American Journal of Transplantation

BACKGROUND: Increased left ventricular mass (LVM) at a single time point after heart transplantation (HT) predicts future adverse outcomes. However, dynamic changes in LVM could have better biological relevance and reflect adverse graft remodeling (AGR). The prognostic significance of such serial changes has not been studied. METHODS: Using an automated, electronic health record-based institutional data infrastructure, we studied 439 HT recipients with 5,563 LVM measurements. Separate Bayesian joint models estimated the simultaneous associations of current LVM and its instantaneous rate of change with graft dysfunction (GD) and mortality. A joint-model-derived remodeling score combining patient-specific deviations in LVM and slope was dichotomized to define AGR and non-AGR groups. A mixed-effects analysis of all clinical variables was performed to assess associations with LVM both between and within patients. An independent cohort of 35 patients with 79 surveillance-biopsy RNA-sequencing samples was used to examine early stress-responsive pathways associated with the remodeling score. RESULTS: LVM declined by approximately 7 g/year after transplantation, with regression attenuating over time. Sixty patients (13.7%) had GD, and 75 (17.1%) died. Higher LVM was associated with subsequent GD (hazard ratio [HR] per 10 g, 1.14; 95% credible interval [CrI], 1.02-1.28) and mortality (HR, 1.10; 95% CrI, 1.02-1.19). A more positive LVM slope was associated with GD (HR per 1 g/year, 1.21; 95% CrI, 1.06-1.42) and with cardiac allograft vasculopathy (CAV) grade 2 or 3 (HR, 1.39; 95% Crl, 1.02-1.96). LVM regressed more slowly in the AGR group (-5.8 vs -8.4 g/year), with higher GD (21.0% vs 6.4%) and mortality (24.2% vs 10.0%). Time-updated GD was associated with subsequent death (HR, 8.12; 95% Confidence Interval [CI], 4.67-14.14). Transcriptomic analysis showed enrichment of interferon-mediated signaling and vascular endothelial activation with higher remodeling scores, whereas lower scores were associated with mitochondrial and metabolic processes, ribosome biogenesis, and pathways related to tissue repair and stress responses. CONCLUSIONS: AGR is an easily accessible imaging biomarker that reflects the changes in the allograft in response to various stressors and predicts future adverse outcomes. Discovery of molecular mechanisms of AGR could lead to novel therapies to protect the allograft from chronic rejection.

BackgroundLupus nephritis remains a major cause of chronic kidney disease and kidney failure in systemic lupus erythematosus. Glucocorticoids are central to treatment but are limited by systemic toxicity. We evaluated whether a previously characterized collagen IV 3-targeted liposomal nanoparticle formulation carrying low-dose prednisolone could attenuate established lupus nephritis in MRL/lpr mice. MethodsFemale MRL/lpr mice with disease present at treatment initiation and C57BL/6J control mice received saline or collagen IV 3-targeted prednisolone-loaded nanoparticles (Col4-3-Pred-NPs). Renal outcomes were assessed by longitudinal proteinuria, glomerular filtration rate (GFR), survival, kidney histopathology, renal IgG and C3d deposition, dUTP/TUNEL-associated injury staining, and renal cytokine/chemokine profiling. Body weight, food and water intake, and blood glucose were monitored as measures of general condition and preliminary tolerability. ResultsCol4-3-Pred-NPs improved survival in MRL/lpr mice, reduced cumulative proteinuria burden, and attenuated terminal GFR decline compared with saline-treated MRL/lpr controls. Treatment reduced glomerular and tubulointerstitial injury, lowered composite EGTI histopathology scores, decreased terminal kidney enlargement, reduced glomerular IgG deposition and renal dUTP-positive injury signals, and reduced renal signals for IL-28A/B, IL-7, PD-ECGF, IL-11, CCL6/C10, and IL-15. C3d deposition was not significantly altered. Nanoparticle treatment was not associated with sustained treatment-related increases in blood glucose or body-weight loss during the measured study period. ConclusionsCollagen IV 3-targeted liposomal delivery of low-dose prednisolone attenuated established lupus nephritis in MRL/lpr mice and improved renal structural, functional, inflammatory, and survival outcomes. These findings support further evaluation of glomerulus-targeted nanotherapy as a potential strategy to improve the precision and therapeutic index of glucocorticoid treatment in lupus nephritis.

Background: Adult congenital heart disease (ACHD) patients are prone to HLA-antibody formation from multiple surgeries, transfusions, and prosthetic surgical material. Females with ACHD may accrue additional, non-surgical alloantigen exposure. Whether sex modifies the impact of allosensitization on heart transplant (HT) access and outcomes in ACHD remains unknown. Methods: We retrospectively analyzed the OPTN/UNOS registry of adults with ACHD listed for first-time HT (2018-2025). Sensitization was defined by calculated panel reactive antibodies (cPRA) at listing. We tested the sex x sensitization (highly sensitized, cPRA >50%) interaction on transplant access using Fine-Gray competing-risks regression, treating transplantation as the event of interest and death or removal from the waitlist as competing events, and on post-transplant survival using multivariable Cox proportional-hazards regression, both adjusted for age at listing, mechanical support at listing, and the number of distinct prior cardiac surgery categories. Results: Among 856 candidates (38% female), females were more often highly sensitized than males (23% vs 14%; age-adjusted OR 1.81, 95% CI 1.26-2.61), even after adjusting for surgical burden. Sensitization reduced transplant access in females (84% to 71%; median wait 60 to 110 days, p < 0.001) but not males (79% vs 79%, median wait 88 vs 98 days). In adjusted Fine-Gray models, the subdistribution hazard for transplant was reduced in sensitized females (sHR 0.54, 95% CI 0.41-0.72) with no effect in males (sHR 0.96, 95% CI 0.73-1.26), and the sex x sensitization interaction was significant (interaction sHR 0.64, 95% CI 0.44-0.94, p = 0.02). Post-transplant mortality was numerically higher in sensitized than non-sensitized candidates in both sexes and the sex x sensitization interaction on 1-year mortality was not significant. The sex-asymmetric effect persisted and was more pronounced in the multiorgan candidates. Conclusions: Allosensitization is not a sex-neutral barrier to transplant in HT candidates with ACHD. Females are more sensitized and have reduced transplant access without differences in 1-year mortality. The female excess in sensitization is not accounted for by surgical burden, and the exposures responsible remain to be defined. These findings warrant a sex-aware listing strategy and further studies.

Background. Cardiovascular-kidney-metabolic (CKM) syndrome affects nearly 90% of US adults, yet most individuals at early, modifiable stages remain unidentified outside clinical care. Blood donation centers offer a scalable, non-clinical venue for CKM screening, but the potential benefit of screening in this context remains unclear. We projected the population-level impact of effective digital return of results (ROR) to inform the design of a pragmatic trial. Methods. We developed a Monte Carlo simulation (100,000 iterations) of the incident major adverse cardiovascular events (MACE), end-stage renal disease (ESRD), and type 2 diabetes (T2DM) preventable by ROR-prompted, guideline-concordant follow-up among donors in CKM Stages 1-2. The estimand counts only events averted by donors who act because of ROR; the intervention effect was modeled directly on strictly positive support, and action was translated into prevented events through a hazard-based cumulative-incidence difference that counts each donor at most once. We evaluated 18 design cells (donor volumes 300,000, 1 million, and 8 million/year; 5- and 10-year horizons; action-rate gains of +10, +20, and +30 percentage points [pp]) and, in a complementary two-arm simulation, the assurance (expected power) of detecting the effect in a single deployment. Results. Under the primary +20 pp scenario, ROR at a single large blood center (300,000 donors/year) is projected to prevent a median of 2,201 events (95% uncertainty interval [UI], 1,099-4,364) over 10 years, scaling to 58,526 (29,154-116,769) at the national donor pool. All 18 design cells had strictly positive 95% lower bounds. The number needed to screen was 136 and the screening cost $2,045 per event prevented (at $15/donor), both invariant to donor volume. Impact scaled linearly with volume and effect size but sub-linearly with the horizon. Detection of the effect was effectively certain at gains of +20 pp or larger (assurance [&ge;]99.6% in every cell and >99.9% in all but the smallest 5-year cell). Conclusions. Even under the conservative scenario, digital CKM ROR at blood donation centers is projected to prevent hundreds to tens of thousands of incident cardiometabolic events at a screening cost per event well within accepted prevention benchmarks, providing prospective, quantitative justification for a pragmatic, randomized evaluation of digital ROR in non-clinical screening settings.

Accurate, reproducible interpretation of kidney allograft biopsies is critical for diagnosis of graft injury to guide prognosis and management. The international Banff classification is a consensus diagnostic system based on semiquantitative histological lesion scoring on either extent or severity of kidney transplant biopsies. However, pathologist scoring is limited by substantial interobserver variability, constrained scalability, and the inherent nature of the scoring system itself. Here we present BanffNET, a weakly supervised, probabilistic deep learning framework that combines self-supervised feature extraction with a novel Bayesian multiple-instance learning framework to predict (continuously) the full spectrum of Banff lesion scores directly from whole-slide images (WSIs). Using lesion-specific aggregation functions tailored to localized (modeling lesion severity) and diffuse pathologies (modeling lesion extent), BanffNET generates interpretable, patch-level probability maps and calibrated slide-level scores. BanffNET's performance was assessed relative to consensus, biological correlates of rejection and clinical outcome, demonstrating superior consistency, transportability and generalization. Trained on 7,249 WSIs from three cohorts, BanffNET demonstrates consistent performance on 11,028 WSIs across five external test sets, performing on par or exceeding expert consensus across lesions. BanffNET scores align more closely than pathologist Banff scores with molecular profiles of rejection, offering a transparent, biologically grounded framework for computational pathology with relevance beyond transplantation.

Despite immunosuppressive regimens targeting adaptive immunity, chronic lung allograft dysfunction (CLAD) remains the major obstacle to durable lung allograft survival. Here, we identify colony-stimulating factor 1 receptor (CSF1R)-expressing interstitial macrophages as critical orchestrators of CLAD. Using lung tissue from patients with CLAD and a mouse model of mismatched lung transplantation, we show that both donor-derived tissue-resident and recipient- monocyte-derived interstitial macrophages spatially co-localize within peribronchial immune aggregates in patients with CLAD. These interstitial macrophages express distinct cytokine programs that include those implicated in the recruitment of T and B cells. Pharmacological inhibition of CSF1R after lung transplantation in mice reduced interstitial macrophage abundance and attenuated CLAD pathology. Our findings identify donor- and recipient-derived interstitial macrophages as upstream regulators of CLAD and suggest CSF1R as a therapeutic target for its prevention and treatment.

Background: Whether benchmark performance reflects robust clinical reasoning rather than surface-level pattern recognition remains uncertain. We evaluated the robustness of state-of-the-art large language models (LLMs) on nephrology board renewal questions using "None of the other answers" (NOTA) substitution. Methods: From 210 Japanese Society of Nephrology board renewal questions (2014-2023), two nephrologists independently reviewed all items. Questions in which NOTA became the sole correct answer after replacement were included, yielding 145 validated questions. GPT-5, GPT-4o, Gemini 2.5 Pro, and Gemini 2.0 Flash were evaluated via application programming interfaces under default settings. The primary endpoint was accuracy, and paired differences were assessed using the exact two-sided McNemar test. Results: Accuracy was significantly lower after NOTA substitution for all models: GPT-4o, 66.21% to 19.31% (drop, 46.90 percentage points [pp]); GPT-5, 87.59% to 73.10% (14.48 pp); Gemini 2.0 Flash, 58.62% to 31.03% (27.59 pp); and Gemini 2.5 Pro, 86.90% to 55.86% (31.03 pp); all P < .001. GPT-5 showed the smallest decline and the highest accuracy in both versions. Conclusions: All evaluated LLMs showed a significant robustness gap after NOTA replacement. Newer models may be more robust, but multiple-choice accuracy remains an incomplete measure of clinical reasoning robustness.

Background & Aims: Immune-mediated liver injury from immune checkpoint inhibitors (ILICI) is a major immune-related adverse event that limits cancer immunotherapy, yet its tissue-level immunobiology is poorly defined and its management is largely extrapolated from autoimmune hepatitis (AIH). We previously identified a tri-cellular CD8+ T cell-macrophage-hepatocyte injury niche in a murine model of ILICI; here, we tested whether this niche is recapitulated in human disease. Methods: We applied imaging mass cytometry with a 32-marker panel to liver biopsies from patients with ILICI (n = 12), AIH as a disease comparator (n = 14), and healthy controls (n = 2), profiling approximately 297,000 single cells across 144 regions of interest with spatially resolved detection of apoptosis (cleaved caspase-3, cC3) and pyroptosis (cleaved gasdermin D, cGSDMD). Results: We detected histiocyte-rich granulomas in ILICI consisting of macrophages and CD8+ T cells, including activated memory-effector subsets. Permutation-based spatial analysis identified CD8+ T cell-macrophage co-localization as the most frequent significant interaction in ILICI, organizing into integrated innate-adaptive cellular neighborhoods that concentrated cC3- and cGSDMD-positive cells. Descriptively, this contrasted with AIH, in which immune cells and stroma were more spatially compartmentalized. CD8+ T-cell and macrophage densities correlated with Ishak necroinflammation scores, jaundice, and granuloma formation. Conclusions: These findings provide the first single-cell spatial proteomic characterization of human ILICI in situ; they recapitulate the tri-cellular CD8-macrophage-hepatocyte niche we previously defined in a murine model and characterize ILICI as a spatially organized innate-adaptive inflammatory process, nominating myeloid signaling and CD8-macrophage interactions as candidate liver-directed targets to uncouple hepatotoxicity from anti-tumor immunity.

Background Cardiac magnetic resonance imaging (CMR) T1 and T2 mapping accurately detect acute heart transplant rejection, but the diagnostic value of CMR-derived strain imaging remains uncertain, particularly for right ventricular strain. Data incorporating donor-derived cell-free DNA (dd-cfDNA) into a composite reference standard are limited. We evaluated the diagnostic accuracy of CMR-derived left and right ventricular strain and ejection fraction for detecting acute rejection in pediatric and adult heart transplant recipients. Methods Blinded analysis of 1.5T CMR studies was performed in pediatric and adult heart transplant recipients 1-24 months post-transplant, as well as during five additional episodes of acute rejection occurring 3-14 years post-transplant. Left and right ventricular strain and ejection fraction were quantified using semi-automated post-processing. Acute rejection was defined using a composite reference standard comprising endomyocardial biopsy (EMB), clinical assessment, and dd-cfDNA. Diagnostic performance was assessed using cut-off values derived from receiver operator characteristic (ROC) analysis. Results Among 214 CMR studies in 58 patients, 13 cases of acute rejection were identified. Diagnostic performance for detecting acute rejection was moderate for pediatric right ventricular longitudinal strain (AUC 0.782, 95% CI 0.565-0.999), whereas all other cardiac functional parameters demonstrated limited discrimination in both pediatric and adult patients (AUC 0.536-0.739). Models based on individual rejection indicators (EMB, clinical assessment, and dd-cfDNA) also showed poor diagnostic accuracy. Conclusion CMR-derived left and right ventricular strain and ejection fraction demonstrated limited ability to independently detect acute rejection. However, strain abnormalities, particularly RVLS in pediatric patients, may reflect downstream functional effects in more advanced rejection and may complement T1 and T2 mapping in assessing rejection severity.

Immune checkpoint inhibitor-induced myocarditis (ICIM) is a severe immune-related adverse event with heterogeneous clinical presentations and potential genetic susceptibility. Here, we established a human induced pluripotent stem cell (iPSC) line from an ICIM patient with an HLA-type distinct from previously reported line, who developed concurrent type I diabetes following ICI treatment. This line exhibited typical morphology, normal female karyotype, pluripotency, trilineage differentiation into all three germ layers, Sendai virus clearance, and no mycoplasma contamination. Given the fulminant nature and diverse clinical presentations of ICIM, expanding the repertoire of iPSC lines are critical for investigating ICIM heterogeneity and its underlying mechanisms.

Introduction: B cell depletion with rituximab leads to complete or partial remission (CR/PR) in only ~60% of patients with primary membranous nephropathy (PMN). Adding belimumab to rituximab may result in greater depletion of memory B cells, limit the re-emergence of autoreactive B cells, and improve clinical responses. Methods: REBOOT Part A (NCT03949855) is a single arm, open-label, pharmacokinetic study where all participants had proteinuria [&ge;] 4g/day and detectable serum anti-phospholipase A2 receptor (anti-PLA2R) antibodies. Participants received belimumab 200 mg subcutaneously weekly for 52 weeks and rituximab 1000 mg intravenously at weeks 4 and 6. Assessments included belimumab exposure at week 4 and CR/PR at week 104. Results: Seventeen participants started belimumab. Belimumab exposure was not significantly reduced in those with high (> 9 g/day) proteinuria at week 4. Among all treated participants, 59% (10/17) achieved CR/PR at week 104, while in per protocol analyses, 91% (10/11) achieved CR/PR at week 104. All participants in per protocol analyses had normal serum albumin and undetectable serum anti-PLA2R by week 104. Circulating memory B cells increased before rituximab and were depleted by rituximab. B cell re-constitution occurred after week 52 with primarily naive and transitional B cells. Belimumab with rituximab was well-tolerated, with one participant discontinuing belimumab due to infection. Conclusion: In this study, a high proportion of participants receiving belimumab with rituximab achieved CR/PR. Thus, a multi-targeted approach to B cell depletion may improve immunologic and clinical outcomes in PMN and is being studied in a larger, randomized, placebo-controlled clinical trial.

Background: The rising burden of metabolic dysfunction-associated steatotic liver disease (MASLD)-associated hepatocellular carcinoma (HCC) underscores the need for innovative therapeutic strategies. Methods: We integrated RNA-seq fusion detection, immunopeptidomics, and proteogenomics to systematically prioritize tumor-specific neoantigen candidates arising from gene fusions in MASLD-HCC. Results: We elucidated a landscape of private, clonally expressed fusions, and identified a previously unrecognized class of predicted phosphorylated fusion-neoepitopes. Cross-tumor proteomic analysis revealed that these phospho-motifs are present across malignancies, providing a broader context for their biological relevance. Importantly, fusion-positive tumors display immunosuppressive microenvironments, highlighting the need for future therapeutic strategies that combine fusion-targeted immunotherapy with approaches that overcome T-cell dysfunction. Conclusions: This study establishes a discovery pipeline and publicly available resource for fusion-derived phospho-neoepitopes in MASLD-HCC. The identified candidates provide a prioritized framework to guide and accelerate rigorous functional immunogenicity testing for future clinical validation.

Background: Current understanding of acute kidney injury (AKI) risk factors remains largely descriptive, offering limited precision into how specific biomarker values or physiologic thresholds influence susceptibility. We aimed to synthesize knowledge from machine learning models trained across multiple health systems to identify generalizable, value-specific risk drivers and biomarker interactions contributing to AKI risk. Methods: We analyzed electronic health records (EHRs) from 785,497 adult inpatients between 2010 and 2019 across nine U.S. academic medical centers within PCORnet. Interpretable gradient boosting machine models were independently developed at each health system to quantify predictor-outcome associations. Meta-regression was applied to integrate these site-level results, characterize nonlinear value-risk relationships, and identify bivariate interactions between predictors. Results: Meta-analysis revealed consistent, value-specific risk drivers across health systems. An increase in glucose from 100 mg/dL to 140 mg/dL was associated with a 1.46-fold higher risk of AKI. Chloride and anion gap also demonstrated elevated AKI risk with risk increases overlapping portions of their reference ranges, with anion gap showing a 1.14-fold increase across 4-12 mmol/L and chloride a 1.28-fold increase across 96-100 mEq/L. Electrolytes including potassium, calcium, and sodium showed quadratic associations with AKI risk. Bivariate meta-regression identified interactions between key predictors, highlighting pathways that jointly modulate AKI risk. Conclusion: This cross-system meta-analysis synthesizes machine learning-derived evidence into clinically interpretable knowledge, revealing how specific biomarker ranges and interactions modulate AKI risk. By moving beyond surface-level associations to quantitative, generalizable physiologic thresholds, these findings provide actionable insights to enhance risk stratification and personalized prevention in hospital care.

Background: Faecal microbiota transplantation (FMT) is an effective treatment for recurrent Clostridioides difficile infections, yet the diversity of FMT formulations and delivery routes hampers comparisons across studies. Oral frozen capsules are widely used and current guidelines recommend storage at -80C for up to two years. Despite extensive use of FMT, data on the long-term persistence and maintenance of their microbial composition remains limited. Method: In this prospective study, we assessed the temporal stability of bacterial profiles in frozen FMT capsules derived from 48 donations of 10 healthy donors. Using metabarcoding, we longitudinally profiled one capsule per donation thawed within a month of production and after 3, 6, 12, and 24 months of storage. We used linear mixed effect models to evaluate changes in alpha diversity and community composition over time. Results: Species richness remained stable across all timepoints, whilst species evenness decreased slightly. Although changes in community composition were detectable, they were small and mostly affected low-abundance genera. Clinical efficacy, assessed in a subset of recipients, was not associated with storage duration. Conclusion: Our findings demonstrate that frozen FMT capsules preserve their bacterial community structure for at least two years of storage at -80C, supporting their suitability for long-term biobanking and standardised clinical or research use.

Background IgA vasculitis (IgAV) is the most common systemic vasculitis in children, and its prognosis is largely determined by renal involvement (IgAV nephritis). No routine blood test identifies IgAV or stratifies the risk of nephritis, although aberrant O-glycosylation of the IgA1 hinge region is central to its pathogenesis. We developed a mass-spectrometry assay to profile IgA1 hinge O-glycoforms and define signatures of disease activity and renal involvement. Methods IgA was affinity-purified from 5 uL of plasma from 91 children (27 with acute IgAV, 26 in remission, and 38 age-matched healthy controls; 24 with and 29 without nephritis), trypsin-digested, and hinge-region O-glycopeptides were quantified by LC-MS. Sixty-nine glycoforms were normalized to a total-IgA1 tryptic peptide. Duplicate measurements showed good analytical repeatability, with a median coefficient of variation of 6%. Groups were compared using Mann-Whitney and Kruskal-Wallis tests (Benjamini-Hochberg FDR). Discrimination was assessed by ROC analysis and cross-validated logistic regression panels. Results Acute IgAV showed broad remodeling of the hinge glycoform profile (35 glycoforms differed with excellent discrimination (AUC 0.93-0.95) for the best ones), with an increase in low-sialylated, agalactosylated species and a decrease in complex sialylated species. The profile was normalized in remission (no glycoform differed from the controls). Two distinct renal patterns emerged: disease-associated glycoforms already altered without nephritis and renal-specific glycoforms altered only in nephritis (H2N2S1, H3N3S5, H3N4S4, and H4N4S3). A four-marker panel discriminated nephritis among IgAV children with a cross-validated AUC of 0.86 (IC95 % 0.75-0.94). Conclusions A single mass-spectrometry assay, from a small blood volume, captures an IgAV-associated IgA1 hinge O-glycoform signature that normalizes in remission, together with a distinct renal involvement associated signature. These findings identify candidate IgA1 O-glycoform signatures associated with IgAV activity and documented renal involvement. Prospective longitudinal studies are required to determine whether the renal-associated panel can predict subsequent nephritis.

ABSTRACT Importance: The prevalence of chronic kidney disease (CKD) is increasing, with aging being a major contributor. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are well established therapies for CKD; however, adults aged 80 years or older have been underrepresented in previous large-scale trials. Consequently, evidence regarding effects of SGLT2i therapy in this cohort remains limited. Objective: To evaluate the association of SGLT2i initiation with mortality, kidney outcomes and cardiovascular outcomes among patients over 80 years of age and CKD. Design, Setting, Participants: This retrospective cohort study used data from TriNetX Research Network, a multicenter electronic health record database. To ensure comparable standard of care and SGLT2i eligibility, the period for the occurrence of the index event was restricted to January 1, 2021, until January 1, 2025. Propensity score matching was performed to balance comorbidities, laboratory parameters, concomitant medications, and frailty-associated factors between groups. Exposures: Initiation of SGLT2i therapy vs. non-use Main Outcomes and Measures: Outcome analysis focused on all-cause mortality, major adverse kidney events (MAKE) and major adverse cardiovascular events (MACE). Cox proportional hazards models were used to estimate hazard ratios with 95% confidence intervals; following propensity score matching, results were considered as adjusted hazard ratios (aHR). Results: After propensity score matching, 5,038 patients were included in each group. During two years of follow-up, SGLT2i initiation was associated with lower all-cause mortality (aHR 0.818; 95% CI 0.746 - 0.896, p<0.0001) and fewer MAKE events (aHR 0.779; 95% CI 0.0.715 - 0.850, p<0.0001). No significant difference in MACE was observed (aHR 1.007; 95%CI 0.938 - 1.082, p=0.84). Results were generally consistent across subgroups. Risk of acute kidney injury was higher in the SGLT2i group, while incident dialysis and end-stage renal disease were significantly reduced. Acute myocardial infarction and acute heart failure were increased in the SGLT2i group. Conclusion and Relevance: Regarding survival and kidney endpoints, even the oldest CKD patients seem to benefit from SGLT2i treatment, which was associated with reduced mortality as well as improved long-term renal outcomes. MACE showed no significant differences, while specific cardiac events were increased, reflecting possible safety concerns requiring further investigation in this specific age group.

T cell repertoire sequencing has unveiled a vast, complex array of T cells responsible for the human immune responses. Traditional analytic methodology fails to fully characterize and quantify the diversity of T cell receptors constituting the T cell repertoire. T cell receptor clonal frequency measured in terms of T cell receptor beta (TRB) V gene segment usage when arrayed in correspondence with the respective V gene segment positions on the TRB loci yields a periodic, undulating curve in the spatial domain of the TRB genomic locus. Using the genomic distance from the TRB-D1 segment to the TRB-V1-29 segments, Fourier analysis was performed utilizing Lomb-Scargle periodogram to obtain Spectral Power curves quantifying the TRB V clonal frequencies from 6 allogeneic stem cell transplant donors (baseline) and recipients (>/=100 days) using a variety of analytic software. Spectral Power curves revealed dominant spectral peaks at wavelengths ranging from 4-9 kb (113-252 millicycles/kb) in the six donors, with consistent frequency domain spectral patterns. This is consistent with similar use of V segments across healthy individuals. Recipients on the other hand demonstrated more dispersed spectra, with a spectral centroid shifted towards higher frequencies compared to donors (260 vs. 247 millicycles/kb). Consistent with this observation, the Low Frequency Index was lower in the recipients (0.18 vs 0.20). Power was concentrated in the <3 kb and 3-12 kb wavelengths in both groups. The analyses reported here demonstrate that the healthy SCT donors have a remarkably similar spectral signature occupying short to intermediate wavelegnths in the frequency domain, whereas recipients tend to shift towards higher frequencies. These findings are consistent with a normal organized distribution of TRB V segment usage in healthy individuals (by analogy other loci), and a more diffuse and disorderly usage in recipients, consistent with the notion of T cell responses constituting a dynamical system which evolves as a function of time. Fourier analysis of TRB (and potentially TRA) sequencing data provides a repertoire wide summary of T cell clonal distribution.

Background: Fibrosis, characterised by excessive accumulation of collagen type I (COL1), is a common feature of chronic diseases, including liver diseases (LDs), chronic kidney disease (CKD) and heart failure (HF). COL1 degradation products can be detected in urine by proteomics/ peptidomics analyses and may serve as non-invasive biomarkers of fibrosis. We aimed to identify a common molecular signature of fibrosis across these diseases that may ultimately guide interventions to slow disease progression and prevent organ damage. Methods: Using capillary electrophoresis coupled to mass spectrometry (CE-MS), naturally occurring COL1 degradation products (peptides) in the urine of patients with fibrotic disease, LDs (n=127), CKD (n=263) or HF (n=187), were investigated and compared with the same number of matched controls. Disease-associated COL1 peptides were identified separately for each condition, and peptides showing consistent associations across the three diseases were selected to define a common fibrosis signature. A support vector machine model based on the selected peptides was developed and validated in independent cohorts of patients with LDs (n=110), CKD (n=93), HF (n=32) and controls (n=643). Results: We identified a common fibrotic signature consisting of 50 COL1 degradation products, mainly downregulated in fibrosis. A model based on these peptides achieved a strong performance, with an area under the receiver operating characteristic curve (AUC) of 0.935 (95% confidence interval (CI) 0.917-0.953, p<0.0001) in an external validation cohort comprising pooled disease groups (LDs, CKD, and HF) and controls. Performance was maintained in LDs, CKD and HF, with AUCs of 0.917 (95% CI 0.890-0.944, p<0.0001), 0.951 (95% CI 0.931-0.971, p<0.0001) and 0.950 (95% CI 0.903-0.997, p<0.0001), respectively. The model scores were significantly associated with fibrosis stage in LDs (p=0.0097) and with interstitial fibrosis and tubular atrophy in CKD (p=0.045). Conclusion: A model of urinary COL1 peptides captures a shared collagen degradation signature across organs and diseases, enabling the non-invasive assessment of fibrosis irrespective of its origin. As these peptides exclusively reflect collagen degradation, the findings suggest impaired collagen degradation as a driver in fibrosis. Future clinical studies are warranted to evaluate the utility of this model for early fibrosis detection and earlier implementation of anti-fibrotic interventions.

Major histocompatibility complexes (MHC) govern antigen presentation and T cell receptor (TCR) selection. Accurate in vivo modeling of human immunity therefore requires physiological human MHC TCR interactions. Humanized NOD scid IL2null (NSG) mice engrafted with human CD34+ hematopoietic stem cells are widely used to provide preclinical platforms for the development of advanced therapies; however, interactions between murine MHC and human TCR can promote xenoreactivity and alter T cell development. Here, we investigated how elimination of murine MHC together with different conditioning regimens shapes human T cell maturation in vivo. CD34+ cells from ten cord blood donors were transplanted into conventional NSG mice or murine MHC deficient NSG derivatives (DKO) following either sublethal irradiation or myeloablative busulfan conditioning. Integrated analyses combining flow cytometry, plasma cytokine profiling, and bulk and single cell TCR sequencing revealed marked differences in T cell differentiation across models. Busulfan conditioned DKO mice developed highly proliferative, activated, and cytotoxic T cells together with clonally expanded TCR repertoires. In contrast, irradiated NSG mice preferentially accumulated naive, NKT, and regulatory T cell populations. Busulfan-conditioned DKO mice showed no evidence of xenogeneic graft versus host disease and represent a refined enabling platform for human T cell development and provide a foundation for future preclinical evaluation of advanced gene and cell therapies.

Background: The dietary approaches to stop hypertension (DASH) diet is often recommended to patients with chronic kidney disease, although evidence regarding its efficacy in this population is limited. Our study tested the hypothesis that increased adherence to the dietary approaches to stop hypertension (DASH) diet score would be associated with longer time to kidney function decline among Veterans. Methods: We conducted a retrospective cohort study of 251,921 Veterans enrolled in the Million Veteran Program (MVP). The DASH diet score was calculated from the food frequency questionnaire and categorized into tertiles. The primary outcome was a composite of: Kidney event or death, where a kidney event was defined as a sustained 40% decline in estimated glomerular filtration rate (eGFR) or end-stage kidney disease (ESKD). Cox regression models compared the hazard for both outcomes by DASH score tertiles. We examined modification by ancestry, sex and other clinical characteristics Results: The median age was 67 years and 90% of Veterans were men. There were 59,269 (23.5%) who experienced the primary composite outcome, during the maximum follow-up of 10 years (median 6.1 years). Crude incidence rates for the kidney event and death outcome were 43.3, 40.4, and 36.8 per 1000 person-years of DASH score by tertiles. DASH score was associated with a lower hazard ratio (HR) for the primary composite outcome; third vs first tertile 0.81 (95% Confidence Interval (CI) 0.80 - 0.83) and second vs first tertile HR 0.90 [95% CI 0.88 - 0.92]. In subgroup analysis for individuals of African ancestry, Admixed American, and Females, only the third tertile of the DASH score was associated with a statistically significant reduction in composite outcome. Conclusion: Beneficial associations of the DASH diet were observed across subgroups. Future research is needed to understand gene and environmental factors that influence the observed subgroup differences