Policy Challenges for Organ Allocation in an Era of "Precision Medicine"

Palliative care for end-stage liver disease and acute on chronic liver failure: A systematic review

BACKGROUND

End stage liver disease (ESLD) represents a growing health concern characterized by elevated morbidity and mortality, particularly among individual ineligible for liver transplantation. The demand for palliative care (PC) is pronounced in patients grappling with ESLD and acute on chronic liver failure (ACLF). Unfortunately, the historical underutilization of PC in ESLD patients, despite their substantial needs and those of their family caregivers, underscores the imperative of seamlessly integrating PC principles into routine healthcare practices across the entire disease spectrum.

AIM

To comprehensively investigate the evidence surrounding the benefits of incorporating PC into the comprehensive care plan for individuals confronting ESLD and/or ACLF.

METHODS

A systematic search in the Medline (PubMed) database was performed using a predetermined search command, encompassing studies published in English without any restrictions on the publication date. Subsequently, the retrieved studies were manually examined. Simple descriptive analyses were employed to summarize the results.

RESULTS

The search strategies yielded 721 references. Following the final analysis, 32 full-length references met the inclusion criteria and were consequently incorporated into the study. Meticulous data extraction from these 32 studies was undertaken, leading to the execution of a comprehensive narrative systematic review. The review found that PC provides significant benefits, reducing symptom burden, depressive symptoms, readmission rates, and hospital stays. Yet, barriers like the appeal of transplants and misconceptions about PC hinder optimal utilization. Integrating PC early, upon the diagnosis of ESLD and ACLF, regardless of transplant eligibility and availability, improves the quality of life for these patients.

CONCLUSION

Despite the substantial suffering and poor prognosis associated with ESLD and ACLF, where liver transplantation stands as the only curative treatment, albeit largely inaccessible, PC services have been overtly provided too late in the course of the illness. A comprehensive understanding of PC's pivotal role in treating ESLD and ACLF is crucial for overcoming these barriers, involving healthcare providers, patients, and caregivers.

Deceased Kidney Donor Biomarkers: Relationship between Delayed Kidney Function and Graft Function Three Years after Transplantation

With an increasing number of marginal donors, additional methods for the evaluation of cadaveric kidney quality are required. This study aimed to evaluate pretransplant deceased donor serum (s) and urine (u) biomarkers, including neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), interleukin-18, and C-X-C motif chemokine 10 (CXCL10) for predicting early and late graft function. In total, 43 deceased kidney donors and 76 corresponding recipients were enrolled. Delayed graft function (DGF) occurred in 27.6% of cases. sIL-18, sKIM-1, uNGAL, and uKIM-1 were predictors of DGF. A model incorporating sIL-18, uKIM-1, and clinical factors was developed to predict DGF (AUROC 0.863). Univariate analysis showed a negative association between uKIM and graft eGFR at 6, 12, 24, and 36 months, but this was not confirmed in the multivariate analysis. In conclusion, we report a superior performance of donor biomarkers for predicting DGF and later graft function over serum creatinine. Higher levels of donor sIL-18 and uKIM in conjunction with expanded-criteria donors and longer cold ischemia times predicted DGF. With no renal tubular damage in zero-time donor biopsies, higher pretransplant urine and serum NGAL levels were associated with better allograft function one year after transplantation, and sNGAL with graft function three years after transplantation.

Communicating About Precision Transplantation Tools

Purpose of review

Precision tools that ensure molecular compatibility can help prevent rejection and improve kidney transplantation outcomes. However, these tools will generate controversy because they are perceived to and can in fact impact equity in the ethics of allocation. They may also affect the extent to which physicians can advocate for their patient fiduciaries, as generally required by Canadian professional ethics and law.

Sources of information

Electronic databases such as Google Scholar and PubMed were searched for peer-reviewed literature, and Google search engine was used to identify the news articles, jurisprudence, legal information, and other relevant websites cited.

Methods

We discuss controversies precision transplantation tools will likely generate, consider what challenges will arise from their implementation, and provide recommendations of avenues and content for communication to address these issues.

Key findings

Communication about the translation of new precision tools will be challenging as media portrayals of transplantation often focus on individual narratives about access to transplantation and fail to center the issues of utility, allocation, and rejection. Incomplete portrayals of this nature will need to be countered with explanations of how new precision tools can be of net benefit when implemented equitably, as maintaining trust in the donation and transplantation system is key.

Limitations

Our manuscript focuses on precision medicine applications pertaining to the implementation of molecular compatibility in transplantation. Distinct communication content and avenues may need to be considered in other contexts.

Implications

Clear, accurate, and strategic communication is key to managing translation of precision medicine tools. For this purpose, we provide detailed recommendations for stakeholder engagement, content, and avenues for communicating about precision transplantation tools.

Canadian Kidney Transplant Professionals' Perspectives on Precision Medicine and Molecular Matching in Kidney Allocation

Background

Antibody-mediated rejection is an important cause of kidney transplant loss. A new strategy requiring application of precision medicine tools in transplantation considers molecular compatibility between donors and recipients and holds the promise of improved immunologic risk, preventing rejection and premature graft loss. The objective of this study was to gather Canadian transplant professionals' perspectives on molecular compatibility in kidney transplantation.

Methods

Seventeen Canadian transplant professionals (14 nephrologists, 2 nurses, and 1 surgeon) participated in semistructured interviews in 2021. The interviews were digitally recorded, transcribed, and analyzed using the qualitative description approach.

Results

Participants identified fair access to transplantation as the most important principle in kidney allocation. Molecular compatibility was viewed as a promising innovation. However, participants were concerned about increased waiting times, negative impact on some patients, and potential problems related to the adequacy of information explaining this new technology. To mitigate the challenges associated with molecular matching, participants suggested integrating a maximum waiting time for molecular-matched kidneys and expanding the program nationally/internationally.

Conclusions

Molecular matching in kidney transplantation is viewed as a promising technology for decreasing the incidence of antibody-mediated rejection and improving graft survival. Further studies are needed to determine how to ethically integrate this technology into the kidney allocation algorithm.

Public values and guiding principles for implementing epitope compatibility in kidney transplantation allocation criteria: results from a Canadian online public deliberation

BACKGROUND

Epitope compatibility in deceased donor kidney allocation is an emerging area of precision medicine (PM), seeking to improve compatibility between donor kidneys to transplant candidates in the hope of avoiding kidney rejection. Though the potential benefits of using epitope compatibility are promising, the implied modification of deceased organ allocation criteria requires consideration of significant clinical and ethical trade-offs. As a matter of public policy, these trade-offs should consider public values and preferences. We invited members of the Canadian public to participate in a deliberation about epitope compatibility in deceased donor kidney transplantation; to identify what is important to them and to provide recommendations to policymakers.

METHODS

An online public deliberation was conducted with members of the Canadian public, in which participants were asked to construct recommendations for policymakers regarding the introduction of epitope compatibility to kidney allocation criteria. In the present paper, a qualitative analysis was conducted to identify the values reflected in participants' recommendations. All virtual sessions were recorded, transcribed, and analyzed using NVivo 12 software.

RESULTS

Thirty-two participants constructed nine recommendations regarding the adoption of epitope compatibility into deceased donor kidney allocation. Five values were identified that drove participants' recommendations: Health Maximization, Protection/Mitigation of Negative Impacts, Fairness, Science/Evidence-based Healthcare, and Responsibility to Maintain Trust. Conflicts between these values were discussed in terms of operational principles that were required for epitope compatibility to be implemented in an acceptable manner: the needs for Flexibility, Accountability, Transparent Communication and a Transition Plan. All nine recommendations were informed by these four principles. Participant deliberations were often dominated by the conflict between Health Maximization and Fairness or Protection/Mitigation of Negative Impacts, which was discussed as the need for Flexibility. Two additional values (Efficient Use of Resources and Logic/Rationality) were also discussed and were reasons for some participants voting against some recommendations.

CONCLUSIONS

Public recommendations indicate support for using epitope compatibility in deceased donor kidney allocation. A flexible approach to organ allocation decision-making may allow for the balancing of Health Maximization against maintaining Fairness and Mitigating Negative Impacts. Flexibility is particularly important in the context of epitope compatibility and other PM initiatives where evidence is still emerging.

A Systematic Review of Kidney Transplantation Decision Modelling Studies

BACKGROUND

Genome-based precision medicine strategies promise to minimize premature graft loss after renal transplantation, through precision approaches to immune compatibility matching between kidney donors and recipients. The potential adoption of this technology calls for important changes to clinical management processes and allocation policy. Such potential policy change decisions may be supported by decision models from health economics, comparative effectiveness research and operations management.

OBJECTIVE

We used a systematic approach to identify and extract information about models published in the kidney transplantation literature and provide an overview of the status of our collective model-based knowledge about the kidney transplant process.

METHODS

Database searches were conducted in MEDLINE, Embase, Web of Science and other sources, for reviews and primary studies. We reviewed all English-language papers that presented a model that could be a tool to support decision making in kidney transplantation. Data were extracted on the clinical context and modelling methods used.

RESULTS

A total of 144 studies were included, most of which focused on a single component of the transplantation process, such as immunosuppressive therapy or donor-recipient matching and organ allocation policies. Pre- and post-transplant processes have rarely been modelled together.

CONCLUSION

A whole-disease modelling approach is preferred to inform precision medicine policy, given its potential upstream implementation in the treatment pathway. This requires consideration of pre- and post-transplant natural history, risk factors for allograft dysfunction and failure, and other post-transplant outcomes. Our call is for greater collaboration across disciplines and whole-disease modelling approaches to more accurately simulate complex policy decisions about the integration of precision medicine tools in kidney transplantation.

Recent Advances on Biomarkers of Early and Late Kidney Graft Dysfunction

New biomarkers of early and late graft dysfunction are needed in renal transplant to improve management of complications and prolong graft survival. A wide range of potential diagnostic and prognostic biomarkers, measured in different biological fluids (serum, plasma, urine) and in renal tissues, have been proposed for post-transplant delayed graft function (DGF), acute rejection (AR), and chronic allograft dysfunction (CAD). This review investigates old and new potential biomarkers for each of these clinical domains, seeking to underline their limits and strengths. OMICs technology has allowed identifying many candidate biomarkers, providing diagnostic and prognostic information at very early stages of pathological processes, such as AR. Donor-derived cell-free DNA (ddcfDNA) and extracellular vesicles (EVs) are further promising tools. Although most of these biomarkers still need to be validated in multiple independent cohorts and standardized, they are paving the way for substantial advances, such as the possibility of accurately predicting risk of DGF before graft is implanted, of making a “molecular” diagnosis of subclinical rejection even before histological lesions develop, or of dissecting etiology of CAD. Identification of “immunoquiescent” or even tolerant patients to guide minimization of immunosuppressive therapy is another area of active research. The parallel progress in imaging techniques, bioinformatics, and artificial intelligence (AI) is helping to fully exploit the wealth of information provided by biomarkers, leading to improved disease nosology of old entities such as transplant glomerulopathy. Prospective studies are needed to assess whether introduction of these new sets of biomarkers into clinical practice could actually reduce the need for renal biopsy, integrate traditional tools, and ultimately improve graft survival compared to current management.