Global Perspective on Kidney Transplantation: France

Design, cohort profile and comparison of the KTD-Innov study: a prospective multidimensional biomarker validation study in kidney allograft rejection

There is an unmet need for robust and clinically validated biomarkers of kidney allograft rejection. Here we present the KTD-Innov study (ClinicalTrials.gov, NCT03582436), an unselected deeply phenotyped cohort of kidney transplant recipients with a holistic approach to validate the clinical utility of precision diagnostic biomarkers. In 2018-2019, we prospectively enrolled consecutive adult patients who received a kidney allograft at seven French centers and followed them for a year. We performed multimodal phenotyping at follow-up visits, by collecting clinical, biological, immunological, and histological parameters, and analyzing a panel of 147 blood, urinary and kidney tissue biomarkers. The primary outcome was allograft rejection, assessed at each visit according to the international Banff 2019 classification. We evaluated the representativeness of participants by comparing them with patients from French, European, and American transplant programs transplanted during the same period. A total of 733 kidney transplant recipients (64.1% male and 35.9% female) were included during the study. The median follow-up after transplantation was 12.3 months (interquartile range, 11.9-13.1 months). The cumulative incidence of rejection was 9.7% at one year post-transplant. We developed a distributed and secured data repository in compliance with the general data protection regulation. We established a multimodal biomarker biobank of 16,736 samples, including 9331 blood, 4425 urinary and 2980 kidney tissue samples, managed and secured in a collaborative network involving 7 clinical centers, 4 analytical platforms and 2 industrial partners. Patients' characteristics, immune profiles and treatments closely resembled those of 41,238 French, European and American kidney transplant recipients. The KTD-Innov study is a unique holistic and multidimensional biomarker validation cohort of kidney transplant recipients representative of the real-world transplant population. Future findings from this cohort are likely to be robust and generalizable.

European Consensus on the Management of Sensitized Kidney Transplant Recipients: A Delphi Study

An increasing number of sensitized patients awaiting transplantation face limited options, leading to fatalities during dialysis and higher costs. The absence of established evidence highlights the need for collaborative consensus. Donor-specific antibodies (DSA)-triggered antibody-mediated rejection (AMR) significantly contributes to kidney graft failure, especially in sensitized patients. The European Society for Organ Transplantation (ESOT) launched the ENGAGE initiative, categorizing sensitized candidates by AMR risk to improve patient care. A systematic review assessed induction and maintenance regimens as well as antibody removal strategies, with statements subjected to the Delphi methodology. A Likert-scale survey was distributed to 53 European experts (Nephrologists, Transplant surgeons and Immunologists) with experience in kidney transplant recipient care. A rate ≥75% with the same answer was considered consensus. Consensus was achieved in 95.3% of statements. While most recommendations aligned, two statements related to complement inhibitors for AMR prophylaxis lacked consensus. The ENGAGE consensus presents contemporary recommendations for desensitization and immunomodulation strategies, grounded in predefined risk categories. The adoption of tailored, patient-specific measures is anticipated to streamline the care of sensitized recipients undergoing renal allografts. While this approach holds the promise of enhancing transplant accessibility and fostering long-term success in transplantation outcomes, its efficacy will need to be assessed through dedicated studies.

Long-term Kidney Transplant Survival Across the Globe

BACKGROUND

The outcomes after kidney transplantation (KT), including access, wait time, and other issues around the globe, have been studied. However, issues do vary from one country to another.

METHODS

We obtained data from several countries from North America, South America, Europe, Asia, and Australia, including the number of patients awaiting KT from 2015, transplant rate per million population (pmp), proportion of living donor and deceased donor (LD/DD) KT, and posttransplant survival. We also sought opinions on key difficulties faced by each of these countries with respect to KT and long-term survival.

RESULTS

Variation in access to KT across the globe was noted. Countries with the highest rates of KT pmp included the United States (79%) and Spain (71%). A higher proportion of LD transplants was noted in Japan (93%), India (85%), Singapore (63%), and South Korea (63%). A higher proportion of DD KTs was noted in Spain (90%), Brazil (90%), France (85%), Italy (85%), Finland (85%), Australia-New Zealand (80%), and the United States (77%). The 5-y graft survival for LD was highest in South Korea (95%), Singapore (94%), Italy (93%), Finland (93%), and Japan (93%), whereas for DD, it was South Korea (93%), Italy (88%), Japan (86%), and Singapore (86%). The common issues surrounding KTs are access and a limited number of LDs and DDs. Key issues identified for long-term survival were increasing age of donors and recipients, higher recipient comorbidity, and posttransplant events, such as alloimmune injury to the kidney, infection, cancer, and suboptimal adherence to therapy.

CONCLUSIONS

A unified approach is necessary to improve issues surrounding KT as the demand continues to increase.

Outcomes in kidney transplant recipients treated with immediate-release tacrolimus capsules versus extended-release tacrolimus capsules: A cohort study

INTRODUCTION

Prior randomized trials and observational studies have generally reported similar outcomes in kidney transplant recipients (KTRs) treated with immediate-release tacrolimus (IR-TAC) versus extended-release tacrolimus (ER-TAC). However, many of these previous studies focused on patients with low immunological risks, had small sample sizes and brief follow-up periods, and excluded outcomes associated with graft loss, such as chronic rejection.

METHODS

To address these limitations, we conducted a cohort study of 848 KTRs at a single transplantation center who had generally high immunological risks and were treated with either IR-TAC capsules (589 patients, 65.9%) or ER-TAC capsules (289 patients, 34.1%). All patients received their designated maintenance immunosuppressive regimen for at least 3 months post-transplantation. Afterwards, tacrolimus formulation was at the discretion of each patient's transplant nephrologist. For the two treatment groups, we compared the hazards of experiencing a composite outcome of acute or chronic antibody-mediated rejection (AMR), acute or chronic T-cell-mediated rejection, de novo DSA, and/or graft loss over a 3-year period starting at 3 months post-transplantation.

RESULTS

In a multivariable Cox proportional hazards regression model, KTRs treated with IR-TAC capsules had an increased hazard of experiencing the composite outcome when compared to patients treated with ER-TAC capsules; however, this result was not significant (adj HR 1.24, 95% CI .92-1.68, p = .163). Similar results were obtained with inverse probability of treatment weighting (IPTW) using a propensity score (adj HR 1.25, 95% CI .93-1.68, p = .146).

CONCLUSION

These findings suggest that when compared to IR-TAC capsules, ER-TAC capsules do not reduce the hazard of poor outcomes in KTRs with generally high immunological risks.

Women's Access to Kidney Transplantation in France: A Mixed Methods Research Protocol

Kidney transplantation is the best renal replacement therapy (medically and economically) for eligible patients with end-stage kidney disease. Studies in some French regions and in other countries suggest a lower access to the kidney transplant waiting listing and also to kidney transplantation, once waitlisted, for women. Using a mixed methods approach, this study aims to precisely understand these potential sex disparities and their causes. The quantitative study will explore the geographic disparities, compare the determinants of access to the waiting list and to kidney transplantation, and compare the reasons and duration of inactive status on the waiting list in women and men at different scales (national, regional, departmental, and census-block). The qualitative study will allow describing and comparing women's and men's views about their disease and transplantation, as well as nephrologists' practices relative to the French national guidelines on waiting list registration. This type of study is important in the current societal context in which the reduction of sex/gender-based inequalities is a major social expectation.

Robotic Versus Open Kidney Transplantation from Deceased Donors: A Prospective Observational Study

Background

While robot-assisted kidney transplantation (RAKT) from living donors has been shown to achieve favourable outcomes, there is a lack of evidence on the safety and efficacy of RAKT as compared with the gold standard open kidney transplantation (OKT) in the setting of deceased donors, who represent the source of most grafts worldwide.

Objective

To compare the intraoperative, perioperative, and midterm outcomes of RAKT versus OKT from donors after brain death (DBDs).

Design, setting, and participants

Data from consecutive patients undergoing RAKT or OKT from DBDs at a single academic centre between October 2017 and December 2020 were prospectively collected.

Intervention

RAKT or OKT.

Outcome measurements and statistical analysis

The primary outcomes were intraoperative adverse events, postoperative surgical complications, delayed graft function (DGF), and midterm functional outcomes. A multivariable logistic regression analysis assessed the independent predictors of DGF, trifecta, and suboptimal graft function (estimated glomerular filtration rate [eGFR] <45 ml/min/1.73 m²) at the last follow-up.

Results and limitations

Overall, 138 patients were included (117 [84.7%] OKTs and 21 [15.3%] RAKTs). The yearly proportion of RAKT ranged between 10% and 18% during the study period. The OKT and RAKT cohorts were comparable regarding all graft-related characteristics, while they differed regarding a few donor- and recipient-related factors. The median second warm ischaemic time, ureterovesical anastomosis time, postoperative complication rate, and eGFR trajectories did not differ significantly between the groups. A higher proportion of patients undergoing OKT experienced DGF; yet, at a median follow-up of 31 mo (interquartile range 19–44), there was no difference between the groups regarding the dialysis-free and overall survival. At the multivariable analysis, donor- and/or recipient-related factors, but not the surgical approach, were independent predictors of DGF, trifecta, and suboptimal graft function at the last follow-up. The study is limited by its nonrandomised nature and the small sample size.

Conclusions

Our study provides preliminary evidence supporting the noninferiority of RAKT from DBDs as compared with the gold standard OKT in carefully selected recipients.

Patient summary

Kidney transplantation using kidneys from deceased donors is still being performed with an open surgical approach in most transplant centres worldwide. In fact, no study has compared the outcomes of open and minimally invasive (robotic) kidney transplantation from deceased donors. In this study, we evaluated whether robotic kidney transplantation using grafts from deceased donors was not inferior to open kidney transplantation regarding the intraoperative, postoperative, and midterm functional outcomes. We found that, in experienced hands and provided that there was a time-efficient organisation of the transplantation pathway, robotic kidney transplantation from deceased donors was feasible and achieved noninferior outcomes as compared with open kidney transplantation.