Acute kidney injury and chronic kidney disease as interconnected syndromes

Risk prediction for acute kidney disease and adverse outcomes in patients with chronic obstructive pulmonary disease: an interpretable machine learning approach

BACKGROUND

Little is known about acute kidney injury (AKI) and acute kidney disease (AKD) in patients with chronic obstructive pulmonary disease (COPD) and COPD mortality based on the acute/subacute renal injury. This study develops machine learning models to predict AKI, AKD, and mortality in COPD patients, utilizing web applications for clinical decisions.

METHODS

We included 2,829 inpatients from January 2016 to December 2018. Data were split into 80% for training and 20% for testing. Eight machine learning algorithms were used, and model performance was evaluated using various metrics. SHAP was used to visualize the decision process. The best models, assessed using AUROC were used to develop web applications for identifying high-risk patients.

RESULTS

The incidence rates were 13.71% for AKI and 15.11% for AKD. The overall mortality rate was 4.84%. LightGBM performed best with AUROC of 0.815, 0.827, and 0.934 in AKI, AKD, and mortality, respectively. Key predictors for AKI were Scr, neutrophil percentage, cystatin c, BUN, and LDH. For AKD, the key predictors were age, AKI grade, HDL-C, Scr, and BUN. The key predictors for mortality included the use of dopamine and epinephrine drugs, cystatin c, renal function trajectory, albumin, and neutrophil percentage. Force plots visualized the prediction process for individual patients.

CONCLUSIONS

The incidence of AKI and AKD is significant in patients with COPD. Renal function trajectory is crucial for predicting mortality in these patients. Web applications were developed to predict AKI, AKD, and mortality, improving prognosis by identifying high-risk patients and reducing adverse events and disease progression.

Association of mean arterial pressure and in-hospital mortality in critically ill patients with acute pancreatitis-associated acute kidney injury: a retrospective cohort study

Acute pancreatitis (AP) is a common gastrointestinal disorder, and acute kidney injury (AKI) is a frequent and severe complication, significantly increasing mortality risk. Mean arterial pressure (MAP) is crucial for maintaining organ perfusion in critically ill patients. However, the optimal MAP target for minimizing mortality in AP patients complicated by AKI (AP-AKI) remains unclear. This retrospective cohort study analyzed data from the MIMIC-IV database, including 934 critically ill adult patients diagnosed with AP-AKI between 2008 and 2019. We investigated the relationship between MAP and in-hospital mortality using logistic regression models, adjusting for demographics, comorbidities, disease severity scores and intensive care interventions. Smooth curve fitting was used to explore potential non-linear associations. Subgroup analyses were performed to assess the impact of MAP across different clinical and demographic groups. Our analysis revealed a non-linear, L-shaped relationship between MAP and in-hospital mortality, with an inflection point at 71.32 mmHg. Below this threshold, increasing MAP was associated with significantly decreased odds of mortality (OR: 0.93, 95% CI: 0.87-0.99, p = 0.026). However, above this threshold, the association was no longer significant (OR: 1.015, 95% CI: 0.98-1.03, p = 0.699). Subgroup analyses showed consistent trends across most subgroups, with the benefit of maintaining MAP above the threshold being most pronounced in AKI stage 1 and 2 patients. This study suggests a potential association between maintaining specific MAP levels, particularly above 71.32 mmHg, and reduced in-hospital mortality in critically ill AP-AKI patients.

Global, regional, and national burden of cardiovascular disease attributable to kidney dysfunction (1990-2021) with projections to 2050: analysis of the 2021 Global Burden of Disease study

AIMS

This study examines global trends in cardiovascular disease (CVD) associated with kidney dysfunction (KD) from 1990 to 2021 and projects future trends through 2050.

METHODS

This study analyzed the 2021 Global Burden of Disease (GBD) database, focusing on age-standardized mortality rate (ASMR), age-standardized disability-adjusted life years rate (ASDR), absolute numbers, estimated annual percentage change, and average annual percent change. A Bayesian age-period-cohort model was employed to project global trends from 2022 to 2050. Variables included age, gender, national levels, and Socio-demographic Index (SDI) regions.

RESULTS

From 1990 to 2021, the CVD burden from KD increased, with deaths rising from 1,312,393 to 2,095,800 and DALYs from 27,382,767 to 41,589,861. However, the ASMR decreased from 40.58 per 100,000 in 1990 to 25.55 in 2021, while ASDR fell from 742.17 to 489.81 during the same period. The burden was higher in men, peaking at ages 70-74 and in women at ages 85-89. Regions with lower-middle and low SDI recorded the highest CVD burden, inversely related to SDI levels. Geographically, Central Asia and Eastern Europe recorded the highest rates, while high-income Asia Pacific and Southern Latin America had the lowest. Projections suggest a sustained decline in global CVD burden due to KD from 2022 to 2050, although disparities between sexes are expected to persist, with men bearing a heavier burden.

CONCLUSION

CVD attributable to KD remains a major global public health challenge, especially for men, the elderly, and low SDI regions. These spatial and temporal variations highlight the need for region-specific healthcare strategies.

Ferroptosis, necroptosis, and pyroptosis in calcium oxalate crystal-induced kidney injury

Kidney stones represent a highly prevalent urological disorder worldwide, with high incidence and recurrence rates. Calcium oxalate (CaOx) crystal-induced kidney injury serves as the foundational mechanism for the formation and progression of CaOx stones. Regulated cell death (RCD) such as ferroptosis, necroptosis, and pyroptosis are essential in the pathophysiological process of kidney injury. Ferroptosis, a newly discovered RCD, is characterized by its reliance on iron-mediated lipid peroxidation. Necroptosis, a widely studied programmed necrosis, initiates with a necrotic phenotype that resembles apoptosis in appearance. Pyroptosis, a type of RCD that involves the gasdermin protein, is accompanied by inflammation and immune response. In recent years, increasing amounts of evidence has demonstrated that ferroptosis, necroptosis, and pyroptosis are significant pathophysiological processes involved in CaOx crystal-induced kidney injury. Herein, we summed up the roles of ferroptosis, necroptosis, and pyroptosis in CaOx crystal-induced kidney injury. Furthermore, we delved into the curative potential of ferroptosis, necroptosis, and pyroptosis in CaOx crystal-induced kidney injury.

Suppressing SPARC gene with siRNA exerts therapeutic effects and inhibits MMP-2/9 and ADAMTS1 overexpression in a murine model of ischemia/reperfusion-induced acute kidney injury

Secreted protein acidic and rich in cysteine (SPARC), a collagen-binding matricellular protein, is reported to facilitate inflammation and fibrosis in various tissues including the kidneys. Ischemia/reperfusion (I/R) is a major process of acute kidney injury. To investigate whether SPARC inhibition might attenuate renal I/R injury, we injected small interfering RNA (siRNA) targeting SPARC into male BALB/c mice one day before 45 min of renal ischemia followed by 72 h of reperfusion. Serum creatinine concentration, blood urea nitrogen, histological tubular damage, tubulointerstitial fibrosis, and expression of collagen I and transforming growth factor-β were increased after I/R. Expression of 4-hydroxy-2-nonenal, an oxidative stress marker, and the inflammatory cytokines monocyte chemoattractant protein-1 and tumor necrosis factor-α, were also upregulated in I/R kidneys. Overexpression of SPARC mRNA was observed after I/R, and immunohistochemistry revealed that SPARC was localized mainly in damaged tubuloepithelial cells. Additionally, a disintegrin and metalloproteinase with thrombospondin type 1 motif (ADAMTS1) expression colocalized with SPARC. Injection of siRNA targeting SPARC attenuated renal dysfunction, histological abnormalities, collagen deposition, oxidative stress, and renal inflammation. In addition, SPARC gene knockdown suppressed the I/R-induced increases in ADAMTS1 and matrix metalloproteinase-2/9 expression. In conclusion, I/R-induced SPARC could be a novel therapeutic target against acute kidney injury.

Macrophage membrane-biomimetic ROS-responsive platinum nanozyme clusters for acute kidney injury treatment

Acute kidney injury (AKI) is a common clinical syndrome characterized by the rapid loss of renal filtration function. No standard therapeutic agent option is currently available. The development and progression of AKI is a continuous and dynamical pathological process. Oxidative stress and inflammatory responses are the primary influencing factors. Here, we developed a biomimetic nano-system (MM-PtNCs) with reactive oxygen species (ROS)-responsive platinum nanozyme clusters (PtNCs) wrapped in macrophage membrane (MM) to alleviate AKI by modulating oxidative stress and inflammation. The inflammatory cytokines receptors retained on MM surface allowed the biomimetic nano-system to target renal inflammation and neutralize these pro-inflammatory cytokines to ameliorate inflammation. PtNCs exhibit free radical scavenging-ability and catalase (CAT)-like activity to scavenge ROS and regulate the oxidative stress situations both in injured cells and tissues. Meanwhile, it could responsively dissociate into ultrasmall platinum nanoparticles under AKI-specific ROS conditions to eliminate ROS and eventually excreted through the renal filtration system. In a mouse model of ischemia/reperfusion-induced AKI, systemic injection of MM-PtNCs significantly reduced renal damage and restored kidney function. Additionally, MM-PtNCs effectively prevented the progression of AKI to chronic kidney disease. In conclusion, MM-PtNCs may propose a multi-faceted regulatory approach for clinical AKI treatment.

Acute Kidney Injury in Latin America

Acute kidney injury (AKI) is a major global health issue with significant morbidity and mortality, particularly in low- and middle-income regions like Latin America. AKI prevalence varies across Latin America, with higher rates in rural and underserved areas. Key risk factors include socioeconomic disparities, comorbid conditions such as diabetes and hypertension, and environmental hazards. Infections, especially tropical diseases, and exposure to nephrotoxins, including herbal remedies, are common causes of AKI. Management of AKI faces significant hurdles because of limited access to diagnostic tools, variability in clinical practices, and a shortage of trained health care professionals. The availability of dialysis and renal replacement therapies is often constrained by economic and infrastructural limitations. Public health initiatives focusing on prevention, screening, and early detection are critical to mitigate the impact of AKI. Research in AKI across Latin America is hampered by data gaps and limited funding. Multicenter collaborations and the development of region-specific guidelines are essential to improving outcomes. Addressing these challenges will help reduce the burden of AKI and improve health care systems across the region. This review examines the unique epidemiology, risk factors, and health care challenges surrounding AKI in the region.

Relationship between complement and macrophage markers with kidney survival in patients with diabetic nephropathy

BACKGROUND

Diabetic nephropathy (DN) is the leading cause of end-stage kidney disease (ESKD) worldwide. Macrophages and the complement system have interrelated roles in DN. We aimed to determine associations between macrophage and complement markers with the progression of DN.

METHODS

This retrospective cohort study included patients diagnosed with sole DN by kidney biopsy. Using immunohistochemistry, CD68+ and CD163+ cells and complement markers were counted in glomerular and tubulointerstitial areas. The primary outcome was evolution to ESKD and/or doubling serum creatinine (SCr).

RESULTS

Forty-six patients were included. The median SCr at baseline was 2.7 (1.41-3.1) mg/dL. During the median follow-up of 32 months (range 6-54), 50% of patients reached the primary outcome. Most of the clinical and histological findings were comparable between progressors and non-progressors, while progressors had a higher median number of glomerular CD68+ cells and a higher percentage of glomerulosclerosis. After adjustments for age, sex, and SCr, the median glomerular CD68+ cell number was the sole independent predictor of progression. Glomerular C4d was associated with nephrotic-range proteinuria but not with the progression of kidney failure.

CONCLUSIONS

Glomerular CD68+ cell count may serve as a promising predictor of kidney disease progression among patients with DN. Glomerular C4d was associated with nephrotic-range proteinuria but not with the progression of kidney failure.

Tubular specific glutathione peroxidase 3 deletion exacerbates kidney damage in IRI-AKI mice

Ischemia-reperfusion injury stands as a primary instigator of acute kidney injury (AKI), prominently driven by oxidative stress. Among the critical antioxidant defenses is glutathione peroxidase 3 (GPX3), an enzyme generated by renal tubular epithelial cells. Our prior investigations have unveiled a substantial downregulation of GPX3 in renal tissues gleaned from AKI patients and murine models. This study aims to investigate the role of tubular cell-specific Gpx3 deletion on ischemia-reperfusion injury-induced AKI (IRI-AKI) in a murine model and delineate the potential underlying mechanisms. By generating renal tubular epithelial cell-specific Gpx3 knockout mice and inducing IRI-AKI, we assessed a spectrum of kidney injury indices including renal function, oxidative stress, apoptosis and mitochondrial dynamics. Additionally, we conducted transcriptome sequencing and bioinformatics analyses. The outcomes underscore that the deficiency of GPX3 in tubular cells exacerbates tubular injury, renal dysfunction, oxidative stress, apoptosis, and mitochondrial dynamic disturbances in the context of IRI-AKI. Sequencing and bioinformatics analysis suggest that the Gpx3 deletion predominantly impacts pathways associated with metabolism and inflammation. In conclusion, the tubular cell-specific deficiency of GPX3 exacerbates renal injury by intensifying oxidative stress, fostering mitochondrial impairment, perturbing metabolic processes and fueling inflammation. The targeted restoration of GPX3 in the renal tubular emerges as a potential therapeutic avenue for mitigating IRI-AKI.

Effects of an extended therapeutic strategy versus standard-of-care therapy on persistent acute kidney injury in high-risk patients after major surgery: study protocol for the randomised controlled single-centre PrevProgAKI trial

INTRODUCTION

Persistent acute kidney injury (AKI) is associated with an increased morbidity and mortality. In patients with an already established AKI, the new urinary biomarker C-C motif chemokine ligand 14 (CCL14) can predict a persistent AKI. However, it is still unknown whether the implementation of nephroprotective measures in patients with an already established moderate/severe AKI can positively influence the trajectory of AKI and patients' outcome.

METHODS AND ANALYSIS

The PrevProgAKI trial is a randomised, controlled, single-centre trial designed to evaluate the effectiveness of nephroprotective measures in patients with established moderate/severe AKI. We aim to enrol 480 patients with moderate or severe AKI (Kidney Disease: Imroving Global Outcomes, KDIGO, stage 2 or 3) within 72 hours of major surgery. Eligible patients will be randomised to receive either standard of care (control group) or an extended therapeutic strategy that consists of different supportive measures (intervention group). The randomisation will be stratified by urinary CCL14 results (CCL14<1.3 ng/mL or CCL14≥1.3 ng/mL). Treating physicians will be blinded to the test results. The primary endpoint is a composite of the development of persistent severe (stage 3) AKI, need for renal replacement therapy or death within 72 hours. The key secondary endpoint is the composite of death, initiation of renal replacement therapy within 90 or persistent renal dysfunction at day 90.

ETHICS AND DISSEMINATION

The PrevProgAKI trial has been approved by the Ethics Committee of the Chamber of Physicians Westfalen-Lippe and the University of Muenster (no. 2021-569 f-S). Results will be disseminated widely and published in peer-reviewed journals, presented at conferences and will guide patient care and further research.

TRIAL REGISTRATION NUMBER

NCT05275218 (clinicaltrials.gov), first posted 11 March 2022.

An NAG-Activatable Glow-Type Chemiluminescent Probe for Sensitive and Early Diagnosis of Acute Kidney Injury through Urinalysis

The current clinical diagnostic criteria for acute kidney injury (AKI) are based on the evaluation of changes in serum biomarkers (sCr, BUN) and urine output, which are insensitive and typically do not show significant differences until the middle to late stages, thereby hindering the time diagnosis of AKI. Herein, we report an N-acetyl-β-d-glucosaminidase (NAG)-activatable glow-type chemiluminescent probe (CL-NAG) for sensitive detection of urinary NAG and early diagnosis of AKI. CL-NAG was designed and synthesized by incorporating N-acetyl-β-d-glucosamine into the phenoxy-dioxetane scaffolds through a self-immolative linker. Molecular docking calculations predicted a strong interaction between CL-NAG and the catalytic cavity of the NAG enzyme. CL-NAG exhibited high detection sensitivity (LOD = 0.042 U/L) for NAG activity, low autofluorescence interference, and an extremely high signal-to-noise ratio (1628-fold). Furthermore, using this probe, we achieved not only the imaging detection of NAG in HUVEC and HK-2 cells but also the quantitative detection of NAG activity in the urine of an AKI mouse model at different time points. Most importantly, CL-NAG successfully identified 19 positive and 149 negative samples out of 168 clinical urine specimens, proving a high consistency rate of 95.24% compared with clinical biochemical methods. This research demonstrates the sensitive urinary NAG detection ability of CL-NAG and suggests the enormous clinical application potential of CL-NAG in the early diagnosis of AKI.

L-Shaped Association of 24-Hour Urine Output with 3-Month and 1-Year All-Cause Mortality in Patients with Acute Pulmonary Embolism: A Retrospective Cohort Study

AIM

To explore the prognostic value of the first 24-h urine output (UO) after admission in patients with acute pulmonary embolism (APE) in the intensive-care unit (ICU) for short- and long-term all-cause mortality risk.

METHODS

This retrospective cohort study used the MIMIC-IV database. Patients with APE were divided into 4 teams (T1-T4) by their first 24-h UO after admission: T1 (UO ≤ 400 ml), T2 (400＜UO ≤ 800 ml ), T3 (800＜UO ≤ 2500 ml), and T4 (UO＞2500 ml). The primary endpoints were the three-month and one-year all-cause mortality rates. The relationship between UO and mortality was assessed using Kaplan-Meier survival curves and Cox proportional hazards models.

RESULTS

This study included 2012 patients with APE, of whom 50.75% were female. Compared to the T3 group, patients in the T1 and T2 groups had higher all-cause mortality rates. Kaplan-Meier survival curves showed that patients in the T1 and T2 groups had a higher risk of death, while those in the T4 group seemed to have a lower risk of death (P＜0.001). The results remained stable in all three adjusted models and subgroup analyses. A restricted cubic spline analysis (RCS) revealed that the risk of all-cause mortality gradually decreased with an increase in UO, showing an "L"-shaped relationship. A UO of ＜1283 ml increased the risk of death in patients. Subgroup analysis indicated that the first 24-h UO was associated with 3-month and 1-year all-cause mortality rates in most subgroups of patients.

CONCLUSIONS

The first 24-h UO after admission is an important indicator for the prognosis of APE patients. A lower 24-h UO is strongly related to a higher risk of short-term and long-term all-cause mortality in ICU patients with APE.

Postoperative mid-to-long-term adverse event prediction model for patients receiving non-cardiac surgery: An extension of the Simple Postoperative AKI RisK (SPARK) model

Background

Postoperative acute kidney injury (PO-AKI) is a critical complication of adverse kidney outcomes, both short and long-term. We aimed to expand our pre-existing PO-AKI prediction model to predict mid-to long-term adverse kidney outcomes.

Methods

We included patients who underwent major non-cardiac surgeries from the original SPARK cohort, two external validation cohorts, and a temporal validation cohort. Mid-to-long-term adverse kidney outcomes were defined as end-stage kidney disease progression or death within 1 or 3 years after surgery. We verified and tuned the original Simple Postoperative AKI RisK (SPARK) model to predict mid-to-long-term adverse kidney events.

Results

We included 33 636 patients in development, 71 232 patients in external validation, and 33 944 patients in temporal validation cohorts, respectively. One- and 3-year adverse kidney events occurred in 5.5% and 13.2% in the development cohort, respectively. The original SPARK score demonstrated an acceptable discriminative power for 1-year and 3-year adverse outcome risks with C indices mostly >0.7. However, the power was relatively poor when restricted to high-risk patients or those who actually developed PO-AKI. When we re-calculated the regression coefficients from a Cox model, the discriminative performances were better, especially for those with high-risk characteristics (e.g. 1-year outcome, C-index 0.72 in developmental and 0.73‒0.77 in validation datasets). Furthermore, when the model integrated the PO-AKI stage and history of malignancy with the SPARK variables, the performance was significantly enhanced (1-year, C-index 0.86 in development and 0.86‒0.88 in validation results). With the above findings, we constructed an online postoperative risk prediction system (https://snuhnephrology.github.io/postop/).

Conclusions

The addition of two clinical factors and recalibration of SPARK variables significantly improved mid-to-long-term postoperative risk prediction for mortality or dialysis after non-cardiac surgery. Our calculator helps clinicians easily predict a mid-to-long-term risk and PO-AKI occurrence by entering a few variables.

MC16 promotes mitochondrial biogenesis and ameliorates acute and diabetic nephropathy

BACKGROUND AND PURPOSE

Kidney disease (KD) is a leading cause of mortality worldwide, affecting 〉10% of the global population. Two of the most common causes of KD are diabetes and acute kidney injury (AKI), both of which induce mitochondrial dysfunction resulting in renal proximal tubular damage/necrosis. Thus, pharmacological induction of mitochondrial biogenesis (MB) may provide a therapeutic strategy to block the onset/progression of KD. Here, we evaluated the pharmacological and potential therapeutic effects of a novel MB-inducing oxindole agent, MC16.

EXPERIMENTAL APPROACH

Primary cultures of rabbit renal proximal tubule cells (RPTCs) were used to evaluate the cellular signalling and MB-inducing effects of MC16. Mice were used to determine the MB-inducing effects of MC16 in vivo, and the metabolic effects of MC16 on the renal cortical metabolome. Mouse models of AKI and diabetic kidney disease (DKD) were used to demonstrate the therapeutic potential of MC16 to ameliorate acute and diabetic nephropathy.

KEY RESULTS

MC16 activated the PI3K-AKT-eNOS-FOXO1 axis and induced MB in RPTCs. MC16 induced MB and altered the renal cortical metabolome of mice. MC16 accelerated renal recovery, reduced vascular permeability, and diminished mitochondrial dysfunction following AKI. MC16 decreased diabetes-induced renal swelling, improved renal and mitochondrial function, and diminished interstitial fibrosis in DKD mouse models.

CONCLUSION AND IMPLICATIONS

MC16 is a novel compound that induces MB and ameliorates acute and diabetic nephropathy in mice. This study underscores that targeting MB following the onset of renal/metabolic insults may provide a therapeutic strategy to mitigate the onset and/or progression of KD.

Repression of peroxisome proliferation-activated receptor γ coactivator-1α by p53 after kidney injury promotes mitochondrial damage and maladaptive kidney repair

Maladaptive kidney repair after injury is associated with a loss of mitochondrial homeostasis, but the underlying mechanism is largely unknown. Moreover, it remains unclear whether this mitochondrial change contributes to maladaptive kidney repair or the development of chronic kidney problems after injury. Here, we report that the transcriptional coactivator peroxisome proliferation-activated receptor γ coactivator-1α (PGC1a), a master regulator of mitochondrial biogenesis, was persistently downregulated during maladaptive kidney repair after repeated low-dose cisplatin nephrotoxicity or unilateral ischemia/reperfusion injury. Administration of the PGC1α activator ZLN005 after either kidney injury not only preserved mitochondria but also attenuated kidney dysfunction, tubular damage, interstitial fibrosis, and inflammation. PGC1α downregulation in these models was associated with p53 activation. Notably, knockout of p53 from proximal tubules prevented PGC1α downregulation, attenuated chronic kidney pathologies and minimized functional decline. Inhibition of p53 with pifithrin-α, a cell permeable p53 inhibitor, had similar effects. Mechanistically, p53 bound to the PGC1α gene promoter during maladaptive kidney repair, and this binding was suppressed by pifithrin-α. Together, our results indicate that p53 is induced during maladaptive kidney repair to repress PGC1α transcriptionally, resulting in mitochondrial dysfunction for the development of chronic kidney problems. Activation of PGC1α and inhibition of p53 may improve kidney repair after injury and prevent the development of chronic kidney problems.

Explainable Machine Learning Model for Predicting Persistent Sepsis-Associated Acute Kidney Injury: Development and Validation Study

BACKGROUND

Persistent sepsis-associated acute kidney injury (SA-AKI) shows poor clinical outcomes and remains a therapeutic challenge for clinicians. Early identification and prediction of persistent SA-AKI are crucial.

OBJECTIVE

The aim of this study was to develop and validate an interpretable machine learning (ML) model that predicts persistent SA-AKI and to compare its diagnostic performance with that of C-C motif chemokine ligand 14 (CCL14) in a prospective cohort.

METHODS

The study used 4 retrospective cohorts and 1 prospective cohort for model derivation and validation. The derivation cohort used the MIMIC-IV database, which was randomly split into 2 parts (80% for model construction and 20% for internal validation). External validation was conducted using subsets of the MIMIC-III dataset and e-ICU dataset, and retrospective cohorts from the intensive care unit (ICU) of Northern Jiangsu People's Hospital. Prospective data from the same ICU were used for validation and comparison with urinary CCL14 biomarker measurements. Acute kidney injury (AKI) was defined based on serum creatinine and urine output, using the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Routine clinical data within the first 24 hours of ICU admission were collected, and 8 ML algorithms were used to construct the prediction model. Multiple evaluation metrics, including area under the receiver operating characteristic curve (AUC), were used to compare predictive performance. Feature importance was ranked using Shapley Additive Explanations (SHAP), and the final model was explained accordingly. In addition, the model was developed into a web-based application using the Streamlit framework to facilitate its clinical application.

RESULTS

A total of 46,097 patients with sepsis from multiple cohorts were enrolled for analysis. Among 17,928 patients with sepsis in the derivation cohort, 8081 patients (45.1%) showed progression to persistent SA-AKI. Among the 8 ML models, the gradient boosting machine (GBM) model demonstrated superior discriminative ability. Following feature importance ranking, a final interpretable GBM model comprising 12 features (AKI stage, ΔCreatinine, urine output, furosemide dose, BMI, Sequential Organ Failure Assessment score, kidney replacement therapy, mechanical ventilation, lactate, blood urea nitrogen, prothrombin time, and age) was established. The final model accurately predicted the occurrence of persistent SA-AKI in both internal (AUC=0.870) and external validation cohorts (MIMIC-III subset: AUC=0.891; e-ICU dataset: AUC=0.932; Northern Jiangsu People's Hospital retrospective cohort: AUC=0.983). In the prospective cohort, the GBM model outperformed urinary CCL14 in predicting persistent SA-AKI (GBM AUC=0.852 vs CCL14 AUC=0.821). The model has been transformed into an online clinical tool to facilitate its application in clinical settings.

CONCLUSIONS

The interpretable GBM model was shown to successfully and accurately predict the occurrence of persistent SA-AKI, demonstrating good predictive ability in both internal and external validation cohorts. Furthermore, the model was demonstrated to outperform the biomarker CCL14 in prospective cohort validation.

Innate immune cells in acute and chronic kidney disease

Acute kidney injury (AKI) and chronic kidney disease (CKD) are inter-related clinical and pathophysiological disorders. Cells of the innate immune system, such as granulocytes and macrophages, can induce AKI through the secretion of pro-inflammatory mediators such as cytokines, chemokines and enzymes, and the release of extracellular traps. In addition, macrophages and dendritic cells can drive the progression of CKD through a wide range of pro-inflammatory and pro-fibrotic mechanisms, and by regulation of the adaptive immune response. However, innate immune cells can also promote kidney repair after acute injury. These actions highlight the multifaceted nature of the way by which innate immune cells respond to signals within the kidney microenvironment, including interaction with the complement and coagulation cascades, cells of the adaptive immune system, intrinsic renal cells and infiltrating mesenchymal cells. The factors and mechanisms that underpin the ability of innate immune cells to contribute to renal injury or repair and to drive the progression of CKD are of great interest for understanding disease processes and for developing new therapeutic approaches to limit AKI and the AKI-to-CKD transition.

Histone deacetylases and their inhibitors in kidney diseases

Histone deacetylases (HDACs) have emerged as key regulators in the pathogenesis of various kidney diseases. This review explores recent advancements in HDAC research, focusing on their role in kidney development and their critical involvement in the progression of chronic kidney disease (CKD), acute kidney injury (AKI), autosomal dominant polycystic kidney disease (ADPKD), and diabetic kidney disease (DKD). It also discusses the therapeutic potential of HDAC inhibitors in treating these conditions. Various HDAC inhibitors have shown promise by targeting specific HDAC isoforms and modulating a range of biological pathways. Their protective effects include modulation of apoptosis, autophagy, inflammation, and fibrosis, underscoring their broad therapeutic potential for kidney diseases. However, further research is essential to improve the selectivity of HDAC inhibitors, minimize toxicity, overcome drug resistance, and enhance their pharmacokinetic properties. This review offers insights to guide future research and prevention strategies for kidney disease management.

Integrated multiomics analysis identifies potential biomarkers and therapeutic targets for autophagy associated AKI to CKD transition

This study explored the relationship between acute kidney injury (AKI) and chronic kidney disease (CKD), focusing on autophagy-related genes and their immune infiltration during the transition from AKI to CKD. We performed weighted correlation network analysis (WGCNA) using two microarray datasets (GSE139061 and GSE66494) in the GEO database and identified autophagy signatures by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG), and GSEA enrichment analysis. Machine learning algorithms such as LASSO, random forest, and XGBoost were used to construct the diagnostic model, and the diagnostic performance of GSE30718 (AKI) and GSE37171 (CKD) was used as validation cohorts to evaluate its diagnostic performance. The study identified 14 autophagy candidate genes, among which ATP6V1C1 and COPA were identified as key biomarkers that were able to effectively distinguish between AKI and CKD. Immune cell infiltration and GSEA analysis revealed immune dysregulation in AKI, and these genes were associated with inflammation and immune pathways. Single-cell analysis showed that ATP6V1C1 and COPA were specifically expressed in AKI and CKD, which may be related to renal fibrosis. In addition, drug prediction and molecular docking analysis proposed SZ(+)-(S)-202-791 and PDE4 inhibitor 16 as potential therapeutic agents. In summary, this study provides new insights into the relationship between AKI and CKD and lays a foundation for the development of new treatment strategies.

Recent Advances in Enzyme-Activated Dual-Locked Probes for Biological Applications

Enzymes catalyze reactions involved in diverse physiological, pathological, and pharmacological processes. By employing the optical probe, fluorescence imaging enables non-invasive, real-time detection and assessment of disease states based on enzymatic activity. However, most enzyme-activated probes are single-locked probes that respond to a single biomarker. In comparison to single-locked probes, enzyme-activated dual-locked probes can effectively minimize the occurrence of false-positive signals, circumvent the problem of low specificity associated with biologically active substances, and facilitate precise imaging. This review systematically summarizes the design and application of dual-locked probes in disease diagnosis, with the aim of providing inspiration for researchers in the field.

Independent and interactive roles of hirudin and HMGB1 interference in protecting renal function by regulating autophagy, apoptosis, and kidney injury in chronic kidney disease

Chronic kidney disease (CKD) is a progressive disorder characterized by renal fibrosis, inflammation, and dysregulated autophagy and apoptosis. High-mobility group box 1 (HMGB1) plays a crucial role in regulating autophagy in CKD. Hirudin, a potent thrombin inhibitor, has demonstrated antifibrotic and anti-inflammatory properties, but its effects on autophagy and apoptosis in CKD remain unclear. In this study, a rat model of renal interstitial fibrosis (RIF) and an HK-2 cell culture model were established to assess the effects of varying doses of hirudin and HMGB1 interference. Molecular and histological analyses, including RTqPCR, Western blot, TUNEL staining, hematoxylin-eosin (H&E) staining, immunofluorescence, and immunohistochemistry (IHC), were performed to assess renal injury, fibrosis, apoptosis, and autophagy-related markers. Hirudin treatment significantly reduced the expression of LC3, ATG12, ATG5, α-SMA, COL1A1, caspase-3, and caspase-9 while increasing P62 levels (p<0.05). It also lowered the renal coefficient (p<0.001) and apoptosis levels. The optimal effective concentration of hirudin in vitro was determined to be 4.8 ATU/mL (p<0.001). HMGB1 interference suppressed autophagy and apoptosis, as indicated by decreased LC3-II/LC3-I, ATG12, ATG5, caspase-3, and caspase-9 levels, increased P62 expression (p<0.001), and reduced apoptosis. However, simultaneous HMGB1 interference in hirudin-treated cells weakened the therapeutic effects of hirudin, leading to increased autophagy and apoptosis markers, decreased P62 levels, and a higher renal coefficient. These findings indicate that hirudin exerts protective effects in CKD by modulating autophagy and apoptosis, potentially through HMGB1 regulation. These findings highlight the therapeutic potential of targeting these mechanisms in renal dysfunction and underscore the necessity for further research to support clinical applications.

Nanoparticle-mediated Klotho gene therapy prevents acute kidney injury to chronic kidney disease transition through regulating PPARα signaling in renal tubular epithelial cells

Klotho is an anti-aging protein produced primarily by tubular epithelial cells (TECs). Down-regulated expression of Klotho in injured TECs plays a key pathogenic role in promoting acute kidney injury (AKI) to chronic kidney disease (CKD) transition, yet therapeutic approaches targeting the restoration of renal Klotho levels remain challenging for clinical application. Here, we synthesize polydopamine-polyethylenimine-l-serine-Klotho plasmid nanoparticles (PPSK NPs), which can safely and selectively deliver the Klotho gene to the injured TECs through binding kidney injury molecule-1 and maintain the expression of Klotho protein. In vitro, PPSK NPs effectively reduce the hypoxia-reoxygenation-induced reactive oxygen species production and fibrotic gene expression. In the unilateral ischemia-reperfusion injury- and folic acid-induced AKI-CKD transition mouse models, a single low-dose injection of PPSK NPs is sufficient to preserve the normal kidney architecture and prevent renal fibrosis. Mechanismly, the protective effect of PPSK NPs relies on upregulating a key molecule peroxisome proliferator-activated receptor alpha (PPARα) via the inhibition of p38 and JNK phosphorylation, which in turn improves tubular fatty acid beta-oxidation and reduces renal lipid accumulation, thereby protecting against kidney fibrosis. In conclusion, our results highlight the translational potential of nanoparticle-based Klotho gene therapy in preventing the AKI-CKD transition.

Severe sepsis-associated acute kidney injury and outcomes: a longitudinal cohort study

BACKGROUND

Sepsis-associated acute kidney injury (SA-AKI) is common among patients admitted to the intensive care unit (ICU) with sepsis.

AIMS

This study aimed to demonstrate an association between an episode of SA-AKI and progression to dialysis dependence, with a view to identifying a cohort who may be suitable for intensive nephrology follow-up.

METHODS

Design: Retrospective data-linkage cohort study.

SETTING

Alice Springs Hospital ICU, 10-bed regional facility, housed in a 200-bed regional hospital, located in Central Australia.

PARTICIPANTS

All patients admitted with a diagnosis code associated with sepsis between 2015 and 2017.

MAIN OUTCOME MEASURES

Primary outcome was a composite measure comprising death or initiation of maintenance dialysis within 5 years of the index case of sepsis leading to ICU admission.

RESULTS

The unadjusted risk of the composite outcome was significantly higher in the SA-AKI group (odds ratio (OR) 3.22, 95% confidence interval (CI) 1.81-5.74, P < 0.01). This effect remains after adjustment for age, illness severity and co-morbidities (adjusted OR (aOR) 2.64, 95% CI 1.22-5.68, P = 0.01). Progression to maintenance dialysis was the primary driver of this effect (OR 7.56, 95% CI 2.23-25.65, P = 0.02), although it was modified by the effect of confounders (aOR 7.3, 95% CI 0.7-75.94, P = 0.10).

CONCLUSIONS

These results demonstrate an association between an index episode involving SA-AKI and the composite outcome in a defined population. Identification of this group may allow intensive nephrology follow-up and secondary prevention with the goal of mitigating the risk of progression of disease with significant economic and personal benefits.

CKD Progression after Acute Kidney Injury: A Secondary Analysis of the Standard versus Accelerated Initiation of Renal Replacement Therapy in Acute Kidney Injury Trial

Key Points

Development or progression of CKD occurred in almost 40% of patients after an episode of severe AKI. Receipt of KRT, regardless of allocation to an accelerated or standard initiation strategy, was associated with development or progression of CKD. This study helps identify a subset of patients at risk of CKD after severe AKI who would benefit from dedicated kidney follow-up after discharge.

Background

CKD is a common complication after AKI. We aimed to evaluate whether a KRT initiation strategy had an effect on CKD progression. Secondarily, we aimed to identify factors that influenced the development or progression of CKD after severe AKI.

Methods

This secondary analysis of the Standard versus Accelerated Initiation of Renal Replacement Therapy in AKI trial included patients with outpatient serum creatinine values available in the year before hospitalization and who were alive at 90 days after randomization. Our main analysis focused on patients who had definitive assessment of kidney function at 90 days after randomization. Predictor markers included patient demographics, comorbidities, markers of acute illness, laboratory values, receipt of KRT, and KRT treatment strategy (accelerated versus standard). The primary outcome was CKD progression, a composite of de novo CKD, defined as new eGFR <60 ml/min per 1.73 m2 if baseline eGFR was ≥60 ml/min; a decline in eGFR ≥25% if baseline eGFR was <60 ml/min; or KRT dependence at day 90. The association of KRT treatment strategy with CKD progression was assessed in an unadjusted mixed-effect logistic regression model.

Results

Of the 401 surviving patients with a baseline serum creatinine, 39% experienced CKD progression. KRT initiation strategy had no effect on CKD progression (accelerated arm [41%], versus the standard arm [38%], odds ratio, 1.13 [95% confidence interval, 0.75 to 1.72]). Receipt of KRT and aortic surgery were the most potent risks of CKD progression.

Conclusions

These findings suggest that CKD progression is common after severe AKI. Risk factors of CKD progression included receipt of KRT and aortic surgery, suggesting that these patients should be prioritized for dedicated kidney follow-up after hospital discharge.

Clinical Trial registry name and registration number:

NCT01557361 .

Myeloid FtH Regulates Macrophage Response to Kidney Injury by Modulating Snca and Ferroptosis

This study explored the role of myeloid ferritin heavy chain (FtH) in coordinating kidney iron trafficking in health and disease. Synuclein-α (Snca) was the sole iron-binding protein upregulated in response to myeloid FtH deletion (FtH Δ/Δ ). Following kidney injury, FtH Δ/Δ mice showed worsened kidney function. Transcriptome analysis revealed coupling of FtH deficiency with ferroptosis activation, a regulated cell death associated with iron accumulation. Adverse effects of ferroptosis were evidenced by upregulation of ferroptosis-related genes, increased oxidative stress markers, and significant iron deposition in kidney tissues. This iron buildup in FtH Δ/Δ kidneys stemmed from macrophage reprogramming into an iron-recycling phenotype, driven by Spic induction. Mechanistically, we establish that monomeric Snca functions as a ferrireductase catalyst, intensifying oxidative stress and triggering ferroptosis. Additionally, Snca accumulates in kidney diseases distinguished by leukocyte expansion across species. These findings position myeloid FtH as a pivotal orchestrator of the FtH-Snca-Spic axis driving macrophage reprogramming and kidney injury.

Highlights

Myeloid FtH deficiency drives kidney injury via activation of ferroptosisMΦ FtH deficiency induces Snca, linking iron dysregulation to MΦ function and response to kidney injuryFerrireductase activity of monomeric Snca augments oxidative stress, promoting lipid peroxidation and ferroptosis.

In brief

MΦ FtH modulates Snca and Spic to coordinate the injury response, linking iron trafficking to ferroptosis-induced kidney injury.

Systematic Review and Meta-Analysis of Machine Learning Models for Acute Kidney Injury Risk Classification

Key Points

Background

Artificial intelligence through machine learning models seems to provide accurate and precise AKI risk classification in some clinical settings, but their performance and implementation in real-world settings has not been established.

Methods

PubMed, Excerpta Medica (EMBASE) database, Web of Science, and Scopus were searched until August 2023. Articles reporting on externally validated models for prediction of AKI onset, AKI severity, and post-AKI complications in hospitalized adult and pediatric patients were searched using text words related to AKI, artificial intelligence, and machine learning. Two independent reviewers screened article titles, abstracts, and full texts. Areas under the receiver operating characteristic curves (AUCs) were used to compare model discrimination and pooled using a random-effects model.

Results

Of the 4816 articles initially identified and screened, 95 were included, representing 3.8 million admissions. The Kidney Disease Improving Global Outcomes (KDIGO)-AKI criteria were most frequently used to define AKI (72%). We identified 302 models, with the most common being logistic regression (37%), neural networks (10%), random forest (9%), and eXtreme gradient boosting (9%). The most frequently reported predictors of hospitalized incident AKI were age, sex, diabetes, serum creatinine, and hemoglobin. The pooled AUCs for AKI onset were 0.82 (95% confidence interval, 0.80 to 0.84) and 0.78 (95% confidence interval, 0.76 to 0.80) for internal and external validation, respectively. Pooled AUCs across multiple clinical settings, AKI severities, and post-AKI complications ranged from 0.78 to 0.87 for internal validation and 0.73 to 0.84 for external validation. Although data were limited, results in the pediatric population aligned with those observed in adults. Between-study heterogeneity was high for all outcomes (I2>90%), and most studies presented high risk of bias (86%) according to the Prediction Model Risk of Bias Assessment Tool.

Conclusions

Most externally validated models performed well in predicting AKI onset, AKI severity, and post-AKI complications in hospitalized adult and pediatric populations. However, heterogeneity in clinical settings, study populations, and predictors limits their generalizability and implementation at the bedside.

Anoctamin 9 determines Ca2+ signals during activation of T-lymphocytes

Background

Activation of T-cells is initiated by an increase in intracellular Ca2+, which underlies positive and negative regulation. Because the phospholipid scramblase and ion channel ANO9 (TMEM16J) was shown previously to regulated Ca2+ signals in renal epithelial cells, we asked whether ANO9 demonstrates a similar regulation in T-cells.

Methods

We used measurements of the intracellular Ca2+ concentration to examine the effects of ANO9 on intracellular Ca2+ signaling and demonstrated expression of ANO9 and its effects on cellular and molecular parameters.

Results

ANO9 was found to be expressed in human lymphocytes, including the Jurkat T-lymphocyte cell line and mouse lymphocytes. ANO9 has been shown to affect intracellular Ca2+ signals in renal epithelial cells. Here we demonstrate the essential role of ANO9 during initiation of intracellular Ca2+ signals in Jurkat T-cells and isolated mouse lymphocytes. ANO9 is essential for the initial rise in intracellular Ca2+ due to influx of extracellular Ca2+ through store-operated ORAI1 Ca2+ entry channels. ANO9 is indispensable for T-cell function, independent on whether cells are activated by stimulation of the T-cell receptor with CD3-antibody or by PMA/phytohemagglutinin.

Conclusions

Upon activation of T-cells and formation of the immunological synapse, ANO9 recruits the Ca2+-ATPase (PMCA) to the plasma membrane, which is supported by the scaffolding protein discs large 1 (DLG1). PMCAs maintain low Ca2+ levels near ORAI1 channels thereby suppressing Ca2+-inhibition of ORAI1 and thus retaining store-operated Ca2+ entry (SOCE). It is suggested that ANO9 has a role in interorganelle communication and regulation of cellular protein trafficking, which probably requires its phospholipid scramblase function.

Transition from acute kidney injury to chronic kidney disease in liver cirrhosis patients: Current perspective

In liver cirrhosis patients, acute kidney injury (AKI) is a common and severe complication associated with significant morbidity and mortality, often leading to chronic kidney disease (CKD). This progression reflects a complex interplay of renal and hepatic pathophysiology, with AKI acting as an initiator through maladaptive repair mechanisms. These mechanisms-such as tubular cell cycle arrest, inflammatory cascades, and fibrotic processes-are exacerbated by the hemodynamic and neurohormonal disturbances characteristic of cirrhosis. Following AKI episodes, persistent kidney dysfunction or acute kidney disease (AKD) often serves as a bridge to CKD. AKD represents a critical phase in renal deterioration, characterized by prolonged kidney injury that does not fully meet CKD criteria but exceeds the temporal scope of AKI. The progression from AKD to CKD is further influenced by recurrent AKI episodes, impaired renal autoregulation, and systemic comorbidities such as diabetes and metabolic dysfunction-associated steatotic liver disease, which compound kidney damage. The clinical management of AKI and CKD in cirrhotic patients requires a multidimensional approach that includes early identification of kidney injury, the application of novel biomarkers, and precision interventions. Recent evidence underscores the inadequacy of traditional biomarkers in predicting the AKI-to-CKD progression, necessitating novel biomarkers for early detection and intervention.

The association between anti-inflammatory therapies and renal outcomes in patients with established cardiovascular disease or high cardiovascular risks: a meta-analysis of randomised controlled trials

BACKGROUND

To assess the relationship between anti-inflammatory therapy and renal events risk in participants with cardiovascular risks or diagnosed cardiovascular disease (CVD).

METHODS

Literature searches were carried out in PubMed, Embase, clinicaltrial.gov and the Cochrane Central Register of Controlled Trials. Randomised controlled trials that were published from January 1995 to July 2024, compared anti-inflammatory therapy and placebo in participants at cardiovascular risks or with diagnosed CVD and with reports of renal outcomes were included. The results were shown as risk ratio (RR) and 95% confidence interval (CI).

RESULTS

In comparison to placebo, therapies targeting inflammation did not exhibit a significant association with the risk of composite renal outcomes (worsening of renal function, death due to kidney disease and end-stage renal disease) (RR = 0.89, 95% CI 0.40 to 1.99, I2 = 0%). The risk of worsening of renal function (RR = 0.81, 95% CI 0.21 to 3.07, I2 = NA), end-stage renal disease (RR = 0.94, 95% CI 0.31 to 2.85, I2 = 0%), death due to kidney disease (RR = 3.00, 95% CI 0.12 to 73.56, I2 = NA), chronic kidney disease (RR = 1.77, 95% CI 0.74 to 4.23, I2 = 0%), chronic renal failure (RR = 1.70, 95% CI 0.56 to 5.15, I2 = 61%) and acute kidney injury (RR = 1.16, 95% CI 0.95 to 1.42, I2 = 0%) showed no significant difference between patients receiving anti-inflammatory therapy and placebo.

CONCLUSION

Current evidence did not indicate associations between anti-inflammatory therapies and adverse renal events risks in patients with cardiovascular risks or established CVD. Future researches are needed to explore the renal effects of anti-inflammatory therapy.

Population pharmacokinetics of polymyxin B in critically ill patients with carbapenem-resistant organisms infections: insights from steady-state trough and peak plasma concentration

Aims

To establish a population pharmacokinetic (PopPK) model of polymyxin B (PMB) in critically ill patients based on steady-state trough (Ctrough,ss) and peak (Cpeak,ss) concentrations, optimize the dosing regimen, and evaluate the consistency of 24-hour steady-state area under the concentration-time curve (AUCss,24h) estimation between model-based and the two-point (Ctrough,ss and Cpeak,ss) methods.

Methods

PopPK modeling was performed using NONMEM, Monte Carlo simulations were used to optimize PMB dosing regimens. Bland-Altman analysis was used to evaluate the consistency between the two AUCss,24h estimation methods.

Results

A total of 95 patients, contributing 214 blood samples, were included and categorized into a modeling group (n = 80) and a validation group (n = 15). A one-compartment model was developed, with creatinine clearance (CrCL) and platelet count (PLT) identified as significant covariates influencing PK parameters. Simulation results indicated that when a Minimum Inhibitory Concentration (MIC) ≤ 0.5 mg·L-1, a probability of target attainment (PTA) ≥ 90% was achieved in all groups except for the 50 mg every 12 h (q12h) maintenance dose group. PTA decreased as CrCL increased, with slight variations observed across different PLT levels. The 75 mg and 100 mg q12h groups showed a higher proportion of AUCss,24h within the therapeutic window. Bland-Altman analysis revealed a mean bias of 12.98 mg·h·L-1 between the two AUCss,24h estimation methods. The Kappa test (κ = 0.51, P < 0.001) and McNemar's test (P = 0.33) demonstrated moderate agreement, reflecting overall consistency with minor discrepancies in classification outcomes.

Conclusion

The PopPK model of PMB is well-suited for critically ill patients. The 75 mg q12h and 100 mg q12h regimens are appropriate for critically ill patients, with CrCL levels guiding individualized dosing. A two-point sampling strategy can be used for routine therapeutic drug monitoring (TDM) of PMB.

Synthetic Bilirubin-Based Nanomedicine Protects Against Renal Ischemia/Reperfusion Injury Through Antioxidant and Immune-Modulating Activity

Renal ischemia/reperfusion injury (IRI) is a common form of acute kidney injury. The basic mechanism underlying renal IRI is acute inflammation, where oxidative stress plays an important role. Although bilirubin exhibits potent reactive oxygen species (ROS)-scavenging properties, its clinical application is hindered by problems associated with solubility, stability, and toxicity. In this study, BX-001N, a synthetic polyethylene glycol-conjugated bilirubin 3α nanoparticle is developed and assessed its renoprotective effects in renal IRI. Intravenous administration of BX-001N led to increase uptake in the kidneys with minimal migration to the brain after IRI. Peri-IRI BX-001N administration improves renal function and attenuates renal tissue injury and tubular apoptosis to a greater extent than free bilirubin on day 1 after IRI. BX-001N suppressed renal infiltration of inflammatory cells and reduced expression of TNF-α and MCP-1. Furthermore, BX-001N increases renal tubular regeneration on day 3 and suppresses renal fibrosis on day 28. BX-001N decreases the renal expressions of dihydroethidium, malondialdehyde, and nitrotyrosine after IRI. In conclusion, BX-001N, the first Good Manufacturing Practice-grade synthetic bilirubin-based nanomedicine attenuates acute renal injury and chronic fibrosis by suppressing ROS generation and inflammation after IRI. It shows adequate safety profiles and holds promise as a new therapy for renal IRI.

Sepsis-Associated Acute Kidney Disease Incidence, Trajectory, and Outcomes

Rationale & Objective

Systematic evaluation of the prognosis from sepsis-associated acute kidney disease (SA-AKD) using real-world data is limited. This study aimed to use data algorithms on the electronic health records to trace the SA-AKD trajectory from acute kidney injury (AKI) to chronic kidney disease (CKD).

Study Design

A retrospective cohort study.

Setting & Participants

Adult inpatients with first sepsis episode surviving 90 days after AKD in a quaternary referral medical center.

Exposure

We defined SA-AKD as having sustained ≥1.5-fold increased serum creatinine levels or initiating kidney replacement therapy after the SA-AKI, and we classified SA-AKD into recovery, relapse, and persistent SA-AKD subgroups.

Outcomes

All-cause mortality, kidney replacement therapy (KRT), de novo nondialysis dependent CKD (CKD-ND), and late-recovery AKD during 1-year follow-up.

Analytical Approach

A multivariable Cox proportional hazards models.

Results

Of 24,038 eligible inpatients with sepsis, 42.2% had SA-AKI, and 17.6% progressed to SA-AKD (43.6% recovery, 8.3% relapse, 32.2% persistent, and 15.9% unclassified). Compared with the recovery subgroup, the 1-year mortality risk for the relapse, persistent, and unclassified SA-AKD subgroups were 1.57 (adjusted hazard ratios [aHRs]; 95% CI, 1.22-2.01), 1.36 (1.13-1.63), and 0.65 (0.48-0.89), respectively. Risks of KRT initiation were 3.27 (2.14-4.98), 6.01 (4.41-8.19), and 0.98 (0.55-1.74), respectively, and corresponding aHRs for de novo CKD-ND were 3.84 (2.82-5.22), 3.35 (2.61-4.29), and 0.48 (0.30-0.77), respectively. Patients with relapse SA-AKD had a higher likelihood of late recovery (aHR, 3.62; 95% CI, 2.52-5.21) than the persistent SA-AKD.

Limitations

Selection bias and information bias could be present because of limiting population to sepsis survivors and because of no standardized follow-up protocol for kidney function.

Conclusions

SA-AKD without recovery is associated with increased and long-term risks of KRT initiation, mortality, and increased risk of de novo CKD-ND for patients initially free of CKD. Further studies are warranted for managing AKI to AKD to CKD in real-world settings.

Crosstalk between glomeruli and tubules

Models of kidney injury have classically concentrated on glomeruli as the primary site of injury leading to glomerulosclerosis or on tubules as the primary site of injury leading to tubulointerstitial fibrosis. However, current evidence on the mechanisms of progression of chronic kidney disease indicates that a complex interplay between glomeruli and tubules underlies progressive kidney injury. Primary glomerular injury can clearly lead to subsequent tubule injury. For example, damage to the glomerular filtration barrier can expose tubular cells to serum proteins, including complement and cytokines, that would not be present in physiological conditions and can promote the development of tubulointerstitial fibrosis and progressive decline in kidney function. In addition, although less well-studied, increasing evidence suggests that tubule injury, whether primary or secondary, can also promote glomerular damage. This feedback from the tubule to the glomerulus might be mediated by changes in the reabsorptive capacity of the tubule, which can affect the glomerular filtration rate, or by mediators released by injured proximal tubular cells that can induce damage in both podocytes and parietal epithelial cells. Examining the crosstalk between the various compartments of the kidney is important for understanding the mechanisms underlying kidney pathology and identifying potential therapeutic interventions.

Unraveling the Epidemiology of Acute Kidney Injury Recovery

Acute kidney injury (AKI) is a common complication among hospitalized patients and is associated with significant long-term morbidity, including the development of major adverse kidney events such as kidney failure. By definition, AKI holds the promise of potential kidney recovery, yet clearly not all patients will recover, and some will develop worsening kidney function even after initial recovery. Being able to identify which patients with AKI will recover vs have persistent or future kidney complications is a critically important question, both for counseling patients and for determining appropriate care of AKI survivors. In this article, we review and describe the key factors associated with kidney function nonrecovery after AKI, some of which are modifiable and may be future targets for intervention. We also describe recent studies developing clinical risk scores to predict post-AKI kidney outcomes and their potential role in the clinical setting. Despite progress, there remains significant opportunity to improve our understanding of the epidemiology of AKI recovery.

Oxidative stress and NRF2 signaling in kidney injury

Oxidative stress plays a crucial role in the pathogenesis of acute kidney injury (AKI), chronic kidney disease (CKD), and the AKI-to-CKD transition. This review examines the intricate relationship between oxidative stress and kidney pathophysiology, emphasizing the potential therapeutic role of nuclear factor erythroid 2-related factor 2 (NRF2), a master regulator of cellular redox homeostasis. In diverse AKI and CKD models, diminished NRF2 activity exacerbates oxidative stress, whereas genetic and pharmacological NRF2 activation alleviates kidney damage induced by nephrotoxic agents, ischemia-reperfusion injury, fibrotic stimuli, and diabetic nephropathy. The renoprotective effects of NRF2 extend beyond antioxidant defense, encompassing its anti-inflammatory and anti-fibrotic properties. The significance of NRF2 in renal fibrosis is further underscored by its interaction with the transforming growth factor-β signaling cascade. Clinical trials using bardoxolone methyl, a potent NRF2 activator, have yielded both encouraging and challenging outcomes, illustrating the intricacy of modulating NRF2 in human subjects. In summary, this overview suggests the therapeutic potential of targeting NRF2 in kidney disorders and highlights the necessity for continued research to refine treatment approaches.

Insights into non-coding RNAS: biogenesis, function and their potential regulatory roles in acute kidney disease and chronic kidney disease

Noncoding RNAs (ncRNAs) have emerged as pivotal regulators of gene expression, and have attracted significant attention because of their various roles in biological processes. These molecules have transcriptional activity despite their inability to encode proteins. Moreover, research has revealed that ncRNAs, especially microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs), are linked to pervasive regulators of kidney disease, including anti-inflammatory, antiapoptotic, antifibrotic, and proangiogenic actions in acute and chronic kidney disease. Although the exact therapeutic mechanism of ncRNAs remains uncertain, their value in treatment has been studied in clinical trials. The numerous renal diseases and the beneficial or harmful effects of NcRNAs on the kidney will be discussed in this article. Afterward, exploring the biological characteristics of ncRNAs, as well as their purpose and potential contributions to acute and chronic renal disease, were explored. This may offer guidance for treating both acute and long-term kidney illnesses, as well as insights into the potential use of these indicators as kidney disease biomarkers.

Rapid and non-invasive renal injury diagnosis unlocked by a glimpse into urinary protein particle size and charge

Urinary protein, an important marker for early detection of kidney injury, would change in type and content dynamically with the degree of kidney injury due to the particle size and charge selectivity of the glomerular filtration system, making it significantly valuable for accurate classification and early diagnosis. In this study, we developed a fluorescence sensor (Ami-AuNP/DNAs) based on charge interaction to rapidly identify the progression of kidney injury. When the positively charged Ami-AuNP combines with negatively charged DNAs, fluorescence quenching occurs, and urine proteins that appear compete with the DNAs, leading to fluorescence recovery. Based on these signal changes, PCA and PSO-BP neural network analysis were used to successfully identified kidney injury progression in 197 animal kidney injury and 62 clinical chronic kidney disease urine samples through a simple urine sample drop. Additionally, the sensor could also evaluate the effect of Huangkui capsule on kidney injury in adriamycin nephropathy model mice. Accordingly, this method transforms complex biological signals in vivo into macroscopic visual optical signals, amplifying differences of urinary protein, making up for the deficiency of the traditional method in hysteresis and low accuracy, and promoting urinary protein as the potential noninvasive biomarker for evaluating kidney injury.

Urinary Cytokeratin 20 as a Biomarker for AKI-CKD Transition among Patients with Acute Decompensated Heart Failure and Acute Kidney Injury

Key Points

In patients with acute decompensated heart failure and AKI, higher urinary cytokeratin 20 (CK20) associated with higher risk of AKI-to-CKD progression. Urinary CK20, particularly combined with clinical variables, improved the ability of predicting AKI-CKD transition with an accuracy of 90%. Urinary CK20 might be used as a novel tool for early identifying patients at high risk of kidney function loss after AKI.

Background

Predicting the risk of AKI-CKD transition remains a major challenge in the management of acute decompensated heart failure (ADHF) and AKI. This study investigated the clinical utility of urinary cytokeratin 20 (CK20), a novel biomarker reflecting the severity of histological acute tubular injury, for identifying patients at risk of AKI-to-CKD progression.

Methods

This prospective cohort study included a test set comprising 279 consecutive hospitalized patients with ADHF and AKI in five centers and a validation set enrolling 206 similar patients at an external center. Urinary CK20 and seven reported renal tubular injury biomarkers at the time of AKI diagnosis were measured. The primary outcome was a composite of AKI-CKD transition 90 days after AKI or all-cause death within 90 days. The secondary outcome was AKI-to-CKD progression 90 days after AKI.

Results

In the test set, 115 patients (41%) reached the primary end point. Concentrations of urinary CK20 peaked on the day of AKI diagnosis and remained elevated 14 days after AKI. After multivariable adjustment, the highest tertile of urinary CK20 was associated with 21-fold higher risk of the primary outcome and 29-fold higher risk of the secondary outcome. For predicting the primary and secondary outcomes, urinary CK20 at the time of AKI diagnosis had an area under the receiver operating characteristic curve of 0.82 (95% confidence interval [CI], 0.77 to 0.87) and 0.81 (95% CI, 0.75 to 0.87), respectively, and outperformed other reported biomarkers reflecting acute tubular injury and risk of CKD. Adding urinary CK20 to the clinical variables improved the ability for predicting the primary outcome with an area under the receiver operating characteristic curve of 0.90 (95% CI, 0.85 to 0.94) and largely improved risk reclassification. The ability of urinary CK20 in predicting AKI-CKD transition was further confirmed in the validation set.

Conclusions

Urinary CK20 improved prediction of the risk of transition from AKI to CKD in patients with ADHF and AKI.

Progression of chronic kidney disease after non-cardiac surgery: A retrospective cohort study

BACKGROUND

Chronic-kidney-disease (CKD) is prevalent among adults undergoing noncardiac surgery, with surgery-related factors potentially worsening CKD or triggering acute kidney injury (AKI). We hypothesized that CKD patients experience more kidney function decline within one to two years post-surgery than those without CKD, particularly if they develop AKI.

METHODS

We conducted a single-center retrospective cohort study, including noncardiac surgery patients with documented creatinine preoperative and between 1 and 2 years after surgery. The primary outcome was long-term course of kidney function, defined as the change in estimated glomerular filtration rate (eGFR) in mL/min/1.73m2.

RESULTS

Of 58,175 included cases, 17 % had preoperative CKD. Mean eGFR changed from 90.1 ± 16.7 to 92.0 ± 18.8 in non-CKD patients and from 45.6 ± 11.9 to 55.6 ± 20.1 in patients with CKD, with an estimated difference in means of 8.9 (95 % CI: 8.5, 9.3; P < 0.0001). There was a significant interaction between CKD-dependent eGFR change from baseline to follow-up and postoperative AKI (P = 0.001). For cases with preoperative CKD, eGFR increase from baseline to follow-up was 11.7 ± 18.0 with no AKI, 7.7 ± 17.9 with AKI stage 1, 2.4 ± 15.0 with AKI stage 2, and 7.3 ± 25.8 with AKI stage 3. For non-CKD patients, eGFR increased from baseline by 2.3 ± 13.7 with no AKI but decreased by 5.5 ± 19.0 with AKI stage 1, 7.7 ± 21.8 with AKI stage 2, and 9.3 ± 21.3 with AKI stage 3.

CONCLUSIONS

Contrary to expectations, patients with preoperative CKD experienced a significant improvement in eGFR postoperatively. Patients without CKD exhibited minimal change. Postoperative AKI negated the eGFR improvement in CKD patients and exacerbated the decline in non-CKD patients.

Activating soluble guanylyl cyclase attenuates ischemic kidney damage

Can direct activation of soluble guanylyl cyclase (sGC) provide kidney-protection? To answer this, we tested the kidney-protective effects of a sGC activator, which functions independent of nitric oxide and with oxidized sGC, in an acute kidney injury (AKI) model with transition to chronic kidney disease (CKD). We hypothesize this treatment would provide protection of kidney microvasculature, kidney blood flow, fibrosis, inflammation, and kidney damage. Assessment took place on days three, seven, 14 (acute phase) and 84 (late phase) after unilateral ischemia reperfusion injury (IRI) in rats. Post-ischemia, animals received vehicle or the sGC activator BAY 60-2770 orally. In the vehicle group, medullary microvessels narrowed and cortical microvessels showed hypertrophic inward remodeling. The mRNA levels of acute injury markers (Kim-1, Ngal) were high in the acute phase but declined in the late phase. Kidney weight decreased after the acute phase, while fibrosis started after day seven. Abundance of fibrotic (Col1a, Tgf-β1) and inflammatory markers (Il-6, Tnf-α) remained elevated throughout, along with mononuclear cell invasion, with elevated plasma cystatin C and creatinine. BAY 60-2770 treatment increased tissue cGMP concentration, dilated kidney microvasculature, and enhanced blood flow and oxygenation. This intervention significantly attenuated kidney weight loss, cell damage, fibrosis, and inflammation. Plasma cystatin C and creatinine improved significantly with sGC activator treatment indicating functional recovery, though possible GFR increase above kidney reserve in uninjured kidneys could not be excluded. In cultured human tubular cells (HK-2 cells) exposed to hypoxia or profibrotic TGF-β, BAY 60-2770 improved abundance patterns of pathologically relevant genes. Overall, our results show that sGC activation may provide effective kidney-protection and attenuate the AKI-to-CKD transition.

GALNT3 in Ischemia-Reperfusion Injury of the Kidney

Key Points

N -acetylgalactosaminyltransferase-3 (GALNT3) was downregulated in both ischemic AKI and cisplatin nephrotoxicity. GALNT3 played a protective role in renal tubular cells, and its downregulation contributed to AKI. Mechanistically, GALNT3 protected kidney tubular cells at least partially through O-glycosylation of EGF receptor.

Background

Damages to subcellular organelles, such as mitochondria and endoplasmic reticulum, are well recognized in tubular cell injury and death in AKI. However, the changes and involvement of Golgi apparatus are much less known. In this study, we report the regulation and role of N -acetylgalactosaminyltransferase-3 (GALNT3), a key enzyme for protein glycosylation in Golgi apparatus, in AKI.

Methods

AKI was induced in mice by renal ischemia–reperfusion injury or cisplatin. In vitro , rat kidney proximal tubular cells were subjected to hypoxia/reoxygenation (H/R) injury. To determine the role of GALNT3, its specific inhibitor T3inh-1 was tested in mice, and the effects of GALNT3 overexpression as well as knockdown were examined in the rat renal proximal tubular cells. EGF receptor (EGFR) activation was induced by recombinant EGF or by overexpressing EGFR.

Results

GALNT3 was significantly decreased in both in vivo and in vitro models of AKI induced by renal ischemia–reperfusion injury and cisplatin. T3Inh-1, a specific GALNT3 inhibitor, exacerbated ischemic AKI and suppressed tubular cell proliferation in mice. Moreover, knockdown of GALNT3 increased apoptosis during H/R treatment in rat renal proximal tubular cells, whereas overexpression of GALNT3 attenuated H/R-induced apoptosis, further supporting a protective role of GALNT3. Mechanistically, GALNT3 contributed to O-glycosylation of EGFR and associated EGFR signaling. Activation or overexpression of EGFR suppressed the proapoptotic effect of GALNT3 knockdown in H/R-treated rat renal proximal tubular cells.

Conclusions

GALNT3 protected kidney tubular cells in AKI at least partially through O-glycosylation of EGFR.

Long term outcomes of patients with chronic kidney disease after COVID-19 in an urban population in the Bronx

We investigated the long-term kidney and cardiovascular outcomes of patients with chronic kidney disease (CKD) after COVID-19. Our retrospective cohort consisted of 834 CKD patients with COVID-19 and 6,167 CKD patients without COVID-19 between 3/11/2020 to 7/1/2023. Multivariate competing risk regression models were used to estimate risk (as adjusted hazard ratios (aHR) with 95% confidence intervals (CI)) of CKD progression to a more advanced stage (Stage 4 or 5) and major adverse kidney events (MAKE), and risk of major adverse cardiovascular events (MACE) at 6-, 12-, and 24-month follow up. Hospitalized COVID-19 patients at 12 and 24 months (aHR 1.62 95% CI[1.24,2.13] and 1.76 [1.30, 2.40], respectively), but not non-hospitalized COVID-19 patients, were at higher risk of CKD progression compared to those without COVID-19. Both hospitalized and non-hospitalized COVID-19 patients were at higher risk of MAKE at 6-, 12- and 24-months compared to those without COVID-19. Hospitalized COVID-19 patients at 6-, 12- and 24-months (aHR 1.73 [1.21, 2.50], 1.77 [1.34, 2.33], and 1.31 [1.05, 1.64], respectively), but not non-hospitalized COVID-19 patients, were at higher risk of MACE compared to those without COVID-19. COVID-19 increases the risk of long-term CKD progression and cardiovascular events in patients with CKD. These findings highlight the need for close follow up care and therapies that slow CKD progression in this high-risk subgroup.

Persistent subclinical renal injury in female rats following renal ischemia-reperfusion injury

The incidence of acute kidney injury (AKI) continues to rise in both men and women. Although creatinine levels return to normal quicker in females following AKI than in males, it remains unclear whether subclinical renal injury persists in young females post-AKI. This study tested the hypothesis that AKI results in subclinical renal injury in females despite plasma creatinine returning to sham levels. For the present study, 12-13-week-old female Sprague-Dawley (SD) rats were randomized to sham or 45-minute warm bilateral ischemia-reperfusion surgery as an experimental model of ischemic AKI. Rats were euthanized 1, 3, 7, 14, or 30 days post-AKI/sham. Plasma creatinine, cystatin C, kidney injury molecule 1 (KIM-1), and NGAL were quantified via assay kits or immunoblotting. Kidneys were processed for histological analysis to assess tubular injury and fibrosis, and for electron microscopy to examine mitochondrial morphology. Immunoblots on kidney homogenates were performed to determine oxidative stress and apoptosis. Plasma creatinine levels were increased 24 hours post-AKI but returned to sham control levels three days post-AKI. However, cystatin C, KIM-1, and NGAL were increased 30 days post-AKI compared with sham. Tubular injury, tubulointerstitial fibrosis, and mitochondrial dysfunction were all increased in 30-day post-AKI rats compared with sham. Additionally, 30-day post-AKI rats had higher p-JNK expression and lower antioxidant enzyme glutathione peroxidase and catalase levels compared with sham. AKI resulted in higher expression of cleaved caspase 3, TUNEL+ cells, and caspase 9 than sham. Despite the normalization of creatinine levels, our data support the hypothesis that subclinical renal injury persists following ischemia-reperfusion injury in young female rats.

The incidence and outcome of acute kidney injury during pediatric kidney tumor treatment-a national cohort study

BACKGROUND

Acute kidney injury (AKI) is a serious complication of pediatric cancer treatment that is suggested to increase the risk of chronic kidney disease (CKD). Children with a kidney tumor may be at particular risk. This study aimed to determine the incidence and risk factors of AKI and its association with CKD during pediatric kidney tumor treatment.

METHODS

We analyzed data from a prospective national cohort of patients ≤ 18 years old diagnosed with a kidney tumor between 2015 and 2021 in the Princess Máxima Center for Pediatric Oncology in the Netherlands. AKI was defined according to KDIGO criteria. CKD was assessed 1 year post-treatment based on proteinuria and/or decreased estimated glomerular filtration rate (eGFR).

RESULTS

Of 147 patients, we observed AKI in 104 patients (71%) during therapy. AKI occurred most often within 48 h after tumor nephrectomy (88/104), while the rest had non-nephrectomy-related AKI from multifactorial causes. Sixteen patients experienced more than one AKI episode, and 92/104 episodes were reversible. Patients who developed AKI had a higher eGFR prior to surgery compared to those who did not develop AKI. CKD was observed in 16/120 patients (13%). Risk factors for developing CKD included the occurrence of at least 1 AKI event, the use of a > 3-drug regimen, and a lower eGFR at the start of treatment.

CONCLUSION

The high incidence of AKI and its association with early CKD highlights the need for early detection, prevention, and intervention strategies during pediatric kidney tumor treatment.

Ankrd1 as a potential biomarker for the transition from acute kidney injury to chronic kidney disease

Ischemia-reperfusion injury (IRI) is one of the leading causes of acute kidney injury (AKI), predisposing patients to chronic kidney disease (CKD) due to maladaptive renal repair. Nevertheless, the molecular mechanisms and biomarkers that cause maladaptive repair remain unclear. In this study, we used single-nucleus RNA sequencing data from GEO database (GSE139107) to identify molecular markers during the transition from AKI to CKD caused by IRI. Analysis of intercellular crosstalk, trajectory and machine learning algorithms revealed hub cell clusters and genes. Proximal tubule (PT) cells, especially a new cluster (New PT2), significantly interacted with fibroblasts during the transition. The expression levels of hub genes were validated using the bulk RNA-seq data (GSE98622) and further confirmed through RT-qPCR and immunohistochemical analysis in ischemia-reperfusion injury (uIRI) mice. Ankrd1, a hub gene in New PT2, showed sustained upregulation in the proximal tubule in AKI. Compared to the sham-operated group, the expression of Ankrd1 in mice increased at 0.5 days post-reperfusion, peaked at day 1, and remained significantly elevated up to 60 days. This study indicated that the upregulation of Ankrd1 was positively associated with the progression from AKI to CKD and may potentially serve as a valuable biomarker for this transitional process.

Innovative approaches to tissue engineering: Utilizing decellularized extracellular matrix hydrogels for mesenchymal stem cell transport

In recent years, the realm of tissue regeneration experienced significant advancements, leading to the development of innovative therapeutic agents. The systemic delivery of mesenchymal stem cells (MSCs) emerged as a promising strategy for promoting tissue regeneration. However, this approach is hindered by hurdles such as poor cell survival, limited cell propagation, and inadequate cell integration. Decellularized extracellular matrix (dECM) hydrogel serves as an innovative carrier that protects MSCs from the detrimental effects of the hostile microenvironment, facilitates their localization and retention at the injection site, and preserves their viability. Regarding its low immunogenicity, low cytotoxicity, high biocompatibility, and its ability to mimic natural extracellular matrix (ECM), this natural hydrogel offers a new avenue for systemic delivery of MSCs. This review digs into the properties of dECM hydrogels (dECMHs), the methods employed for decellularization and the utilization of dECMH as carriers for various types of MSCs for tissue regeneration purposes. This review also sheds light on the benefits of hybrid hydrogels composed of dECMH and other components such as proteins and polysaccharides. By addressing the limitations of conventional hydrogels and enhancing efficacy of cell therapy, dECMH opens new pathways for the future of tissue regeneration.

Longitudinal trend in post-discharge estimated glomerular filtration rate in intensive care survivors

Background

Acute kidney injury (AKI) within the intensive care unit (ICU) is common but evidence is limited on longer-term renal outcomes. We aimed to model the trend of kidney function in ICU survivors using estimated glomerular filtration rate (eGFR), comparing those with and without AKI, and investigate potential risk factors associated with eGFR decline.

Methods

This observational cohort study included all patients aged 16 or older admitted to two general adult ICUs in Scotland between 1st July 2015 and 30th June 2018 who survived to 30 days following hospital discharge. Baseline serum creatinine and subsequent values were used to identify patients with AKI and calculate eGFR following hospital discharge. Mixed effects modelling was used to control for repeated measures and to allow inclusion of several exploratory variables.

Results

3649 patients were included, with 1252 (34%) experiencing in-ICU AKI. Patients were followed up for up to 2000 days with a median 21 eGFR measurements. eGFR declined at a rate of -1.9 ml/min/1.73m2/year (p-value < 0.001) in the overall ICU survivor cohort. Patients with AKI experienced an accelerated rate of post-ICU eGFR decline of -2.0 ml/min/1.73m2/year compared to a rate of -1.83 ml/min/1.73m2/year in patients who did not experience AKI (p-value 0.007). Pre-existing diabetes or liver disease and in-ICU vasopressor support were associated with accelerated eGFR decline regardless of AKI experience.

Conclusions

ICU survivors experienced a decline in kidney function beyond that which would be expected regardless of in-ICU AKI. Long-term follow-up is warranted in ICU survivors to monitor kidney function and reduce morbidity and mortality.

Dipeptidyl peptidase 4 inhibitors reduce the risk of adverse outcomes after acute kidney injury in diabetic patients

Background

Dipeptidyl peptidase 4 inhibitors (DPP4is) are considered safe for use in patients with diabetes mellitus and kidney dysfunction. We explored whether usage of DPP4is in patients who recovered from dialysis-requiring acute kidney injury (AKI) could reduce the risk of future cardiac and kidney events.

Methods

We used the TriNetX platform to investigate whether the use of DPP4is in diabetes mellitus patients within 90 days of discharge from acute kidney disease could reduce the risk of all-cause mortality, major adverse kidney events (MAKEs), major adverse cardiovascular events (MACEs), and re-dialysis. The patients were followed for 5 years or until the occurrence of significant outcomes, with cohort data collected from 1 January 2016 to 30 September 2022.

Results

The cohort utilizing DPP4is comprised 7348 patients with acute kidney disease, while the control group encompassed 229 417 individuals. After applying propensity score matching, 7343 patients (age 66.2 ± 13.4 years; male, 49.9%) who used DPP4is showed a significant reduction in the risk of all-cause mortality [adjusted hazard ratio (aHR) 0.89; E-value 1.50 , MAKEs (aHR 0.86; E-value 1.59), MACEs (aHR 0.91; E-value 1.44), and re-dialysis (aHR 0.73; E-value 2.10) after a median follow-up of 2.4 years.

Conclusions

We demonstrated that in diabetes mellitus patients concurrently experiencing acute kidney disease, DPP4i usage could decrease the risk of mortality, MAKEs, MACEs, and re-dialysis. These findings emphasize the pivotal role of tailored treatment strategies involving DPP4i for acute kidney disease patients.

Ten tips on how to reduce iatrogenic acute kidney injury

Acute kidney injury (AKI) is a heterogeneous syndrome associated with worse clinical outcomes. Many treatments and procedures in the hospitalized patient can cause AKI. Hence, the incidence of iatrogenic AKI is expected to be high. In this review we provide 10 practical tips on how to manage and avoid iatrogenic AKI. We cover identification of vulnerable patients by epidemiological data and recommend the usage of renal stress biomarkers for enhanced screening of high-risk patients. Further, we discuss the limitations of current diagnostic criteria of AKI. As a key takeaway, we suggest the implementation of novel damage biomarkers in clinical routine to identify subclinical AKI, which may guide novel clinical management pathways. To further reduce the incidence of procedure-associated AKI, we advocate certain preventive measures. Foremost, this includes improvement of hemodynamics and avoidance of nephrotoxic drugs whenever possible. In cases of severe AKI, we provide tips for the implementation and management of renal replacement therapy and highlight the advantages of regional citrate anticoagulation. The furosemide stress test might be of help in recognizing patients who will require renal replacement therapy. Finally, we discuss the progression of AKI to acute and chronic kidney disease and the management of this growing issue. Both can develop after episodes of AKI and have major implications for patient co-morbidity and long-term renal and non-renal outcomes. Hence, we recommend long-term monitoring of kidney parameters after AKI.