Journal of the American Society of Nephrology

Secondary hyperparathyroidism persists in the majority of kidney transplant recipients and is associated with adverse graft and cardiovascular outcomes. The immunosuppressive drug class used post-transplant may modulate parathyroid hormone (PTH) levels through distinct mechanisms: calcineurin inhibitors (CNI) stabilize PTH mRNA, while mTOR inhibitors (mTORi) suppress parathyroid cell proliferation in experimental models. We report supporting evidence from two independent analyses. In a multinational real-world database analysis (TriNetX Global Collaborative Network), kidney transplant recipients with documented mTORi use and eGFR in the target range had lower PTH than those on CNI across eGFR strata examined (15-30, 30-45, 45-60, 60-75, >75 mL/min/1.73 m2), with risk ratios for PTH >130 pg/mL ranging from 0.47 to 0.67 in propensity-matched analyses (all p < 0.05). The known confounders - calcium (higher in CNI) and phosphate (higher in mTORi) - both act to oppose this pattern, strengthening the possibility of a drug effect. In a longitudinal single-center cohort (n = 118; 796 PTH measurements), a linear mixed-effects model with time-varying mTORi exposure confirmed a 42% lower PTH during on-mTORi periods after adjustment for eGFR, transplant vintage, diabetes, age, and sex (fold-change 0.58 [95% CI 0.50-0.68]; p < 0.0001). These findings suggest a direct PTH-lowering effect of mTORi. Immunosuppression choice may be considered in the management of post-transplant hyperparathyroidism in selected patients.

Background.Renoprotective therapies - SGLT2 inhibitors, finerenone, and renin-angiotensin system inhibitors (RASi) - remain underutilisedin chronic kidney disease (CKD). Large language models (LLMs) may detect therapy omissions, but their performance acrossCKD severity strata and at clinical decision boundaries has not been evaluated.Methods.We constructed 100 synthetic CKD vignettes (G3a-G5D; 75 with prespecified omissions, 25 decoys) and queried four LLMsthree times each at temperature 0 (1,200 calls). Omission criteria were adapted from KDIGO 2024, including an investigator-defined gray-zone RASi initiation criterion at eGFR<15. Two nephrologists independently classified a stratified 20-casesubset.Results.For SGLT2 inhibitor and finerenone omissions, all models achieved near-ceiling sensitivity (97-100%). For RASi, performancediverged at the eGFR<15 boundary: Grok 4.1 Fast 85% versus GPT-5.4 55%, Gemini 10%, DeepSeek 10%. Gap-detectioninter-rater agreement was perfect (kappa = 1.000). Clinically incorrect reasoning rates ranged from 0% (GPT-5.4) to 27%(DeepSeek R1); of 52 instances, 31 were factual pharmacology errors and 21 reflected conservative boundary-discordantreasoning. Reproducibility (Jaccard) ranged from 0.74 to 0.93.Conclusions.This boundary-aware synthetic benchmark showed that aggregate sensitivity can conceal clinically important operational-rulediscordance. Rule-based SGLT2 inhibitor and finerenone omissions were detected with near-ceiling sensitivity, whereas aninvestigator-defined gray-zone RASi criterion at eGFR<15 exposed model-specific boundary behaviour. Evaluation of LLM-based CKD decision support should report boundary-specific performance, reproducibility, and clinically incorrect reasoningalongside aggregate metrics.

Background and hypothesis: Sodium-glucose cotransporter-2 inhibitors (SGLT2-inhibitors) slow chronic kidney disease progression, but evidence in non-diabetic kidney transplant recipients is limited. We evaluated associations between SGLT2-inhibitor use and major adverse kidney events (MAKE), major adverse cardiovascular events (MACE), and all-cause mortality. Methods: In this retrospective cohort study using the TriNetX federated research network, adult non-diabetic kidney transplant recipients transplanted between January 2015 and January 2022 were identified. SGLT2-inhibitor users initiating therapy [&ge;]1000 days post-transplant were compared with non-users after 1:1 propensity score matching. The primary outcome was MAKE, defined as dialysis initiation or death. Secondary outcomes included all-cause mortality and MACE. Results: Propensity score matching yielded 867 pairs of SGLT2-inhibitor users and non-users. SGLT2-inhibitor use was associated with lower risks of MAKE (adjusted hazard ratio [aHR] 0.64, 95% CI 0.45-0.91) and all-cause mortality (aHR 0.55, 95% CI 0.36-0.85). No significant association was observed for MACE (aHR 0.86, 95% CI 0.64-1.17). No increased risk of urinary tract infections was observed among SGLT2-inhibitor users. Conclusion: SGLT2-inhibitor use was associated with lower risks of MAKE and all-cause mortality in non-diabetic kidney transplant recipients.

Abstract Background Alport Syndrome (AS), caused by pathogenic variants in type IV collagen genes COL4A3/4/5, is a leading monogenic cause of Kidney Failure (KF). Clinical course varies widely, and disease specific predictors of progression relevant to clinical care and trial design remain incompletely defined. Methods In this retrospective cohort study of individuals with AS in the UK National Registry of Rare Kidney Diseases, patients were classified as having AS or heterozygous genotypes and followed to assess proteinuria progression, eGFR slope and kidney survival. Proteinuria and eGFR trajectories were analysed using mixed effects regression models; kidney survival using Kaplan Meier analysis. Results Among 1032 participants (median follow up 11.6 years; 47% female), 475 (46%) had AS genotypes (Male XLAS or autosomal recessive AS). eGFR decline accelerated with advancing CKD stage across all genotypes (p<0.001). Proteinuria increased as eGFR declined and occurred earlier in AS genotypes. After reaching proteinuria thresholds of more than 1.0 and 3.0g/g, kidney survival over the subsequent 5 years did not differ significantly between genotypes (logrank p=0.14, p=0.17, respectively), although modest differences emerged over longer follow-up. Across eGFR thresholds (90, 60, and 45mL/min/1.73m2), higher proteinuria was associated with shorter time to KF; for example, at eGFR 45mL/min/1.73m2, median time to KF was 3.0 years (IQR, 1.6-5.4) for above-median vs 6.5 years (5.1-not estimable) for below-median proteinuria (p<0.0001). Almost all patients who reached KF had developed proteinuria of more than 0.3g/g. Conclusion In this national cohort, eGFR decline accelerated with CKD stage and proteinuria was strongly associated with progression to KF across genotypes. The non linearity of eGFR decline may inform its interpretation in clinical practice and use as a trial endpoint. Once comparable proteinuria levels were reached, differences in outcomes by genotype were attenuated, supporting proteinuria as a key prognostic marker and strengthening rationale for its use as a surrogate endpoint in AS clinical trials

Rationale & ObjectivePeriodontal disease(PD), a chronic inflammatory condition, may contribute to chronic kidney disease(CKD) through systemic inflammation, but its impact on CKD outcomes and the potential protective effects of periodontal treatment and routine dental prophylaxis remain uncertain. This study evaluated associations between PD, dental interventions, and kidney outcomes in a large U.S. veteran cohort. Study DesignRetrospective cohort study. Setting & ParticipantsUsing Veterans Health Administration data(2009-2019), we identified 86,376 adults eligible for comprehensive dental care with baseline eGFR >60 mL/min/1.73m{superscript 2} and followed them from their initial dental examination. ExposurePatients with PD (Cohort-A) were divided into those who received periodontal treatment (PD-Treated), those who did not receive treatment but had [&ge;]1 dental prophylaxis visit/year (PD-Prophylaxis), and those who received neither (PD-Untreated). Those without PD (Cohort-B) were grouped by presence or absence of regular dental prophylaxis ([&ge;]1 visit/year). OutcomeIncident CKD (eGFR <60 mL/min/1.73 m{superscript 2} and >25% decline from baseline), [&ge;]40% eGFR reduction, and incident albuminuria (>30 mg/g), each confirmed with repeat labs [&ge;]90 days apart. Analytical ApproachMultivariable logistic regression model ResultsOf 86,376 veterans (mean age 57.17{+/-}12.59 years; 91.4% male), 37.6% had PD. Adjusted model showed significantly lower odds of incident CKD, [&ge;]40% eGFR decline, and incident albuminuria noted in both PD-Treated [OR(95%CI): 0.80(0.70-0.91), 0.69(0.56-0.84), 0.88 (0.79-0.99)] and PD-Prophylaxis groups [OR(95%CI): 0.81(0.66-0.98), 0.60(0.43-0.82), 0.79(0.67-0.94)] compared to the PD-Untreated. Similarly, among patients without PD, regular dental prophylaxis was associated with reduced odds of Incident CKD, [&ge;]40% eGFR decline, and incident albuminuria [OR(95%CI): 0.87(0.78-0.96), 0.76(0.65-0.90), 0.85(0.78-0.93)]. LimitationsRetrospective design, unmeasured confounders, and reliance on electronic health records. ConclusionsPD is associated with increased risks of incident CKD, accelerated eGFR decline, and new-onset albuminuria. Periodontal treatment and routine dental prophylaxis mitigate these risks. Even in individuals without PD, regular dental prophylaxis appears protective against CKD development and progression.

Background: Clinical LLM benchmarks rarely test whether algorithmic rankings agree with expert clinical judgment. We developed a trap-embedded peritoneal dialysis (PD) benchmark comparing multiple scoring constructs with blinded nephrologist ratings. Methods: We generated 125 synthetic PD cases containing 13 ISPD-aligned trap types. Five LLMs (Claude Sonnet 4.5, GPT-5.4, Gemini 3.1 Pro, DeepSeek-R1, Grok 4.1 Fast) evaluated each case three times at temperature 0 (1,875 calls). Primary outcome was must-identify TDR_must, analyzed with GEE and case-clustered bootstrap. Secondary analyses included a verbosity-sensitive alarm-burden proxy, WCS, relaxed-match scoring, WCS sensitivity analyses, and a 25-output blinded expert adequacy substudy. Must-identify kappa was 0.89 in Stage 1 and 0.92 in Stage 2. Results: Rankings were discordant. Recall ranked Claude (0.977) and GPT-5.4 (0.955) above the other models (0.86-0.90, p<0.0001). The alarm-burden proxy favored concise models (Grok 0.689; 21.6 vs 2.4 issues/case), while WCS produced a third ordering. In the expert substudy, inter-rater concordance was strong (rho 0.977), but WCS did not show a positive association with expert adequacy (rho -0.17, p=0.41). Conclusion: Clinical LLM rankings in PD prescription review depend strongly on scoring construct. Algorithmic metrics should be reported alongside blinded expert adequacy ratings and should not alone determine deployment.

Importance: Recently, proteinuria has been accepted as a surrogate end point for clinical trials in focal segmental glomerulosclerosis (FSGS) ang IgA nephropathy. However, proteinuria has not been evaluated in Apolipoprotein L1 (APOL1)-mediated kidney disease (AMKD). Methods: Real world data (RWD) analysis of 128 patients of African ancestry with APOL1 high risk genotypes, without diabetes, enrolled in the Million Veteran Program (MVP; n=109) or the biorepository at Vanderbilt University (BioVU; n=19), who had urine albumin-creatinine ratio (UACR) >= 420 mg/g (PCR~0.9 g/g) with a concurrent GFR value. The main predictor was change in the log-UACR at 12 months. The primary outcome was annual GFR slope over 24 months. Secondary outcomes included a kidney composite of a sustained 30% GFR decline, end stage kidney disease (ESKD) or death and ESKD as a single outcome. Linear regression and Cox proportional hazards models were used to assess the effect of changes in UACR and the outcomes. Results: In the pooled analysis the mean age was 56.8 (SD 15.5) y, 116 were male (90.6%) and three patients had diagnosis of FSGS at baseline. Mean baseline eGFR was 46.8 (SD 16.1) mL/min/1.73m2, mean baseline UACR was 1240.8 (1107.7) mg/g, mean eGFR slope was -4.67[-6.00, -3.33] mL/min/1.73m2/year and the geometric mean percentage changes in the UACR at 12 months were -57.5% [-65.0%, -48.4%]. For every 1 unit of log (UACR) increment at 12 months, the annual eGFR slope decreased by -1.80 [-2.56, -1.03] mL/min/1.73m2 in the pooled analysis. For every 1 unit of log (UACR) increment at 12 months, the Cox regression showed a 61% increase in the risk of a kidney composite (p=0.002) and a 98% increase in the risk of ESKD (p<0.001). It was estimated that a 50% reduction of UACR at 12 months was associated with a 28% reduction in the kidney composite endpoint (adjusted hazard ratio [aHR]=0.72; 95% confidence interval [CI]:0.59-0.88; p=0.002), and a 38% reduction in the risk of ESKD (aHR=0.62; 95% CI:0.49-0.80; p<0.001). Conclusions and relevance: Changes in UACR at 12 months significantly modify the rate of decline of GFR over 24 months and clinically meaningful endpoints, supporting the use of UACR changes as surrogate endpoint in AMKD.

Background and ObjectiveSurgical complexity for renal tumors has traditionally been assessed using manual nephrometry scores, which require unreimbursed physician effort and are subject to interobserver variability. This study introduces an objective, fully automated alternative derived from decades of experience at a large academic center. MethodsWe trained a CT classification model to predict whether a patient would ultimately undergo Partial or Radical Nephrectomy (PN or RN). We hypothesized that the models confidence in RN (termed the CLARITY score) would serve as a surrogate for the difficulty of nephron-sparing approaches and thus for tumor complexity. This hypothesis was tested using multivariate logistic regression for failure to achieve trifecta, estimated blood loss (EBL) [&ge;] 500 mL, and length of stay [&ge;] 3 d. CLARITY was compared with tumor size and R.E.N.A.L. score. External validation in a geographically distinct cohort was performed. Key Findings and LimitationsFor predicting RN, CLARITY achieved an AUROC of 0.899 internally and 0.898 externally. In the external PN subgroup, it outperformed tumor size and R.E.N.A.L. score in predicting failure to achieve trifecta (AUROC 0.613), EBL [&ge;] 500 mL (0.727), and length of stay [&ge;] 3 d (0.673). In multivariable analysis, CLARITY remained associated with each outcome, whereas R.E.N.A.L. and size were not. This study is limited by its retrospective design. Conclusions and Clinical ImplicationsCLARITY is an automated CT-derived marker that quantifies renal tumor complexity more effectively than tumor size and R.E.N.A.L. score and may support scalable, objective preoperative complexity assessment. To support reproducibility and external validation, we have released a public inference pipeline and web-based DICOM upload portal for research use.

Introduction: APOL1 high-risk variants markedly increase susceptibility to kidney disease among individuals of African ancestry; however, only a subset of carriers develops clinically significant CKD or ESKD. This discrepancy highlights a gap between genetic risk and clinical trajectory. Current prognostic tools rely primarily on eGFR and albuminuria, which incompletely reflect the underlying biological processes driving APOL1-associated kidney injury. We hypothesized that plasma biomarkers reflecting inflammatory and tubular injury pathways could identify biologically active disease states within this genetically high-risk population and improve prognostic stratification. Methods: Participants from the Mount Sinai BioMe Biobank carrying two APOL1 high-risk alleles (G1, G1; G1, G2; or G2 G2) were followed for a median of 6 years. Baseline plasma biomarkers of inflammation and tubular injury (TNFR1, TNFR2, KIM-1, MCP-1, YKL-40, IL-18, suPAR) were measured. The composite outcome was sustained 40% decline in eGFR or ESKD. Multivariable Cox models assessed associations between biomarkers and outcomes. A weighted biomarker risk score was derived from tertile-based hazard ratios and categorized into low-, moderate-, and high-risk groups. Results: Among 498 participants (median eGFR 83 ml/min/1.73 m2), 80 (16.1%) reached the composite outcome. Higher concentrations of TNFR1, TNFR2, suPAR, KIM-1, and IL-18 were independently associated with kidney events after multivariable adjustment. Event rates were 7% in the low-risk group, 16% in the moderate-risk group, and 36% in the high-risk group. Conclusions: Plasma biomarkers reflecting inflammatory and tubular injury pathways reveal marked heterogeneity in kidney outcomes among individuals with high-risk APOL1 genotypes. Integration of these signals into a biology-weighted score identifies distinct prognostic phenotypes beyond genotype and traditional clinical measures, supporting multidomain biomarker frameworks for risk stratification and potential trial enrichment in APOL1-associated kidney disease.

Ciliogenesis associated kinase 1 (CILK1) deficiency in human and mice results in kidney developmental defects including cystogenesis. However, the biology of CILK1 in autosomal dominant polycystic kidney disease (ADPKD), the most common inherited kidney disease, remains to be investigated. Here, we show that CILK1 is overexpressed in dedifferentiated cells of renal tissue from ADPKD human patients in comparison to normal control tissue samples. We demonstrate that CILK1 overexpression results in protein accumulation in a non-phosphorylated inactive form. Using mouse polycystic kidney disease models, we reveal that inactive CILK1 accumulation is progressive over the course of disease progression. We show that genetic inactivation of the Polycystic Kidney Disease 1 (PKD1) gene is sufficient to trigger CILK1 accumulation. Altogether, these findings demonstrate that CILK1 regulation is altered in ADPKD and it represents a hallmark of disease progression.

Most cases of autosomal dominant polycystic kidney disease (ADPKD) are caused by mutations in PKD1, which reduce polycystin-1 (PC1) levels below a critical functional threshold. Normalizing PC1 dosage mitigates disease progression; therefore, we sought to develop a CRISPR activation (CRISPRa) strategy to transcriptionally upregulate endogenous PKD1. We systematically screened multiple single-guide RNAs using an EGFP-reporter platform and identified potent candidates targeting the proximal PKD1 promoter in mouse and human cell models. Our results demonstrate that CRISPRa effectively increased endogenous Pkd1 mRNA in the mouse collecting duct-derived Pkd1RC/-cell model and in the primary renal epithelial cells from PKD mice. In Pkd1RC/- cells, CRISPRa of Pkd1 increased PC1 protein levels and significantly reduced cell proliferation and in vitro cyst formation in 3D cultures. Mechanistically, Pkd1 activation improved mitochondrial membrane potential, reduced dependency on aerobic glycolysis, and corrected signaling pathways involved in cystogenesis, specifically reducing intracellular cAMP, cMyc, pCreb, and pErk levels, while increasing pYap1 levels. We confirmed the translational potential of this platform by successfully activating PKD1 in primary renal epithelial cells from human kidneys. We observed a heterogeneous response across both normal and ADPKD patient-derived donor lines, with significant upregulation achieved in two of the tested cell preparations. These findings provide a compelling proof-of-concept that CRISPRa-mediated gene augmentation can increase PC1 levels, establishing a foundation for promising gene therapies aimed at successfully suppressing the pathogenic features of ADPKD. New and noteworthyThis study provides proof-of-concept for a CRISPR activation (CRISPRa)-based approach to ADPKD. CRISPRa targeting the PKD1 promoter, increased polycystin-1 levels in mouse and human cells. Upregulation of a hypomorphic Pkd1 allele increased functional polycystin-1, corrected dysregulated signaling pathways, suppressed cell proliferation and in vitro cyst formation. These results establish CRISPRa as a promising therapeutic approach to restore polycystin levels above a critical threshold and suppress cystogenesis in ADPKD.

Background: Patients with CKD and polypharmacy face high rates of drug-related problems, yet comprehensive medication review remains time-intensive and inconsistently performed. Large language models (LLMs) may augment this process, but existing benchmarks use multiple-choice formats that do not reflect open-ended, nephrology-specific review. We developed a trap-embedded synthetic CKD benchmark and evaluated five current-generation LLMs (GPT-5.4, Claude Sonnet 4.6, Gemini 3.1 Pro, Grok 4.1 Fast, DeepSeek R1; tested April-May 2026) for open-ended medication review. Methods: Fifty synthetic CKD cases across three complexity groups (G3a-G3b [n=20], G4 [n=15], G5/G5D/transplant [n=15]) with 8-12 medications and [&ge;]2 embedded clinical traps each were scored against nephrologist-adjudicated gold standards. Each model produced three independent responses per case (temperature 0; 750 total outputs). Primary endpoint was per-case macro F1; secondary endpoints were safety-critical omission rate, PI-adjudicated hallucination rate, and intra-model consistency. Blinded inter-rater reliability for gold-standard item detection was assessed on a 30% sample. Results: Consensus-level macro F1 ranged from 0.41 (Claude Sonnet 4.6) to 0.49 (Grok 4.1 Fast) (Friedman P < 0.001). Phosphate binder timing (11%) and hyperkalemia combinations (33%) were poorly detected across all models. Safety-critical omission rate ranged from 22% to 48% (P < 0.001); PI-adjudicated hallucination ranged from 0% (GPT-5.4) to 54% (DeepSeek R1), including fabricated dose caps and non-existent guideline citations. Blinded reliability for gold-standard item detection was high (kappa = 0.934, n = 92). Conclusions: This nephrology-specific benchmark exposes clinically important LLM blind spots that generic multiple-choice evaluations would not detect. Heterogeneous hallucination and omission rates indicate that model selection and domain-specific guardrails should precede any clinical deployment of LLM-assisted CKD medication review. Prospective validation with real patient data and human comparators is required before deployment recommendations can be made.

Background: Renal effects of statins in type 2 diabetes mellitus (T2DM) remain uncertain. We evaluated whether statin exposure is associated with time to dialysis initiation. Methods: We conducted a retrospective cohort study of adults with T2DM, indexing follow-up at diagnosis during first hospital admission (day 0) between january 2017 and march 2025. Statin use was modeled as time-varying from statin days; (classified in 3 categories: baseline users, new users, and never users). The primary outcome was dialysis. Analysis estimated cause-specific hazards, censoring deaths; proportional hazards were checked with prespecified windows of statin exposure (0?1, 1?3, > 3 years). Competing-risk analyses (Fine?Gray) assessed the sub-distribution hazard of dialysis with death as a competing event in two models: (i) prevalent users at baseline and (ii) new-users with post-initiation intervals of 30 and 90 days. An Observational Medical Outcomes Partnership Common Data Model standardized dataset of a Brazilian quaternary hospital, and the Real-World Data tool MD Clone were used in the study. Results: Of 36,246 adults identified, 32,125 entered the time-varying cohort (39,943 risk intervals; 656 dialysis events); median follow-up among censored patients was 753 days. At baseline, 70.3% never used statins, 5.5% were users (? 0 days), and 24.2% initiated after diagnosis. Crude dialysis incidence was 4.51 vs. 12.31 per 1,000 patient-years during unexposed vs. exposed time. In the adjusted time-varying Cox model, current statin exposure was associated with a modestly higher hazard of dialysis (HR = 1.043, 95% CI 1.011?1.077). In the new-users analysis, HRs were 0.83 (95% CI 0.66?1.05), and 0.73 (95% CI 0.57?0.92) with a 30-day and 90-day intervals, respectively. Conclusions: In this retrospective cohort of hospitalized diabetic patients at baseline, statin initiation at least 90-days in advance is associated with reduced indication of renal replacement therapy.

Nephronophthisis (NPH) is n rare recessive kidney disease caused by biallelic variants in more than 25 NPHP genes encoding proteins that localize to primary cilia. It is characterized by three different forms depending on the age of onset and kidney lesions: infantile (cystic), juvenile/late onset (fibrotic). To date, the pathways linking altered primary cilia function to progressive kidney scarring in NPH remain poorly defined and therapeutic options are lacking. To address these questions, we generated two new mouse NPH models by inactivating Nphp3 specifically in kidney tubules either during embryogenesis or in adult, recapitulating the infantile and juvenile forms of the disease, respectively. Embryonic inactivation produced a rapid and severe cystic phenotype with tubular dedifferentiation, progressive interstitial fibrosis, inflammation and kidney failure, while postnatal inactivation led to a slowly progressive tubulointerstitial nephropathy characterized by tubular atrophy, fibrosis and immune cell infiltration without cyst formation. Strikingly, cilia were preserved in the early stages of both models, indicating that ciliogenesis impairment is not a primary driver of NPH3 pathogenesis. Transcriptomic profiling of the juvenile model revealed that disease initiation is driven by mitochondrial dysfunction, innate immune activation and aberrant cell cycle progression, while epithelial-to-mesenchymal transition and Wnt/{beta}-catenin remodelling emerges only at later stages of disease progression. Therapeutic intervention with the PGE1 (alprostadil) failed to rescue the cystic/infantile model but significantly attenuated fibrosis, inflammation and interstitial fibrosis in the fibrotic/juvenile model. The ability to recapitulate both disease forms through temporal modulation of gene inactivation suggests that primary cilia serve distinct, stage-specific functions in kidney tubular homeostasis, with different cellular processes being selectively vulnerable depending on the causative gene or variant. Collectively, these findings uncover early pathogenic mechanisms that may constitute tractable therapeutic targets for the treatment of nephronophthisis.

BackgroundTubulitis is a defining histologic feature of T cell-mediated rejection (TCMR), while glomerulitis is often characteristic of antibody mediated rejection (AMR). Histologic quantification of tubulitis and glomerulitis using Banff criteria is subject to interobserver variability. Bulk transcriptomic assays (e.g., MMDx) have introduced molecular correlations of tubulitis with TCMR and glomerulitis with AMR, but lack spatial resolution. MethodsWe applied a web-based platform, FUSION (Functional Unit State Identification in Whole Slide Images), to a cohort of 8 cases (n=2 per condition) with kidney allograft biopsy samples acute TCMR, active AMR, chronic active AMR, and no rejection (control). The machine-learning (ML) platform enabled integrated visualization and analysis of spatial transcriptomics (10x Genomics Visium v2) together with high-resolution whole-slide histology. ResultsTranscriptomics-derived immune cell proportions within AI-segmented tubular and glomerular regions were used to generate spatial Banff t- and g-scores. Derived t-scores showed full concordance with pathologist scores in both acute TCMR cases; g-scores showed concordance in 2 of 4 AMR cases, with discordant cases characterized by low absolute immune signal near the classification boundary. ConclusionsWe demonstrate the feasibility of using AI-based FTU segmentation integrated with spatial transcriptomics-derived immune cell proportions to generate spatially informed t- and g-scores aligned with Banff criteria, with full concordance in severe rejection and partial concordance in mild rejection. This approach lays the foundation for validated, spatial transcriptomics-augmented t-scores and g-scores that enhance diagnostic precision, reduces inter-observer variability among renal pathologists, and support potential clinical adoption.

IntroductionImmune checkpoint inhibitors (ICIs) enhance antitumor responses by blocking inhibitory receptors, including PD-1 and CTLA-4. Overactivation can trigger systemic toxicity akin to autoimmune diseases, including kidney manifestations. We sought to 1) profile immune signaling and 2) interrogate potential mechanisms of ICI-related kidney injury in a Human Immune System (HIS) tumor-bearing mouse model treated with nivolumab and ipilimumab. MethodsImmunodeficient BRGS (BALB/c-Rag2nullIl2r{gamma}nullSirpNOD) neonates were engrafted with human CD34+ cells to generate HIS-BRGS mice. Human MDA-MB-231 tumor cells were implanted subcutaneously; once tumors reached [~]150 mm3, mice received weekly intraperitoneal vehicle (PBS) or ICI (nivolumab 20 mg/kg + ipilimumab 10 mg/kg) for 4 weeks (Veh BRGS n=4; ICI BRGS n=6; Veh HIS-BRGS n=7; ICI HIS-BRGS n=7). Kidneys were evaluated by histopathology (H&E, TEM), flow cytometry for human immune phenotypes, multiplex ELISA (80 human proteins; 10 injury biomarkers), bulk RNA sequencing, and targeted qPCR. Pearson correlations identified predictors of histopathological injury. ResultsRenal vasculitis and interstitial nephritis were observed only in ICI-treated HIS-BRGS mice. These kidneys showed a shift toward CD4+ T-cell enrichment with an increased TNF- production capacity compared to CD8+ counterparts. Toxicity was accompanied by increased renal concentrations of human cytokines, chemokines, and soluble receptors. ICI treatment significantly elevated serine proteases (Granzyme A/B) and NGF-{beta}, while decreasing IL-4. Interstitial nephritis correlated with renal PD-1 and MIF. Renal vasculitis correlated with kidney PD-1, CCL1, MIF, Granzyme A, IL-15, and BAFF. Traditional injury biomarkers (KIM-1, NGAL) remained unchanged; however, a trending decrease in EGF was observed. ConclusionsOur study suggests that shifts in human T-cell populations and specific immune proteins could serve as promising biomarkers and mechanistic targets for ICI nephrotoxicity. The tumor-bearing HIS-BRGS mouse model reproducibly recapitulates the histopathological and immunological features of human ICI-induced nephrotoxicity and represents a validated preclinical platform for testing novel therapeutic interventions to preserve kidney function during cancer immunotherapy. Translational StatementImmune checkpoint inhibitor (ICI)-associated nephrotoxicity occurs in up to 25% of treated patients, yet the immunological mechanisms driving renal injury remain poorly characterized due to the scarcity of human biopsy material and the absence of robust preclinical models that recapitulate human immune responses. This study demonstrates that tumor-bearing humanized immune system (HIS) mice treated with combined nivolumab and ipilimumab reproducibly develop renal vasculitis and interstitial nephritis mediated by a human CD4+ T cell-dominant infiltrate, mirroring the clinicopathological features reported in patients with ICI-associated acute kidney injury. By integrating histopathology, flow cytometry, multiplex proteomics, and transcriptomics, we identify a coordinated immune network, including IL-15, CCL1, MIF, GZMA, and BAFF, that correlates with the severity of renal pathology and represents tractable mechanistic targets and candidate biomarkers. These findings provide a validated preclinical platform for dissecting irAE mechanisms and testing novel therapeutic strategies to preserve kidney function during cancer immunotherapy.

PURPOSE: As the armamentarium of BPH therapies continues to expand, it remains imperative to maximize patient satisfaction and minimize decisional regret. We sought to determine the impact of time from BPH diagnosis to index treatment on symptom improvement and subsequent procedural events. MATERIALS AND METHODS: We queried the American Urological Association Quality Registry for men [&ge;] 40 years old with BPH, available IPSS data, and no receipt of prior BPH treatment. Index treatment included medication, surgery, or minimally invasive surgical therapy (MIST). Outcomes included IPSS over 3 years of follow-up, change in percentage of mild lower urinary tract symptoms (LUTS) by 3 months, and time to procedural event. Patients were stratified by time from index diagnosis to treatment by <12 months, 1-3 years, and >3 years. Outcomes were compared across time-to-treatment cohorts with appropriate statistical tests with p < 0.05 as significant. RESULTS: 43,919 patients met criteria with 19,642 pursuing treatments. Patients pursued treatment at comparably lower baseline IPSS compared to prior prospective series. Patients undergoing surgery and MIST had significantly higher baseline IPSS, while medical comorbidities were significantly more common among men initiating pharmacotherapy. Early surgery and MIST were associated with significant improvement in IPSS within 6-12 months and an increase in mild LUTS by 3 months. All forms of early treatment were associated with delayed time to procedural events, including catheterization and fulguration. CONCLUSIONS: Early procedural intervention for BPH is associated with early symptom improvement and delayed time to procedural events among real-world, contemporary practice.

Mammalian single-stranded DNA binding protein 1 (SSB1) has been established as an essential component of genome stability in both human cells and mice. Moreover, SSB1 was recently implicated in cytoplasmic stress response by its involvement in Ras GTPase-activating protein-binding protein 1 (G3BP1)-containing cytoplasmic stress granules (SGs) upon various forms of stress. Here, we generated and analyzed human cellular knockout and rodent ischemia-reperfusion (I/R) models to define SSB1s roles in cytoplasmic stress response. Analysis of wild-type as well as SSB1 and G3BP1 knockout human retinal pigment epithelial (RPE-1) cells shows stress-specific incorporation of SSB1 into SGs and a negative regulator role for SSB1 in SG dynamics under sublethal stress conditions. We find that SSB1 knockout measurably increases cellular sensitivity to oxidative stress but does not alter cell proliferation following mild acute stress. Moreover, we detect SSB1 efflux from the nucleus upon stress that is dependent upon the presence of G3BP1 in a stress-specific manner. In addition, using mouse and rat models we observe significant upregulation and robust cytoplasmic granulation of SSB1 upon renal ischemia-reperfusion stress, establishing SSB1s involvement in complex organismal stress response in vivo. Together, our data demonstrate active involvement of SSB1 in cytoplasmic response to cellular stress and acute kidney injury, with implications for targeting stress response functions in cancerous versus non-cancerous contexts. HIGHLIGHTSO_LISSB1 is incorporated into cytoplasmic stress granules and negatively regulates stress granule assembly under sublethal stress conditions C_LIO_LISSB1 shows stress- and G3BP1-dependent nuclear efflux C_LIO_LISSB1 is upregulated and undergoes apical granulation in renal epithelial cells during renal ischemia-reperfusion injury C_LI

Background: Antibody-mediated rejection (AMR) after heart transplant (HT) is associated with increased risk of mortality and graft loss. Contemporary studies delineating AMR presentation, management, and response to treatment are lacking, especially for patients who do not have typical immunohistological evidence of rejection (biopsy-negative, BN-AMR). In this study, we sought to describe the prevalence and clinical course of BN-AMR compared to biopsy-positive (BP-AMR) patients in a multicenter HT population. Methods: We conducted a retrospective analysis of all adult HT recipients at 2 academic medical centers. AMR was further divided into BP-AMR and BN-AMR, depending on their endomyocardial biopsy findings. The primary outcome was death and secondary outcome was a composite of death, retransplant, and new International Society of Heart and Lung Transplant grade 2 or 3 coronary artery vasculopathy. Results: A total of 742 patients were included in this study. We found that AMR occurred in 10% of HT recipients and was associated with worse overall survival compared to those with only cellular rejection or no rejection. BN-AMR accounted for 33% of AMR cases. Compared to BP-AMR, BN-AMR was diagnosed later, less aggressively treated, and associated with high morbidity and mortality. The long-term outcomes between BP-AMR and BN-AMR were similarly poor, with 5-year mortality approaching 50% after diagnosis. Conclusions: AMR after HT is associated with poor clinical outcomes and BN-AMR is common. Future studies should focus on incorporating novel tools for earlier detection of AMR and investigating AMR sub-phenotypes and optimal modes of treatment.

Sphingosine-1-phosphate lyase insufficiency syndrome (SPLIS) is a rare condition causing nephrotic syndrome, neuropathy, and other manifestations. SPLIS is caused by mutations in SGPL1, which encodes sphingosine-1-phosphate lyase (SPL), a pyridoxal 5-phosphate (PLP)-dependent enzyme needed to degrade the bioactive sphingolipid sphingosine-1-phosphate (S1P). Supplementation with the PLP precursor pyridoxine benefits some individuals with PLP-dependent enzymopathies. We sought to establish whether pyridoxine has therapeutic activity in SPLIS. Neurological improvement, plasma S1P normalization, and increased SPL activity in patient-derived fibroblasts were observed after pyridoxine supplementation in a patient with R222Q-variant SPLIS. Additionally, PLP dose-dependently augmented recombinant R222Q-variant SPL activity. To further explore pyridoxines effects, gene editing was employed to create an R222Q-variant SPLIS mouse model. SPLR222Q mice fed pyridoxine-enriched chow lacked obvious phenotypes. However, SPL inactivation, S1P accumulation, wasting, anemia, proteinuria, and glomerulosclerosis developed in SPLR222Q but not WT mice fed chow with reduced pyridoxine. Ultrastructural analysis and super-resolution microscopy showed podocyte loss and foot process effacement. Transcriptional profiling revealed a pattern of cytokine upregulation and extracellular matrix remodeling. Inhibiting S1P production prevented nephrosis in SPLR222Q mice fed chow lacking pyridoxine. Our findings establish a novel SPLIS mouse model that recapitulates R222Q-variant SPLIS, demonstrates its responsiveness to pyridoxine, and implicates S1P in its pathophysiology.