the other hand, RSD correlated in 82.6% of both kidneys (in 69.6% RSD=0; in 8.7% RSD=1; and in 4.3% RSD=2), while 17.4% showed discrepancies (P=.001). In one case (2.2%), a great discrepancy was observed; one kidney was valid for single transplantation, and the other one not valid for any transplantation, single or double.

CONCLUSIONS

This study demonstrated a correlation between the biopsy findings in both kidneys in 82.6% of marginal organ donors. However, in 17.4% of cases we observed discrepancies. The degree of glomerulosclerosis seemed to be a powerful parameter to define renal severity damage. According to these results we would recommend biopsy of both kidneys.

Kidney transplantation using elderly non-heart-beating donors: a single-center experience

Although acceptable outcomes have been reported in both non-heart-beating (NHB) and elderly donors individually, the large pool of elderly NHB donors has not yet been fully utilized. In 1994, we expanded our transplant protocol to include NHB donors aged over 65 years and this study compares the clinical outcomes with regular NHB transplantations. Up to June 2005, 24 patients were transplanted at our center with kidneys from NHB donors aged 65 years or more, whereas 176 patients received grafts from conventional NHB donors during the same period. Grafts from older donors were associated with inferior glomerular filtration rates (29 vs. 44 mL/min after 1 year, p=0.01) and graft survival (52% vs. 68% after 5 years, p=0.19) compared to younger NHB donor grafts, although the difference in graft survival was not statistically significant. Exclusion of older NHB donor kidneys with severe vascular pathology resulted in similar graft survival of older and younger NHB donor kidneys. We conclude that the use of elderly NHB donors in order to expand the donor pool was associated with unacceptable clinical outcomes and cannot be justified without further refinement in their selection, for example, by histological assessment of pretransplant biopsies.

Excellent Outcomes after Transplantation of Deceased Donor Kidneys with High Terminal Creatinine and Mild Pathologic Lesions

BACKGROUND

Outcomes after kidney transplantation using deceased donors with high terminal creatinine are not well described but potentially represent an underutilized source of renal allografts. Utility of renal biopsy of these kidneys is similarly not well established.

METHODS

To better understand the posttransplant function of kidneys from donors with high terminal creatinine, we reviewed our database of almost 500 cadaveric kidney transplants. We compared the 65 nonexpanded criteria donors with a final donor creatinine > or = 2.0 mg/dl (range 2.0-4.9 mg/dl) with kidneys procured from donors with terminal creatinine of <1.5. Biopsy results were correlated with graft function.

RESULTS

Kidneys from deceased donors with high terminal creatinine performed as well as kidneys from donors with a normal terminal creatinine with respect to primary non-function, acute rejection, 6-year graft and patient survival, and function over the first 48 months. High creatinine kidneys with moderate or severe lesions on biopsy demonstrated poorer function at 6 months and 1 year as compared to those with mild or no histological lesions.

CONCLUSIONS

Under select conditions, kidneys from donors with high terminal creatinine can be used safely with excellent results.

Angiotensin-Converting Enzyme and Endothelial Constitutive Nitric Oxide Synthase Polymorphisms in Turkish Renal Transplant Population and Possible Influence on Renal Artery Atherosclerosis and Graft Survival

BACKGROUND

Renal transplant recipients are prone to accelerated atherosclerosis secondary to immunosuppressants, which may decrease graft survival. We sought to analyze the effects on renal graft survival of atherosclerotic degeneration in the renal artery and the influence of angiotensin-converting enzyme (ACE) endothelial constitutive nitric oxide synthase (ecNOS) gene polymorphisms.

METHODS AND PATIENTS

Thirty three renal transplant recipients (25 men) of mean age 28.4 +/- 9.6 years, received organs from 11 living related donors and were followed for at least 36 months. Genotyping was performed for the insertion/deletion ACE (I/D), angiotensin (AGT) (M-->T, 235), angiotensine 1 receptor (A-->C, 1166), angiotensin 2-receptor (A-->G, 1223), and ecNOS (b-->a, intron4) gene polymorphisms. Renal artery biopsies were performed during transplantation surgery to analyze the presence of atherosclerosis.

RESULTS

Pathological examination indicated that 18 donor specimens and nine recipient specimens had atherosclerotic degeneration. Survival analysis (36 months) indicated that graft survival rates of recipients who had atherosclerosis in the renal artery and who received an organ from donors with an atherosclerotic renal artery were shorter than in their counterparts (P = .02, P = .04, respectively). Comparison of genetic variations of recipients revealed that CC/TC variation of AGT was higher in patients with atherosclerosis (81% vs 53%, P = .03). There was no significant difference between groups in means of other gene polymorphisms.

CONCLUSION

Renin-angiotensin system gene polymorphism analysis of patients in renal transplantation waiting list may provide information about allograft survival and posttransplant atherosclerotic degeneration at graft vasculature of young transplant recipients.

MEASUREMENT OF CHRONIC DAMAGE IN THE DONOR KIDNEY AND GRAFT SURVIVAL

BACKGROUND

So-called marginal kidneys are used increasingly in renal transplantation, but features of marginal kidneys are disputed.

METHODS

To help define marginal, a morphometric measure, the index of chronic damage, was applied retrospectively to 500 implantation biopsy specimens of cadaveric grafts, and death-censored graft survival was calculated, up to 14 years after transplantation.

RESULTS

An index of 0% (n=242) was associated with better survival than 1%, with little difference between 1% and 39% (n=249). An index of 40% or more (n=9) was associated with the worst survival (chi=14.2, 2 df, P <0.001). After controlling for donor age, the only values of the index related to survival were 40% and above (hazard ratio, 2.96; P =0.01). Donor age group 10 to 39 years old (n=238) had better survival than 1 to 9 years old (n=26) and 40 to 73 years old (n=236) (hazard ratios, 2.83 and 2.06, respectively; P <0.001). An early episode of acute rejection affected survival even at 6 years and later after transplantation (hazard ratio, 1.94; P <0.04).

CONCLUSIONS

Marginal kidneys are identified using the index of chronic damage, but they are so rare that measurement is not necessary on every graft. After routine graft allocation and in the absence of acute rejection, a kidney from virtually any donor in an age group has the same potential as a graft from nearly all others in that group.

20-year experience with elderly donors in living renal transplantation

PURPOSE

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Computerized image analysis of Sirius Red-stained renal allograft biopsies as a surrogate marker to predict long-term allograft function

Chronic allograft nephropathy (CAN) is a major problem in posttransplant management. The lack of a reliable and early surrogate marker of CAN has hampered patient care and research. In this study, the Cortical Fractional Interstitial Fibrosis Volume (V(IntFib)), quantitated with computerized image analysis of Sirius Red-stained protocol biopsies, was examined as a potential surrogate for time to graft failure (TTGF) in 68 renal allograft recipients. At 6 mo posttransplant, V(IntFib) was highly correlated with TTGF (r = 0.64, P < 0.001). Both the Banff Chronic Sum and the Acute Sum Scores were also correlated with TTGF, but less strongly (r = 0.28, P < 0.02; r = 0.35, P < 0.003, respectively). As V(IntFib) was not correlated with the Banff Chronic Score, a multivariate model was created that incorporated V(IntFib) and both Acute and Chronic Banff pathology. This model was highly correlated with TTGF (r = 0.7, P < 0.0001). These findings suggest that V(IntFib) determined by computerized image analysis of Sirius Red-stained protocol biopsies at 6 mo posttransplant, with or without incorporation of Banff acute and chronic scoring, may provide an early surrogate for time to graft failure in renal allograft recipients.

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.

Pathophysiology of renal disease associated with liver disorders: implications for liver transplantation. Part I

Renal and hepatic function are often intertwined through both the existence of associated primary organ diseases and hemodynamic interrelationships. This connection occasionally results in the chronic failure of both organs, necessitating combined liver-kidney transplantation (LKT). Since 1988, more than 850 patients in the United States have received such transplants, with patient survival somewhat less than that for patients receiving either organ alone. Patients with renal failure caused by acute injury or hepatorenal syndrome have classically not been included as candidates for combined transplantation because of the reversibility of renal dysfunction after liver transplantation. However, the rate and duration of renal failure before liver transplantation is increasing in association with prolonged waiting list times. Thus, the issue of acquired permanent renal damage in the setting of hepatic failure continues to confront the transplant community. The following article and its sequel (Part II, to be published in vol 8, no 3 of this journal) attempt to review the problem of primary and secondary renal disease in patients with end-stage liver disease, elements involved in renal disease progression and recovery, the impact of renal disease on liver transplant outcome, and results of combined LKT; outline the steps in the pretransplantation renal evaluation; and provide the beginnings of an algorithm for making the decision for combined LKT.