Update on sepsis-associated acute kidney injury: emerging targeted therapies

Machine learning for the prediction of mortality in patients with sepsis-associated acute kidney injury: a systematic review and meta-analysis

BACKGROUND

Predicting mortality in sepsis-related acute kidney injury facilitates early data-driven treatment decisions. Machine learning is predicting mortality in S-AKI in a growing number of studies. Therefore, we conducted this systematic review and meta-analysis to investigate the predictive value of machine learning for mortality in patients with septic acute kidney injury.

METHODS

The PubMed, Web of Science, Cochrane Library and Embase databases were searched up to 20 July 2024 This was supplemented by a manual search of study references and review articles. Data were analysed using STATA 14.0 software. The risk of bias in the prediction model was assessed using the Predictive Model Risk of Bias Assessment Tool.

RESULTS

A total of 8 studies were included, with a total of 53 predictive models and 17 machine learning algorithms used. Meta-analysis using a random effects model showed that the overall C index in the training set was 0.81 (95% CI: 0.78-0.84), sensitivity was 0.39 (0.32-0.47), and specificity was 0.92 (95% CI: 0.89-0.95). The overall C-index in the validation set was 0.73 (95% CI: 0.71-0.74), sensitivity was 0.54 (95% CI: 0.48-0.60) and specificity was 0.90 (95% CI: 0.88-0.91). The results showed that the machine learning algorithms had a good performance in predicting sepsis-related acute kidney injury death prediction.

CONCLUSION

Machine learning has been shown to be an effective tool for predicting sepsis-associated acute kidney injury deaths, which has important implications for enhancing risk assessment and clinical decision-making to improve sepsis patient care. It is also eagerly anticipated that future research efforts will incorporate larger sample sizes and multi-centre studies to more intensively examine the external validation of these models in different patient populations, allowing for a more in-depth exploration of sepsis-associated acute kidney injury in terms of accurate diagnostic efficacy across a diverse range of model and predictor types.

TRIAL REGISTRATION

This study was registered with PROSPERO (CRD42024569420).

Controversies Surrounding Albumin Use in Sepsis: Lessons from Cirrhosis

This narrative review critically examines the role of albumin in sepsis management and compares it to its well-established application in liver cirrhosis. Albumin, a key plasma protein, is effective in the management of fluid imbalance, circulatory dysfunction, and inflammation-related complications. However, its role in sepsis is more intricate and characterized by ongoing debate and varied results from clinical studies. In sepsis, the potential benefits of albumin include maintaining vascular integrity and modulating inflammation, yet its consistent clinical efficacy is not as definitive as that in cirrhosis. This review evaluated various clinical trials and evidence, highlighting their limitations and providing practical insights for clinicians. It emphasizes identifying sepsis patient subgroups that are most likely to benefit from albumin therapy, particularly exploring the correction of hypoalbuminemia. This condition, which is significantly corrected in patients with cirrhosis, may have similar therapeutic advantages in sepsis. The potential effectiveness of albumin in the low-volume resuscitation and deresuscitation phases of sepsis management was noted. Given the safety concerns observed in cirrhosis, such as pulmonary edema and hypervolemia associated with albumin therapy, cautious integration of albumin into sepsis treatment is mandatory. Personalized albumin therapy is advocated for tailoring strategies to the specific needs of each patient, based on their clinical presentation and underlying conditions. The need for further research to delineate the role of albumin in sepsis pathophysiology is underscored. The review emphasizes the importance of conducting trials to assess the effectiveness of albumin in correcting hypoalbuminemia in sepsis, its impact on patient outcomes, and the establishment of appropriate dosing and administration methods. This approach to albumin use in sepsis management is posited as a way to potentially improve patient outcomes in this complex clinical scenario while being mindful of the lessons learned from its use in cirrhosis.

Relationship Between Mean Arterial Pressure and Furosemide Stress Test Success Rates: A Retrospective Cohort Study

BACKGROUND

The furosemide stress test (FST) is a safe and easy assessment of renal tubular function. Other factors, such as mean arterial pressure (MAP), which may influence the success rates of the FST, have not been well defined.

OBJECTIVE

To evaluate the relationship between MAP and success rates of the FST in critically ill patients.

METHODS

Retrospective, single-center, institutional review board (IRB)-approved cohort study. Critically ill adult patients given at least one dose of intravenous (IV) furosemide (≥1-1.5 mg/kg) were included. Primary outcome was whether a MAP ≥ 75 mm Hg would equate to a higher FST success rate. Secondary outcome was the success rates of patient on one or more vasopressors.

RESULTS

Of 225 patients, 88 (39.1%) had a successful FST. In patients with a MAP ≥ 75 mm Hg, 60 out of 104 (57.7%) had a successful FST compared to 28 out of 121 (23.1%) of patients who had a MAP < 75 mm Hg (odds ratio [OR], 4.53, 95% CI, 2.55-8.74, P < 0.001). Patients on vasopressors at the time of the furosemide dose had lower rates of success compared to those not on vasoactive agents (30.4% versus 68.2%, p = 0.026). Limitations of this study include its retrospective design and reliance on documented urine output.

CONCLUSION AND RELEVANCE

Patients with a MAP ≥ 75 mm Hg were significantly more likely to have a successful FST compared to those with a MAP < 75 mm Hg. This represents the first report of factors that may influence FST success rates.

The incidence, mortality and renal outcomes of acute kidney injury in patients with suspected infection at the emergency department

Background

Acute kidney injury (AKI) is a major health problem associated with considerable mortality and morbidity. Studies on clinical outcomes and mortality of AKI in the emergency department are scarce. The aim of this study is to assess incidence, mortality and renal outcomes after AKI in patients with suspected infection at the emergency department.

Methods

We used data from the SPACE-cohort (SePsis in the ACutely ill patients in the Emergency department), which included consecutive patients that presented to the emergency department of the internal medicine with suspected infection. Hazard ratios (HR) were assessed using Cox regression to investigate the association between AKI, 30-days mortality and renal function decline up to 1 year after AKI. Survival in patients with and without AKI was assessed using Kaplan-Meier analyses.

Results

Of the 3105 patients in the SPACE-cohort, we included 1716 patients who fulfilled the inclusion criteria. Of these patients, 10.8% had an AKI episode. Mortality was 12.4% for the AKI group and 4.2% for the non-AKI patients. The adjusted HR for all-cause mortality at 30-days in AKI patients was 2.8 (95% CI 1.7–4.8). Moreover, the cumulative incidence of renal function decline was 69.8% for AKI patients and 39.3% for non-AKI patients. Patients with an episode of AKI had higher risk of developing renal function decline (adjusted HR 3.3, 95% CI 2.4–4.5) at one year after initial AKI-episode at the emergency department.

Conclusion

Acute kidney injury is common in patients with suspected infection in the emergency department and is significantly associated with 30-days mortality and renal function decline one year after AKI.

LncRNA CAIF suppresses LPS-induced inflammation and apoptosis of cardiomyocytes through regulating miR-16 demethylation

BACKGROUND

The long noncoding RNA, cardiac autophagy inhibitory factor (CAIF), and microRNA (miR)-16 are reported to be involved in lipopolysaccharide (LPS)-induced inflammatory responses and cell apoptosis in many diseases. Herein, we investigated the interaction between CAIF and miR-16 in sepsis-induced chronic heart failure (CHF).

METHODS

The expression of CAIF and miR-16 in plasma samples from sepsis-induced CHF patients (n = 60) and healthy controls (n = 60) were measured using quantitative reverse-transcription polymerase chain reaction (qRT-PCR). The correlations between CAIF and miR-16 across plasma samples from patients with sepsis-induced CHF and healthy controls were analyzed using linear regression. The messenger RNA (mRNA) levels of inducible nitric oxide synthase, C-C motif chemokine 2 (CCL2), growth-regulated alpha protein (CXCL1), and interleukin-6 (IL-6) were evaluated using qRT-PCR while nuclear factor κB activation was evaluated using luciferase assay.

RESULTS

The expression levels of CAIF and miR-16 were downregulated in the plasma of sepsis-induced CHF patients and were positively correlated in these patients. In cardiomyocytes, LPS treatment dose-dependently decreased CAIF and miR-16 levels. CAIF overexpression increased miR-16 expression by demethylating miR-16. CAIF and/or miR-16 overexpression suppressed LPS-induced CCL2, CXCL1, and IL-6 expression at both the mRNA and protein levels. Analysis of cell apoptosis and western blot analysis showed that CAIF and/or miR-16 overexpression inhibited LPS-induced cardiomyocyte apoptosis by reducing Bax and cleaved caspase 3 levels and enhancing Bcl-2 levels.

CONCLUSION

Our study is the first to report the abnormal expression of CAIF and miR-16 in heart disease. CAIF plays a protective role in sepsis-induced CHF by inhibiting cardiomyocyte apoptosis and inflammation, possibly by regulating miR-16 demethylation.

A novel risk-predicted nomogram for sepsis associated-acute kidney injury among critically ill patients

Background

Acute kidney injury (AKI) is a prevalent and severe complication of sepsis contributing to high morbidity and mortality among critically ill patients. In this retrospective study, we develop a novel risk-predicted nomogram of sepsis associated-AKI (SA-AKI).

Methods

A total of 2,871 patients from the Medical Information Mart for Intensive Care III (MIMIC-III) critical care database were randomly assigned to primary (2,012 patients) and validation (859 patients) cohorts. A risk-predicted nomogram for SA-AKI was developed through multivariate logistic regression analysis in the primary cohort while the nomogram was evaluated in the validation cohort. Nomogram discrimination and calibration were assessed using C-index and calibration curves in the primary and external validation cohorts. The clinical utility of the final nomogram was evaluated using decision curve analysis.

Results

Risk predictors included in the prediction nomogram included length of stay in intensive care unit (LOS in ICU), baseline serum creatinine (SCr), glucose, anemia, and vasoactive drugs. Nomogram revealed moderate discrimination and calibration in estimating the risk of SA-AKI, with an unadjusted C-index of 0.752, 95 %Cl (0.730–0.774), and a bootstrap-corrected C index of 0.749. Application of the nomogram in the validation cohort provided moderate discrimination (C-index, 0.757 [95 % CI, 0.724–0.790]) and good calibration. Besides, the decision curve analysis (DCA) confirmed the clinical usefulness of the nomogram.

Conclusions

This study developed and validated an AKI risk prediction nomogram applied to critically ill patients with sepsis, which may help identify reasonable risk judgments and treatment strategies to a certain extent. Nevertheless, further verification using external data is essential to enhance its applicability in clinical practice.

MicroRNA-219 alleviates glutamate-induced neurotoxicity in cultured hippocampal neurons by targeting calmodulin-dependent protein kinase II gamma

Septic encephalopathy is a frequent complication of sepsis, but there are few studies examining the role of microRNAs (miRs) in its pathogenesis. In this study, a miR-219 mimic was transfected into rat hippocampal neurons to model miR-219 overexpression. A protective effect of miR-219 was observed for glutamate-induced neurotoxicity of rat hippocampal neurons, and an underlying mechanism involving calmodulin-dependent protein kinase II γ (CaMKIIγ) was demonstrated. miR-219 and CaMKIIγ mRNA expression induced by glutamate in hippocampal neurons was determined by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR). After neurons were transfected with miR-219 mimic, effects on cell viability and apoptosis were measured by 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry. In addition, a luciferase reporter gene system was used to confirm CaMKIIγ as a target gene of miR-219. Western blot assay and rescue experiments were also utilized to detect CaMKIIγ expression and further verify that miR-219 in hippocampal neurons exerted its effect through regulation of CaMKIIγ. MTT assay and qRT-PCR results revealed obvious decreases in cell viability and miR-219 expression after glutamate stimulation, while CaMKIIγ mRNA expression was increased. MTT, flow cytometry, and caspase-3 activity assays showed that miR-219 overexpression could elevate glutamate-induced cell viability, and reduce cell apoptosis and caspase-3 activity. Moreover, luciferase CaMKIIγ-reporter activity was remarkably decreased by co-transfection with miR-219 mimic, and the results of a rescue experiment showed that CaMKIIγ overexpression could reverse the biological effects of miR-219. Collectively, these findings verify that miR-219 expression was decreased in glutamate-induced neurons, CaMKIIγ was a target gene of miR-219, and miR-219 alleviated glutamate-induced neuronal excitotoxicity by negatively controlling CaMKIIγ expression.

Effect of continuous renal replacement therapy on kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin in patients with septic acute kidney injury

Kidney injury molecule-1 (Kim-1) and neutrophil gelatinase-associated lipocalin (NGAL) have been investigated as biomarkers for acute kidney injury (AKI). However, they are seldom investigated in patients with septic AKI treated with continuous renal replacement therapy (CRRT). The aim of the present study was to investigate the therapeutic effectiveness and possible mechanisms of CRRT in septic AKI by observing the changes in Kim-1 and NGAL levels. A group of 38 patients with septic AKI was randomly divided into the conventional drug treatment group (group A) and the CRRT group (group B). All patients were treated with standard antisepsis agents, and group B was additionally submitted to CRRT for 24 h. The levels of Kim-1 and NGAL in serum, urine and the ultrafiltrate of CRRT were measured prior to and at 12, 24, and 48 h after treatment. In group A, urinary Kim-1 (uKim-1) levels at 12, 24 and 48 h were lower than prior to treatment (P<0.05), whereas urinary NGAL (uNGAL) showed no difference among the various time points (P>0.05). In group B, uKim-1 was decreased at 24 and 48 h compared with before treatment (all P<0.05), whereas uNGAL was decreased at 48 h (P<0.05). Serum Kim-1 did not change with time in groups A and B (P>0.05), whereas serum NGAL was increased after treatment in group A (P<0.05) but did not change in group B (P>0.05). Kim-1 and NGAL were not detected in the ultrafiltrate of CRRT. uKim-1 and uNGAL decreased significantly after CRRT, and therefore may be used to reflect the change of renal function during CRRT and to evaluate the therapeutic effectiveness of the method.

RAB10 overexpression promotes tumor growth and indicates poor prognosis of hepatocellular carcinoma

Hepatocellular carcinoma (HCC), one of the most common and lethal cancers worldwide, has a high recurrence rate with current treatment modalities. Identifying biomarkers for early diagnosis and discovering new sufficient molecular targets for the development of targeted therapies are urgently needed. RAB10, a member of the RAS family, has been shown to be highly expressed in HCC. However, the function of RAB10 in HCC is less studied. Here we report that RAB10 acts as an oncogene in HCC. The shRNA-mediated knockdown of RAB10 significantly reduced the proliferation of HCC cells and colony formation, induced cell cycle arrest at G0/G1 phase and increased apoptosis in vitro. In addition, RAB10 knockdown suppressed HCC growth in nude mice. Moreover, RAB10 silencing decreased the phosphorylation of InsR, Met/HGFR, Ron/MST1R, Ret, c-Kit/SCFR, EphA3, EphB4, Tyro3/Dtk, Axl, Tie2/TEK, VEGFR2/KDR, Akt/PKB/Rac, S6 Ribosomal Protein and c-Abl, while the phosphorylation of HSP27, p38 MAPK, Chk2 and TAK1 increased significantly. These results suggest that RAB10 regulates cell survival and proliferation through multiple oncogenic, cell stress and apoptosis pathways. More importantly, high RAB10 expression levels in HCC cells correlated with a poor prognosis in HCC patients. Therefore, our findings revealed an oncogenic role for RAB10 in the pathogenesis of HCC and that RAB10 is a potential molecular target or a biomarker for HCC.