Prediction of kidney graft failure using clinical scoring tools

Role of post-transplant graft scintigraphy in kidney donation after circulatory death

Background

There is no consensus on how to predict post-transplant function of donation after circulatory death (DCD) kidneys. Thus, we aimed to identify renal scintigraphy parameters that could predict 1-year kidney function.

Methods

In this single center study, we included all consecutive DCD kidney recipients between 2013 and 2021 (n = 29). Patients who did not have a scintigraphy within 10 days of transplantation (n = 3), recipients of multiple organs and less than 18 years old were excluded (n = 1). Primary endpoint was the estimated glomerular filtration rate (eGFR).

Results

Median eGFR and serum creatinine at 1 year were 67 µmol/L (56-81) and 111 ml/min (99-132), respectively. Among parameters tested, the 3rd/2nd-minute activity ratio had the best diagnostic performance (AUC: 0.74 and 0.71, for eGFR and creatinine) 1 year post transplantation. Using 1.21 as the best cut off, the 3rd/2nd-minute activity ratio specificity and sensitivity to predict eGFR >60 ml/min was 0.82 and 0.83. Renal function was significantly better at 1 week, 3, 6, and 12 months after transplantation in patients with 3rd/2nd-minute activity ratios above 1.21.

Conclusion

This study suggests that the 3rd/2nd-minute activity ratio can predict graft function at 1 year. The benefit of post-transplant scintigraphy should be further validated in a prospective cohort.

Predictive Models for the Functional Recovery of Transplanted Kidney

BACKGROUND

Renal transplantation is the gold standard treatment for end-stage renal disease, however, in 20% of cases, the graft develops a delayed graft function (DGF) that is associated with both early and late worsening of the outcome. The aim of this study was to examine and validate in a population of transplanted patients the appropriateness of the predictive score systems of DGF available to identify patients who might take advantage of a tailored immunosuppressive therapy.

MATERIALS AND METHODS

We conducted a systematic review of the literature to identify articles concerning scoring systems predicting DGF to identify those applicable to the study population and subsequently comparing their appropriateness for defining the most accurate one.

RESULTS

From an analysis of the scientific literature, we found 7 scoring systems predicting DGF. Of these, 3 can be calculated for the study population. We enrolled 247 renal transplants in the study. DGF was recorded in 41 cases (15.95%). The Irish score recognized 25 of 41 cases (60.98%), the Jeldres score 41 of 41 cases (100%), and the Chapal score only 7 of 41 (17.07%). Although the Irish score did not identify all cases of DGF, the analysis of data revealed that it is the most accurate, with area under the receiver operating characteristic almost overlapping.

CONCLUSIONS

The study resulted in some interesting and promising conclusions about the predictability of DGF, defining the Irish score as the most reliable. This result can be considered the fundamental requirement to develop a custom therapeutic algorithm to be applied to all recipients with higher probability of developing DGF.

Kidney Transplantation in Times of Covid-19: Decision Analysis in the Canadian Context

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic impacted transplant programs across Canada.

OBJECTIVE

We evaluated the implications of delays in transplantation among Canadian end-stage kidney disease (ESKD) patients to allow pretransplant vaccination.

DESIGN

We used a Markov microsimulation model and ESKD patient perspective to study the effectiveness (quality-adjusted life years [QALY]) of living (LD) or deceased donor (DD) kidney transplantation followed by 2-dose SARS-CoV-2 vaccine versus delay in LD ("Delay LD") or refusal of DD offer ("Delay DD") to receive 2-dose SARS-CoV-2 vaccine pretransplant.

SETTING

Canadian dialysis and transplant centers.

PATIENTS

We simulated a 10 000-waitlisted ESKD patient cohort, which was predictively modeled for a lifetime horizon in monthly cycles.

MEASUREMENTS

Inputs on patient and graft survival estimates by patient, LD or DD characteristics, were extracted from the Treatment of End-Stage Organ Failure in Canada, Canadian Organ Replacement Register, 2009 to 2018. In addition, a literature review provided inputs on quality of life, SARS-CoV-2 transmissibility, new variants of concern, mortality risk, and antibody responses to 2-dose SARS-CoV-2 mRNA vaccines.

METHODS

We conducted base case, scenario, and sensitivity analyses to illustrate the impact of patient, donor, vaccine, and pandemic characteristics on the preferred strategy.

RESULTS

In the average waitlisted Canadian patient, receiving 2-dose SARS-CoV-2 vaccine post-transplant provided an effectiveness of 22.32 (95% confidence interval: 22.00-22.7) for LD and 19.34 (19.02-19.67) QALYs for DD. Delaying transplants for 6 months to allow 2-dose SARS-CoV-2 vaccine before LD and DD transplant yielded effectiveness of 22.83 (21.51-23.14) and 20.65 (20.33-20.96) QALYs, respectively. Scenario analysis suggested a benefit to short delays in DD transplants to receive 2-dose SARS-CoV-2 vaccine in waitlisted patients ≥55 years. Two-way sensitivity analysis suggested decreased effectiveness of the strategy prioritizing 2-dose SARS-CoV-2 vaccine prior to DD transplant the longer the delay and the higher the Kidney Donor Risk Index of the eventual DD transplant. When assessing the impact of SARS-CoV-2 variants of concern (infection rates ≥10-fold and associated mortality ≥3-fold vs base case), we found short delays to allow 2-dose SARS-CoV-2 vaccine administration pretransplant to be preferable.

LIMITATIONS

Risks associated with nosocomial exposure of LDs were not considered. There was uncertainty regarding input parameters related to SARS-CoV-2 infection, new variants, and COVID-19 severity in ESKD patients. Given rollout of population-level SARS-CoV-2 vaccination, we assumed a linear decrease in infection rates over 1 year. Proportions of patients mounting an antibody response to 2-dose SARS-CoV-2 mRNA vaccines were considered in lieu of data on vaccine efficacy in dialysis and following transplantation. Non-age-stratified annual mortality rates were used for waitlisted candidates.

CONCLUSIONS

Our analyses suggest that short delays allowing pretransplant vaccination offered comparable to greater effectiveness than pursuing transplantation without delay, proposing transplant candidates should be prioritized to receive at least 2 doses of SARS-CoV-2 vaccine. Our scenario and sensitivity analyses suggest that caution must be exercised when declining DD offers in patients offered low risk DD and who are likely to incur significant delays in access to transplantation. While population-level herd immunity may decrease infection risk in transplant patients, more data are required on vaccine efficacy against SARS-CoV-2 and variants of concern in ESKD, and how efficacy may be modified by a third vaccine dose, maintenance immunosuppression and timing of induction and rejection therapies.

Donor Kidney Quality and Transplant Outcome: An Economic Evaluation of Contemporary Practice

OBJECTIVES

The study had two main aims. First, we assessed the cost-effectiveness of transplanting deceased donor kidneys of differing quality levels based on the Kidney Donor Profile Index (KDPI). Second, we assessed the cost-effectiveness of remaining on the waiting list until a high-quality kidney becomes available compared to transplanting a lower-quality kidney.

METHODS

A decision analytic model to estimate cost-effectiveness was developed using a Markov process. Separate models were developed for 4 separate KDPI bands, with higher values indicating lower quality. Models were simulated in 1-year cycles for a 20-year time horizon, with transitions through distinct health states relevant to the kidney recipient from the healthcare payer's perspective. Weibull regression was used to calculate the time-dependent transition probabilities in the base analysis. The impact uncertainty arising in model parameters was included by probabilistic sensitivity analysis using the Monte Carlo simulation method. Willingness to pay was considered as Australian $28 000.

RESULTS

Transplanting a kidney of any quality is cost-effective compared to remaining on a waitlist. Transplanting a lower KDPI kidney is cost-effective compared to a higher KDPI kidney. Transplanting lower KDPI kidneys to younger patients and higher KDPI kidneys to older patients is also cost-effective. Depending on dialysis in hopes of receiving a lower KDPI kidney is not a cost-effective strategy for any age group.

CONCLUSION

Efforts should be made by the health systems to reduce the discard rates of low-quality kidneys with the view of increasing the transplant rates.

Predicting Clinical Outcome in Expanded Criteria Donor Kidney Transplantation: A Retrospective Cohort Study

Background:

The gaps in organ supply and demand necessitate the use of expanded criteria donor (ECD) kidneys.

Objective:

To identify which pre-transplant and post-transplant predictors are most informative regarding short- and long-term ECD transplant outcomes.

Design:

Retrospective cohort study.

Setting:

Single center, Quebec, Canada.

Patients:

The patients were 163 consecutive first-time ECD kidney only transplant recipients who underwent transplantation at McGill University Health Centre (MUHC) between January 1, 2008 and December 31, 2014 and had frozen section wedge procurement biopsies.

Measurements:

Short-term graft outcomes, including delayed graft function and 1-year estimated glomerular filtration rate (eGFR), as well as long-term outcomes including all-cause graft loss (defined as return to dialysis, retransplantation, and death with function).

Methods:

Pre-transplant donor, recipient, and transplant characteristics were assessed as predictors of transplant outcomes. The added value of post-transplant predictors, including longitudinal eGFR, was also assessed using time-varying Cox proportional hazards models.

Results:

In univariate analyses, among the pre-transplant donor characteristics, histopathologic variables did not show evidence of association with delayed graft function, 1-year post-transplant eGFR or all cause graft loss. Recipient age was associated with all-cause graft loss (hazard ratio: 1.038 [95% confidence interval: 1.002-1.075] and the model produced only modest discrimination (C-index: 0.590; standard error [SE]: 0.045). Inclusion of time-dependent post-transplant eGFR improved the model’s prediction accuracy (C-index: 0.711; SE = 0.047). Pre-transplant ECD characteristics were not associated with long-term survival, whereas post-transplant characteristics allowed better model discrimination.

Limitations:

Single-center study, small sample size, and potential incomplete capture of all covariate data.

Conclusions:

Incorporation of dynamic prediction models into electronic health records may enable timely mitigation of ECD graft failure risk and/or facilitate planning for renal replacement therapies. Histopathologic findings on preimplantation biopsies have a limited role in predicting long-term ECD outcomes.

Trial registration:

Not applicable.

Assessment of Organ Quality in Kidney Transplantation by Molecular Analysis and Why It May Not Have Been Achieved, Yet

Donor organ shortage, growing waiting lists and substantial organ discard rates are key problems in transplantation. The critical importance of organ quality in determining long-term function is becoming increasingly clear. However, organ quality is difficult to predict. The lack of good measures of organ quality is a serious challenge in terms of acceptance and allocation of an organ. The underlying review summarizes currently available methods used to assess donor organ quality such as histopathology, clinical scores and machine perfusion characteristics with special focus on molecular analyses of kidney quality. The majority of studies testing molecular markers of organ quality focused on identifying organs at risk for delayed graft function, yet without prediction of long-term graft outcome. Recently, interest has emerged in looking for molecular markers associated with biological age to predict organ quality. However, molecular gene sets have not entered the clinical routine or impacted discard rates so far. The current review critically discusses the potential reasons why clinically applicable molecular quality assessment using early kidney biopsies might not have been achieved yet. Besides a critical analysis of the inherent limitations of surrogate markers used for organ quality, i.e., delayed graft function, the intrinsic methodological limitations of studies assessing organ quality will be discussed. These comprise the multitude of unpredictable hits as well as lack of markers of nephron mass, functional reserve and regenerative capacity.

Risk Indices in Deceased-donor Organ Allocation for Transplantation: Review From an Australian Perspective

Over the last decade, organ donation and transplantation rates have increased in Australia and worldwide. Donor and recipient characteristics for most organ types have generally broadened, resulting in the need to consider more complex data in transplant decision-making. As a result of some of these pressures, the Australian software used for donor and recipient data management is currently being updated. Because of the in-built capacity for improved data management, organ allocation processes will have the opportunity to be significantly reviewed, in particular the possible use of risk indices (RIs) to guide organ allocation and transplantation decisions. We aimed to review RIs used in organ allocation policies worldwide and to compare their use to current Australian protocols. Significant donor, recipient, and transplant variables in the indices were summarized. We conclude that Australia has the opportunity to incorporate greater use of RIs in its allocation policies and in transplant decision-making processes. However, while RIs can assist with organ allocation and help guide prognosis, they often have significant limitations which need to be properly appreciated when deciding how to best use them to guide clinical decisions.

Prediction models for delayed graft function: external validation on The Dutch Prospective Renal Transplantation Registry

Background

Delayed graft function (DGF) is a common complication after kidney transplantation in the era of accepting an equal number of brain- and circulatory-death donor kidneys in the Netherlands. To identify those cases with an increased risk of developing DGF, various multivariable algorithms have been proposed. The objective was to validate the reproducibility of four predictive algorithms by Irish et al. (A risk prediction model for delayed graft function in the current era of deceased donor renal transplantation. Am J Transplant 2010;10:2279-2286) (USA), Jeldres et al. (Prediction of delayed graft function after renal transplantation. Can Urol Assoc J 2009;3:377-382) (Canada), Chapal et al. (A useful scoring system for the prediction and management of delayed graft function following kidney transplantation from cadaveric donors. Kidney Int 2014;86:1130-1139) (France) and Zaza et al. (Predictive model for delayed graft function based on easily available pre-renal transplant variables. Intern Emerg Med 2015;10:135-141) (Italy) according to a novel framework for external validation.

Methods

We conducted a prospective observational study with data from the Dutch Organ Transplantation Registry (NOTR). Renal transplant recipients from all eight Dutch academic medical centers between 2002 and 2012 who received a deceased allograft were included (N = 3333). The four prediction algorithms were reconstructed from donor, recipient and transplantation data. Their predictive value for DGF was validated by c-statistics, calibration statistics and net benefit analysis. Case-mix (un)relatedness was investigated with a membership model and mean and standard deviation of the linear predictor.

Results

The prevalence of DGF was 37%. Despite a significantly different case-mix, the US algorithm by Irish was best reproducible, with a c-index of 0.761 (range 0.756 - 0.762), and well-calibrated over the complete range of predicted probabilities of having DGF. The US model had a net benefit of 0.242 at a threshold probability of 0.25, compared with 0.089 net benefit for the same threshold in the original study, equivalent to correctly identifying DGF in 24 cases per 100 patients (true positive results) without an increase in the number of false-positive results.

Conclusions

The US model by Irish et al. was generalizable and best transportable to Dutch recipients with a deceased donor kidney. The algorithm detects an increased risk of DGF after allocation and enables us to improve individual patient management.

Prediction of Three-Year Mortality After Deceased Donor Kidney Transplantation in Adults with Pre-Transplant Donor and Recipient Variables

Background

Prognostic models for 3-year mortality after kidney transplantation based on pre-transplant donor and recipient variables may avoid futility and thus improve donor organ allocation.

Material/Methods

There were 1546 consecutive deceased-donor kidney transplants in adults (January 1, 2000 to December 31, 2012) used to identify pre-transplant donor and recipient variables with significant independent influence on long-term survival (Cox regression modelling). Detected factors were used to develop a prognostic model for 3-year mortality in 1289 patients with follow-up of >3 years (multivariable logistic regression). The sensitivity and specificity of this model’s prognostic ability was assessed with the area under the receiver operating characteristic curve (AUROC).

Results

Highly immunized recipients [hazard ratio (HR: 2.579, 95% CI: 1.272–4.631], high urgency recipients (HR: 3.062, 95% CI: 1.294–6.082), recipients with diabetic nephropathy (HR: 3.471, 95% CI: 2.476–4.751), as well as 0, 1, or 2 HLA DR mismatches (HR: 1.349, 95% CI: 1.160–1.569) were independent and significant risk factors for patient survival. Younger recipient age ≤42.1 years (HR: 0.137, 95% CI: 0.090–0.203), recipient age 42.2–52.8 years (HR: 0.374, 95% CI: 0.278–0.498), recipient age 52.9–62.8 years (HR: 0.553, 95% CI: 0.421–0.723), short cold ischemic times ≤11.8 hours (HR: 0.602, 95% CI: 0.438–0.814) and cold ischemic times 11.9–15.3 hours (HR: 0.736, 95% CI: 0.557–0.962) reduced this risk independently and significantly. The AUROC of the derived model for 3-year post-transplant mortality with these variables was 0.748 (95% CI: 0.689–0.788).

Conclusions

Older, highly immunized or high urgency transplant candidates with anticipated longer cold ischemic times, who were transplanted with the indication of diabetic nephropathy should receive donor organs with no HLA DR mismatches to improve their mortality risk.

Is the Kidney Donor Risk Index a Useful Tool in Non-US Patients?

Background:

Deceased donor kidney allocation in the United States is guided by the Kidney Donor Risk Index (KDRI). The generalizability of the KDRI beyond the United States has not been widely studied.

Objective:

To assess the generalizability of the KDRI in a cohort of non-US (Canadian) deceased donor kidney transplant recipients.

Design:

Population-based retrospective cohort study.

Setting:

Ontario, Canada.

Patients:

Recipients of deceased donor kidneys from January 1, 2005, to March 31, 2011.

Methods:

Using administrative data, we analyzed a cohort of deceased donor kidney recipients in Ontario, Canada. The Kaplan-Meier method and Cox proportional hazards models were used to assess the relationship between KDRI and the outcomes of graft loss and death. KDRI was modeled continuously and categorically. The ability of models with KDRI to predict recipient outcomes beyond donor age was also explored. Model discrimination was assessed using c-statistics, evaluated at 5 years of follow-up.

Results:

A total of 1299 consecutive deceased donor kidney transplant recipients were included. The median follow-up was 5.5 years. Mean donor age increased from 27 to 64 years across ascending KDRI quintiles. The adjusted relative hazards (95% confidence interval) for total graft loss from Q2 to Q5 (referent = Q1) were 1.27 (0.89-1.80), 1.58 (1.13-2.22), 1.43 (1.01-2.02), and 2.15 (1.54-2.99), respectively. Increased relative hazards across KDRI quintiles were also observed for death-censored graft loss, but not death with graft function. All-cause mortality was increased for the highest KDRI quintile only. In this cohort, a model with KDRI performed better than a model with donor age alone (P = .009).

Limitations:

Large health care databases may have precluded the complete capture of covariate data.

Conclusions:

In conclusion, the KDRI is generalizable to Canadian patients in Ontario and may help inform risk assessment beyond donor age. The performance of KDRI in other non-US settings, and the need for additional model refinement, warrants further study.

Systematic review of kidney transplantation functional predictors

CONTEXT

Kidney transplantation from donors with expanded criteria has increased the pool of kidneys at the cost of a higher risk of short and long-term graft dysfunction. The main issue lies in determining which kidneys will offer acceptable function and survival compared with the risk represented by surgery and subsequent immunosuppression.

OBJECTIVE

The objective of our article is to review the current evidence on the tools for predicting the functionality of kidney transplantation from cadaveric donors with expanded criteria and determining the validity for their use in standard practice.

ACQUISITION OF EVIDENCE

We conducted a systematic literature review according to the PRISM criteria, through Medline (http://www.ncbi.nlm.nih.gov) and using the keywords (in isolation or in conjunction) "cadaveric renal transplantation; kidney graft function appraisal, graft function predictors". We selected prospective and retrospective series and review articles. A total of 375 articles were analysed, 39 of which were ultimately selected for review.

SUMMARY OF THE EVIDENCE

The predictors of functionality include the following: The donor risk indices; the calculation of the renal functional weight or the assessment of the nephronic mass; the measurement of vascular resistances during perfusion in hypothermia; the measurement of the donor's biomarkers in urine and in the perfusion liquid; the measurement of functional and reperfusion parameters in normothermia; and the measurement of morphological parameters (microscopic and macroscopic) of the target organ. In this article, we present an explanatory summary of each of these parameters, as well as their most recent evidence on this issue.

DISCUSSION

None of the reviewed parameters in isolation could reliably predict renal function and graft survival. There is a significant void in terms of the macroscopic assessment of kidney transplantation.

CONCLUSIONS

We need to continue developing predictors of renal functionality to accurately define the distribution of each currently available donor kidney.

An Examination of the Application of the Kidney Donor Risk Index in British Columbia

Background:

The Kidney Donor Risk Index (KDRI) is a continuous measure of deceased donor kidney transplant failure risk that was derived in US patients based on 10 donor characteristics. In the United States, the KDRI is utilized to guide organ allocation and to inform clinical decisions regarding organ acceptance.

Objective:

To examine the application of the US-derived KDRI in a large Canadian province.

Patients:

All deceased donor kidney-only transplant recipients in British Columbia (BC) between 2005 and 2014.

Methods:

We examined the predictive performance of KDRI in BC transplant recipients and compared the overall performance of KDRI with donor age alone in predicting transplant failure (from all causes including death).

Results:

Donors in BC (N = 785) were older but included no black donors and few Hepatitis C virus (HCV)-positive donors compared with the original derivation cohort of the KDRI in the United States. The KDRI was moderately predictive of transplant failure (c statistic, 0.63) and had similar predictive performance to donor age alone (c statistic, 0.64).

Conclusion:

Our findings suggest that the US-derived KDRI does not improve the prediction of kidney transplant failure compared with donor age alone in a Canadian cohort and highlight the need to determine the applicability of KDRI in different regions.

Validation of KDRI/KDPI for the selection of expanded criteria kidney donors

INTRODUCTION

KDRI / KDPI are tools use in kidney donor evaluation. It has been proposed as a substitute of, or complementary to preimplantation renal biopsy. These scores has not been validated in Spain.

OBJECTIVE

1) To investigate the concordance between KDPI and histological scores (preimplantation renal biopsy) and 2) To assess the relationship between KDRI, KDPI and histological score on graft survival in the expanded criteria donors group.

METHODOLOGY

Retrospective cohort study from 1 January 1998 until 31 December 2010.

RESULTS

During the study 120 donors were recruited, that resulted in 220 preimplantation renal biopsies. 144 (65%) grafts were considered suitable for kidney transplantation. 76 (34.5%) were discarded. Median follow up has been 6.4 years (sd 3.9). Median age 63.1 years (sd 8.2), males (145; 65.9%), non-diabetic (191; 86.8%) and without another cardiovascular risk factors (173; 78.6%). 153 (69.5%) donors died of cerebrovascular disease. There were significant differences in KDRI/KDPI score in both groups 1.56/89 (sd 0.22) vs 1.66/93 (sd 0.15), p<0.01). The KDPI showed moderate concordance and correlation with the histological score (AUC 0.64 / correlation coefficient 0.24, p <0.01). KDPI (HR 24.3, p<0.01) and KDRI (HR 23.3, p<0.01) scores were associated with graft survival in multivariate analysis.

CONCLUSION

1) KPDI and histological scores show moderate concordance. The utility of both scores as combined tools it has to be determined. 2) KDPI score, and especially KDRI score, are valid for estimating graft survival and combined with the biopsy can help to individualized decision making in the expanded criteria donors pool.

Proteins in Preservation Fluid as Predictors of Delayed Graft Function in Kidneys from Donors after Circulatory Death

BACKGROUND AND OBJECTIVES

Kidney transplantation is the preferred treatment for ESRD, and donor kidney shortage urges proper donor-recipient matching. Zero-hour biopsies provide predictive values for short- and long-term transplantation outcomes, but are invasive and may not reflect the entire organ. Alternative, more representative methods to predict transplantation outcome are required. We hypothesized that proteins accumulating in preservation fluid during cold ischemic storage can serve as biomarkers to predict post-transplantation graft function.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Levels of 158 proteins were measured in preservation fluids from kidneys donated after circulatory death (Maastricht category III) collected in two Dutch centers (University Medical Center Utrecht and Erasmus Medical Center Rotterdam) between 2013 and 2015. Five candidate biomarkers identified in a discovery set of eight kidneys with immediate function (IF) versus eight with delayed graft function (DGF) were subsequently analyzed in a verification set of 40 additional preservation fluids to establish a prediction model.

RESULTS

Variables tested for their contribution to a prediction model included five proteins (leptin, periostin, GM-CSF, plasminogen activator inhibitor-1, and osteopontin) and two clinical parameters (recipient body mass index [BMI] and dialysis duration) that distinguished between IF and DGF in the discovery set. Stepwise multivariable logistic regression provided a prediction model on the basis of leptin and GM-CSF. Receiver operating characteristic analysis showed an area under the curve (AUC) of 0.87, and addition of recipient BMI generated a model with an AUC of 0.89, outperforming the Kidney Donor Risk Index and the DGF risk calculator, showing AUCs of 0.55 and 0.59, respectively.

CONCLUSIONS

We demonstrate that donor kidney preservation fluid harbors biomarkers that, together with information on recipient BMI, predict short-term post-transplantation kidney function. Our approach is safe, easy, and performs better than current prediction algorithms, which are only on the basis of clinical parameters.

Identification of patients at risk for renal impairment after living donor kidney transplantation

PURPOSE

Outcome after living donor kidney transplantation is highly relevant, since recipient and donor were exposed to notable harm. Reliable identification of risk factors is necessary.

METHODS

Three hundred sixty-six living donor kidney transplants were included in this observational retrospective study. Relevant risk factors for renal impairment 1 year after transplantation and delayed graft function were identified with univariable and multivariable binary logistic regression and ordinal regression analysis.

RESULTS

Eighty-four patients (26.6 %) suffered from renal impairment KDIGO stage ≥4 1 year post-transplant; median estimated glomerular filtration rate was 35.3 ml/min. In multivariable ordinal regression, male recipient sex (p < 0.001), recipient body mass index (p = 0.006), donor age (p = 0.002) and high percentages of panel reactive antibodies (p = 0.021) were revealed as independent risk factors for higher KDIGO stages. After adjustment for post-transplant data, recipient male sex (p < 0.001), donor age (p = 0.026) and decreased early renal function at the first post-transplant outpatient visit (p < 0.001) were identified as independent risk factors. Delayed graft function was independently associated with long stay on the waiting list (p = 0.011), high donor body mass index (p = 0.043), prolonged warm ischemic time (p = 0.016) and the presence of preformed donor-specific antibodies (p = 0.043).

CONCLUSIONS

Broadening the donor pool with non-blood related donors seems to be legitimate, although with respect to careful medical selection, since donor age in combination with male recipient sex were shown to be risk factors for decreased graft function. Warm ischemic time and waiting time need to be kept as short as possible to avoid delayed graft function. Transplantation across HLA and ABO borders did not affect outcome significantly.

Metabolic consequences of modern immunosuppressive agents in solid organ transplantation

Among other factors, sophistication of immunosuppressive (IS) regimen accounts for the remarkable success attained in the short- and medium-term solid organ transplant (SOT) survival. The use of steroids, mycophenolate mofetil and calcineurin inhibitors (CNI) have led to annual renal graft survival rates exceeding 90% in the last six decades. On the other hand, attrition rates of the allograft beyond the first year have remained unchanged. In addition, there is a persistent high cardiovascular (CV) mortality rate among transplant recipients with functioning grafts. These shortcomings are in part due to the metabolic effects of steroids, CNI and sirolimus (SRL), all of which are implicated in hypertension, new onset diabetes after transplant (NODAT), and dyslipidemia. In a bid to reduce the required amount of harmful maintenance agents, T-cell-depleting antibodies are increasingly used for induction therapy. The downsides to their use are greater incidence of opportunistic viral infections and malignancy. On the other hand, inadequate immunosuppression causes recurrent rejection episodes and therefore early-onset chronic allograft dysfunction. In addition to the adverse metabolic effects of the steroid rescue needed in these settings, the generated proinflammatory milieu may promote accelerated atherosclerotic disorders, thus setting up a vicious cycle. The recent availability of newer agent, belatacept holds a promise in reducing the incidence of metabolic disorders and hopefully its long-term CV consequences. Although therapeutic drug monitoring as applied to CNI may be helpful, pharmacodynamic tools are needed to promote a customized selection of IS agents that offer the most benefit to an individual without jeopardizing the allograft survival.

Delayed graft function and chronic allograft nephropathy: diagnostic and prognostic role of neutrophil gelatinase-associated lipocalin

CONTEXT

Available markers are not reliable parameters to early detect kidney injury in transplanted patients.

OBJECTIVE

Examine neutrophil gelatinase associated lipocalin (NGAL) in early detection of delayed graft function (DGF) and as a long-term predictor of graft outcome.

PATIENTS AND METHODS

NGAL was evaluated in 124 transplanted patients.

RESULTS

Urinary NGAL levels were associated to a 10% (HR: 1.10; 95% CI: 1.04-1.25; p < 0.001) and 15% (HR: 1.15; 95% CI: 1.09-1.26; p < 0.001) increased risk of DGF and allograft nephropathy progression, respectively.

CONCLUSION

NGAL reflects the entity of renal impairment in transplanted patients, representing a biomarker and an independent risk factor for DGF and chronic allograft nephropathy progression.

Acute kidney injury: preclinical innovations, challenges, and opportunities for translation

BACKGROUND

Acute kidney injury (AKI) is a clinically important condition that has attracted a great deal of interest from the biomedical research community. However, acute kidney injury AKI research findings have yet to be translated into significant changes in clinical practice.

OBJECTIVE

This article reviews many of the preclinical innovations in acute kidney injury AKI treatment, and explores challenges and opportunities to translate these finding into clinical practice.

SOURCES OF INFORMATION

MEDLINE, ISI Web of Science.

FINDINGS

This paper details areas in biomedical research where translation of pre-clinical findings into clinical trials is ongoing, or nearing a point where trial design is warranted. Further, the paper examines ways that best practice in the management of AKI can reach a broader proportion of the patient population experiencing this condition.

LIMITATIONS

This review highlights pertinent literature from the perspective of the research interests of the authors for new translational work in AKI. As such, it does not represent a systematic review of all of the AKI literature.

IMPLICATIONS

Translation of findings from biomedical research into AKI therapy presents several challenges. These may be partly overcome by targeting populations for interventional trials where the likelihood of AKI is very high, and readily predictable. Further, specific clinics to follow-up with patients after AKI events hold promise to provide best practice in care, and to translate therapies into treatment for the broadest possible patient populations.

Kidney donor risk index is a good prognostic tool for graft outcomes in deceased donor kidney transplantation with short, cold ischemic time

BACKGROUND

We performed a retrospective cohort study to determine the prognostic value of standard criteria donor/expanded criteria donor (SCD/ECD) designation, with regard to one-yr GFR and graft survival rate, in a region with short, cold ischemic time (CIT), and how this designation compares with the kidney donor risk index (KDRI) and zero-time kidney biopsies.

METHODS

We reviewed 362 cases of deceased donor kidney transplantation (DDKT). Donor kidneys were classified as SCD or ECD. They were also assessed by the KDRI. Zero-time kidney biopsy was performed in 196 patients, and histologic score was assessed.

RESULTS

Median follow-up duration was 46 months. Forty-two cases (11.6%) used ECD kidneys. The mean CIT was only 4.9 ± 2.7 h. Graft survival rates were not significantly different between ECD and SCD groups. The KDRI showed the best correlation with one-yr estimations of glomerular filtration rate (eGFR) (R(2) = 0.230, p < 0.001), and higher KDRI was associated with a higher risk of graft failure (hazard ratio 2.63, 95% confidence interval 1.01-6.87). However, higher histologic score was not associated with a higher risk of graft failure.

CONCLUSION

KDRI has greater predictive value for short-term outcomes in DDKT with short CIT than the SCD/ECD designation or pathology.