Acute kidney injury in the critically ill: an updated review on pathophysiology and management

FTO attenuates TNF-α-induced damage of proximal tubular epithelial cells in acute pancreatitis-induced acute kidney injury via targeting AQP3 in an N6-methyladenosine-dependent manner

BACKGROUND

Acute kidney injury (AKI) is a frequent complication of severe acute pancreatitis (SAP). Previous investigations have revealed the involvement of FTO alpha-ketoglutarate-dependent dioxygenase (FTO) and aquaporin 3 (AQP3) in AKI. Therefore, the aim of this study is to explore the association of FTO and AQP3 on proximal tubular epithelial cell damage in SAP-induced AKI.

METHODS

An in-vitro AKI model was established in human proximal tubular epithelial cells (PTECs) HK-2 via tumor necrosis factor-α (TNF-α) induction (20 ng/mL), after which FTO and AQP3 expression was manipulated and quantified by quantitative real-time PCR and Western blotting. The viability and apoptosis of PTECs under various conditions, and reactive oxygen species (ROS), superoxide dismutase (SOD), and malonaldehyde (MDA) levels within these cells were measured using commercial assay kits and flow cytometry. Methylated RNA immunoprecipitation and mRNA stability assays were performed to elucidate the mechanism of FTO-mediated N6-methyladenosine (m6A) modification. Western blotting was performed to quantify β-catenin protein levels in the PTECs.

RESULTS

FTO overexpression attenuated the TNF-α-induced decrease in viability and SOD levels, elevated apoptosis, increased levels of ROS and MDA, and diminished TNF-α-induced AQP3 expression and reduced β-catenin expression, but its silencing led to contradictory results. FTO negatively modulates AQP3 levels in RTECs in an m6A-depednent manner and compromises AQP3 stability. In addition, all FTO overexpression-induced effects in TNF-α-induced PTECs were neutralized following AQP3 upregulation.

CONCLUSION

FTO alleviates TNF-α-induced damage to PTECs in vitro by targeting AQP3 in an m6A-dependent manner.

Association between platelet count and neonatal acute kidney injury: a cohort study using the medical information mart for intensive care III database

OBJECTIVE

A decrease in platelet count has been reported to be associated with several neonatal inflammatory diseases, including sepsis and necrotizing enterocolitis; while its association with neonatal acute kidney injury (AKI) has not been reported. This study aims to explore the association between platelet count and neonatal AKI.

METHODS

This was a retrospective cohort study based on the Medical Information Mart for Intensive Care III (MIMIC-III) database. Data were extracted based on baseline characteristics, comorbidities, vital signs, laboratory parameters, and intervention measures. Logistic regression analysis was used to assess the association between platelet count and AKI, and results were shown as odds ratios (OR) with 95% confidence intervals (CI).

RESULTS

A total of 1,576 neonates were finally included in the analysis. After adjusting birth weight, sepsis, patent ductus arteriosus, hematocrit, percentage of neutrophils, and vasopressor use, we found that platelet count in the lowest quartile (Q1) was significantly associated with the higher odds of AKI than platelet count in the highest quartile (Q4) (OR = 1.70, 95% CI: 1.01-2.87).

CONCLUSIONS

Low platelet count was associated with the high odds of AKI in the neonatal intensive care unit (NICU), indicating that platelet count might be a biomarker for neonatal AKI. Large-scale multicenter studies should be performed to verify the results.

Mitochondrial dysfunction in acute kidney injury

Acute kidney injury (AKI) is a systemic clinical syndrome increasing morbidity and mortality worldwide in recent years. Renal tubular epithelial cells (TECs) death caused by mitochondrial dysfunction is one of the pathogeneses. The imbalance of mitochondrial quality control is the main cause of mitochondrial dysfunction. Mitochondrial quality control plays a crucial role in AKI. Mitochondrial quality control mechanisms are involved in regulating mitochondrial integrity and function, including antioxidant defense, mitochondrial quality control, mitochondrial DNA (mtDNA) repair, mitochondrial dynamics, mitophagy, and mitochondrial biogenesis. Currently, many studies have used mitochondrial dysfunction as a targeted therapeutic strategy for AKI. Therefore, this review aims to present the latest research advancements on mitochondrial dysfunction in AKI, providing a valuable reference and theoretical foundation for clinical prevention and treatment of this condition, ultimately enhancing patient prognosis.

Mechanism of dexmedetomidine protection against cisplatin induced acute kidney injury in rats

OBJECTIVE

This study explored the molecular mechanisms by which dexmedetomidine (Dex) alleviates cisplatin (CP)-induced acute kidney injury (AKI) in rats.

METHODS

CP-induced AKI models were established, and Dex was intraperitoneally injected at different concentrations into rats in the model groups. Subsequently, rats were assigned to the control, CP, CP + Dex 10 μg/kg, and CP + Dex 25 μg/kg groups. After weighing the kidneys of the rats, the kidney arterial resistive index was calculated, and CP-induced AKI was evaluated. In addition, four serum biochemical indices were measured: histopathological damage in rat kidneys was detected; levels of inflammatory factors, interleukin (IL)-1β, IL-18, IL-6, and tumor necrosis factor alpha, in kidney tissue homogenate of rats were assessed through enzyme-linked immunosorbent assay (ELISA); and levels of NLRP-3, caspase-1, cleaved caspase-1, gasdermin D (GSDMD), and GSDMD-N in kidney tissues of rats were determined via western blotting.

RESULTS

Dex treatment reduced nephromegaly and serum clinical marker upregulation caused by CP-induced AKI. In addition, hematoxylin and eosin staining revealed that Dex treatment relieved CP-induced kidney tissue injury in AKI rats. ELISA analyses demonstrated that Dex treatment reduced the upregulated levels of proinflammatory cytokines in the kidney tissue of AKI rats induced by CP, thereby alleviating kidney tissue injury. Western blotting indicated that Dex alleviated CP-induced AKI by inhibiting pyroptosis mediated by NLRP-3 and caspase-1.

CONCLUSION

Dex protected rats from CP-induced AKI, and the mechanism may be related to NLRP-3/Caspase-1-mediated pyroptosis.

AST-120 alleviates renal ischemia-reperfusion injury by inhibiting HK2-mediated glycolysis

OBJECTIVE

Renal ischemia/reperfusion injury (IRI) is a major cause of acute kidney injury (AKI), which is associated with high incidence and mortality. AST-120 is an oral carbonaceous adsorbent that can alleviate kidney damage. This study aimed to explore the effects of AST-120 on renal IRI and the molecular mechanism.

METHODS

A renal IRI mouse model was established and administrated AST-120, and differentially expressed genes were screened using RNA sequencing. Renal function and pathology were analyzed in mice. Hypoxia/reoxygenation (H/R) cell model was generated, and glycolysis was evaluated by detecting lactate levels and Seahorse analysis. Histone lactylation was analyzed by western blotting, and its relationship with hexokinase 2 (HK2) was assessed using chromatin immunoprecipitation.

RESULTS

The results showed that HK2 expression was increased after IRI, and AST-120 decreased HK2 expression. Knockout of HK2 attenuated renal IRI and inhibits glycolysis. AST-120 inhibited renal IRI in the presence of HK2 rather than HK2 absence. In proximal tubular cells, knockdown of HK2 suppressed glycolysis and H3K18 lactylation caused by H/R. H3K18 lactylation was enriched in HK2 promoter and upregulated HK2 levels. Rescue experiments revealed that lactate reversed IRI that suppressed by HK2 knockdown.

CONCLUSIONS

In conclusion, AST-120 alleviates renal IRI via suppressing HK2-mediated glycolysis, which suppresses H3K18 lactylation and further reduces HK2 levels. This study proposes a novel mechanism by which AST-120 alleviates IRI.

Acute kidney injury associated with thrombotic microangiopathy: Characterization, prevalence, and prognosis

Acute kidney injury (AKI) is an important feature of thrombotic microangiopathy (TMA). This present study aimed to describe and analyze the characterization, prevalence, and prognosis in TMA patients with AKI. This study was an observational, retrospective patient cohort study in which patients were classified as AKI and non-AKI groups. An analysis of the relationship between the risk factors and AKI and in-hospital mortality was conducted using logistic regression. Kaplan-Meier curves were adopted to obtain the link between AKI and in-hospital mortality. There were 27 and 51 patients in the AKI and non-AKI groups, respectively, and the morbidity and mortality of AKI were 34.62% and 40.74%, respectively. AKI was associated with an older age (P = .033) and higher infection rates (P < .001). In comparison with the non-AKI group, the AKI group had tremendously intrarenal manifestations: hematuria (P < .001), proteinuria (P < .001). The AKI group received all continuous renal replacement therapy treatment (P < .001), but fewer glucocorticoids were used (P = .045). In-hospital mortality (P = .045) were higher in the AKI group. The risk factors for AKI (P = .037) were age. In addition, higher total bilirubin (P = .011) and age (P = .022) were significantly correlated with increasing risk of in-hospital mortality. Survival analysis by Kaplan-Meier revealed a significantly poor prognosis predicted by the AKI group (P = .045). Acute kidney injury could be commonly seen in TMA pneumonia and was related to a higher mortality rate.

DUSP5 deficiency suppresses the progression of acute kidney injury by enhancing autophagy through AMPK/ULK1 pathway

Acute kidney injury (AKI) represents a critical clinical disease characterized by the rapid decline in renal function, carrying a substantial burden of morbidity and mortality. The treatment of AKI is frequently limited by its variable clinical presentations and intricate pathophysiology, highlighting the urgent need for a deeper understanding of its pathogenesis and potential therapeutic targets. Dual-specific protein phosphatase 5 (DUSP5), a member of the serine-threonine phosphatase family, possesses the capability to dephosphorylate extracellular regulated protein kinases (ERK). DUSP5 has emerged as a pivotal player in modulating metabolic signals, inflammatory responses, and cancer progression, while also being closely associated with various kidney diseases. This study systematically scrutinized the function and mechanism of DUSP5 in AKI for the first time, unveiling a substantial increase in DUSP5 expression during AKI. Moreover, DUSP5 knockdown was observed to attenuate the production of inflammatory factors and apoptotic cells in renal tubular epithelial cells by enhancing AMPK/ULK1-mediated autophagy, thus improving renal function. In a word, DUSP5 knockdown in AKI effectively impede disease progression by activating autophagy. This finding holds promise for introducing fresh perspectives and targets for AKI treatment.

Understanding fluid dynamics and renal perfusion in acute kidney injury management

Acute kidney injury (AKI) is associated with an increased risk of morbidity, mortality, and healthcare expenditure, posing a major challenge in clinical practice, and affecting about 50% of patients in the intensive care unit (ICU), particularly the elderly and those with pre-existing chronic comorbidities. In health, intra-renal blood flow is maintained and auto-regulated within a wide range of renal perfusion pressures (60-100 mmHg), mediated predominantly through changes in pre-glomerular vascular tone of the afferent arteriole in response to changes of the intratubular NaCl concentration, i.e. tubuloglomerular feedback. Several neurohormonal processes contribute to regulation of the renal microcirculation, including the sympathetic nervous system, vasodilators such as nitric oxide and prostaglandin E2, and vasoconstrictors such as endothelin, angiotensin II and adenosine. The most common risk factors for AKI include volume depletion, haemodynamic instability, inflammation, nephrotoxic exposure and mitochondrial dysfunction. Fluid management is an essential component of AKI prevention and management. While traditional approaches emphasize fluid resuscitation to ensure renal perfusion, recent evidence urges caution against excessive fluid administration, given AKI patients' susceptibility to volume overload. This review examines the main characteristics of AKI in ICU patients and provides guidance on fluid management, use of biomarkers, and pharmacological strategies.

Formononetin Alleviates Ischemic Acute Kidney Injury by Regulating Macrophage Polarization through KLF6/STAT3 Pathway

Recent research has indicated that formononetin demonstrates a potent anti-inflammatory effect in various diseases. However, its impact on sterile inflammation kidney injury, specifically acute kidney injury (AKI), remains unclear. In this study, we utilized an ischemia/reperfusion-induced AKI (IRI-AKI) mouse model and bone marrow-derived macrophages (BMDMs) to investigate the effects of formononetin on sterile inflammation of AKI and to explore the underlying mechanism. The administration of formononetin significantly preserved kidney function from injury, as evidenced by lower serum creatinine and blood urea nitrogen levels compared to IRI-AKI mice without treatment. This was further confirmed by less pathological changes in renal tubules and low expression of tubular injury markers such as KIM-1 and NGAL in the formononetin-treated IRI-AKI group. Furthermore, formononetin effectively suppressed the expression of pro-inflammatory cytokines (MCP-1, TNF-[Formula: see text], and IL-1[Formula: see text]) and macrophage infiltration into the kidneys of AKI mice. In vitro studies showed that formononetin led to less macrophage polarization towards a pro-inflammatory phenotype in BMDMs stimulated by LPS and IFN-[Formula: see text]. The mechanism involved the KLF6 and p-STAT3 pathway, as overexpression of KLF6 restored pro-inflammatory cytokine levels and pro-inflammatory polarization. Our findings demonstrate that formononetin can significantly improve renal function and reduce inflammation in IRI-AKI, which may be attributed to the inhibition of KLF6/STAT3-mediated macrophage pro-inflammatory polarization. This discovery presents a new promising therapeutic option for the treatment of IRI-AKI.

Detection strip of anti-NGAL antibody coupled with fluorescent microspheres-A novel tool for reliable and accurate prediction of renal injury

OBJECTIVE

Neutrophil gelatinase-associated lipocalin (NGAL) has been identified by the International Nephrology Association (INA) as a promising biomarker for the early evaluation of renal injury. This study aimed to develop and evaluate NGAL test strips as a rapid, simple, and economical method for the early diagnosis of acute kidney injury (AKI).

METHODS

Recombinant prokaryotic expression vectors, purified NGAL protein, and anti-NGAL monoclonal antibodies were prepared. NGAL test strips were developed, and serum samples were collected from healthy individuals and patients with early-stage kidney injury at the Third Affiliated Hospital of Sun Yat-sen University between January 2023 and May 2024. Samples were tested using both the self-made strips and commercially available reagents.

RESULTS

The NGAL test strip comprised a conjugate pad containing 0.2 μL of fluorescent microspheres conjugated with anti-NGAL monoclonal antibody (McAb7#), a test line containing 1 mg/mL of a different anti-NGAL monoclonal antibody (McAb3#), and a control line containing 0.5 mg/mL of goat anti-mouse IgG. The test utilized 60 μL of sample (30 μL serum diluted with 30 μL of sample diluent) and was completed within 15 min at 25 °C and 35 %-85 % relative humidity. The developed strip accurately detected NGAL, demonstrating good linearity within the range of 0-160 ng/mL (R2 = 0.9943). The sensitivity and specificity of the NGAL strip for AKI diagnosis were 86.1 % and 78.8 %, respectively, comparable to the performance of commercially available testing reagents.

CONCLUSION

The developed test strip, utilizing anti-NGAL antibodies coupled with fluorescent microspheres, effectively detected trace amounts of NGAL protein in serum samples.

Research progress on miR-124-3p in the field of kidney disease

MicroRNAs (miRNAs) are 18-25 nucleotides long, single-stranded, non-coding RNA molecules that regulate gene expression. They play a crucial role in maintaining normal cellular functions and homeostasis in organisms. Studies have shown that miR-124-3p is highly expressed in brain tissue and plays a significant role in nervous system development. It is also described as a tumor suppressor, regulating biological processes like cancer cell proliferation, apoptosis, migration, and invasion by controlling multiple downstream target genes. miR-124-3p has been found to be involved in the progression of various kidney diseases, including diabetic kidney disease, calcium oxalate kidney stones, acute kidney injury, lupus nephritis, and renal interstitial fibrosis. It mediates these processes through mechanisms like oxidative stress, inflammation, autophagy, and ferroptosis. To lay the foundation for future therapeutic strategies, this research group reviewed recent studies on the functional roles of miR-124-3p in renal diseases and the regulation of its downstream target genes. Additionally, the feasibility, limitations, and potential application of miR-124-3p as a diagnostic biomarker and therapeutic target were thoroughly investigated.

[Biomarkers of oxidative stress and inflammation in contrast-associated acute kidney injury]

BACKGROUND

Iodinated contrast-induced acute kidney injury (CI-AKI) is a common cause of renal failure, especially in patients with risk factors. This study analyses different renal biomarkers in patients undergoing computed tomography scans with iodinated contrast to identify the molecular and cellular mechanisms involved in the pathogenesis of CI-AKI.

METHODOLOGY

Prospective study that included patients with high risk of renal disease who received iodinated contrast (iohexol) for the computed tomography scans. Functional biomarkers (creatinine and cystatin C), inflammatory and oxidative stress markers (neutrophil gelatinase-associated lipocalin [NGAL], interleukin-8 [IL-8], superoxide dismutase [SOD], F2-isoprostanes, and cardiotrophin-1), and cell cycle biomarkers (Nephrocheck®) were analysed before the iodinated contrast and 4, 12, 24, and 48 hours post-contrast, in relation to the incidence of IC-AKI.

RESULTS

IC-AKI was observed in 30.6% of the 62 study participants and in 57.1% of the patients with diabetes and renal dysfunction. Factors associated with IC-AKI were a higher mean age (74.4 vs 64.9 years), pre-existing renal dysfunction (60 vs 16.7%), and higher adjusted mean volume of iohexol (42.9 vs 32.1%). As for non-functional biomarkers. No differences were found between patients with and without CI-AKI. The use of iodinated contrast was associated with a decrease in SOD antioxidant activity at 4 hours and an increase in IL-8 at 12 hours post-administration of the iodinated contrast.

CONCLUSIONS

Administration of iohexol in computed tomography scans in patients with high risk of renal disease results in an elevated percentage of CI-AKI, attributable to ischemia/reperfusion injury and/or direct toxicity of the iodinated contrast.

Biomarkers of acute kidney injury: From discovery to the future of clinical practice

Purpose of this review Acute kidney injury (AKI) is a complex syndrome whose development is associated with an increased morbidity and mortality. Recent studies show that this syndrome is a common complication in critically ill and surgical patients the trajectory of which may differ. As AKI can be induced by different triggers, it is complex and therefore challenging to manage patients with AKI. This review strives to provide a brief historical perspective on AKI, elucidate recent developments in diagnosing and managing AKI, and show the current usage of novel biomarkers in both clinical routine and research. In addition, we provide a perspective on potential future developments and their impact of AKI understanding and management. Recent findings/developments Recent studies show the merits of stress and damage biomarkers, highlighting limitations of the current KDIGO definition that only uses the functional biomarkers serum creatinine and urine output. The use of novel biomarkers led to the introduction of the concept of "subclinical AKI". This new classification may allow a more distinct management of affected or at risk patients. Ongoing studies, such as BigpAK-2 and PrevProgAKI, investigate the implementation of biomarker-guided interventions in clinical practice and may demonstrate an improvement in patients' outcome. Summary The ongoing scientific efforts surrounding AKI have deepened our understanding of the syndrome prompting an expansion of existing concepts. A future integration of stress and damage biomarkers in AKI management, may lead to an individualized therapy in this area.

The evaluation of cytokines in predicting the organ injury of critically pediatric patients: a retrospective study

Background

The current early warning model for organ damage in critically ill patients has certain limitations. Based on the pathological mechanism, the establishment of an early warning system for organ damage in critically ill children using cytokines profile has not been explored. The aim of this study is to explore the predicting value of cytokines in critically ill patients.

Methods

There were 200 critically pediatric patients and 49 general patients between August 22, 2018 and April 28, 2023 from Children's Hospital of Soochow University enrolled in this study. The clinical information was retrospectively collected and analyzed. The cytokine profiles of these patients were detected by flow cytometry. Receiver operating characteristic (ROC) curves were plotted to determine the association between the cytokines and organ injury.

Results

There were no statistically significant differences in gender, age and underlying disease between critically ill patients and general patients. The interleukin (IL)-6 (P<0.001), IL-10 (P<0.001), IL-17A (P=0.001), tumor necrosis factor-α (TNF-α) (P=0.02) and interferon-γ (IFN-γ) (P=0.02) level in the critically patients were significantly higher than those in the general patients. The results showed that the incidence of acute gastrointestinal injury (AGI) and acute kidney injury (AKI) in critically ill patients was 39% and 23.5%, respectively. Moreover, there were 4% and 3.5% patients with the occurrence of cardiac arrest and acute live injury. The IFN-γ level was increased in these patients with acute liver injury compared to those without these organ injuries, but reduced in the patients with AGI compared to those without. The patients with AKI showed a significant increase in IL-10 in contrast to those without. The IL-2, IL-4, IL-6, IL-10 and IL-17A were higher in patients with acute liver failure (ALF), but TNF-α was reduced, compared to those without. The IL-2, IL-4, IL-6 and IL-10 were significantly increased in the patients with cardiac arrest compared to those without. When IL-10 was higher than 279.45 pg/mL, the sensitivity and specificity for predicting cardiac arrest were 0.875 and 0.927, respectively. While the sensitivity and specificity of IL-6 (more than 1,425.6 pg/mL) were 0.625 and 0.844, respectively. However, no synergistic effect of IL-6 and IL-10 was observed for predicting cardiac arrest. Additionally, the IL-17A (more than 21.6 pg/mL) was a good predictor for the incidence of ALF (sensitivity =0.714, specificity =0.876).

Conclusions

The cytokines profile was different between critically ill patients with organ injury and those without organ injury. The IL-6 and IL-10 levels were good predictors for cardiac arrest in critically ill patients. Additionally, higher IL-17A predicted the incidence of ALF of the critically ill patients.

Role of artificial intelligence in critical care nutrition support and research

Nutrition plays a key role in the comprehensive care of critically ill patients. Determining optimal nutrition strategy, however, remains a subject of intense debate. Artificial intelligence (AI) applications are becoming increasingly common in medicine, and specifically in critical care, driven by the data-rich environment of intensive care units. In this review, we will examine the evidence regarding the application of AI in critical care nutrition. As of now, the use of AI in critical care nutrition is relatively limited, with its primary emphasis on malnutrition screening and tolerance of enteral nutrition. Despite the current scarcity of evidence, the potential for AI for more personalized nutrition management for critically ill patients is substantial. This stems from the ability of AI to integrate multiple data streams reflecting patients' changing needs while addressing inherent heterogeneity. The application of AI in critical care nutrition holds promise for optimizing patient outcomes through tailored and adaptive nutrition interventions. A successful implementation of AI, however, necessitates a multidisciplinary approach, coupled with careful consideration of challenges related to data management, financial aspects, and patient privacy.

Association between amoxicillin administration and outcomes in critically ill patients with acute kidney injury

Purpose

This study assessed the effect of amoxicillin on outcomes in intensive care unit (ICU) patients with acute kidney injury (AKI), focusing on mortality rates and acute kidney disease (AKD) occurrence.

Materials and Methods

We conducted a retrospective cohort analysis utilizing data from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. The study included intensive care unit patients diagnosed with AKI to assess the effects of post-admission amoxicillin administration on 30-day and 90-day mortality rates and acute kidney disease incidence. We employed Cox proportional hazards models, propensity score matching, and inverse probability of treatment weighting to control for potential confounders.

Results

Among 24,650 AKI patients, 676 (2.7%) received amoxicillin. The results indicated significantly lower mortality rates at 30 days (hazard ratio [HR] 0.54, 95% confidence interval [CI] 0.42-0.69) and 90 days (HR 0.64, 95% CI 0.52-0.77) in the amoxicillin group compared to non-recipients. Additionally, amoxicillin administration was associated with a reduced incidence of AKD (HR 0.49, 95% CI 0.36-0.65) but resulted in a modestly increased length of hospital stay (mean difference [MD] 1.95 days, 95% CI 1.15-2.75). A dose‒response relationship was evident, with higher doses (>875 mg) further decreasing mortality rates. Subgroup analysis revealed consistent benefits across most patient groups.

Conclusion

Amoxicillin administration following ICU admission in patients with AKI was associated with improved survival rates and a lower incidence of AKD, highlighting its potential as a therapeutic measure for AKI management.

Application of interpretable machine learning algorithms to predict acute kidney injury in patients with cerebral infarction in ICU

BACKGROUND

Acute kidney injury (AKI) is not only a complication but also a serious threat to patients with cerebral infarction (CI). This study aimed to explore the application of interpretable machine learning algorithms in predicting AKI in patients with cerebral infarction.

METHODS

The study included 3920 patients with CI admitted to the Intensive Care Unit and Emergency Medicine of the Central Hospital of Lishui City, Zhejiang Province. Nine machine learning techniques, including XGBoost, logistics, LightGBM, random forest (RF), AdaBoost, GaussianNB (GNB), Multi-Layer Perceptron (MLP), support vector machine (SVM), and k-nearest neighbors (KNN) classification, were used to develop a predictive model for AKI in these patients. SHapley Additive exPlanations (SHAP) analysis provided visual explanations for each patient. Finally, model effectiveness was assessed using metrics such as average precision (AP), sensitivity, specificity, accuracy, F1 score, precision-recall (PR) curve, calibration plot, and decision curve analysis (DCA).

RESULTS

The XGBoost model performed better in the internal validation set and the external validation set, with an AUC of 0.940 and 0.887, respectively. The five most important variables in the model were, in order, glomerular filtration rate, low-density lipoprotein, total cholesterol, hemiplegia and serum kalium.

CONCLUSION

This study demonstrates the potential of interpretable machine learning algorithms in predicting CI patients with AKI.

Ultrasound molecular imaging for early detection of acute renal ischemia-reperfusion injury

Background

Microcirculatory perfusion disorder and inflammatory response are critical links in acute kidney injury (AKI). We aim to construct anti-vascular cell adhesion molecule-1(VCAM-1) targeted microbubbles (TM) to monitor renal microcirculatory perfusion and inflammatory response.

Methods

TM carrying VCAM-1 polypeptide was constructed by biological coupling. The binding ability of TM to human umbilical vein endothelial cells (HUVECs) was detected. Bilateral renal ischemia-reperfusion injury (IRI) models of mice were established to evaluate microcirculatory perfusion and inflammatory response using TM. Thirty-six mice were randomly divided into six groups according to the different reperfusion time (0.5, 2, 6, 12, and 24 h) and sham-operated group (Sham group). The correlation of TM imaging with serum and histopathological biomarkers was investigated.

Results

TM has advantages such as uniform distribution, regular shape, high stability, and good biosafety. TM could bind specifically to VCAM-1 molecule expressed by tumor necrosis factor-alpha (TNF-α)-treated HUVECs. In the renal IRI-AKI model, the area under the curve (AUC) of TM significantly decreased both in the renal cortical and medullary after 2 h of reperfusion compared with the Sham group (p < 0.05). Normalized intensity difference (NID) of TM at different reperfusion time was all higher than that of blank microbubbles (BM) and the Sham group (p < 0.05). Ultrasound molecular imaging of TM could detect AKI early before commonly used renal function markers, histopathological biomarkers, and BM imaging. AUC of TM was negatively correlated with serum creatinine (Scr), blood urea nitrogen (BUN), and Cystatin C (Cys-C) levels, and NID of TM was linearly correlated with VCAM-1, TNF-α, and interleukin-6 (IL-6) expression (p < 0.05).

Conclusions

Ultrasound molecular imaging based on TM carrying VCAM-1 polypeptide can accurately evaluate the changes in renal microcirculatory perfusion and inflammatory response, which might be a promising modality for early diagnosis of AKI.

Mitochondrial GPX4 acetylation is involved in cadmium-induced renal cell ferroptosis

Increasing evidences demonstrate that environmental stressors are important inducers of acute kidney injury (AKI). This study aimed to investigate the impact of exposure to Cd, an environmental stressor, on renal cell ferroptosis. Transcriptomics analyses showed that arachidonic acid (ARA) metabolic pathway was disrupted in Cd-exposed mouse kidneys. Targeted metabolomics showed that renal oxidized ARA metabolites were increased in Cd-exposed mice. Renal 4-HNE, MDA, and ACSL4, were upregulated in Cd-exposed mouse kidneys. Consistent with animal experiments, the in vitro experiments showed that mitochondrial oxidized lipids were elevated in Cd-exposed HK-2 cells. Ultrastructure showed mitochondrial membrane rupture in Cd-exposed mouse kidneys. Mitochondrial cristae were accordingly reduced in Cd-exposed mouse kidneys. Mitochondrial SIRT3, an NAD+-dependent deacetylase that regulates mitochondrial protein stability, was reduced in Cd-exposed mouse kidneys. Subsequently, mitochondrial GPX4 acetylation was elevated and mitochondrial GPX4 protein was reduced in Cd-exposed mouse kidneys. Interestingly, Cd-induced mitochondrial GPX4 acetylation and renal cell ferroptosis were exacerbated in Sirt3-/- mice. Conversely, Cd-induced mitochondrial oxidized lipids were attenuated in nicotinamide mononucleotide (NMN)-pretreated HK-2 cells. Moreover, Cd-evoked mitochondrial GPX4 acetylation and renal cell ferroptosis were alleviated in NMN-pretreated mouse kidneys. These results suggest that mitochondrial GPX4 acetylation, probably caused by SIRT3 downregulation, is involved in Cd-evoked renal cell ferroptosis.

Differences in the incidence, characteristics, and outcomes of patients with acute kidney injury in the medical and surgical intensive care units

BACKGROUND

Though acute kidney injury (AKI) is a prevalent complication in critically ill patients, knowledge on the epidemiological differences and clinical characteristics of patients with AKI admitted to medical and surgical intensive care units (ICUs) remains limited.

METHODS

Electronic medical records of patients in ICUs in Pusan National University Hospital and Pusan National University Hospital Yangsan, from January 2011 to December 2020, were retrospectively analyzed. Different characteristics of AKI between patients were analyzed. The contribution of AKI to the in-hospital mortality rate was assessed using a Cox proportional hazards model.

RESULTS

A total of 7,150 patients were included in this study. AKI was more frequent in medical (48.7%) than in surgical patients (19.7%), with the severity of AKI higher in medical patients. In surgical patients, hospital-acquired AKI was more frequent (51.0% vs. 49.0%), whereas community-acquired AKI was more common in medical patients (58.5% vs. 41.5%). 16.9% and 5.9% of medical and surgical patients died in the hospital, respectively. AKI affected patient groups to different degrees. In surgical patients, AKI patients had 4.778 folds higher risk of mortality (95% confidence interval [CI], 3.577-6.382; p < 0.001) than non-AKI patients; whereas in medical AKI patients, it was 1.239 (95% CI, 1.051-1.461; p = 0.01).

CONCLUSION

While the prevalence of AKI itself is higher in medical patients, the impact of AKI on mortality was stronger in surgical patients compared to medical patients. This suggests that more attention is needed for perioperative patients to prevent and manage AKI.

Association Between Loop Diuretics and Mortality in Patients With Cardiac Surgery-Associated Acute Kidney Injury: A Retrospective Propensity Score-Weighted Analysis

BACKGROUND

Although loop diuretics (LDs) have been widely used in clinical practice, their effect on mortality when administered to patients experiencing cardiac surgery-associated acute kidney injury (CS-AKI) remains unknown. The study aimed to investigate the effectiveness of LD use in patients with CS-AKI.

METHODS

Patients who underwent cardiac surgery with AKI were identified from the Medical Information Mart for Intensive Care III. Postoperative LD use in intensive care units (ICUs) was exposure. There were 2 primary outcome measures, the in-hospital mortality and ICU mortality; both were treated as time-to-event data and were analyzed via multivariable Cox proportional hazard models. Inverse probability weighting (IPW) was used to minimize bias.

RESULTS

The study enrolled a total of 5478 patients, with a median age of 67 years, among which 2205 (40.3%) were women. The crude in-hospital and ICU mortality rates were significantly lower in the LD use group (525 of 4150 [12.7%] vs 434 of 1328 [32.7%], P < .001; 402 of 4150 [9.69%] vs 333 of 1328 [25.1%], P < .001). Adjusted hazard ratios suggested significant reductions in both in-hospital (hazard ratio [HR], 0.428; 95% confidence interval [CI], 0.374-0.489) and ICU mortality (HR, 0.278; 95% CI, 0.238-0.327). The IPW data showed a similar reduction, in-hospital mortality (HR, 0.434; 95% CI, 0.376-0.502) and ICU mortality (HR, 0.296; 95% CI, 0.251-0.349). Such association may act differently for patients with different fluid balance ( P value for interaction < .001).

CONCLUSIONS

LD use is associated with lower hospital and ICU mortality in CS-AKI patients in general. Patients under different conditions showed diverse responses toward such treatment indicating that personalized management is needed.

Pediatric acute kidney injury and adverse health outcomes: using a foundational framework to evaluate a causal link

Acute kidney injury (AKI) is a major global health problem, expensive to manage, and its associations with negative pediatric health outcomes have been clearly demonstrated. One of the most fundamental questions to consider as we use previous epidemiological information to advance research and care paradigms is the strength of the causal link between pediatric AKI and health outcomes. In this review, we apply the foundational framework of the Bradford Hill criteria to evaluate the extent to which a causal link exists between AKI and the associated adverse outcomes in children. Available data in children support a causal link between AKI and short-term outcomes including mortality, length of stay, and ventilation time. Clarifying the causal nature of longer term associations requires further high-quality observational studies in children, careful consideration of what defines the most meaningful and measurable longer term outcomes after pediatric AKI, and integration of evolving biological data related to mechanisms of disease. Preventing or mitigating AKI should lead to improved outcomes. Demonstrating such reversibility will solidify confidence in the causal relationship, improve child health, and highlight an aspect which is highly relevant to clinicians, scientists, and policy makers.

Biomarkers in pursuit of precision medicine for acute kidney injury: hard to get rid of customs

Traditional acute kidney injury (AKI) classifications, which are centered around semi-anatomical lines, can no longer capture the complexity of AKI. By employing strategies to identify predictive and prognostic enrichment targets, experts could gain a deeper comprehension of AKI's pathophysiology, allowing for the development of treatment-specific targets and enhancing individualized care. Subphenotyping, which is enriched with AKI biomarkers, holds insights into distinct risk profiles and tailored treatment strategies that redefine AKI and contribute to improved clinical management. The utilization of biomarkers such as N-acetyl-β-D-glucosaminidase, tissue inhibitor of metalloprotease-2·insulin-like growth factor-binding protein 7, kidney injury molecule-1, and liver fatty acid-binding protein garnered significant attention as a means to predict subclinical AKI. Novel biomarkers offer promise in predicting persistent AKI, with urinary motif chemokine ligand 14 displaying significant sensitivity and specificity. Furthermore, they serve as predictive markers for weaning patients from acute dialysis and offer valuable insights into distinct AKI subgroups. The proposed management of AKI, which is encapsulated in a structured flowchart, bridges the gap between research and clinical practice. It streamlines the utilization of biomarkers and subphenotyping, promising a future in which AKI is swiftly identified and managed with unprecedented precision. Incorporating kidney biomarkers into strategies for early AKI detection and the initiation of AKI care bundles has proven to be more effective than using care bundles without these novel biomarkers. This comprehensive approach represents a significant stride toward precision medicine, enabling the identification of high-risk subphenotypes in patients with AKI.

Effects of early recovery of renal function on adverse renal outcomes and mortality in patients with acute kidney injury: a systematic review and meta-analysis

AIM

This study intended to scrutinize the effect of RFR time on adverse renal outcomes and mortality and try to define the cutoff of early RFR.

METHODS

We conducted a literature search from database inception to February 2023. Outcome measures incorporated the progression of CKD, delivery of RRT, incidence of composite renal outcomes, and mortality. And pooled results were depicted as odds ratio (OR) and 95% confidence interval (CI).

RESULTS

A total of 11 studies were finally selected (507,989 patients, mean follow-up, 3.89 years). The results exhibited that the crude mortality was lower in patients with early RFR (OR = 0.39, 95% CI: 0.16-0.95, P = 0.037). In addition, patients with early RFR had a lower incidence of progression to CKD (OR = 0.38, 95% CI: 0.17-0.85, P < 0.018), RRT (OR = 0.37, 95% CI: 0.20-0.71, P = 0.03), and composite renal outcomes (OR = 0.18, 95% CI: 0.15-0.20, P < 0.001). CKD progression-related events were significantly higher in patients whose renal function recovered after 7 days (OR = 0.69, 95% CI: 0.47-1.09, P = 0.112) than in those whose renal function recovered within 7 days (OR = 0.23, 95% CI: 0.06-0.92, P = 0.038), and the risk of RRT was lower in patients who recovered within 7 days (OR = 0.32, 95% CI: 0.15-0.66, P = 0.002) than in those who recovered after 7 days (OR = 0.72, 95% CI: 0.17-3.09, P = 0.654) or longer.

CONCLUSION

Patients with early RFR had a lower risk of CKD progression, RRT, and composite renal outcomes, as well as lower crude mortality than those without early recovery, despite no marked difference in 30-day, 90-day, and 1-year mortality. We speculated that 7 days may be used as a cutoff for early RFR.

Understanding the relationship between HCV infection and progression of kidney disease

Hepatitis C virus (HCV) can cause a range of kidney diseases. HCV is the primary cause of mixed cryoglobulinaemia, which leads to cryoglobulinaemic vasculitis and cryoglobulinaemic glomerulonephritis (GN). Patients with acute cryoglobulinaemic vasculitis often exhibit acute kidney disease due to HCV infection, which typically progresses to acute kidney injury (AKI). HCV also increases the risk of chronic kidney disease (CKD) and the likelihood of developing end-stage renal disease (ESRD). Currently, direct-acting antiviral agents (DAAs) can be used to treat kidney disease at different stages. This review focuses on key findings regarding HCV and kidney disease, discusses the impact of DAAs, and highlights the need for further research and treatment.

Short-Term Preconditioning with Insulin and Glucose Efficiently Protected the Kidney Against Ischemia-Reperfusion Injury via the P-AKT-Bax-Caspase-3 Signaling Pathway in Mice

Objective

Insulin attaches insulin receptor to activate the PI3-kinase/Akt signaling to maintain glucose homeostasis and inhibit apoptosis. This study determined whether preconditioning with insulin and glucose protects the kidney against ischemia-reperfusion injury (IRI).

Methods

Kidney IRI was performed in C57BL/6 mice by clamping the renal vessels for 30 min, followed by reperfusion for 24 h. A total subcutaneous 0.1 unit of insulin along with 10% glucose in drinking water was treated on the mice for 24 h before kidney IRI. The kidney function and injuries were investigated through the determination of BUN and Cr in blood plasma, as well as the apoptosis and the expression of P-AKT, BAX, and caspase-3 in the kidneys. The role of P-AKT in insulin-treated IRI kidneys was tested using an AKT inhibitor. The effects of the preconditional duration of insulin and glucose on IRI kidneys were investigated by expanding the treatment duration to 1, 3, and 6 days.

Results

Preconditioning with insulin and glucose protected the kidney against IRI as manifested by a decrease in creatinine and BUN and a reduction of kidney tubular injury. The protection effect was mediated by P-AKT-BAX-caspase-3 signaling pathway resulting in suppression of apoptotic cell death. An AKT inhibitor partially reversed the protective effects of preconditional insulin. The preconditional duration for 1, 3, and 6 days had no differences in improving kidney functions and pathology.

Conclusion

A short-term preconditioning with insulin and glucose protected the kidney from IRI through the activation of p-AKT and subsequent reduction of BAX-caspase-3-induced apoptosis. The short-term precondition provides a practicable strategy for protecting the kidney against predictable IRI, such as kidney transplant and major surgical operations with high risk of hypotension.

Magnesium Derangement among Critically Ill Patients with Acute Kidney Injury: An Association with Acute Kidney Disease

INTRODUCTION

The association between magnesium level and progression to acute kidney disease (AKD) in acute kidney injury (AKI) patients was not well studied. With AKI transition to AKD, the burden of the disease on mortality, morbidity, and healthcare costs increases. Serum magnesium disturbances are linked with a decline in renal function and increased risk of death in CKD and hemodialysis patients. This study aims to assess the significance of magnesium derangements as a risk factor for the progression of AKI to AKD in critically ill patients.

METHODS

This study was conducted among patients with AKI admitted to the intensive care units at Mayo Clinic from 2007 to 2017. Serum magnesium at AKI onset was categorized into five groups of <1.7, 1.7-1.9, 1.9-2.1, 2.1-2.3, and ≥2.3 mg/dL, with 1.9-2.1 mg/dL as the reference group. AKD was defined as AKI that persisted >7 days following the AKI onset. Logistic regression was used to evaluate the association between magnesium and AKD.

RESULTS

Among 20,198 critically ill patients with AKI, the mean age was 66 ± 16 years, and 57% were male. The mean serum magnesium at AKI onset was 1.9 ± 0.4 mg/dL. The overall incidence of AKD was 31.4%. The association between serum magnesium and AKD followed a U-shaped pattern. In multivariable analysis, serum magnesium levels were associated with increased risk of AKD with the odds ratio of 1.17 (95% CI: 1.07-1.29), 1.13 (95% CI: 1.01-1.26), and 1.65 (95% CI: 1.48-1.84) when magnesium levels were <1.7, 2.1-2.3, and ≥2.3 mg/dL, respectively.

CONCLUSION

Among patients with AKI, magnesium level derangement was an independent risk for AKD in critically ill AKI patients. Monitoring serum magnesium and proper correction in critically ill patients with AKI should be considered an AKD preventive intervention in future trials.

Association of Postoperative Serum Lactate Levels with Acute Kidney Injury in Mexican Patients Undergoing Cardiac Surgery

Acute kidney injury (AKI) is a highly prevalent and a critical complication of cardiac surgery (CS). Serum lactate (sLac) levels have consistently shown an association with morbimortality after CS. We performed a cross-sectional study including 264 adult patients that had a cardiac surgery between January and December 2020. Logistic regression analysis was performed to determine factors associated with AKI development. We measured the postoperative levels of sLac for all participants immediately after CS (T0) and at 4 h (T4) after the surgical intervention. A linear regression model was used to identify the factors influencing both sLac metrics. We identified four risk predictors of AKI; one was preoperative (atrial fibrillation), one intraoperative (cardiopulmonary bypass time), and two were postoperative (length of hospital stay and postoperative sLac). T0 and T4 sLac levels were higher among CS-AKI patients than in Non-CS-AKI patients. Postoperative sLac levels were significant independent predictors of CSA-AKI, and sLac levels are influenced by length of hospital stay, the number of transfused packed red blood cells, and the use of furosemide in CS-AKI patients. These findings may facilitate the earlier identification of patients susceptible to AKI after CS.

Association between Serum Magnesium Levels and Risk of Acute Kidney Injury in Patients with Traumatic Brain Injury: A Retrospective Cohort Study from the MIMIC-IV Database

INTRODUCTION

The occurrence of acute kidney injury (AKI) is associated with a higher risk of mortality in patients with traumatic brain injury (TBI). This study aimed to explore the relationship between serum magnesium levels and the risk of AKI in patients with TBI.

METHODS

Patients with TBI were identified from the Medical Information Mart Intensive Care IV (MIMIC-IV) 2008-2019. The relationship between serum magnesium levels at admission and magnesium coefficient of variation (CV) during hospitalization and the risk of AKI was analyzed using multivariable logistic regression analysis and expressed as odds ratio (OR) and 95% confidence interval (CI). Subgroup analyses were performed according to Glasgow Coma Scale (GCS) score (<14, ≥14), sepsis (no, yes), and estimated glomerular filtration rate (eGFR; <60, ≥60).

RESULTS

Of the 991 patients included, 140 (14.13%) developed AKI during hospitalization. Patients with magnesium levels ≤1.7 mg/dL (tertile 1) (OR = 1.68, 95% CI: 1.01-2.81) were associated with a higher risk of AKI compared to those with magnesium levels of 1.7-2.0 mg/dL (tertile 2), but no association was found in those with magnesium levels >2.0 mg/dL (tertile 3) (p = 0.479). For magnesium CV, patients with magnesium CV >10% (tertile 3) (OR = 2.26, 95% CI: 1.16-4.41) were linked to an increased risk of AKI compared to those with magnesium CV ≤4% (tertile 1), but there may be a slight association between magnesium CV of 4%-10% (tertile 2) and AKI risk (OR = 1.86, 95% CI: 0.99-3.48; p = 0.053). Subgroup analyses showed that lower magnesium levels (≤1.7 mg/dL) or greater magnesium CV (>10%) were associated with a higher risk of AKI only in patients with a GCS score ≥14, non-sepsis, or eGFR ≥60 mL/min/1.73 m2 (p < 0.05).

CONCLUSION

Lower serum magnesium levels at admission or greater magnesium CV during hospitalization were associated with a higher risk of AKI in patients with TBI.

Cigarette Smoking and Risk of Hospitalization With Acute Kidney Injury: The Atherosclerosis Risk in Communities (ARIC) Study

RATIONALE & OBJECTIVE

Smoking is a modifiable risk factor for various adverse events. However, little is known about the association of smoking with the incidence of acute kidney injury (AKI) in the general population. This study investigated the association of cigarette smoking with the risk of AKI.

STUDY DESIGN

Prospective observational study.

SETTING & PARTICIPANTS

14,571 participants (mean age 55±6 years, 55% women, and 25% Black participants) from the ARIC study visit 1 (1987-1989) followed through December 31, 2019.

EXPOSURE

Smoking parameters (status, duration, pack-years, intensity, and years since cessation).

OUTCOME

Incident hospitalization with AKI, defined by a hospital discharge with a diagnostic code relevant to AKI.

ANALYTICAL APPROACH

Multivariable Cox regression models.

RESULTS

Over a median follow-up period of 26.3 years, 2,984 participants had an incident hospitalization with AKI. Current and former smokers had a significantly higher risk of AKI compared to never smokers after adjusting for potential confounders (HR, 2.22 [95% CI, 2.02-2.45] and 1.12 [1.02-1.23], respectively). A dose-response association was consistently seen for each of smoking duration, pack-years, and intensity with AKI (eg, HR, 1.19 [95% CI, 1.16-1.22] per 10 years of smoking). When years since cessation were considered as a time-varying exposure, the risk of AKI associated with smoking compared with current smokers began to decrease after 10 years, and became similar to never smokers at 30 years (HR for≥30 years, 1.07 [95% CI, 0.97-1.20] vs never smokers).

LIMITATIONS

Self-reported smoking measurements and missing outpatient AKI cases.

CONCLUSIONS

In a community-based cohort, all smoking parameters were robustly associated with the risk of AKI. Smoking cessation was associated with decreased risk of AKI, although the excess risk lasted up to 30 years. Our study supports the importance of preventing smoking initiation and promoting smoking cessation for the risk of AKI.

PLAIN-LANGUAGE SUMMARY

Smoking is a behavior that is associated with many negative health effects. It is not well understood how smoking relates to the occurrence of acute kidney injury (AKI) in the community. In this study, we looked at data from a group of 14,571 adults who were followed for 26 years to see how different aspects of smoking (such as whether someone smoked, how long they smoked for, how many cigarettes they smoked per day, and whether they quit smoking) were related to AKI. We found that smoking was strongly linked to an increased risk of AKI. This risk decreased after 5-10 years of quitting smoking, but the excess risk lasted up to 30 years. This study shows the importance of preventing people from starting smoking and to encourage smokers to quit to reduce their risk of AKI.

Mean arterial pressure to norepinephrine equivalent dose ratio for predicting renal replacement therapy requirement: a retrospective analysis from the MIMIC-IV

BACKGROUND

This study aimed to assess the predictive value of the ratio of mean arterial pressure (MAP) to the corresponding peak rate of norepinephrine equivalent dose (NEQ) within the first day in patients with shock for the subsequent renal replacement therapy (RRT) requirement.

METHODS

Patients were identified using the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. The relationship was investigated using a restricted cubic spline curve, and propensity score matching(PSM) was used to eliminate differences between groups. Odds ratios (OR) with 95% confidence intervals (CI) were calculated using logistic regression. Variable significance was assessed using extreme gradient boosting (XGBoost), and receiver operating characteristic (ROC) curves were generated.

RESULTS

Of the 5775 patients, 301 (5.2%) received RRT. The MAP/NEQ index showed a declining L-shaped relationship for RRT. After PSM, the adjusted OR per 100 mmHg/mcg/kg/min for RRT was 0.93(95% CI 0.88-0.98). The most influential factors for RRT were fluid balance, baseline creatinine, and the MAP/NEQ index. The threshold for the MAP/NEQ index predicting RRT was 161.7 mmHg/mcg/kg/min (specificity: 65.8%, sensitivity: 74.8%) with an area under the ROC curve of 75.9% (95% CI 73.1-78.8).

CONCLUSIONS

The MAP/NEQ index served as an alternative predictor of RRT necessity based on the NEQ for adult patients who received at least one vasopressor over 6 h within the first 24 h of intensive care unit(ICU) admission. Dynamic modulation of the MAP/NEQ index by the synergistic use of various low-dose vasopressors targeting urine output may be beneficial for exploring individualized optimization of MAP.

LLL 44-4 : Micronutrients in acute disease and critical illness

Micronutrients (MN), i.e. trace elements and vitamins, are essential components of the diet in relatively small amounts in any form of nutrition, with special needs in critically ill patients. Critical illness is characterised by the presence of inflammation and oxidative stress. MNs are tightly involved in antioxidant and immune defences. In addition, some conditions, and treatments result in large losses of biological fluids containing MNs: therefore, acute renal injury requiring renal replacement therapy, acute intestinal failure, and major burns and trauma are at high risk of acute depletion of body stores, and of deficiency. MN requirements are increased above standard DRI. Blood level interpretation is complicated by inflammation: some biomarkers assist the status determination. Due to the acute challenges of critical illness, it of utmost importance to cover the needs to maintain the organism's endogenous immune and antioxidant defences, and capacity to repair tissues. Practical strategies are proposed.

AKIMLpred: An interpretable machine learning model for predicting acute kidney injury within seven days in critically ill patients based on a prospective cohort study

BACKGROUND

Early recognition and timely intervention for AKI in critically ill patients were crucial to reduce morbidity and mortality. This study aimed to use biomarkers to construct a optimal machine learning model for early prediction of AKI in critically ill patients within seven days.

METHODS

The prospective cohort study enrolled 929 patients altogether who were admitted in ICU including 680 patients in training set (Jiefang Campus) and 249 patients in external testing set (Binjiang Campus). After performing strict inclusion and exclusion criteria, 421 patients were selected in training set for constructing predictive model and 167 patients were selected in external testing for evaluating the predictive performance of resulting model. Urine and blood samples were collected for kidney injury associated biomarkers detection. Baseline clinical information and laboratory data of the study participants were collected. We determined the average prediction efficiency of six machine learning models through 10-fold cross validation.

RESULTS

In total, 78 variables were collected when admission in ICU and 43 variables were statistically significant between AKI and non-AKI cohort. Then, 35 variables were selected as independent features for AKI by univariate logistic regression. Spearman correlation analysis was used to remove two highly correlated variables. Three ranking methods were used to explore the influence of 33 variables for further determining the best combination of variables. The gini importance ranking method was found to be applicable for variables filtering. The predictive performance of AKIMLpred which constructed by the XGBoost algorithm was the best among six machine learning models. When the AKIMLpred included the nine features (NGAL, IGFBP7, sCysC, CAF22, KIM-1, NT-proBNP, IL-6, IL-18 and L-FABP) with the highest influence ranking, its model had the best prediction performance, with an AUC of 0.881 and an accuracy of 0.815 in training set, similarly, with an AUC of 0.889 and an accuracy of 0.846 in validation set. Moreover, the performace was slightly outperformed in testing set with an AUC of 0.902 and an accuracy of 0.846. The SHAP algorithm was used to interpret the prediction results of AKIMLpred. The web-calculator of AKIMLpred was shown for predicting AKI with more convenient(https://www.xsmartanalysis.com/model/list/predict/model/html?mid=8065&symbol=11gk693982SU6AE1ms21). AKIMLpred was better than the optimal model built with only routine tests for predicting AKI in critically ill patients within 7 days.

CONCLUSION

The model AKIMLpred constructed by the XGBoost algorithm with selecting the nine most influential biomarkers in the gini importance ranking method had the best performance in predicting AKI in critically ill patients within 7 days. This data-driven predictive model will help clinicians to make quick and accurate diagnosis.

Using artificial intelligence to predict mortality in AKI patients: a systematic review/meta-analysis

Background

Acute kidney injury (AKI) is associated with increased morbidity/mortality. With artificial intelligence (AI), more dynamic models for mortality prediction in AKI patients have been developed using machine learning (ML) algorithms. The performance of various ML models was reviewed in terms of their ability to predict in-hospital mortality for AKI patients.

Methods

A literature search was conducted through PubMed, Embase and Web of Science databases. Included studies contained variables regarding the efficacy of the AI model [the AUC, accuracy, sensitivity, specificity, negative predictive value and positive predictive value]. Only original studies that consisted of cross-sectional studies, prospective and retrospective studies were included, while reviews and self-reported outcomes were excluded. There was no restriction on time and geographic location.

Results

Eight studies with 37 032 AKI patients were included, with a mean age of 65.3 years. The in-hospital mortality was 18.0% in the derivation and 15.8% in the validation cohorts. The pooled [95% confidence interval (CI)] AUC was observed to be highest for the broad learning system (BLS) model [0.852 (0.820-0.883)] and elastic net final (ENF) model [0.852 (0.813-0.891)], and lowest for proposed clinical model (PCM) [0.765 (0.716-0.814)]. The pooled (95% CI) AUC of BLS and ENF did not differ significantly from other models except PCM [Delong's test P = .022]. PCM exhibited the highest negative predictive value, which supports this model's use as a possible rule-out tool.

Conclusion

Our results show that BLS and ENF models are equally effective as other ML models in predicting in-hospital mortality, with variability across all models. Additional studies are needed.

Hippo pathway activated by circulating reactive oxygen species mediates cardiac diastolic dysfunction after acute kidney injury

Acute kidney injury (AKI) can cause distal cardiac dysfunction; however, the underlying mechanism is unknown. Oxidative stress is proved prominent in AKI-induced cardiac dysfunction, and a possible bridge role of oxidative-stress products in cardio-renal interaction has been reported. Therefore, this study aimed to investigate the critical role of circulating reactive oxygen species (ROS) in mediating cardiac dysfunction after bilateral renal ischemia-reperfusion injury (IRI). We observed the diastolic dysfunction in the mice following renal IRI, accompanied by reduced ATP levels, oxidative stress, and branched-chain amino acids (BCAA) accumulation in the heart. Notably, ROS levels showed a sequential increase in the kidneys, circulation, and heart. Treatment with tempol, an ROS scavenger, significantly restored cardiac diastolic function in the renal IRI mice, corroborating the bridge role of circulating ROS. Accumulating evidence has identified oxidative stress as upstream of Mst1/Hippo in cardiac injury, which could regulate the expression of downstream genes related to mitochondrial quality control, leading to lower ATP, higher ROS and metabolic disorder. To verify this, we examined the activation of the Mst1/Hippo pathway in the heart of renal IRI mice, which was alleviated by tempol treatment as well. In vitro, analysis revealed that Mst1-knockdown cardiomyocytes could be activated by hydrogen peroxide (H2O2). Analysis of Mst1-overexpression cardiomyocytes confirmed the critical role of the Mst1/Hippo pathway in oxidative stress and BCAA dysmetabolism. Therefore, our results indicated that circulating ROS following renal IRI activates the Mst1/Hippo pathway of myocardium, leading to cardiac oxidative stress and diastolic dysfunction. This finding provides new insights for the clinical exploration of improved treatment options for cardiorenal syndrome.

Protective Effect of CXCR7 Against Hypoxia/Reoxygenation Injury in Renal Tubular Epithelial Cells

Acute kidney injury (AKI) is a multifactorial syndrome with complex pathophysiology and prognosis. Ischaemia‒reperfusion injury (IRI) is a major cause of induced AKI. The aim of this study was to investigate the effect of upregulated CXCR7 expression on renal tubular epithelial cell apoptosis induced by hypoxia/reoxygenation (H/R). HK-2 cells were divided into three groups: control group (pcDNA3.1), hypoxia/reoxygenation + pcDNA3.1 group (H/R+pcDNA3.1) and CXCR7 overexpression + hypoxia/reoxygenation group (H/R+ Flag-CXCR7). Protein levels of renal tubular epithelial cell injury-, apoptosis- and autophagy-related markers were assessed by qRT‒PCR, Western blotting, flow cytometry (FCM), immunofluorescence and transmission electron microscopy (TEM). In addition, HK-2 cells were treated with the autophagy inhibitor 3-MA and divided into 3 groups: control group, 3-MA + pcDNA3.1 group, and 3-MA + Flag-CXCR7 group. Changes in autophagy and apoptosis in renal tubule epithelial cells were assessed by Western blotting and FCM. Compared with those in the control group, the protein and mRNA expression levels of CXCR7 in HK-2 cells were significantly lower under H/R conditions. Under H/R conditions, CXCR7 overexpression in HK-2 cells significantly downregulated the expression of NGAL. Moreover, CXCR7 overexpression significantly decreased H/R-induced cleaved PARP-1 and cleaved Caspase 3 levels, increased the level of the antiapoptotic protein BCL-2 and the autophagy-related molecules ATG5 and LC3B II, and significantly inhibited the expression of P62. Autophagy flow and TEM also showed that CXCR7 significantly promoted autophagy. CXCR7 significantly alleviated the 3-MA-induced inhibition of autophagy and increase in apoptosis. Upregulated CXCR7 expression can inhibit renal tubular epithelial cell apoptosis and damage by regulating autophagy. In conclusion, CXCR7 is a promising target for the prevention and/or treatment of AKI.

Lactate metabolism and acute kidney injury

ABSTRACT

Acute kidney injury (AKI) is a common clinically critical syndrome in hospitalized patients with high morbidity and mortality. At present, the mechanism of AKI has not been fully elucidated, and no therapeutic drugs exist. As known, glycolytic product lactate is a key metabolite in physiological and pathological processes. The kidney is an important gluconeogenic organ, where lactate is the primary substrate of renal gluconeogenesis in physiological conditions. During AKI, altered glycolysis and gluconeogenesis in kidneys significantly disturb the lactate metabolic balance, which exert impacts on the severity and prognosis of AKI. Additionally, lactate-derived posttranslational modification, namely lactylation, is novel to AKI as it could regulate gene transcription of metabolic enzymes involved in glycolysis or Warburg effect. Protein lactylation widely exists in human tissues and may severely affect non-histone functions. Moreover, the strategies of intervening lactate metabolic pathways are expected to bring a new dawn for the treatment of AKI. This review focused on renal lactate metabolism, especially in proximal renal tubules after AKI, and updated recent advances of lactylation modification, which may help to explore potential therapeutic targets against AKI.

Acteoside and isoacteoside alleviate renal dysfunction and inflammation in lipopolysaccharide-induced acute kidney injuries through inhibition of NF-κB signaling pathway

Acute kidney injury (AKI) is a sudden loss of renal function with a high mortality rate and inflammation is thought to be the underlying cause. The phenylpropanoid components acteoside (ACT) and isoacteoside (ISO), which were isolated from Cistanche deserticola Y.C.Ma, have been reported to have preventive effects against kidney disorders. This study aimed to investigate the anti-inflammatory properties and protective mechanisms of ACT and ISO. In this investigation, kidney function was assessed using a semi-automatic biochemical analyzer, histopathology was examined using Hematoxylin-Eosin staining and immunohistochemistry, and the concentration of inflammatory cytokines was assessed using an enzyme-linked immunosorbent assay (ELISA) test. In addition, using Western blot and q-PCR, the expression of proteins and genes connected to the NF-κB signaling pathway in mice with lipopolysaccharide (LPS)-induced AKI was found. The findings showed that under AKI intervention in LPS group, ACT group and ISO group, the expression of Rela (Rela gene is responsible for the expression of NFκB p65 protein) and Tlr4 mRNA was considerably elevated (P<0.01), which led to a significant improvement in the expression of MyD88, TLR4, Iκ-Bɑ and NF-κB p65 protein (P<0.001). The levels of Alb, Crea and BUN (P<0.001) increased along with the release of downstream inflammatory factors such as IL-1β, IL-6, Cys-C, SOD1 and TNF-α (P<0.001). More importantly, the study showed that ISO had a more favorable impact on LPS-induced AKI mice than ACT. In conclusion, by inhibiting NF-κB signaling pathway, ACT and ISO could relieve renal failure and inflammation in AKI, offering a fresh possibility for the therapeutic management of the condition.

Ultrasmall Nanoparticles Regulate Immune Microenvironment by Activating IL-33/ST2 to Alleviate Renal Ischemia-Reperfusion Injury

Renal ischemia-reperfusion injury (IRI) is a common disease with high morbidity and mortality. Renal IRI can cause the disorder of immune microenvironment and reprograming the immune microenvironment to alleviate excessive inflammatory response is crucial for its treatment. Cytokine IL-33 can improve the immune inflammatory microenvironment by modulating both innate and adaptive immune cells, and serve as an important target for modulating immune microenvironment of renal IRI. Herein, we report that bilobetin-functionalized ultrasmall Cu2- xSe nanoparticles (i.e., CSPB NPs) can activate the PKA/p-CREB/IL-33/ST2 signaling pathway to regulate innate and adaptive immune cells for reprograming the immune microenvironment of IRI-induced acute kidney injury. The biocompatible CSPB NPs can promote the polarization of M1-like macrophages into M2-like macrophages, and the expansion of ILC2 and Treg cells by activating IL-33/ST2 to modulate the excessive immune inflammatory response of renal IRI. More importantly, they can rapidly accumulate at the injured kidney to significantly alleviate IRI. This work demonstrates that modulating the expression of cytokines to reprogram immune microenvironment has great potential in the treatment of renal IRI and other ischemic diseases.

Elevated Activated Partial Thromboplastin Time as a Predictor of 28-Day Mortality in Sepsis-Associated Acute Kidney Injury: A Retrospective Cohort Analysis

Purpose

To address the critical mortality rates among sepsis-associated acute kidney injury (SA-AKI) patients, early prognosis is vital. This study investigates the relationship between coagulation indices and the 28-day mortality rate in patients with SA-AKI.

Patients and Methods

This study was a retrospective cohort analysis including patients with SA-AKI admitted to the First Hospital of Fujian Medical University as a training cohort (n = 119) and patients admitted to the Third People's Hospital of Fujian University of Traditional Chinese Medicine as a validation cohort (n = 51). We examined the relationship between coagulation indices and 28-day mortality in SA-AKI, the cumulative mortality at different activated partial thromboplastin time (APTT) levels, and the nonlinear relationship between APTT and 28-day mortality. Receiver operating characteristic curves were plotted, and the area under the curve was calculated to assess the predictive power of APTT. Finally, subgroup analyses were performed to assess the robustness of the association.

Results

Overall, 119 participants with a mean±standard deviation age of 70.47±15.20 years were included in the training cohort: 54 died, 65 survived. According to univariate and multivariate COX regression analyses, APACHE II score, CRP level, Lac level, and APTT level were independent risk factors for 28-day adverse prognosis. After controlling for some variables, an elevated baseline APTT (≥ 37.7 s) was associated with an elevated risk of 28-day mortality (HR, 1.017; 95% CI, 1.001-1.032), and Kaplan-Meier analyses further confirmed the increased mortality in the group with a higher APTT. The same results were shown when the validation cohort was analyzed (HR, 1.024; 95% CI, 0.958-1.096). Subgroup analyses showed the stability of the association between APTT and poor prognosis in SA-AKI.

Conclusion

In essence, APTT elevation is synonymous with increased 28-day mortality rates, indicating a poor prognosis in SA-AKI scenarios.

The Role of Biomarkers in Diagnosis of Sepsis and Acute Kidney Injury

Sepsis and acute kidney injury (AKI) are two major public health concerns that contribute significantly to illness and death worldwide. Early diagnosis and prompt treatment are essential for achieving the best possible outcomes. To date, there are no specific clinical, imaging, or biochemical indicators available to diagnose sepsis, and diagnosis of AKI based on the KDIGO criterion has limitations. To improve the diagnostic process for sepsis and AKI, it is essential to continually evolve our understanding of these conditions. Delays in diagnosis and appropriate treatment can have serious consequences. Sepsis and AKI often occur together, and patients with kidney dysfunction are more prone to developing sepsis. Therefore, identifying potential biomarkers for both conditions is crucial. In this review, we talk about the main biomarkers that evolve the diagnostic of sepsis and AKI, namely neutrophil gelatinase-associated lipocalin (NGAL), proenkephalin (PENK), and cell-free DNA.

Association between the blood urea nitrogen-to-creatinine ratio and 3-month outcomes in patients with acute ischemic stroke: a secondary analysis based on a prospective cohort study

Introduction

This study aimed to assess the correlation between the blood urea nitrogen (BUN)-to-creatinine (BUN/Cr) ratio and adverse outcomes (AOs) at 3 months in patients with acute ischemic stroke (AIS) in the Korean population.

Methods

This cohort study encompassed 1906 cases of AIS at a South Korean hospital from January 2010 to December 2016. To determine the linear correlation between the BUN/Cr ratio and AOs in AIS, a binary logistic regression model (BLRM) was employed. Additionally, generalized additive models and techniques for smooth curve fitting were utilized to reveal the nonlinear dynamics between the BUN/Cr ratio and AOs in patients with AIS.

Results

The prevalence of AOs was 28.65%, with a median BUN/Cr ratio of 18.96. Following adjustments for covariates, the BLRM disclosed that the association between the BUN/Cr ratio and the risk of AOs in patients with AIS did not attain statistical significance. Nevertheless, a nonlinear relationship surfaced, pinpointing an inflection point at 21.591. To the left of this inflection point, a 31.42% reduction in the risk of AOs was noted for every 1-unit surge in the Z score of the BUN/Cr ratio [odds ratio (OR) = 0.686, 95% confidence interval (CI): 0.519, 0.906, p = 0.008]. On the right side of the inflection point, the effect size (OR = 1.405, 95% CI: 1.018, 1.902, p = 0.039) was determined.

Conclusion

The findings of this study underscore the intricate nature of the relationship between the BUN/Cr ratio and 3-month outcomes in patients with AIS, establishing a robust groundwork for future investigations.

New-onset organ dysfunction as a screening tool for the identification of sepsis and outcome prediction in dogs with systemic inflammation

Introduction

Sepsis in people is defined as a life-threatening organ dysfunction (OD) caused by a dysregulated host response to infection. In veterinary medicine, sepsis is still defined by the presence of systemic inflammation plus the evidence of infection. Based on recent veterinary studies, multiorgan dysfunction syndrome (MODS) has been associated with a worse outcome in sepsis. Thus, the screening for OD is warranted to identify the most critically ill patients. The aim of this study was to investigate the diagnostic value of new-onset OD for the prediction of sepsis and outcome in a population of critically ill dogs with systemic inflammation.

Materials and methods

Dogs admitted to the Emergency Room and/or the Intensive Care Unit with systemic inflammation, defined by a serum C-reactive protein concentration > 1.6 mg/dL, were retrospectively included. Enrolled dogs were categorized according to the presence of sepsis or non-infectious systemic inflammation. The presence of newly diagnosed OD was assessed based on criteria adapted from human literature and previously reported canine criteria.

Results

275 dogs were included: 128 had sepsis and 147 had non-infectious systemic inflammation. The frequency of new-onset OD was not different between these groups. Only the presence of fluid-refractory hypotension was significantly associated with a diagnosis of sepsis (OR 10.51, 3.08-35.94; p < 0.0001). The frequency of at least two ODs was significantly higher in non-survivors compared to survivors, according to both the human and the veterinary criteria considered for the study (p = 0.0001 and p = 0.0004, respectively). Specifically, the presence of acute kidney injury, stupor or coma, prolonged Prothrombin Time and decreased Base Excess were associated with a higher risk of death in the multivariate binary logistic regression.

Discussion

In this population of critically ill dogs with systemic inflammation, the detection of newly diagnosed ODs was not able to predict sepsis diagnosis, other than the presence of fluid-refractory hypotension. However, given the strong prognostic significance associated with ODs, our results support the early screening for ODs in any severe inflammatory critical care condition to identify high-risk patients and optimize their management.

Site 1 protease aggravates acute kidney injury by promoting tubular epithelial cell ferroptosis through SIRT3-SOD2-mtROS signaling

Ischemia/reperfusion (I/R)-induced acute kidney injury (AKI) is a common clinical syndrome with high morbidity and mortality. Ferroptosis, a newly discovered form of oxidative cell death, is involved in the pathogenesis of renal I/R injury; however, the underlying mechanism remains to be explored. Here, we reported that site 1 protease (S1P) promotes ischemic kidney injury by regulating ferroptotic cell death of tubular epithelial cells. S1P abundance was measured in hypoxia/reoxygenation (H/R)-treated Boston University mouse proximal tubular (BUMPT) cells and I/R-induced murine kidney tissue. S1P expression in BUMPT cells and kidneys was initially activated by hypoxic stimulation, accompanied by the ferroptotic response. Blocking S1P blunted H/R-induced ferroptotic cell death, which also restored sirtuin 3 (SIRT3) expression and superoxide dismutase 2 (SOD2) activity in BUMPT cells. Next, inhibition of S1P expression restored I/R-suppressed SIRT3 abundance, SOD2 activity and reduced the elevated level of mitochondria reactive oxygen species (mtROS), which attenuated tubular cell ferroptosis and renal I/R injury. In conclusion, S1P promoted renal tubular epithelial cell ferroptosis under I/R status by activating SIRT3-SOD2-mtROS signaling, thereby accelerating kidney injury. Thus, targeting S1P signaling may serve as a promising strategy for I/R kidney injury.

Acute kidney injury in hospitalized children with proteinuria: A multicenter retrospective analysis

BACKGROUND AND OBJECTIVE

Acute kidney injury (AKI) is a common complication in hospitalized pediatric patients. Previous studies focused on adults found that proteinuria detected during an admission urinalysis is fit to serve as an indicator for AKI and associated clinical outcomes. The objective of this study is to evaluate if proteinuria on the first day of hospital services in hospitalized children is associated with AKI, need for renal replacement therapy, shock and/or antibiotic use, critical care services, and all-cause mortality at 30 days, hypothesizing that it is associated with these outcomes.

METHODS

This is a retrospective cohort study using TriNetX electronic health record data of patients 2 to 18 years of age who underwent urinalysis laboratory testing on hospital admission, had three subsequent days of hospital or critical care services billing codes and creatinine laboratory values, and no pre-existing renal-related complex chronic condition. This study evaluated for the frequency, odds, and severity of AKI as defined by Kidney Disease: Improving Global Outcomes modified criteria and assessed for associated clinical outcomes.

RESULTS

This study included 971 pediatric subjects [435 (44.7%) with proteinuria]. Proteinuria on the first day of hospital services was associated with an increased odds for higher severity AKI on any day of hospitalization (odds ratio [OR] 2.41, CI 1.8-3.23, p<0.001), need for renal replacement therapy (OR 4.58, CI 1.69-12.4, p = 0.001), shock and/or antibiotic use (OR 1.34, CI 1.03-1.75, p = 0.033), and all-cause mortality at 30 days post-admission (OR 10.0, CI 1.25-80.5, p = 0.013).

CONCLUSION

Children with proteinuria on the first day of hospital care services may have an increased odds of higher severity AKI, need for renal replacement therapy, shock and/or antibiotic use, and all-cause mortality at 30 days post-admission, with no significant association found for critical care services, mechanical intubation, or inotrope or vasopressor use.

Arachidonic acid metabolism as a therapeutic target in AKI-to-CKD transition

Arachidonic acid (AA) is a main component of cell membrane lipids. AA is mainly metabolized by three enzymes: cyclooxygenase (COX), lipoxygenase (LOX) and cytochrome P450 (CYP450). Esterified AA is hydrolysed by phospholipase A2 into a free form that is further metabolized by COX, LOX and CYP450 to a wide range of bioactive mediators, including prostaglandins, lipoxins, thromboxanes, leukotrienes, hydroxyeicosatetraenoic acids and epoxyeicosatrienoic acids. Increased mitochondrial oxidative stress is considered to be a central mechanism in the pathophysiology of the kidney. Along with increased oxidative stress, apoptosis, inflammation and tissue fibrosis drive the progressive loss of kidney function, affecting the glomerular filtration barrier and the tubulointerstitium. Recent studies have shown that AA and its active derivative eicosanoids play important roles in the regulation of physiological kidney function and the pathogenesis of kidney disease. These factors are potentially novel biomarkers, especially in the context of their involvement in inflammatory processes and oxidative stress. In this review, we introduce the three main metabolic pathways of AA and discuss the molecular mechanisms by which these pathways affect the progression of acute kidney injury (AKI), diabetic nephropathy (DN) and renal cell carcinoma (RCC). This review may provide new therapeutic targets for the identification of AKI to CKD continuum.

Inhibition of Drp1- Fis1 interaction alleviates aberrant mitochondrial fragmentation and acute kidney injury

BACKGROUND

Acute kidney injury (AKI) is a common clinical disorder with complex etiology and poor prognosis, and currently lacks specific and effective treatment options. Mitochondrial dynamics dysfunction is a prominent feature in AKI, and modulation of mitochondrial morphology may serve as a potential therapeutic approach for AKI.

METHODS

We induced ischemia-reperfusion injury (IRI) in mice (bilateral) and Bama pigs (unilateral) by occluding the renal arteries. ATP depletion and recovery (ATP-DR) was performed on proximal renal tubular cells to simulate in vitro IRI. Renal function was evaluated using creatinine and urea nitrogen levels, while renal structural damage was assessed through histopathological staining. The role of Drp1 was investigated using immunoblotting, immunohistochemistry, immunofluorescence, and immunoprecipitation techniques. Mitochondrial morphology was evaluated using confocal microscopy.

RESULTS

Renal IRI induced significant mitochondrial fragmentation, accompanied by Dynamin-related protein 1 (Drp1) translocation to the mitochondria and Drp1 phosphorylation at Ser616 in the early stages (30 min after reperfusion), when there was no apparent structural damage to the kidney. The use of the Drp1 inhibitor P110 significantly improved kidney function and structural damage. P110 reduced Drp1 mitochondrial translocation, disrupted the interaction between Drp1 and Fis1, without affecting the binding of Drp1 to other mitochondrial receptors such as MFF and Mid51. High-dose administration had no apparent toxic side effects. Furthermore, ATP-DR induced mitochondrial fission in renal tubular cells, accompanied by a decrease in mitochondrial membrane potential and an increase in the translocation of the pro-apoptotic protein Bax. This process facilitated the release of dsDNA, triggering the activation of the cGAS-STING pathway and promoting inflammation. P110 attenuated mitochondrial fission, suppressed Bax mitochondrial translocation, prevented dsDNA release, and reduced the activation of the cGAS-STING pathway. Furthermore, these protective effects of P110 were also observed renal IRI model in the Bama pig and folic acid-induced nephropathy in mice.

CONCLUSIONS

Dysfunction of mitochondrial dynamics mediated by Drp1 contributes to renal IRI. The specific inhibitor of Drp1, P110, demonstrated protective effects in both in vivo and in vitro models of AKI.

Prognostic Value of Leukocyte-Based Risk Model for Acute Kidney Injury Prediction in Critically Ill Acute Exacerbation of Chronic Obstructive Pulmonary Disease Patients

Purpose

Acute kidney injury (AKI) is a common complication of acute exacerbation of chronic obstructive pulmonary disease (AECOPD), and inflammation is the potential link between AKI and AECOPD. However, little is known about the incidence and risk stratification of AKI in critically ill AECOPD patients. In this study, we aimed to establish risk model based on white blood cell (WBC)-related indicators to predict AKI in critically ill AECOPD patients.

Material and Methods

For the training cohort, data were taken from the Medical Information Mart for eICU Collaborative Research Database (eICU-CRD) database, and for the validation cohort, data were taken from the Medical Information Mart for Intensive Care-IV (MIMIC-IV) database. The study employed logistic regression analysis to identify the major predictors of WBC-related biomarkers on AKI prediction. Subsequently, a risk model was developed by multivariate logistic regression, utilizing the identified significant indicators.

Results

Finally, 3551 patients were enrolled in training cohort, 926 patients were enrolled in validation cohort. AKI occurred in 1206 (33.4%) patients in training cohort and 521 (56.3%) patients in validation cohort. According to the multivariate logistic regression analysis, four WBC-related indicators were finally included in the novel risk model, and the risk model had a relatively good accuracy for AKI in the training set (C-index, 0.764, 95% CI 0.749-0.780) as well as in the validation set (C-index, 0.738, 95% CI: 0.706-0.770). Even after accounting for other models, the critically ill AECOPD patients in the high-risk group (risk score > 3.44) still showed an increased risk of AKI (odds ratio: 4.74, 95% CI: 4.07-5.54) compared to those in low-risk group (risk score ≤ 3.44). Moreover, the risk model showed outstanding calibration capability as well as therapeutic usefulness in both groups for AKI and ICU mortality and in-hospital mortality of critical ill AECOPD patients.

Conclusion

The novel risk model showed good AKI prediction performance. This risk model has certain reference value for the risk stratification of AECOPD complicated with AKI in clinically.

Acute kidney injury in patients with burns

Burn injury is associated with a high risk of acute kidney injury (AKI) with a prevalence of AKI among patients with burns of 9-50%. Despite an improvement in burn injury survival in the past decade, AKI in patients with burns is associated with an extremely poor short-term and long-term prognosis, with a mortality of >80% among those with severe AKI. Factors that contribute to the development of AKI in patients with burns include haemodynamic alterations, burn-induced systemic inflammation and apoptosis, haemolysis, rhabdomyolysis, smoke inhalation injury, drug nephrotoxicity and sepsis. Early and late AKI after burn injury differ in their aetiologies and outcomes. Sepsis is the main driver of late AKI in patients with burns and late AKI has been associated with higher mortality than early AKI. Prevention of early AKI involves correction of hypovolaemia and avoidance of nephrotoxic drugs (for example, hydroxocobalamin), whereas prevention of late AKI involves prevention and early recognition of sepsis as well as avoidance of nephrotoxins. Treatment of AKI in patients with burns remains supportive, including prevention of fluid overload, treatment of electrolyte disturbance and use of kidney replacement therapy when indicated.