The economic burden of kidney graft failure in the United States

Apolipoprotein B-48 and late graft failure in kidney transplant recipients

Introduction

Transplant vasculopathy resembles atherosclerotic plaque formation and is a major contributor to late graft failure in kidney transplant recipients (KTR). Remnant lipoproteins and associated triglycerides are causal risk factors for atherosclerotic plaques and have been implicated in late kidney graft failure. However, whether remnants derived from liver (containing apolipoprotein [apo] B100) or intestine (containing apoB48) are clinically more important is unclear. The current study investigated the association between baseline fasting apoB48 levels and late kidney graft failure.

Methods

481 KTR with a functioning graft for at least 1 year were included in this retrospective, observational longitudinal single center cohort study. The primary endpoint was death-censored late graft failure, defined as need for initiation of dialysis or re-transplantation. ApoB48 was measured by enzyme-linked immunosorbent assay.

Results

During a median follow-up of 9.5 years, 61 KTR developed graft failure (12.7%). At baseline, KTR with higher apoB48 levels had lower eGFR (P < .001), lower high-density lipoprotein (HDL) cholesterol (P < .001), increased triglycerides (P < .001) and used cyclosporine more frequently (P = .003). Cox regression showed that higher baseline apoB48 was associated with higher risk of late graft failure [hazard ratio (95% confidence interval), 1.59 (1.22, 2.07), P < .001], independent of stepwise adjustment for potential confounders, including age and sex, immunosuppression type and proteinuria, triglycerides, and waist circumference (fully adjusted HR, 1.78 (1.29, 2.47), P < .001].

Conclusion

ApoB48 is strongly associated with late graft failure, independent of potential confounders. Since apoB48-containing lipoproteins originate from the intestine, this study provides a rationale for considering pharmacological interventions targeting lipid absorption to improve graft outcome.

A Transplant-Inclusive Value-Based Kidney Care Payment Model

In the United States, kidney care payment models are migrating toward value-based care (VBC) models incentivizing quality of care at lower cost. Current kidney VBC models will continue through 2026. We propose a future transplant-inclusive VBC (TIVBC) model designed to supplement current models focusing on patients with advanced chronic kidney disease (CKD) and end-stage kidney disease (ESKD). The proposed TIVBC is structured as an episode-of-care model with risk-based reimbursement for "referral/evaluation/waitlisting" (REW, referencing kidney transplantation), "primary hospitalization to 180 days posttransplant," and "long-term graft survival." Challenges around organ acquisition costs, adjustments to quality metrics, and potential criticisms of the proposed model are discussed. We propose next steps in risk-adjustment and cost-prediction to develop as an end-to-end, TIVBC model.

Economic and humanistic burden in kidney transplant rejection: a literature review

INTRODUCTION

Antibody-mediated rejection (ABMR) is a major cause of late kidney allograft failure, but its economic and humanistic impacts have not been well-characterized in the literature.

AREAS COVERED

We reviewed available literature on economic burden (costs and healthcare resource use) and humanistic burden (health-related quality of life impacts [HRQOL] and utility estimates) in patients diagnosed with kidney transplant rejection; ABMR-specific studies were of particular interest. In total, 21 publications reporting economic and humanistic burden were included in the review; 9 of these reported ABMR-specific outcomes. The reviewed studies consistently showed a greater burden associated with ABMR-related transplant rejection than with non-ABMR transplant rejection.

EXPERT OPINION

Evidence suggests greater economic burden and increased HRQOL impairment with ABMR-related kidney transplant rejection relative to non-ABMR, although small sample sizes and missing definitions for ABMR make meaningful comparisons between studies challenging. Because no International Classification of Diseases (ICD)-10 codes currently describe the etiologies of transplant rejection, it is difficult to characterize the burden of distinct types of transplant rejection. The paucity of high-quality data on the burden of ABMR in kidney transplant rejection demonstrates the need for more etiology-centric ICD-10 codes.

Proteomic analysis investigating kidney transplantation outcomes- a scoping review

BACKGROUND

Kidney transplantation is the optimal treatment option for most patients with end-stage kidney disease given the significantly lower morbidity and mortality rates compared to remaining on dialysis. Rejection and graft failure remain common in transplant recipients with limited improvement in long-term transplant outcomes despite therapeutic advances. There is an unmet need in the development of non-invasive biomarkers that specifically monitor graft function and predict transplant pathologies that affect outcomes. Despite the potential of proteomic investigatory approaches, up to now, no candidate biomarkers of sufficient sensitivity or specificity have translated into clinical use. The aim of this review was to collate and summarise protein findings and protein pathways implicated in the literature to date, and potentially flag putative biomarkers worth validating in independent patient cohorts.

METHODS

This review followed the Joanna Briggs' Institute Methodology for a scoping review. MedlineALL, Embase, Web of Science Core Collection, Scopus and Google Scholar databases were searched from inception until December 2022. Abstract and full text review were undertaken independently by two reviewers. Data was collated using a pre-designed data extraction tool.

RESULTS

One hundred one articles met the inclusion criteria. The majority were single-centre retrospective studies of small sample size. Mass spectrometry was the most used technique to evaluate differentially expressed proteins between diagnostic groups and studies identified various candidate biomarkers such as immune or structural proteins.

DISCUSSION

Putative immune or structural protein candidate biomarkers have been identified using proteomic techniques in multiple sample types including urine, serum and fluid used to perfuse donor kidneys. The most consistent findings implicated proteins associated with tubular dysfunction and immunological regulatory pathways such as leukocyte trafficking. However, clinical translation and adoption of candidate biomarkers is limited, and these will require comprehensive evaluation in larger prospective, multicentre trials.

MyKidneyCoach, Patient Activation, and Clinical Outcomes in Diverse Kidney Transplant Recipients: A Randomized Control Pilot Trial

Kidney transplant (KT) recipients who are not actively engaged in their care and lack self-management skills have poor transplant outcomes, which are disproportionately observed among Black KT recipients. This pilot study aimed to determine whether the MyKidneyCoach app, an mHealth intervention that provides self-management monitoring and coaching, improved patient activation, engagement, and nutritional behaviors in a diverse KT population.

Methods

This was a randomized, age-stratified, parallel-group, attention-control, pilot study in post-KT patients. Participants were randomized into the attention-control with access to MyKidneyCoach for education and self-management (n = 9) or the intervention with additional tailored nurse coaching (n = 7). Feasibility, acceptability, and clinical outcomes were assessed.

Results

The acceptability of MyKidneyCoach by System Usability Scale was 67.5 (95% confidence interval [CI], 59.1-75.9). Completion rates based on actively using MyKidneyCoach were 81% (95% CI, 57%-93%) and study retention rate of 73%. Patient activation measure significantly increased overall by a mean of 11 points (95% CI, 3.2-18.8). Additionally, Black patients (n = 7) had higher nutrition self-efficacy scores of 80.5 (95% CI, 74.4-86.7) compared with 75.6 (95% CI, 71.1-80.1) in non-Black patients (n = 9) but lower patient activation measure scores of 69.3 (95% CI, 56.3-82.3) compared with 71.8 (95% CI, 62.5-81) in non-Black patients after 3 mo.

Conclusions

MyKidneyCoach was easy to use and readily accepted with low attrition, and improvements were demonstrated in patient-reported outcomes. Both Black and non-Black participants using MyKidneyCoach showed improvement in self-management competencies; thus, this intervention may help reduce healthcare inequities in KT.

Evaluation of Eculizumab Use in Renal Transplant Recipients

Introduction: Eculizumab is a monoclonal antibody that binds to complement protein C5, inhibiting complement-mediated thrombotic microangiopathy. It is approved for several indications including atypical hemolytic uremic syndrome. Additionally, eculizumab is used off-label for antibody-mediated rejection and C3 glomerulopathy in renal transplant recipients. Due to limited data available, the purpose of this study was to describe the use of eculizumab treatment in renal transplant recipients. Design: This retrospective single-center study evaluated the safety and efficacy of eculizumab for on- and off-label indications in renal transplant recipients. Adult renal transplant recipients receiving at least 1 dose of eculizumab posttransplant between October 2018 and September 2021 were included. The primary outcome evaluated was graft failure in patients treated with eculizumab. Results: Forty-seven patients were included in analysis. The median age at eculizumab initiation was 51 years [IQR 38-60], with 55% being female. Indications for eculizumab included atypical hemolytic uremic syndrome/thrombotic microangiopathy (63.8%), antibody-mediated rejection (27.7%), C3 glomerulopathy (4.3%), and other (4.3%). Graft failure occurred in 10 patients (21.3%) with a median of 2.4 weeks [IQR 0.5-23.3] from transplant to graft failure. At last follow-up (median 56.1 weeks), 44 (93.6%) patients were alive. After eculizumab initiation, renal function improved at 1 week, 1 month, and last follow-up. Conclusion: Eculizumab treatment demonstrated a benefit on graft and patient survival compared to reported incidence in thrombotic microangiopathy and antibody-mediated rejection. Due to the small sample size and retrospective design, further research is warranted to confirm these results.

Conservative Kidney Management in Kidney Transplant Populations

Conservative kidney management (CKM) has been increasingly accepted as a therapeutic option for seriously ill patients with advanced chronic kidney disease. CKM is active medical management of advanced chronic kidney disease without dialysis, with a focus on delaying the worsening of kidney disease and minimizing symptom burden. CKM may be considered a suitable option for kidney transplant recipients with poorly functioning and declining allografts, defined as patients with low estimated glomerular filtration rate (<20 mL/min per 1.73 m2) who are approaching allograft failure. CKM may be a fitting option for transplant patients facing high morbidity and mortality with or without dialysis resumption, and it should be offered as a choice for this patient population. In this review, we describe clinical considerations in caring for patients with poorly functioning and declining kidney allografts, especially the unique decision-making process around kidney replacement therapies. We discuss ways to incorporate CKM as an option for these patients. We also discuss financial and policy considerations in providing CKM for this population. Patients with poorly functioning and declining kidney allografts should be supported throughout transitions of care by an interprofessional and multidisciplinary team attuned to their unique challenges. Further research on when, who, and how to integrate CKM into existing care structures for patients with poorly functioning and declining kidney allografts is needed.

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.

BK Virus Infection and BK-Virus-Associated Nephropathy in Renal Transplant Recipients

Poliomavirus BK virus (BKV) is highly infective, causing asymptomatic infections during childhood. After the initial infection, a stable state of latent infection is recognized in kidney tubular cells and the uroepithelium with negligible clinical consequences. BKV is an important risk factor for BKV-associated diseases, and, in particular, for BKV-associated nephropathy (BKVN) in renal transplanted recipients (RTRs). BKVN affects up to 10% of renal transplanted recipients, and results in graft loss in up to 50% of those affected. Unfortunately, treatments for BK virus infection are restricted, and there is no efficient prophylaxis. In addition, consequent immunosuppressive therapy reduction contributes to immune rejection. Increasing surveillance and early diagnosis based upon easy and rapid analyses are resulting in more beneficial outcomes. In this report, the current status and perspectives in the diagnosis and treatment of BKV in RTRs are reviewed.

Hypothermic Machine Perfusion as a National Standard Preservation Method for Deceased Donor Kidneys

BACKGROUND

Recently, continuous nonoxygenated hypothermic machine perfusion (HMP) has been implemented as standard preservation method for deceased donor kidneys in the Netherlands. This study was designed to assess the effect of the implementation of HMP on early outcomes after transplantation.

METHODS

Kidneys donated in the Netherlands in 2016 and 2017 were intended to be preserved by HMP. A historical cohort (2010-2014) preserved by static cold storage was chosen as the control group. Primary outcome was delayed graft function (DGF). Additional analyses were performed on safety, graft function, and survival up until 2 y after transplantation.

RESULTS

Data were collected on 2493 kidneys. Analyses showed significantly more donation after circulatory death, preemptive transplantation, and retransplants in the project cohort. Of the 681 kidneys that were transplanted during the project, 81% were preserved by HMP. No kidneys were discarded due to HMP-related complications. DGF occurred in 38.2% of the project cohort versus 43.7% of the historical cohort (P < 0.001), with a significantly shorter duration within the project cohort (7 versus 9 d, P = 0.003). Multivariate regression analysis showed an odds ratio of 0.69 (95% confidence interval, 0.553-0.855) for the risk of DGF when using HMP compared with cold storage (P = 0.001). There was no significant difference in kidney function, graft survival, and recipient survival up until 2 y posttransplantation.

CONCLUSIONS

This study showed that HMP as a standard preservation method for deceased donor kidneys is safe and feasible. HMP was associated with a significant reduction of DGF.

Impact of Extending Eligibility for Reinstatement of Waiting Time After Early Allograft Failure: A Decision Analysis

RATIONALE & OBJECTIVE

The shortage of deceased donor kidneys identified for potential transplantation in the United States is exacerbated by a high proportion of deceased donor kidneys being discarded after procurement. We estimated the impact of a policy proposal aiming to increase organ utilization by extending eligibility for waiting time reinstatement for recipients experiencing early allograft failure after transplantation.

STUDY DESIGN

Decision analysis informed by clinical registry data.

SETTING & POPULATION

We used Organ Procurement and Transplantation Network data to identify 76,044 deceased-donor kidneys procured in the United States from 2013 to 2017, 80% of which were transplanted and 20% discarded.

INTERVENTION

Extend waiting time reinstatement for recipients experiencing allograft failure from the current 90 days to 1 year after transplantation.

OUTCOME

Net impact to the waitlist, defined as the estimated number of additional transplants minus estimated increase in waiting list reinstatements.

MODEL, PERSPECTIVE, & TIMEFRAME

We estimated (1) the number of additional deceased donor kidneys that would be transplanted if there was a 5%-25% relative reduction in discards, and (2) the number of recipients who would regain waiting time under a 6-, 12-, 18-, and 24-month reinstatement policy.

RESULTS

Reinstating a waiting time for recipients experiencing allograft failure up to 1 year after transplantation yielded more additional transplants than growth in additions to the waiting list for all model assumptions except the combination of a very low relative reduction in discards (5%) and a very high failure rate of transplanted kidneys that would previously have been discarded (≥5 times the rate of currently transplanted kidneys).

LIMITATIONS

Lack of empirical evidence supporting the proposed impact of such a policy change.

CONCLUSIONS

A policy change reinstating waiting time for deceased donor kidneys recipients with allograft failure up to 1 year after transplantation should explored as a decision science-based intervention to improve organ utilization.

US payer budget impact of a microarray assay with machine learning to evaluate kidney transplant rejection in for-cause biopsies

AIM

This study evaluates the economic impact to US commercial payers of MMDx-Kidney used in conjunction with histologic evaluation of for-cause kidney transplant biopsies.

MATERIALS AND METHODS

An Excel-based model was developed to assess the cost impact of histology plus MMDx-Kidney versus histology alone for the evaluation of potential rejection in kidney transplant patients who receive a for-cause biopsy. Different model time periods were assessed, ranging from 1 to 5 years post-biopsy. A targeted literature review was used to identify parameter estimates, validated by two external clinicians with expertise in managing kidney transplant rejection. A sensitivity analysis was conducted to evaluate the relative impact of key clinical and cost parameters. In particular, the model identified the magnitude of MMDx-Kidney's impact on graft failure from rejection that would be required for MMDx-Kidney to be cost-neutral.

RESULTS

By more accurately characterizing rejection, MMDx-Kidney is estimated to increase antirejection treatment costs by $1,126 per test. Nevertheless, a break-even analysis shows that the costs of MMDx-Kidney and anti-rejection medication, as well as the costs associated with an increase in the number of patients with functioning transplants, may be offset by reductions in costs associated with graft failure (i.e. costs of hospitalizations, dialysis, and repeat transplants) over 5 years, assuming MMDx-Kidney reduces annual graft failure from rejection by at least 5%. For the base case, with a 25% relative reduction in annual rate of graft failures from rejection, MMDx-Kidney increases overall costs incurred in the first year of the model but starts generating savings by the second year of the model.

CONCLUSIONS

Compared with histologic evaluation of for-cause kidney transplant biopsies alone, the use of MMDx-Kidney in conjunction with histologic evaluation improves the diagnoses of graft dysfunction and may have the potential to generate overall savings from reductions in rejection-related graft failure.

Incorporation of Donor-derived Cell-free DNA Into Clinical Practice for Renal Allograft Management

BACKGROUND

Donor-derived cell-free DNA (dd-cfDNA) in plasma is an established noninvasive biomarker for allograft injury and rejection. A single-nucleotide polymorphism (SNP)-based massively multiplexed polymerase chain reaction methodology can be used to quantify dd-cfDNA in kidney transplant recipients. In this study we describe our clinical experience in using a SNP-based dd-cfDNA assay for the management of active rejection in renal transplant recipients.

METHODS

To assess the clinical utility of a clinically available SNP-based massively multiplexed polymerase chain reaction dd-cfDNA assay, we analyzed biopsy data contemporaneous to dd-cfDNA results at 33 participating clinics and calculated the rate of rejection in dd-cfDNA-matched biopsy results.

RESULTS

A total of 1347 dd-cfDNA test samples from 879 patients were accessioned from October 3, 2019, to November 2, 2020. The dd-cfDNA testing classified 25.2% (340/1347) of samples as high-risk (dd-cfDNA fraction ≥ 1%). Clinical follow-up was available for 32.1% (109/340) of the high-risk results, which included samples from 28 patients with definitive biopsy results within 2 weeks of dd-cfDNA testing. Pathology reports indicated a 64% (18/28) rate of active rejection in biopsy result-matched samples. Total cfDNA measurements indicated a skewed distribution and a correlation with dd-cfDNA-derived patient risk classification.

CONCLUSIONS

This is the first report showing the impact of dd-cfDNA on patient management in a multicenter real-world clinical cohort. The data indicate that incorporating dd-cfDNA testing into practice may improve physician decision making regarding renal allograft recipients.

Maintenance phase of a physical activity intervention in older kidney transplant recipients: A 12-month follow-up

Daily walking activities are associated with improving cardiovascular outcomes in older kidney transplant recipients. However, little is known regarding physical activity adherence outcomes in older kidney recipients. The purpose of this randomized controlled trial 12-month follow-up study was to evaluate the feasibility of the intervention (SystemCHANGE™ + activity tracker) during the maintenance period (7-12 months), compared to an attention-control group (activity tracker only) in older kidney recipients (age 60 and older). The sample included 60 participants (n = 30 IG; n = 30 ACG). Adherence rates for wearing the activity tracker daily were 96.5% in the IG and 80.8% in the ACG. The IG demonstrated within-group improvements for blood pressure at 12 months. Overall, there was a decrease in the average daily steps observed in both groups. These data suggest this intervention is feasible and additional boosters should be considered during the maintenance period to encourage physical activity.

Understanding and using AlloSure donor derived cell-free DNA

Renal transplant is a lifesaving and cost-effective intervention for patients with End Stage Renal Failure. Yet it is often regarded as replacement therapy rather than a cure given the overall failure rate over time. With a shortage of organs, this global issue has been further compounded by increased incidences of obesity, hypertension and diabetes, such that the disease burden and need for transplantation continues to increase. Considering the lifetime of immunosupression in transplant patients, there will also be significant associated co-morbidities By leveraging the advances in innovation in Next Generation Sequencing, the field of transplant can now monitor patients with an optimized surveillance schedule, and change the care paradigm in the post-transplant landscape. Notably, low grade inflammation is an independent risk for mortality across different disease states. In transplantation, sub-clinical inflammation enhances acute and chronic rejection, as well as accelerates pathologies that leads to graft loss. Cell free DNA has been shown to be increased in inflammatory processes as we all as provide an independent predictor of all-cause mortality. This review considers the utility of AlloSure, a donor derived cell free DNA molecular surveillance tool, which has shown new clinical insights on how best to manage renal transplant patients, and how to improve patient outcomes.