Optimizing In Vivo Data Acquisition for Robust Clinical Microvascular Imaging Using Ultrasound Localization Microscopy.

Ultrasound localization microscopy (ULM) enables microvascular imaging at spatial resolutions beyond the acoustic diffraction limit, offering significant clinical potentials. However, ULM performance relies heavily on microbubble (MB) signal sparsity, the number of detected MBs, and signal-to-noise ratio (SNR), all of which vary in clinical scenarios involving bolus MB injections. These sources of variations underscore the need to optimize MB dosage, data acquisition timing, and imaging settings in order to standardize and optimize ULM of microvasculature.

Treatment With mTOR Inhibitors as Primary Immunosuppression After Combined Heart and Kidney Transplantation.

Introduction: Sirolimus (SRL) mitigates cardiac allograft vasculopathy (CAV) progression and confers renal protection after heart transplantation (HT). However, its safety and efficacy in patients undergoing combined heart and kidney transplantation (HKT) are unclear. This study aimed to investigate the impact of conversion from calcineurin inhibitors (CNIs) to SRL on CAV progression, renal function, and outcomes in HKT compared with isolated HT.

Increased Pretransplant Inflammatory Biomarkers Predict Death With Function After Kidney Transplantation.

Background: Chronic systemic inflammation is associated with mortality in patients with chronic kidney disease, cardiovascular disease, and diabetes. The goal of this study was to examine the relationship between pretransplant inflammatory biomarkers (growth differentiation factor-15 [GDF-15], interleukin-6 [IL-6], soluble tumor necrosis factor receptor-1, monokine induced by gamma interferon/chemokine [C-X-C motif] ligand 9 [MIG/CXCL9], monocyte chemoattractant protein-1, soluble FAS, tumor necrosis factor-α, interleukin-15, and interleukin-1β) and death with function (DWF) after kidney transplantation (KT).

Methods: We retrospectively measured inflammatory biomarker levels in serum collected up to 1 y before KT (time from blood draw to KT was 130 ± 110 d) in recipients transplanted between January 2006 and December 2018.

Highly Sensitized Candidates Remain at Risk for Microvascular Inflammation Even When Donor-specific Antibody Is Avoided: A Matched Cohort Study.

Background: Microvascular inflammation (MVI) is a key feature of antibody-mediated rejection (AMR) among patients with HLA donor-specific antibody (DSA), but MVI at AMR thresholds (Banff glomerulitis [g] + peritubular capillaritis [ptc] score ≥ 2) without DSA has been increasingly recognized. We aimed to determine the incidence of MVI among highly sensitized kidney transplant recipients without DSA.

Methods: We performed a single-center, retrospective, matched cohort study comparing outcomes of kidney transplant recipients with cPRA ≥90% with preexisting DSA (n = 49), cPRA ≥90% without preexisting DSA (n = 47), and matched controls with cPRA = 0 without preexisting DSA (n = 49).

A Machine Learning-Driven Virtual Biopsy System For Kidney Transplant Patients.

In kidney transplantation, day-zero biopsies are used to assess organ quality and discriminate between donor-inherited lesions and those acquired post-transplantation. However, many centers do not perform such biopsies since they are invasive, costly and may delay the transplant procedure. We aim to generate a non-invasive virtual biopsy system using routinely collected donor parameters.

Exploring the single-cell immune landscape of kidney allograft inflammation using imaging mass cytometry.

Kidney allograft inflammation, mostly attributed to rejection and infection, is an important cause of graft injury and loss. Standard histopathological assessment of allograft inflammation provides limited insights into biological processes and the immune landscape. Here, using imaging mass cytometry with a panel of 28 validated biomarkers, we explored the single-cell landscape of kidney allograft inflammation in 32 kidney transplant biopsies and 247 high-dimensional histopathology images of various phenotypes of allograft inflammation (antibody-mediated rejection, T cell-mediated rejection, BK nephropathy, and chronic pyelonephritis).

Race-free estimated glomerular filtration rate equation in kidney transplant recipients: development and validation study.

Objective: To compare the performance of a newly developed race-free kidney recipient specific glomerular filtration rate (GFR) equation with the three current main equations for measuring GFR in kidney transplant recipients.

Design: Development and validation study SETTING: 17 cohorts in Europe, the United States, and Australia (14 transplant centres, three clinical trials).

Participants: 15 489 adults (3622 in development cohort (Necker, Saint Louis, and Toulouse hospitals, France), 11 867 in multiple external validation cohorts) who received kidney transplants between 1 January 2000 and 1 January 2021.

Early post-transplant recurrence of ANCA vasculitis while on belatacept maintenance immunosuppression.

Post-transplant recurrence of ANCA-associated vasculitis (AAV) is infrequent, with recurrence within weeks of transplantation being even rarer. We describe an unusual case of AAV recurrence within 2 weeks post-transplant. Our patient received a deceased donor kidney transplant (KDPI 60%) after 6 years on hemodialysis for end-stage renal disease from AAV.

Machine learning does not outperform traditional statistical modelling for kidney allograft failure prediction.

Machine learning (ML) models have recently shown potential for predicting kidney allograft outcomes. However, their ability to outperform traditional approaches remains poorly investigated. Therefore, using large cohorts of kidney transplant recipients from 14 centers worldwide, we developed ML-based prediction models for kidney allograft survival and compared their prediction performances to those achieved by a validated Cox-Based Prognostication System (CBPS).

Effect of Maintaining Immunosuppression After Kidney Allograft Failure on Mortality and Retransplantation.

Unlabelled: Few studies have addressed immunosuppression management after allograft failure (AF). Immunosuppression withdrawal to minimize complications must be balanced with the risk of sensitization and potentially reduced retransplantation. We aimed to determine relationships between immunosuppression, death, sensitization, and retransplantation among patients with AF.

Changes in Glomerular Volume, Sclerosis, and Ischemia at 5 Years after Kidney Transplantation: Incidence and Correlation with Late Graft Failure.

Significance Statement: Glomerular volume, ischemic glomeruli, and global glomerulosclerosis are not consistently assessed on kidney transplant biopsies. The authors evaluated morphometric measures of glomerular volume, the percentage of global glomerulosclerosis, and the percentage of ischemic glomeruli and assessed changes in these measures over time to determine whether such changes predict late allograft failure. All three features increased from transplant to five-year biopsy.

Guiding Kidney Transplantation Candidates for Effective Weight Loss: A Clinical Cohort Study.

Background: Obesity is increasingly common in kidney transplant candidates and may limit access to transplantation. Obesity and diabetes are associated with a high risk for post-transplant complications. The best approach to weight loss to facilitate active transplant listing is unknown, but bariatric surgery is rarely considered due to patient- and physician-related apprehension, among other factors.

Development and Validation of a Kidney-Transplant Specific Measure of Treatment Burden.

Background: Treatment burden refers to the work involved in managing one's health and its impact on well-being and has been associated with nonadherence in patients with chronic illnesses. No kidney transplant (KT)-specific measure of treatment burden exists. The aim of this study was to develop a KT-specific supplement to the Patient Experience with Treatment and Self-Management (PETS), a general measure of treatment burden.

Kidney Transplant Outcomes of Patients With Multiple Myeloma.

Introduction: Data on kidney transplantation (KTx) outcomes of patients with multiple myeloma (MM) are very limited.

Methods: We investigated the outcomes of patients with MM who underwent KTx between 1994 and 2019.

Results: A total of 12 transplants from 11 patients were included.

Death With Function and Graft Failure After Kidney Transplantation: Risk Factors at Baseline Suggest New Approaches to Management.

Background: Improving both patient and graft survival after kidney transplantation are major unmet needs. The goal of this study was to assess risk factors for specific causes of graft loss to determine to what extent patients who develop either death with a functioning graft (DWFG) or graft failure (GF) have similar baseline risk factors for graft loss.

Methods: We retrospectively studied all solitary renal transplants performed between January 1, 2006, and December 31, 2018, at 3 centers and determined the specific causes of DWFG and GF.

Dynamic prediction of renal survival among deeply phenotyped kidney transplant recipients using artificial intelligence: an observational, international, multicohort study.

Background: Kidney allograft failure is a common cause of end-stage renal disease. We aimed to develop a dynamic artificial intelligence approach to enhance risk stratification for kidney transplant recipients by generating continuously refined predictions of survival using updates of clinical data.

Methods: In this observational study, we used data from adult recipients of kidney transplants from 18 academic transplant centres in Europe, the USA, and South America, and a cohort of patients from six randomised controlled trials.

Kidney Transplantation in Patients With Monoclonal Gammopathy of Renal Significance (MGRS)-Associated Lesions: A Case Series.

Rationale & Objective: Data on kidney transplantation outcomes among patients with monoclonal gammopathy of renal significance (MGRS) are lacking.

Study Design: Case series of patients with MGRS, some of whom received clone-directed therapies before kidney transplantation.

Setting & Participants: 28 patients who underwent kidney transplantation from 1987 through 2016 after diagnosis with MGRS-associated lesions including light-chain deposition disease (LCDD), C3 glomerulopathy with monoclonal gammopathy (C3G-MG), and light-chain proximal tubulopathy (LCPT).

Identification of Genetic Causes of Focal Segmental Glomerulosclerosis Increases With Proper Patient Selection.

Objective: To increase the likelihood of finding a causative genetic variant in patients with a focal segmental glomerulosclerosis (FSGS) lesion, clinical and histologic characteristics were analyzed.

Patients And Methods: Individuals 18 years and older with an FSGS lesion on kidney biopsy evaluated at Mayo Clinic from November 1, 1999, through October 31, 2019, were divided into 4 groups based on clinical and histologic characteristics: primary FSGS, secondary FSGS with known cause, secondary FSGS without known cause, and undetermined FSGS. A targeted gene panel and a customized gene panel retrieved from exome sequencing were performed.

Immunoglobulin isotype compositions of ABO specific antibodies are dependent on the individual patient blood group and blood group specificity: Results from a healthy donor cohort.

Antibodies specific for the blood group ABO system antigens are of clinical significance and immunological interest. Routine clinical methods typically employ direct or indirect haemagglutination methods to measure IgM and IgG, respectively. We have developed a simple, single tube method to quantify IgM, IgG, and IgA specific for A and B antigens in order to improve accuracy and reproducibility, and to investigate the relationships between ABO group antibody type, and antibody level.