A cross-sectional study of the role of epithelial cell injury in kidney transplant outcomes.

Background: Expression of acute kidney injury-associated (AKI-associated) transcripts in kidney transplants may reflect recent injury and accumulation of epithelial cells in "failed repair" states. We hypothesized that the phenomenon of failed repair could be associated with deterioration and failure in kidney transplants.

Methods: We defined injury-induced transcriptome states in 4,502 kidney transplant biopsies injury-induced gene sets and classifiers previously developed in transplants.

Combination Automated Microfluidics Measurement of Urine C-C Motif Ligand 2, CXC-Motif Chemokine 9, CXC-Motif Chemokine 10, and Vascular Endothelial Growth Factor A for Monitoring Patients with a Kidney Transplant.

Key Points: Combining urine C-C motif ligand 2, CXC-motif chemokine 9, CXC-motif chemokine 10, and vascular endothelial growth factor A identifies stable transplant recipients without biopsy-proven acute rejection with >75% specificity and 94% negative predictive value. Measuring four urine analytes in combination using an automated platform is highly efficient (<70 minutes) and reproducible across three independent sites. Automated urine analyte measurement provides critical decision support and outperforms eGFR measurements alone for post-transplantation monitoring.

Sex and gender as predictors for allograft and patient-relevant outcomes after kidney transplantation.

Background: Sex, as a biological construct, and gender, defined as the cultural attitudes and behaviours attributed by society, may be associated with allograft loss, death, cancer, and rejection. Other factors, such as recipient age and donor sex, may modify the association between sex/gender and post-transplant outcomes.

Objectives: We sought to evaluate the prognostic effects of recipient sex and, separately, gender as independent predictors of graft loss, death, cancer, and allograft rejection following kidney or simultaneous pancreas-kidney (SPK) transplantation.

Association of COVID-19 With Risk of Posttransplant Diabetes Mellitus.

Background: Posttransplant diabetes mellitus (PTDM) is an important complication for solid organ transplant recipients (SOTRs). COVID-19 has been associated with an increased risk of incident diabetes in the general population. However, the association between COVID-19 and new-onset PTDM has not been explored.

The Relative Risk of COVID-19 in Solid Organ Transplant Recipients Over Waves of the Pandemic.

Solid organ transplant recipients (SOTR) are at increased risk from COVID-19. Over time, the absolute risk of adverse outcomes after COVID-19 has decreased in both the non-immunosuppressed/immunocompromised (non-ISC) general population, and amongst SOTR. Using the N3C, we examined the absolute risk of mortality, major adverse renal or cardiac events, and hospitalization after COVID-19 diagnosis amongst non-ISC and SOTR populations over five waves of the pandemic (Wave 1: Ancestral COVID; Wave 2: Alpha; Wave 3: Delta; Wave 4: Omicron; Wave 5: Omicron).

Extreme phenotype sampling and next generation sequencing to identify genetic variants associated with tacrolimus in African American kidney transplant recipients.

African American (AA) kidney transplant recipients (KTRs) have poor outcomes, which may in-part be due to tacrolimus (TAC) sub-optimal immunosuppression. We previously determined the common genetic regulators of TAC pharmacokinetics in AAs which were CYP3A5 *3, *6, and *7. To identify low-frequency variants that impact TAC pharmacokinetics, we used extreme phenotype sampling and compared individuals with extreme high (n = 58) and low (n = 60) TAC troughs (N = 515 AA KTRs).

Steroid-tacrolimus drug-drug interaction and the effect of CYP3A genotypes.

Aims: Tacrolimus, metabolized by CYP3A4 and CYP3A5 enzymes, is susceptible to drug-drug interactions (DDI). Steroids induce CYP3A genes to increase tacrolimus clearance, but the effect is variable. We hypothesized that the extent of the steroid-tacrolimus DDI differs by CYP3A4/5 genotypes.

Comparing the prognostic performance of iBOX and biopsy-proven acute rejection for long-term kidney graft survival.

Biopsy-proven acute rejection (BPAR) occurs in approximately 10% of kidney transplant recipients in the first year, making superiority trials unfeasible. iBOX, a quantitative composite of estimated glomerular filtration rate, proteinuria, antihuman leukocyte antigen donor-specific antibody, and + full/- abbreviated kidney histopathology, is a new proposed surrogate endpoint. BPAR's prognostic ability was compared with iBOX in a pooled cohort of 1534 kidney transplant recipients from 4 data sets, including 2 prospective randomized controlled trials.

Effectiveness of mRNA Booster Vaccine Against Coronavirus Disease 2019 Infection and Severe Outcomes Among Persons With and Without Immune Dysfunction: A Retrospective Cohort Study of National Electronic Medical Record Data in the United States.

Background: Real-world evidence of coronavirus disease 2019 (COVID-19) messenger RNA (mRNA) booster effectiveness among patients with immune dysfunction are limited.

Methods: We included data from patients in the United States National COVID Cohort Collaborative (N3C) who completed ≥2 doses of mRNA vaccination between 10 December 2020 and 27 May 2022. Immune dysfunction conditions included human immunodeficiency virus infection, solid organ or bone marrow transplant, autoimmune diseases, and cancer.

A multicenter prospective study to define the natural history of BK viral infections in kidney transplantation.

Background: BK polyomavirus (BKV) can cause permanent loss of allograft function due to BKV-associated nephropathy (BKVN) in kidney transplant recipients. Besides immunosuppression reduction, there are no consistently effective interventions for BKV infection. Study purpose was to define natural history of BKV infection, identify risk factors for BKV reactivation and BKVN in kidney transplant recipients, and inform the design/conduct of future clinical trials of BKV-targeted therapeutics.

Advancing mouse models for transplantation research.

Mouse models have been instrumental in understanding mechanisms of transplant rejection and tolerance, but cross-study reproducibility and translation of experimental findings into effective clinical therapies are issues of concern. The Mouse Models in Transplantation symposium gathered scientists and physician-scientists involved in basic and clinical research in transplantation to discuss the strengths and limitations of mouse transplant models and strategies to enhance their utility. Participants recognized that increased procedure standardization, including the use of prespecified, defined endpoints, and statistical power analyses, would benefit the field.

Impact of Centers for Medicare and Medicaid Services Final Rule on Organ Procurement Organization Metrics and Procedural Trends in the Procurement of Pancreata for Research.

Objective: Pancreata recovered for research are included as a success (or positive) in the Centers for Medicare and Medicaid Services' (CMS) donation and organ transplantation rate metrics for recertification of organ procurement organizations (OPOs).

Materials And Methods: Given these metrics directly incentivize recovery of pancreata for research, this study tracks trends in recovery of pancreata for research across the implementation of the CMS metrics.

Results: In the 26 months before the December 2, 2020, publication of the CMS metrics, research pancreata as a percent of organs transplanted, including research pancreata, was 1.

The Banff 2022 Kidney Meeting Report: Reappraisal of microvascular inflammation and the role of biopsy-based transcript diagnostics.

The XVI-th Banff Meeting for Allograft Pathology was held at Banff, Alberta, Canada, from 19th to 23rd September 2022, as a joint meeting with the Canadian Society of Transplantation. To mark the 30th anniversary of the first Banff Classification, premeeting discussions were held on the past, present, and future of the Banff Classification. This report is a summary of the meeting highlights that were most important in terms of their effect on the Classification, including discussions around microvascular inflammation and biopsy-based transcript analysis for diagnosis.

Chronic Active Antibody-mediated Rejection: Opportunity to Determine the Role of Interleukin-6 Blockade.

Chronic active antibody-mediated rejection (caAMR) is arguably the most important cause of late kidney allograft failure. However, there are no US Food and Drug Administration (FDA)-approved treatments for acute or chronic AMR and there is no consensus on effective treatment. Many trials in transplantation have failed because of slow and/or inadequate enrollment, and no new agent has been approved by the FDA for transplantation in over a decade.

The Banff 2022 Kidney Meeting Work Plan: Data-driven refinement of the Banff Classification for renal allografts.

The XVIth Banff Meeting for Allograft Pathology was held in Banff, Alberta, Canada, from September 19 to 23, 2022, as a joint meeting with the Canadian Society of Transplantation. In addition to a key focus on the impact of microvascular inflammation and biopsy-based transcript analysis on the Banff Classification, further sessions were devoted to other aspects of kidney transplant pathology, in particular T cell-mediated rejection, activity and chronicity indices, digital pathology, xenotransplantation, clinical trials, and surrogate endpoints. Although the output of these sessions has not led to any changes in the classification, the key role of Banff Working Groups in phrasing unanswered questions, and coordinating and disseminating results of investigations addressing these unanswered questions was emphasized.

The Impact of Ethnicity on Research Authorization at the Time of Organ Donation: A Single-Center Experience Among Deceased Donor Kidney Transplantation.

Objective: Research on deceased organ donors is needed to expand the donor organ supply. Little is known about the rate of research authorization among various groups. We aimed to determine the percentage of research authorization by the deceased donor family across different donor characteristics.