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

Kidney accelerated placement project: Outcomes and lessons learned

Opportunities continue to be lost with a high rate of kidneys recovered for transplant but not utilized, particularly those considered less than ideal quality. The Organ Procurement and Transplantation Network (OPTN) Organ Center is tasked with allocating arguably the most difficult-to-place kidneys, and we hypothesized an accelerated placement pathway would increase utilization of kidneys placed by the Organ Center. The Kidney Accelerated Placement (KAP) project, implemented by the Organ Center from July 18, 2019 to July 15, 2020, aimed to offer kidneys with a high kidney donor profile index to programs that had a history of accepting such organs. We compared OPTN kidney match run, donor, and transplant recipient data during the project period and 1 year prior. There was no statistically significant change in the percentage of KAP-eligible donors accepted during the project period (16.4%) compared to the prior year (17.5%). Conversion from acceptance to transplant was higher under KAP (72.7% vs. 71.2%), though not significant. Waiting to accelerate placement after kidneys have been declined by multiple transplant programs locally and regionally is an intervention that may come too late to effectively increase utilization. Transplant rates of nationally shared and marginal kidneys remain a challenge, and future iterations of this project should be investigated.

Impacto de la perfusión hipotérmica pulsativa en el injerto renal de donante subóptimo: nuestra experiencia inicial

Objetivo: Estudios recientes han demostrado que el mantenimiento de la viabilidad de riñones con criterios expandidos durante su preservación sea un reto. La máquina de perfusión hipotérmica pretende mitigar el efecto del almacenamiento en frío sobre la calidad del órgano cuando el tiempo de isquemia fría es prolongada o el donante subóptimo.Objetivo: Evaluar las complicaciones que presentan los pacientes trasplantados renales con preservación está-tica fría o perfusión hipotérmica pulsátil.Material y Método: Estudio observacional retrospec-tivo durante 2010-2012 donde se incluyeron todos los trasplantes renales realizados en un hospital de tercer nivel. Las variables de estudio: estancia hospitalaria, horas de isquemia, necesidad de diálisis y número de sesiones post trasplante y el dispositivo de almacena-miento, edad y patologías asociadas al donante.Resultados: Se realizaron 175 trasplantes donde 70 procedieron de donantes ≥65 años. Se perfundieron en máquina 30 riñones y en 40 se utilizó la preservación estática. Nuestros hallazgos respecto al uso de la má-quina de perfusión conllevan un descenso en la estancia media hospitalaria y una menor necesidad de hemodiá-lisis postrasplante.Conclusiones: Debido al alto porcentaje de órganos procedentes de donantes de edad avanzada y difíciles de preservar, resulta fundamental buscar técnicas de perfusión intravascular continua para una preservación más efectiva del órgano.

Perirenal Adipose Tissue Displays an Age-Dependent Inflammatory Signature Associated With Early Graft Dysfunction of Marginal Kidney Transplants

Background: Better understanding of the contribution of donor aging and comorbidity factors of expanded criteria donors (ECD) to the clinical outcome of a transplant is a challenge in kidney transplantation. We investigated whether the features of donor-derived stromal vascular fraction of perirenal adipose tissue (PRAT-SVF) could be indicative of the deleterious impact of the ECD microenvironment on a renal transplant.

Methods: A comparative analysis of cellular components, transcriptomic and vasculogenic profiles was performed in PRAT-SVF obtained from 22 optimal donors and 31 ECD deceased donors. We then investigated whether these parameters could be associated with donor aging and early allograft dysfunction.

Results: When compared with the PRAT-SVF of non-ECD donors, ECD PRAT-SVF displayed a lower proportion of stromal cells, a higher proportion of inflammatory NK cells. The global RNA sequencing approach indicated a differential molecular signature in the PRAT-SVF of ECD donors characterized by the over-expression of CXCL1 and IL1-β inflammatory transcripts. The vasculogenic activity of PRAT-SVF was highly variable but was not significantly affected in marginal donors. Periorgan recruitment of monocytes/macrophages and NK cells in PRAT-SVF was associated with donor aging. The presence of NK cell infiltrates was associated with lower PRAT-SVF angiogenic activity and with early allograft dysfunction evaluated on day 7 and at 1 month post-transplant.

Conclusions: Our results indicate that human NK cell subsets are differentially recruited in the periorgan environment of aging kidney transplants. We provide novel evidence that PRAT-SVF represents a non-invasive and timely source of donor material with potential value to assess inflammatory features that impact organ quality and function.

Development and validation of a new prediction model for graft function using preoperative marginal factors in living-donor kidney transplantation

BACKGROUND

Recently, living-donor kidney transplantation from marginal donors has been increasing. However, a simple prediction model for graft function including preoperative marginal factors is limited. Here, we developed and validated a new prediction model for graft function using preoperative marginal factors in living-donor kidney transplantation.

METHODS

We retrospectively investigated 343 patients who underwent living-donor kidney transplantation at Kyushu University Hospital (derivation cohort). Low graft function was defined as an estimated glomerular filtration rate of < 45 mL/min/1.73 m² at 1 year. A prediction model was developed using a multivariable logistic regression model, and verified using data from 232 patients who underwent living-donor kidney transplantation at Tokyo Women's Medical University Hospital (validation cohort).

RESULTS

In the derivation cohort, 89 patients (25.9%) had low graft function at 1 year. Donor age, donor-estimated glomerular filtration rate, donor hypertension, and donor/recipient body weight ratio were selected as predictive factors. This model demonstrated modest discrimination (c-statistic = 0.77) and calibration (Hosmer-Lemeshow test, P = 0.83). Furthermore, this model demonstrated good discrimination (c-statistic = 0.76) and calibration (Hosmer-Lemeshow test, P = 0.54) in the validation cohort. Furthermore, donor age, donor-estimated glomerular filtration rate, and donor hypertension were strongly associated with glomerulosclerosis and atherosclerotic vascular changes in the "zero-time" biopsy.

CONCLUSIONS

This model using four pre-operative variables will be a simple, but useful guide to estimate graft function at 1 year after kidney transplantation, especially in marginal donors, in the clinical setting.

Fifteen-Year Analysis of Deceased Kidney Donation: A Single Transplant Center Experience in a Region of Northern Italy

Background

The rising number of patients on waiting lists for kidney transplant and the shortage of available organs has intensified efforts to increase the number of potential donors.

Material/Methods

This study investigated changes in clinical parameters among potential deceased donors in the 15-year period between 1999 and 2013 and their impact on transplantation procedure and outcomes. A total of 1634 potential deceased donors were examined and divided into 2 groups: 707 of them identified from 1999 to 2005 (Group A), and 927 from 2006 to 2013 (Group B).

Results

The comparison between the potential donors in Group A vs. Group B revealed an increase over time in donor age (54.6±17.2 vs. 58.8±16.3, p<0.001), a reduction in the percentage of standard donors (52.3% vs. 39.8%, p<0.001), a broader utilization of organs from expanded criteria donors, and a greater number of comorbidities, particularly cardiovascular disease and dyslipidemia. However, renal function parameters and the bioptic scores did not change significantly over the years.

Conclusions

These results suggest the usefulness of strategies to increase the number of potential donors suitable for organ donation, especially among elderly and marginal donors.

Experiences of renal transplants from donors with renal cell carcinoma after ex vivo partial nephrectomy

Purpose

Routine evaluation of kidney donors occasionally reveals an incidental renal mass with an otherwise satisfactory kidney function. The use of such a kidney with an enhancing mass for transplantation is a matter of debate owing to a possible risk of transmission of donor malignancies. We report our experience of kidney transplants from donors with renal cell carcinoma, after ex vivo resection of the renal mass.

Methods

Two women aged 44 and 56 years were diagnosed with enhancing renal masses measuring 0.9 cm and 0.7 cm, respectively, during donor evaluation for kidney transplantation. Both patients and their families were informed of a potential risk of recurrent renal cell carcinoma following transplantation.

Results

Renal function test results of both donors satisfied the living donor selection criteria. Laparoscopic live donor nephrectomy was performed with ex vivo resection of renal masses on the bench table. Immediate pathological analysis revealed a renal cell carcinoma with a margin of normal renal parenchyma before transplantation. Regimens based on mammalian target of rapamycin inhibitors, which are known for their antitumoral properties, were used for immunosuppression in both recipients. None of the recipients showed recurrence or metastasis during the follow-up period, which was longer than 3 years after transplantation.

Conclusion

In light of the ongoing shortage of kidney donors, kidneys with small renal cell carcinoma could be considered for transplantation after appropriate removal of the lesion, with a very low risk of recurrent disease.

Long-Term Outcomes in Belatacept- Versus Cyclosporine-Treated Recipients of Extended Criteria Donor Kidneys: Final Results From BENEFIT-EXT, a Phase III Randomized Study

In the Belatacept Evaluation of Nephroprotection and Efficacy as First-Line Immunosuppression Trial-Extended Criteria Donors (BENEFIT-EXT), extended criteria donor kidney recipients were randomized to receive belatacept-based (more intense [MI] or less intense [LI]) or cyclosporine-based immunosuppression. In prior analyses, belatacept was associated with significantly better renal function compared with cyclosporine. In this prospective analysis of the intent-to-treat population, efficacy and safety were compared across regimens at 7 years after transplant. Overall, 128 of 184 belatacept MI-treated, 138 of 175 belatacept LI-treated and 108 of 184 cyclosporine-treated patients contributed data to these analyses. Hazard ratios (HRs) comparing time to death or graft loss were 0.915 (95% confidence interval [CI] 0.625-1.339; p = 0.65) for belatacept MI versus cyclosporine and 0.927 (95% CI 0.634-1.356; p = 0.70) for belatacept LI versus cyclosporine. Mean estimated GFR (eGFR) plus or minus standard error at 7 years was 53.9 ± 1.9, 54.2 ± 1.9, and 35.3 ± 2.0 mL/min per 1.73 m² for belatacept MI, belatacept LI and cyclosporine, respectively (p < 0.001 for overall treatment effect). HRs comparing freedom from death, graft loss or eGFR <20 mL/min per 1.73 m² were 0.754 (95% CI 0.536-1.061; p = 0.10) for belatacept MI versus cyclosporine and 0.706 (95% CI 0.499-0.998; p = 0.05) for belatacept LI versus cyclosporine. Acute rejection rates and safety profiles of belatacept- and cyclosporine-based treatment were similar. De novo donor-specific antibody incidence was lower for belatacept (p ≤ 0.0001). Relative to cyclosporine, belatacept was associated with similar death and graft loss and improved renal function at 7 years after transplant and had a safety profile consistent with previous reports.

Survival Benefit From Kidney Transplantation Using Kidneys From Deceased Donors Aged ≥75 Years: A Time-Dependent Analysis

Patients with end-stage renal disease have longer survival after kidney transplantation than they would by remaining on dialysis; however, outcome with kidneys from donors aged ≥75 years and the survival of recipients of these organs compared with their dialysis counterparts with the same probability of obtaining an organ is unknown. In a longitudinal mortality study, 2040 patients on dialysis were placed on a waiting list, and 389 of them received a first transplant from a deceased donor aged ≥75 years. The adjusted risk of death and survival were calculated by non-proportional hazards analysis with being transplanted as a time-dependent effect. Projected years of life since placement on the waiting list was almost twofold higher for transplanted patients. Nonproportional adjusted risk of death after transplantation was 0.44 (95% confidence interval [CI] 0.61-0.32; p < 0.001) in comparison with those that remained on dialysis. Stratifying by age, adjusted hazard ratios for death were 0.17 (95% CI 0.47-0.06; p = 0.001) for those aged <65 years, 0.56 (95% CI 0.92-0.34; p = 0.022) for those aged 65-69 years and 0.82 (95% CI 1.28-0.52; p = 0.389) for those aged ≥70 years. Although kidney transplantation from elderly deceased donors is associated with reduced graft survival, transplanted patients have lower mortality than those remaining on dialysis.

Access to Transplantation and Transplant Outcome Measures (ATTOM): study protocol of a UK wide, in-depth, prospective cohort analysis

INTRODUCTION

There is significant intercentre variability in access to renal transplantation in the UK due to poorly understood factors. The overarching aims of this study are to improve equity of access to kidney and kidney-pancreas transplantation across the UK and to optimise organ allocation to maximise the benefit and cost-effectiveness of transplantation.

METHODS AND ANALYSIS

6844 patients aged 18-75 years starting dialysis and/or receiving a transplant together with matched patients active on the transplant list from all 72 UK renal units were recruited between November 2011 and March 2013 and will be followed for at least 3 years. The outcomes of interest include patient survival, access to the transplant list, receipt of a transplant, patient-reported outcome measures (PROMs) including quality of life, treatment satisfaction, well-being and health status on different forms of renal replacement therapy. Sociodemographic and clinical data were prospectively collected from case notes and from interviews with patients and local clinical teams. Qualitative process exploration with clinical staff will help identify unit-specific factors that influence access to renal transplantation. A health economic analysis will explore costs and outcomes associated with alternative approaches to organ allocation. The study will deliver: (1) an understanding of patient and unit-specific factors influencing access to renal transplantation in the UK, informing potential changes to practices and policies to optimise outcomes and reduce intercentre variability; (2) a patient-survival probability model to standardise access to the renal transplant list and (3) an understanding of PROMs and health economic impact of kidney and kidney-pancreas transplantation to inform the development of a more sophisticated and fairer organ allocation algorithm.

ETHICS AND DISSEMINATION

The protocol has been independently peer reviewed by National Institute for Health Research (NIHR) and approved by the East of England Research Ethics Committee. The results will be published in peer-reviewed journals and presented at conferences.

Comparison of clinical outcomes between ABO-compatible and ABO-incompatible spousal donor kidney transplantation

Background

Kidney transplantation (KT) is the treatment of choice for end-stage renal disease patients. The spouse is a major donor in living KT. Clinical outcomes of spousal donor KT are not inferior to those of living related donor KT. In this study, we compared clinical outcomes between ABO-compatible (ABOc) and ABO-incompatible (ABOi) spousal donor KTs.

Methods

Thirty-two cases of spousal donor KT performed from January 2011 to August 2013 were analyzed retrospectively. Twenty-one ABOc KTs and 11 ABOi KTs were performed. We investigated patient survival, graft survival, acute rejection, graft function, and complications.

Results

During follow-up, patient and graft survival rates were 100% in both groups. There were no significant differences in the incidence of delayed graft function, acute rejection, and the change in graft function between the 2 groups. Medical and surgical complications were not significantly different between the groups.

Conclusion

The clinical outcomes of ABOc and ABOi spousal donor KTs were equivalent. In ABOi KT, an emotionally motivated spousal donor KT may be a good alternative to the problem of the absolute shortage of kidney donations.

Class-specific histone/protein deacetylase inhibition protects against renal ischemia reperfusion injury and fibrosis formation

Renal ischemia-reperfusion injury (IRI) is a common cause of renal dysfunction and renal failure. Histone/protein deacetylases (HDACs) regulate gene accessibility and higher order protein structures and may alter cellular responses to a variety of stresses. We investigated whether use of pan- and class-specific HDAC inhibitors (HDACi) could improve IRI tolerance in the kidney. Using a model of unilateral renal IRI, we investigated early renal function after IRI, and calculated fibrosis after IRI using an automated scoring system. We found that pan-HDAC inhibition using trichostatin (TSA) yielded significant renal functional benefit at 24-96 hours (p < 0.001). Treated mice developed significantly less fibrosis at 30 days (p < 0.0004). Class I HDAC inhibition with MS-275 yielded similar effects. Protection from fibrosis formation was also noted in a cold ischemia transplant model (p < 0.008) with a trend toward improved cold ischemic survival in TSA-treated mice. These effects were not accompanied by induction of typical ischemic tolerance pathways or by priming of heat shock protein expression. In fact, heat shock protein 70 deletion or overexpression did not alter renal ischemia tolerance. Micro-RNA 21, known to be enhanced in vitro in renal tubular cells that survive stress, was enhanced by treatment with HDACi, pointing to possible mechanism.

Protective effects of astaxanthin against ischemia/reperfusion induced renal injury in mice

Astaxanthin (ATX) is a powerful antioxidant that occurs naturally in a wide variety of living organisms. Previous studies have shown that ATX has effects of eliminating oxygen free radicals and can protect organs from ischemia/reperfusion (IR) induced injury. The present study was designed to further investigate the protective effects of ATX on oxidative stress induced toxicity in tubular epithelial cells and on IR induced renal injury in mice. ATX, at a concentration of 250 nM, attenuated 100 μM H₂O₂-inudced viability decrease of tubular epithelial cells. In vivo, ATX preserved renal function 12 h or 24 h post IR. Pretreatment of ATX via oral gavage for 14 consecutive days prior to IR dramatically prevented IR induced histological damage 24 h post IR. Histological results showed that the pathohistological score, number of apoptotic cells, and the expression of α-smooth muscle actin were significantly decreased by pretreatment of ATX. In addition, oxidative stress and inflammation in kidney samples were significantly reduced by ATX 24 h post IR. Taken together, the current study suggests that pretreatment of ATX is effective in preserving renal function and histology via antioxidant activity.

[Abdominal organ retrieval: strategies to improve quality]

The blatant problem of organ shortage leads to an increasing acceptance of organs from extended criteria donors. This increases the importance of the process of organ donation and retrieval. A working group of representatives of Bavarian retrieval surgeons and the procurement organization German Foundation of Organ Transplantation (DSO) was initiated to develop consensus-based recommendations for quality improvements in the field of organ retrieval on the basis of regional data. The main aim was to professionalize retrieval teams by specified training standards and to define objective qualifications for retrieval surgeons. Initial measures of the working group included agreement on standardized retrieval techniques and improvement of documentation in terms of quality forms and the return rate of the forms. Quality data are being analyzed prospectively with a new categorization of complications. Communication among centers and teams and complication reporting has already been improved and initial structural changes have been set up.

Detrimental effects of rat mesenchymal stromal cell pre-treatment in a model of acute kidney rejection

Mesenchymal stromal cells (MSC) have shown immunomodulatory and tissue repair potential including partial tolerance induction by pre-treatment of donor-specific cells in a rat heart transplantation model. Very recently, we could show that autologous MSC attenuated ischemia reperfusion injury in a highly mismatched donor–recipient rat kidney transplant model. Therefore, we investigated donor-specific MSC pre-treatment in this rat kidney transplantation model to study whether graft function could be improved, or if tolerance could be induced. Donor- and recipient-type MSC or phosphate buffered saline (PBS) as a control was injected i.v. 4 days before kidney transplantation. Mycophenolate mofetil immunosuppression (20mg/kg body weight) was applied for 7 days. Kidney grafts and spleens were harvested between days 8 and 10 and analyzed by quantitative RT-PCR and immunohistology. In addition, creatinine levels in the blood were measured and serum was screened for the presence of donor-specific antibodies. Surprisingly, application of both donor- and recipient-specific MSC resulted in enhanced humoral immune responses verified by intragraft B cell infiltration and complement factor C4d deposits. Moreover, signs of inflammation and rejection were generally enhanced in both MSC-treated groups relative to PBS control group. Additionally, pre-treatment with donor-specific MSC significantly enhanced the level of donor-specific antibody formation when compared with PBS- or recipient MSC-treated groups. Pre-treatment with both MSC types resulted in a higher degree of kidney cortex tissue damage and elevated creatinine levels at the time point of rejection. Thus, MSC pre-sensitization in this model impairs the allograft outcome. Our data from this pre-clinical kidney transplantation model indicate that pre-operative MSC administration may not be optimal in kidney transplantation and caution must be exerted before moving forward with clinical studies in order to avoid adverse effects.

Contribution of large pig for renal ischemia-reperfusion and transplantation studies: the preclinical model

Animal experimentation is necessary to characterize human diseases and design adequate therapeutic interventions. In renal transplantation research, the limited number of in vitro models involves a crucial role for in vivo models and particularly for the porcine model. Pig and human kidneys are anatomically similar (characterized by multilobular structure in contrast to rodent and dog kidneys unilobular). The human proximity of porcine physiology and immune systems provides a basic knowledge of graft recovery and inflammatory physiopathology through in vivo studies. In addition, pig large body size allows surgical procedures similar to humans, repeated collections of peripheral blood or renal biopsies making pigs ideal for medical training and for the assessment of preclinical technologies. However, its size is also its main drawback implying expensive housing. Nevertheless, pig models are relevant alternatives to primate models, offering promising perspectives with developments of transgenic modulation and marginal donor models facilitating data extrapolation to human conditions.

Analysis of the Results of ABO-Incompatible Kidney Transplantation: In Comparison with ABO-Compatible Kidney Transplantation

Purpose

The number of patients waiting for kidney transplantation is incessantly increasing, but the number of cadaveric kidney transplantations or ABO-compatible donors is so insufficient that ABO-incompatible kidney transplantation is being performed as an alternative. There are overseas studies and research showing that the 5-year survival rate and 5-year graft survival rate of ABO-incompatible kidney transplantation are not much different from those of ABO-compatible kidney transplantation. However, domestic research on the subject is rare. Therefore, we report the results of 22 ABO-incompatible kidney transplantation cases performed in our hospital.

Materials and Methods

This research was from 22 patients in our hospital who underwent ABO-incompatible kidney transplantation from 15 February 2007 to 20 May 2010.

Results

As yet, there have been no donor graft losses and no deaths after transplantation. The results of the two groups were analyzed by analysis of covariance of the creatinine value of the recipients at 6 months after the operation, corrected for the preoperative value in order to statistically identify whether there were differences in renal function after the operation between ABO-compatible and ABO-incompatible kidney transplantation. The results of the analysis of covariance showed no statistical difference in renal function after the operation between the two groups.

Conclusions

Even though there were not many cases, our initial results for ABO-incompatible kidney transplantation were positive. Considering the increasing number of patients waiting for kidney transplantation, longer-term domestic research studies of ABO-incompatible kidney transplantation are necessary.

Use of marginal organs in kidney transplantation for marginal recipients: too close to the margins of safety?

Objective

Due to organ shortage, average waiting time for a kidney in Germany is about 4 years after start of dialysis. Number of kidney grafts recovered can only be maintained by accepting older and expanded criteria donors. The aim of this study was to analyse the impact of donor and recipient risk on kidney long-term function.

Methods

All deceased kidney transplantations were considered. We retrospectively studied 332 patients between 2002 and 2006; divided in 4 groups reflecting donor and recipient risk.

Results

Non-marginal recipients were less likely to receive a marginal organ (69 of 207, 33%) as compared to marginal recipients, of whom two-thirds received a marginal organ (p < 0.0001). Graft function significantly differed between the groups, but detrimental effect of marginal recipient status on eGFR after 12 months (-6 ml/min/1.73 qm, 95% CI -2 to -9) was clearly smaller than the effect of marginal donor status (-10 ml/min/1.73 qm, 95% CI -7 to -14).

Conclusions

As we were able to show expanded criteria donor has a far bigger effect on long-term graft function than the "extra risk" recipient. Although there have been attempts to define groups of recipients who should be offered ECD kidneys primarily the discussion is still ongoing.

THE POLITICS OF RISK AND EU GOVERNANCE OF HUMAN MATERIAL

This paper examines the politics of EU risk governance in relation to human material. It is argued that the political context has informed the way in which risks in relation to various types of human material have come to be defined as policy problems at EU level. In turn, this has influenced the design and/or persistence of institutional arrangements to manage such problems. It is further argued that this political context has resulted in a significant level of disconnection in risk governance in the area. This has happened in two ways. First, there has been a growing level of disconnection between institutional and stakeholder demands for a more expansive approach to risk governance in the area and the narrowly-circumscribed competence under Article 152(4)(a) EC, which permits the adoption of risk regulation regimes that set minimum standards of quality and safety in relation to blood, tissue/cells and organs. Second, it has led to the development of institutional arrangements that promote a bifurcated approach to risk governance, specifically in relation to blood and tissues/cells. Although a hybrid of traditional and new governance mechanisms have been employed to address this problem of disconnection, this has nevertheless added a further layer to already complex institutional arrangements for risk governance in the area. It is suggested that a more integrated approach to EU risk governance in relation to human material is needed. Implementing such an approach would contribute to greater clarity, transparency and accountability in decision-making processes, and this could enhance public trust in what is a politically-sensitive area of governance at EU level.