Infliximab Induction Lacks Efficacy and Increases BK Virus Infection in Deceased Donor Kidney Transplant Recipients: Results of the CTOT-19 Trial.

BACKGROUND: Ischemia-reperfusion (IR) of a kidney transplant (KTx) upregulates TNF α production that amplifies allograft inflammation and may negatively affect transplant outcomes. METHODS: We tested the effects of blocking TNF peri-KTx via a randomized, double-blind, placebo-controlled, 15-center, phase 2 clinical trial. A total of 225 primary transplant recipients of deceased-donor kidneys (KTx; 38.2% Black/African American, 44% White) were randomized to receive intravenous infliximab (IFX) 3 mg/kg or saline placebo (PLBO) initiated before kidney reperfusion. All patients received rabbit anti-thymocyte globulin induction and maintenance immunosuppression (IS) with tacrolimus, mycophenolate mofetil, and prednisone. The primary end point was the difference between groups in mean 24-month eGFR. RESULTS: There was no difference in the primary end point of 24-month eGFR between IFX (52.45 ml/min per 1.73 m 2 ; 95% CI, 48.38 to 56.52) versus PLBO (57.35 ml/min per 1.73 m 2 ; 95% CI, 53.18 to 61.52; P =0.1). There were no significant differences between groups in rates of delayed graft function, biopsy-proven acute rejection (BPAR), development of de novo donor-specific antibodies, or graft loss/death. Immunosuppression did not differ, and day 7 post-KTx plasma analyses showed approximately ten-fold lower TNF ( P <0.001) in IFX versus PLBO. BK viremia requiring IS change occurred more frequently in IFX (28.9%) versus PLBO (13.4%; P =0.004), with a strong trend toward higher rates of BKV nephropathy in IFX (13.3%) versus PLBO (4.9%; P =0.06). CONCLUSIONS: IFX induction therapy does not benefit recipients of kidney transplants from deceased donors on this IS regimen. Because the intervention unexpectedly increased rates of BK virus infections, our findings underscore the complexities of targeting peritransplant inflammation as a strategy to improve KTx outcomes.Clinical Trial registry name and registration number:clinicaltrials.gov (NCT02495077).

Stakeholders' perspectives on transplant metrics: the 2022 Scientific Registry of Transplant Recipients' consensus conference.

In July 2022, the Scientific Registry of Transplant Recipients (SRTR) hosted an innovative, multistakeholder consensus conference to identify information and metrics desired by stakeholders in the transplantation system, including patients, living donors, caregivers, deceased donor family members, transplant professionals, organ procurement organization professionals, payers, and regulators. Crucially, patients, caregivers, living donors, and deceased donor family members were included in all aspects of this conference, including serving on the planning committee, participating in preconference focus groups and learning sessions, speaking at the conference, moderating conference sessions and breakout groups, and shaping the conclusions. Patients constituted 24% of the meeting participants. In this report, we document the proceedings and enumerate 160 recommendations, 10 of which have been highly prioritized. SRTR will use the recommendations to develop new presentations of information and metrics requested by stakeholders to support informed decision-making.

A Composite End Point of Graft Status and eGFR at 1 Year to Improve the Scientific Registry of Transplant Recipients' Five-Tier Rating System.

BACKGROUND: Performance of kidney transplant programs in the United States is monitored and publicly reported by the Scientific Registry of Transplant Recipients (SRTR). With relatively few allograft failure events per program and increasing homogeneity in program performance, quantifying meaningful differences in program competency based only on 1-year survival rates is challenging. METHODS: We explored whether the traditional end point of allograft failure at 1 year can be improved by incorporating a measure of allograft function (i.e., eGFR) into a composite end point. We divided SRTR data from 2008 through 2018 into a training and validation set and recreated SRTR tiers, using the traditional and composite end points. The conditional 5-year deceased donor allograft survival and 5-year eGFR were then assessed using each approach. RESULTS: Compared with the traditional end point, the composite end point of graft failure or eGFR <30 ml/min per 1.73 m2 at 1-year post-transplant performed better in stratifying transplant programs based on long-term deceased donor graft survival. For tiers 1 through 5 respectively, the 5-year conditional graft survival was 72.9%, 74.8%, 75.4%, 77.0%, and 79.7% using the traditional end point and 71.1%, 74.4%, 76.9%, 77.0%, and 78.4% with the composite end point. Additionally, with the five-tier system derived from the composite end point, programs in tier 3, tier 4, and tier 5 had significantly higher mean eGFRs at 5 years compared with programs in tier 1. There were no significant eGFR differences among tiers derived from the traditional end point alone. CONCLUSIONS: This proof-of-concept study suggests that a composite end point incorporating allograft function may improve the post-transplant component of the five-tier system by better differentiating between transplant programs with respect to long-term graft outcomes.

Blood Transcriptomes of SARS-CoV-2-Infected Kidney Transplant Recipients Associated with Immune Insufficiency Proportionate to Severity.

BACKGROUND: Among patients with COVID-19, kidney transplant recipients (KTRs) have poor outcomes compared with non-KTRs. To provide insight into management of immunosuppression during acute illness, we studied immune signatures from the peripheral blood during and after COVID-19 infection from a multicenter KTR cohort. METHODS: We ascertained clinical data by chart review. A single sample of blood was collected for transcriptome analysis. Total RNA was poly-A selected and RNA was sequenced to evaluate transcriptome changes. We also measured cytokines and chemokines of serum samples collected during acute infection. RESULTS: A total of 64 patients with COVID-19 in KTRs were enrolled, including 31 with acute COVID-19 (<4 weeks from diagnosis) and 33 with post-acute COVID-19 (>4 weeks postdiagnosis). In the blood transcriptome of acute cases, we identified genes in positive or negative association with COVID-19 severity scores. Functional enrichment analyses showed upregulation of neutrophil and innate immune pathways but downregulation of T cell and adaptive immune activation pathways. This finding was independent of lymphocyte count, despite reduced immunosuppressant use in most KTRs. Compared with acute cases, post-acute cases showed "normalization" of these enriched pathways after 4 weeks, suggesting recovery of adaptive immune system activation despite reinstitution of immunosuppression. Analysis of the non-KTR cohort with COVID-19 showed significant overlap with KTRs in these functions. Serum inflammatory cytokines followed an opposite trend (i.e., increased with disease severity), indicating that blood lymphocytes are not the primary source. CONCLUSIONS: The blood transcriptome of KTRs affected by COVID-19 shows decreases in T cell and adaptive immune activation pathways during acute disease that, despite reduced immunosuppressant use, associate with severity. These pathways show recovery after acute illness.

Role of time from transplantation to biopsy in histologic ABMR: A single center report.

BACKGROUND: Allograft biopsies with lesions of Antibody-Mediated Rejection (ABMR) with Microvascular Inflammation (MVI) have shown heterogeneous etiologies and outcomes. METHODS: To examine factors associated with outcomes in biopsies that meet histologic ABMR criteria, we retrospectively evaluated for-cause biopsies at our center between 2011 and 2017. We included biopsies that met the diagnosis of ABMR by histology, along with simultaneous evaluation for anti-Human Leukocyte Antigen (HLA) donor-specific antibodies (DSA). We evaluated death-censored graft loss (DCGL) and used a principal component analysis (PCA) approach to identify key predictors of outcomes. RESULTS: Out of the histologic ABMR cohort (n = 118), 70 were DSA-positive ABMR, while 48 had no DSA. DSA(+)ABMR were younger and more often female recipients. DSA(+)ABMR occurred significantly later post-transplant than DSA(-)ABMR suggesting time-dependence. DSA(+)ABMR had higher inflammatory scores (i,t), chronicity scores (ci, ct) and tended to have higher MVI scores. Immunodominance of DQ-DSA in DSA(+)ABMR was associated with higher i+t scores. Clinical/histologic factors significantly associated with DCGL after biopsy were inputted into the PCA. Principal component-1 (PC-1), which contributed 34.8% of the variance, significantly correlated with time from transplantation to biopsy, ci/ct scores and DCGL. In the PCA analyses, i, t scores, DQ-DSA, and creatinine at biopsy retained significant correlations with GL-associated PCs. CONCLUSIONS: Time from transplantation to biopsy plays a major role in the prognosis of biopsies with histologic ABMR and MVI, likely due to ongoing chronic allograft injury over time.

Discovery and Validation of a Urinary Exosome mRNA Signature for the Diagnosis of Human Kidney Transplant Rejection.

BACKGROUND: Developing a noninvasive clinical test to accurately diagnose kidney allograft rejection is critical to improve allograft outcomes. Urinary exosomes, tiny vesicles released into the urine that carry parent cells' proteins and nucleic acids, reflect the biologic function of the parent cells within the kidney, including immune cells. Their stability in urine makes them a potentially powerful tool for liquid biopsy and a noninvasive diagnostic biomarker for kidney-transplant rejection. METHODS: Using 192 of 220 urine samples with matched biopsy samples from 175 patients who underwent a clinically indicated kidney-transplant biopsy, we isolated urinary exosomal mRNAs and developed rejection signatures on the basis of differential gene expression. We used crossvalidation to assess the performance of the signatures on multiple data subsets. RESULTS: An exosomal mRNA signature discriminated between biopsy samples from patients with all-cause rejection and those with no rejection, yielding an area under the curve (AUC) of 0.93 (95% CI, 0.87 to 0.98), which is significantly better than the current standard of care (increase in eGFR AUC of 0.57; 95% CI, 0.49 to 0.65). The exosome-based signature's negative predictive value was 93.3% and its positive predictive value was 86.2%. Using the same approach, we identified an additional gene signature that discriminated patients with T cell-mediated rejection from those with antibody-mediated rejection (with an AUC of 0.87; 95% CI, 0.76 to 0.97). This signature's negative predictive value was 90.6% and its positive predictive value was 77.8%. CONCLUSIONS: Our findings show that mRNA signatures derived from urinary exosomes represent a powerful and noninvasive tool to screen for kidney allograft rejection. This finding has the potential to assist clinicians in therapeutic decision making.

Developing simultaneous liver-kidney transplant medical eligibility criteria while providing a safety net: A 2-year review of the OPTN's allocation policy.

The OPTN's simultaneous liver-kidney (SLK) allocation policy, implemented August 10, 2017, established medical eligibility criteria for adult SLK candidates and created Safety Net kidney allocation priority for liver-alone recipients with new/continued renal impairment. OPTN SLK and kidney after liver (KAL) data were analyzed (registrations as of December 31, 2019, transplants pre-policy [March 20, 2015-August 9, 2017] vs. post-policy [August 10, 2017-December 31, 2019]). Ninety-four percent of SLK registrations met eligibility criteria (99% CKD: 50% dialysis, 50% eGFR). SLK transplant volume decreased from a record 740 (2017) to 676 (2018, -9%), with a subsequent increase to 728 (2019, 1.6% below 2017 volume). For KAL listings within 1 year of liver transplant, waitlist mortality rates declined post-policy versus pre-policy (27 [95% CI = 20.6-34.7] vs. 16 [11.7-20.5]) while transplant rates increased fourfold (46 [32.2-60.0] vs. 197 [171.6-224.7]). There were 234 KAL transplants post-policy (94% Safety Net priority eligible), and no significant difference in 1-year patient/graft survival vs. kidney-alone (patient: 95.9% KAL, 97.0% kidney-alone [p = .39]; graft: 94.2% KAL, 94.6% kidney-alone [p = .81]). From pre- to post-policy, the proportion of all deceased donor kidney and liver transplants that were SLK decreased (kidney: 5.1% to 4.3%; liver: 9.7% to 8.7%). SLK policy implementation interrupted the longstanding rise in SLK transplants, while Safety Net priority directed kidneys to liver recipients in need with thus far minimal impact to posttransplant outcomes.

Consensus conference on heart-kidney transplantation.

Simultaneous heart-kidney transplant (sHK) has enabled the successful transplantation of patients with end-stage heart disease and concomitant kidney disease, with non-inferior outcomes to heart transplant (HT) alone. The decision for sHK is challenged by difficulties in differentiating those patients with a significant component of reversible kidney injury due to cardiorenal syndrome who may recover kidney function after HT, from those with intrinsic advanced kidney disease who would benefit most from sHK. A consensus conference on sHK took place on June 1, 2019 in Boston, Massachusetts. The conference represented a collaborative effort by experts in cardiothoracic and kidney transplantation from centers across the United States to explore the development of guidelines for the interdisciplinary criteria for kidney transplantation in the sHK candidate, to evaluate the current allocation of kidneys to follow the heart for sHK, and to recommend standardized care for the management of sHK recipients. The conference served as a forum to unify criteria between the different specialties and to forge a pathway for patients who may need dual organ transplantation. Due to the continuing shortage of available donor organs, ethical problems related to multi-organ transplantation were also debated. The findings and consensus statements are presented.

Economic Evaluation of Extending Medicare Immunosuppressive Drug Coverage for Kidney Transplant Recipients in the Current Era.

BACKGROUND: Kidney transplant recipients must take immunosuppressant drugs to prevent rejection and maintain transplant function. Medicare coverage of immunosuppressant drugs for kidney transplant recipients ceases 36 months after transplantation, potentially increasing the risk of transplant failure. A contemporary economic analysis of extending Medicare coverage for the duration of transplant survival using current costs of immunosuppressant medications in the era of generic equivalents may inform immunosuppressant drug policy. METHODS: A Markov model was used to determine the incremental cost and effectiveness of extending Medicare coverage for immunosuppressive drugs over the duration of transplant survival, compared with the current policy of 36-month coverage, from the perspective of the Medicare payer. The expected improvement in transplant survival by extending immunosuppressive drug coverage was estimated from a cohort of privately insured transplant recipients who receive lifelong immunosuppressant drug coverage compared with a cohort of Medicare-insured transplant recipients, using multivariable survival analysis. RESULTS: Extension of immunosuppression Medicare coverage for kidney transplant recipients led to lower costs of -$3077 and 0.37 additional quality-adjusted life years (QALYs) per patient. When the improvement in transplant survival associated with extending immunosuppressant coverage was reduced to 50% of that observed in privately insured patients, the strategy of extending drug coverage had an incremental cost-utility ratio of $51,694 per QALY gained. In a threshold analysis, the extension of immunosuppression coverage was cost-effective at a willingness-to-pay threshold of $100,000, $50,000, and $0 per QALY if it results in a decrease in risk of transplant failure of 5.5%, 7.8%, and 13.3%, respectively. CONCLUSIONS: Extending immunosuppressive drug coverage under Medicare from the current 36 months to the duration of transplant survival will result in better patient outcomes and cost-savings, and remains cost-effective if only a fraction of anticipated benefit is realized.

Physician and patient acceptance of policies to reduce kidney discard.

Despite the shortage of kidneys for transplantation in the United States, approximately 18%-20% of deceased donor kidneys are discarded each year. These discarded kidneys can offer a survival benefit to suitable patients. Revisions to the current kidney allocation policy may be needed to reduce deceased donor kidney discard. We surveyed transplant physicians and patients to assess their perceived acceptability of policy proposals to reduce the discard of deceased donor kidneys. Members of professional societies (AST, ASTS) and a patient organization (AAKP) were invited to complete the survey. Responses were obtained from 97 physicians and 107 patients. The majority of physicians (73.4%) and patients (73.8%) "somewhat" or "completely" accepted a policy for fast-tracking kidneys at risk of discard. Physicians and patients also supported returning a proportion of waiting time to patients who accept KDPI >85 kidneys and experience graft failure within the first 12 months, with 36% of physicians and 50% of patients electing to return 100% of the waiting time. The majority of physicians (75%) "somewhat or completely" accepted a policy to skip less aggressive centers for KDPI 90 + offers. Physicians and patients provided insights into factors researchers, and policymakers should consider in the design and implementation of these policies.

A call to action: Feasible strategies to reduce the discard of transplantable kidneys in the United States.

Changes to the United States kidney allocation system targeted at reducing organ discard have failed to improve organ utilization. High Kidney Donor Profile Index kidneys continue to be discarded at high rates as a result of the regulatory and financial barriers to widespread utilization of these organs. However, there are potential changes to clinical practice that could improve organ utilization. Expediting the time from initial offer to final organ acceptance would reduce cold ischemic time and should improve utilization. Implementation of procurement biopsy standards to avoid biopsy of low risk organs may prevent organ discards due to inaccurate data or excessive cold ischemia time. Further, standardization of procurement biopsy pathological interpretation coupled with electronic accessibility would enable early acceptance of difficult to transplant organs. These changes to allocation practice patterns are vital given proposals to expand the geographic sharing of deceased donor kidneys. Implementation of new allocation policies must be evaluated to ensure they result in higher transplant rates and acceptable post-transplant outcomes.

Safety, pharmacokinetics, and pharmacodynamic activity of obinutuzumab, a type 2 anti-CD20 monoclonal antibody for the desensitization of candidates for renal transplant.

The limited effectiveness of rituximab plus intravenous immunoglobulin (IVIG) in desensitization may be due to incomplete B cell depletion. Obinutuzumab is a type 2 anti-CD20 antibody that induces increased B cell depletion relative to rituximab and may therefore be more effective for desensitization. This open-label phase 1b study assessed the safety, pharmacokinetics, and pharmacodynamics of obinutuzumab in highly sensitized patients with end-stage renal disease. Patients received 1 (day 1, n = 5) or 2 (days 1 and 15; n = 20) infusions of 1000-mg obinutuzumab followed by 2 doses of IVIG on days 22 and 43. Eleven patients received additional obinutuzumab doses at the time of transplant and/or at week 24. The median follow-up duration was 9.4 months. Obinutuzumab was well tolerated, and most adverse events were grade 1-2 in severity. There were 11 serious adverse events (SAEs) in 9 patients (36%); 10 of these SAEs were infections and 4 occurred after kidney transplant. Obinutuzumab plus IVIG resulted in profound peripheral B cell depletion and appeared to reduce B cells in retroperitoneal lymph nodes. Reductions in anti-HLA antibodies, number of unacceptable antigens, and the calculated panel reactive antibody score as centrally assessed using single-antigen bead assay were limited and not clinically meaningful for most patients (NCT02586051).

Report of National Kidney Foundation Consensus Conference to Decrease Kidney Discards.

The organ shortage is one of the major challenges in the field of organ transplantation, yet the percentage of kidneys procured and discarded prior to transplantation has continued to rise to twenty percent. The causes of organ discard are complex, yet an urgent need exists for collaborative efforts to maximize the utilization of all potentially transplantable renal allografts. The National Kidney Foundation convened a meeting of experts to identify factors contributing to reduced organ utilization, and to propose actionable solutions to decrease the rate of kidney discards.

Solid organ transplantation of viral hepatitis C positive donor organs into viral hepatitis C negative recipients.

PURPOSE OF REVIEW: Strategies are needed to reduce waitlist mortality and increase transplantation rates. Advances in hepatitis C therapy has allowed the transplant community to look toward utilization of grafts from hepatitis C viremic donors to expand the organ pool. Use of such grafts for hepatitis C-negative patients is being evaluated and debated, and early trial data are emerging. RECENT FINDINGS: Both hepatitis C antibody-positive/nucleic acid test-negative and viremic donors are currently underutilized. Outcomes for viral hepatitis C (HCV) viremic transplant recipients are improving in the setting of direct-acting antiviral therapy. Optimization of graft utilization from HCV 'positive' donors and expansion to use of viremic donors for HCV-negative recipients will likely reduce waitlist mortality and result in net overall reduction in healthcare expenditures. SUMMARY: Herein, we provide a review of recent advancements relating to hepatitis C in solid organ transplant and outline future directions. A primary future focus will be data collection of outcomes of transplantation of grafts from HCV 'viremic' donors to nonviremic recipients in formal clinical trial protocols.

Simultaneous liver kidney transplantation.

PURPOSE OF REVIEW: Simultaneous liver kidney transplantation (SLK) has taken center stage since the initiation of the new kidney allocation system (KAS). This review places SLK in the context of the changing landscape of organ allocation. RECENT FINDINGS: The introduction of the Mayo End-Stage Liver Disease score into liver allocation policy in 2002 resulted in a significant increase in the number of SLKs performed in the United States. Except for a brief respite in 2009, the rate of SLK has continued to increase with 2015 seeing 626 SLKs. KAS did not mandate sharing kidneys with regionally shared livers. It was anticipated this would reduce the number of SLKs. Additionally, the Kidney Donor Profile Index in KAS made possible a more granular assessment of the quality of the kidneys being allocated to SLK recipients. This revealed that nearly 50% of Kidney Donor Profile Index kidneys 0.35 or less, those to be allocated to children, were given to SLK recipients and that a significant proportion of them may not need a kidney. SUMMARY: Medical eligibility criteria, rules for the allocation of kidneys simultaneously with livers, and the establishment of a safety net, will provide nephrologists with the framework and authority to decide which liver disease patients truly need a kidney.