Current Opinion in Organ Transplantation最新文献

Purpose of review: The epidemiologic phenomenon known as the "Hispanic paradox" postulates that Hispanic/Latino Americans generally tend to live longer than other racial/ethnic communities, despite facing many socioeconomic disadvantages and other healthcare barriers. Whether this phenomenon is relevant among kidney transplantation (KT) recipients remains unclear. To investigate the possibility of a Hispanic mortality advantage, we conducted a systematic review of the published literature comparing short-term KT outcomes (first 12-months) for US Hispanic versus non-Hispanic White KT recipients.

Recent findings: This systematic review summarizes recent findings from sixteen observational retrospective cohort studies that met our study criteria. Study sample sizes ranged from 42 to 244 037 total KT recipients and examined data between 2005 and 2022. Compared to their Non-Hispanic comparator, the Hispanic sub-samples were more likely to be younger, spend more time on dialysis, and less likely to receive preemptive transplant or living donation. Hispanic KT recipients experienced similar or more favorable outcomes in eleven studies (ten studies examining patient and graft survival, one study examining readmissions), but only three studies with statistical significance.

Summary: As the US Hispanic and Latino population continues to grow into the diverse American melting pot, this review highlights the need for better approaches to studying racial and ethnic variables within kidney transplantation.

Purpose of review: Kidney transplantation (KT) is the preferred treatment for end-stage renal disease (ESRD), yet systemic challenges, including geographic disparities, impede equitable access. This review evaluates transplant center activity and regional disparities using recent trends and discusses the potential of value-based care (VBC) models like the proposed Increasing Organ Transplant Access (IOTA) model to address these challenges.

Recent findings: Analysis of Organ Procurement and Transplantation Network (OPTN) data from 2021 to 2023 identified 185 of 322 transplant centers as potentially eligible for VBC inclusion. High ESRD prevalence states like Texas, California, and New York have the largest number of centers, while states like Wyoming and Vermont lack operational centers, creating access barriers. Growth in KT rates following the 2014 Kidney Allocation System (KAS) reforms has stabilized at 3-5% since 2023. Geographic disparities persist, with regions like the South Atlantic and Pacific showing high transplant activity but unmet demand relative to ESRD prevalence.

Summary: The proposed IOTA model could mitigate disparities by incentivizing infrastructure investment and prioritizing equitable access. Tailored VBC strategies are essential to addressing regional needs and improving KT equity and outcomes nationwide.

Purpose of review: With the kidney nonuse rate approaching 30%, one-fifth of kidneys placed out of sequence, and unsatisfactory long-term recipient outcomes, U.S. kidney allocation is at a crossroads. This review highlights recent studies and efforts geared toward improving the system.

Recent findings: The Organ Procurement & Transplantation Network's kidney transplantation committee is tasked with migrating kidney allocation policy, currently based on 250 nautical mile circles, to a fully continuous, points-based system. Challenges in designing a system assured to improve, not worsen, placement efficiency have hampered progress. OPO and transplant center practice patterns have adapted to a rapidly changing donation landscape. Advances in transplant immunology, particularly involving molecular HLA typing methods, are opening doors for more precise donor-recipient matching that appear to hold promise for improved long-term outcomes.

Summary: The largely one-size-fits-all kidney allocation system is in desperate need of an overhaul. The continuous distribution paradigm is flexible enough to accommodate bold, new ideas for addressing major pain points in an equitable way. The OPTN should use policy variances to conduct time-limited, controlled experiments with various continuous distribution policies and build upon what works. Advances in transplant immunology, such as eplet matching, should increasingly be incorporated into kidney offer decision-making and, eventually, the allocation algorithm.

Purpose of review: Our goal was to review and summarize the current state of global disease burden from organ failure and the efforts to improve outcomes with organ transplantation. We also reviewed intra- and inter-country disparities in organ failure and organ transplantation along with potential mechanisms to improve access to organ transplantation globally.

Recent findings: Many disparities and inequities observed globally can be characterized by the country's income category. Low- and lower-middle income countries (LLMICs) have higher rates of communicable disease-attributed organ failure, while upper-income countries (UICs) have high overall prevalence due to global growth in noncommunicable etiologies of organ failure. Many downstream disparities in access to organ transplantation and outcomes are associated with country income designation. Improvements in data collection and surveillance of populations with organ failure and organ transplantation are urgently needed.

Summary: Improving outcomes for patients with end-organ disease globally will require countries to improve organ transplantation access and care. For LLMICs, collaboration with international transplant systems and engagement with neighboring countries may establish important foundations for organ transplant systems. For UICs, increasing organ donor availability through technological advances and increasing public engagement will help meet the growing needs for organ transplantation as an important treatment modality.

Purpose of review: Patients that present with a physical frail phenotype have a higher risk of poor kidney transplant outcomes and are therefore less likely to be wait listed for a transplant. The physical frailty phonotype is more prevalent in older adults >65years with chronic and end stage kidney disease, thus partly contributing to inequitable access to transplant. Frailty can potentially be reversed by prehabilitation.

Recent findings: Small studies of prehabilitation in kidney transplant candidates have demonstrated feasibility and safety. These pilot studies have shown efficacy for improving functional surrogates of frailty. Encouraging findings from one small pilot study reported a 50% reduction in postoperative length of hospital stay in patients that participated in prehabilitation. Exercise intervention should be supported with nutrition intervention aimed at increasing energy intake. Lifestyle behavior change coaching and case-by-case clinical psychology support are a key for successful uptake of prehabilitation and sustainable lifestyle change.

Summary: There is consensus from the American Society of Transplantation, the European Society of Transplantation, and healthcare providers that prehabilitation is a valuable peri-operative intervention. Robust, multicenter randomized controlled trials will facilitate the establishment of evidence-based guidelines and widespread implementation of prehabilitation into clinical care.

Purpose of review: Highlight the importance of acute kidney injury (AKI) among liver transplant candidates, its importance of survival and the vital role of continuous renal replacement therapy (CRRT) as a supportive therapy.

Recent findings: Kidney dysfunction is common in the preliver transplant patient. Early recognition, broad diagnostic work up, and therapeutic interventions are vital in minimizing morbidity and mortality in this critically ill group of patients. Liver dysfunction can impact kidney function in multiple ways, leading to worsening of clinical illness. High mortality and poor prognosis in those with AKI without CRRT and Liver Transplant are highlighted.

Summary: Etiology of AKI may not be as important as is the potential for liver transplant (LT) listing in offering CRRT. Non eligibility for a LT does not by default imply non eligibility for CRRT. Multidisciplinary approach should be adopted among those with a need for CRRT in the setting of end-stage liver disease. Goals of care conversations are key, in evaluating the role of CRRT in this group of individuals as they have a very high risk of mortality.

Purpose of review: The purpose of this review is to summarize the current knowledge of cholangiocarcinoma molecular biology and to suggest a framework for implementation of next-generation sequencing in all stages of liver transplantation. This is timely as recent guidelines recommend increased use of these technologies with promising results.

Recent findings: The main themes covered here address germline and somatic genetic alterations recently discovered in cholangiocarcinoma, particularly those associated with prognosis and treatment responses, and nascent efforts to translate these into contemporary practice in the peri-liver transplantation period.

Summary: Early efforts to translate molecular profiling to cholangiocarcinoma care demonstrate a growing number of potentially actionable alterations. Still lacking is a consensus on what biomarkers and technologies to adopt, at what scale and cost, and how to integrate them most effectively into care with the ambition of increasing the number of patients eligible for liver transplantation and improving their long-term outcomes.

Purpose of review: The 2022 National Academies of Sciences, Engineering, and Medicine report highlighted inequities in access to kidney transplantation and called for a comprehensive dashboard highlighting early transplant steps, yet data on steps such as referral and evaluation start are limited. Addressing this gap is crucial for improving equity in access to transplantation.

Recent findings: The Early Steps to Transplant Access Registry (E-STAR) provides a model for how prewaitlisting data can be used to inform quality improvement to drive equity in access to transplantation. E-STAR includes data from 37 transplant centers across 13 states and four regions (Southeast, New York, New England, and the Ohio River Valley), representing ∼217 000 adults with end-stage kidney disease (ESKD) treated in 4365 dialysis facilities, in addition to patients preemptively referred. Similar to the Scientific Registry of Transplant Recipients center-specific reports, the E-STAR dashboard was developed as an interactive website offering center-specific and regional insights into pretransplant access measures within and across centers with the intention to improve access to transplantation. Publicly available de-identified reports illustrate trends in referral, evaluation, and waitlisting by subgroup (e.g., race, sex, age, insurance status), while password-protected features enable transplant centers to benchmark their performance against anonymized peers.

Summary: The E-STAR dashboard demonstrates how centralized, standardized data collection can support transplant centers, policymakers, community partners, and regional organizations to identify disparities, drive quality improvement, and develop interventions for the advancement of equity in transplant access. This work may inform future center-specific reports once prewaitlisting data are collected nationally.

Purpose of review: Recent advancements in genetic engineering have propelled the field of xenotransplantation from preclinical models to early compassionate use cases. As first-in-human clinical trials (FIHCTs) approach, we examine recent developments, ethical and regulatory challenges, immunological considerations, and the clinical infrastructure necessary for successful xenotransplantation trials.

Recent findings: Expanded access transplants of pig hearts, kidneys, and livers have identified key challenges. Heart xenotransplants revealed risks of antibody-mediated rejection and zoonotic infections, while kidney xenotransplants suggest that patient selection, rather than immune rejection, may have caused failures. While there has been a report of auxiliary liver transplantation conducted abroad, profound thrombocytopenia poses an obstacle. As FIHCTs draw near, critical clinical challenges include determining the optimal donor genetic constructs and immunosuppressive regimens. Enrollment criteria and patient selection pose additional complexity, alongside ethical concerns such as lifelong zoonosis monitoring. Only a limited number of centers have the expertise needed to conduct these complex trials.

Summary: Xenotransplantation holds great promise as a solution to organ shortages, but success in FIHCTs will require careful design, multidisciplinary collaboration, and strong infrastructure. Addressing immunologic, ethical, and patient selection challenges will be critical. With proper preparation, xenotransplantation could transform organ transplantation.