The definition of acute kidney injury and its use in practice. Kidney Int. 2015;87:62-73. [PMID: 25317932 DOI: 10.1038/ki.2014.328]

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

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

Revealing the elevated sulfite levels in acute kidney injury using a promising ratiometric fluorescent probe

The development of novel biomarkers for the early diagnosis of acute kidney injury (AKI) is critical for enabling timely protective interventions and predicting potential drug toxicity. Recent studies have highlighted metabolic abnormalities in sulfur-containing compounds during AKI progression. A ratiometric fluorescent probe, BP-BT-OH, has been designed for sulfite detection, featuring a covalent bond between benzothiazole and benzopyran-oxonium. The probe's ratio intensity is highly sensitive to sulfite concentration with an almost 80-fold increase. BP-BT-OH showed a rapid response of 50 s, an excellent detection limit of 0.21 μM, and a high selectivity and anti-interference capabilities. The probe can efficiently detects fluctuations in intracellular sulfite, both exogenous and endogenous. In cisplatin-treated cells, the ratio intensity between the two channels was significantly higher compared to untreated cells. More promisingly, BP-BT-OH was successfully used for imaging cisplatin-induced AKI in mice, revealing elevated sulfite levels in the kidneys. These findings validate sulfite as a potential biomarker for AKI. Further analysis of specific kidney proteins indicated that the increased sulfite concentration may be linked to downregulation of sulfur-containing compound metabolic enzymes. This approach offers a novel perspective on using molecular imaging tools for diagnosing early-stage diseases that lack obvious symptoms.

Platinum-based chemotherapies-induced nephrotoxicity: mechanisms, potential treatments, and management

Platinum-based chemotherapies are essential in the treatment of several malignancies. However, such medications can damage the kidneys, frequently leading to both acute and chronic kidney disease. Treatment becomes more difficult for such problems. Physicians may alter chemotherapy regimens and utilize kidney-protecting medications to lessen renal damage. New imaging techniques and biomarkers also aid in the early detection of renal issues. To effectively handle the mentioned situation, oncologists, nephrologists, and pharmacists must collaborate. However, additional study is still required to develop customized therapies, discover strategies to minimize kidney injury and produce new platinum medicines. Hereupon, the present review's authors are being sought to address the causes, prospective treatments, and management of nephrotoxicity caused by platinum-based chemotherapy.

Does combining urine sediment examination to renal cell arrest and damage biomarkers improve prediction of progression and mortality of sepsis associated acute kidney injury?

BACKGROUND

Sepsis associated acute kidney injury (SA-AKI) among hospitalized patients is common with higher morbidity and mortality. There is a need to discover new methods that allow better prediction of its outcomes and prognosis. We aimed to evaluate if combining serial examination of urine sediment to renal cell damage (KIM-1) and arrest (TIMP-2, IGFBP7) biomarkers could improve the prediction of progression and mortality of SA-AKI.

METHODS

This prospective study enrolled 96 patients with stage 1 or 2 SA-AKI. Measuring of urinary TIMP-2, IGFBP7 and KIM-1 was done at time of AKI diagnosis and examination of urine sediment was performed by calculating Chawla score (CS) and Perazella score (PS) at days 1, 3 and 7. Main study outcomes included AKI progression to stage 3 and mortality.

RESULTS

Ninety-six patients were included in the study. 48% of them progressed to AKI stage 3 and 33.3% died. uTIMP2*IGFBP7 and uKIM-1 showed an area under the curve (AUC) of 0.837 and 0.657 respectively for predicting AKI progression and an AUC of 0.679 and 0.626 respectively for predicting mortality. Combining urine sediment examination at day 3 (P2 and C2) to uTIMP2*IGFBP7, uKIM-1 and both biomarkers significantly improved their prediction ability to an AUC of to 0.977, 0.951 and 0.979 respectively to predict AKI progression, and to an AUC of 0.807, 0.796 and 0.803 respectively to predict mortality.

CONCLUSIONS

Combining urine sediment examination with renal cell damage and arrest biomarkers significantly improved their performance of predicting AKI progression and mortality in patients with SA-AKI.

CLINICAL TRIALS REGISTRATION

ClinicalTrials.gov Identifier: NCT06064487. First registration date: 21/09/2023.

Extracellular Vesicles in Renal Inflammatory Diseases: Revealing Mechanisms of Extracellular Vesicle-Mediated Macrophage Regulation

Renal inflammatory diseases are a group of severe conditions marked by significant morbidity and mortality. Extracellular vesicles (EVs), as facilitators of intercellular communication, have been recognized as pivotal regulators of renal inflammatory diseases, significantly contributing to these conditions by modulating immune responses among other mechanisms. This review highlights the intricate mechanisms through which EVs modulate macrophage-kidney cell interactions by regulating macrophages, the principal immune cells within the renal milieu. This regulation subsequently influences the pathophysiology of renal inflammatory diseases such as acute kidney injury and chronic kidney disease. Furthermore, understanding these mechanisms offers novel opportunities to alleviate the severe consequences associated with renal inflammatory diseases. In addition, we summarize the therapeutic landscape based on EV-mediated macrophage regulatory mechanisms, highlighting the potential of EVs as biomarkers and therapeutic targets as well as the challenges and limitations of translating therapies into clinical practice.

Unraveling Acute Cardiorenal Syndrome: Predictors and Consequences in Acute Heart Failure

Introduction: Acute cardiorenal syndrome (ACRS) is a common complication of acute heart failure (AHF), leading to worse outcomes and therapeutic challenges. This study aimed to identify clinical parameters associated with ACRS and evaluate its impact on prognosis in hospitalized AHF patients. Methods: This prospective observational study included patients hospitalized for AHF at the Venizelio Cardiology Department from February to November 2023. Demographic characteristics, comorbidities, medications, laboratory and echocardiographic parameters, hospital stay, and in-hospital mortality were recorded. Patients with incomplete data or end-stage chronic kidney disease (CKD) were excluded. Survivors were followed for six months to assess renal function changes, readmissions, initiation of renal replacement therapy (RRT), and mortality. ACRS was defined as a serum creatinine increase of ≥0.3 mg/dL or ≥1.5 times baseline. Results: Among 218 hospitalized AHF patients, 112 (51.3%) developed ACRS. These patients were older, had higher CKD prevalence, worse New York Heart Association (NYHA) functional class, lower hemoglobin, and higher N-terminal Pro-B-type Natriuretic peptide (NT-proBNP) levels. Multivariate analysis identified CKD stage (OR 2.30, 95% CI 1.64-3.23, p < 0.001) and creatinine change on admission (OR 3.53, 95% CI 2.02-6.18, p < 0.001) as independent predictors of ACRS. ACRS was associated with higher in-hospital mortality, longer hospital stays, increased vasoactive medication use, worsening renal function, and higher six-month all-cause readmission and mortality rates. Conclusions: ACRS is a frequent and severe complication in AHF. CKD stage and creatinine on admission are key predictors. Early recognition for risk stratification and individualized management are crucial to improving outcomes in this high-risk population.

Factors associated with contrast-associated acute kidney injury in an emergency department: A cohort study in Lebanon

BACKGROUND

Contrast-associated acute kidney injury (CA-AKI) is a common problem in hospitals, particularly in low-middle-income countries (LMIC), due to limited resources and a high prevalence of comorbidities. Kidney function evaluation using serum creatinine levels before contrast administration leads to increased length of stay and delayed patient care. This study aimed to identify factors associated with CA-AKI in emergency department (ED) patients in an LMIC. Identifying these factors is essential for enhancing patient care and guiding clinical practice by allowing for the early detection and management of patients at risk.

METHODS

This study is a retrospective cohort study conducted at the largest tertiary care center's ED in Lebanon between November 2018 and December 2019. The study included ED patients who underwent computed-tomography (CT) with contrast. Bivariate and logistic regression analyses were performed to compare the characteristics of patients who developed AKI with those who did not by using SPSS package. The Institutional Review Board (IRB) at the American University of Beirut (AUB) approved this study under protocol ID BIO-2020-0276, which was performed per the Declaration of Helsinki. The IRB waived the need to consent patients since many of them were not followed up at the time of the study.

RESULTS

The study included 1832 patients, of whom 10.4% (n = 190) developed CA-AKI. Patients aged over 65 had a 1.6-fold higher risk of CA-AKI (aOR = 1.55, 95%CI:1.09-2.2). High blood pressure (≥140 mmHg), high respiratory rate ( ≥ 22), and chronic kidney disease were significantly associated with CA-AKI. The use of loop diuretics (aOR = 2.21, 95%CI:1.49-3.28), beta-lactams (aOR = 4.11, 95%CI:2.63-6.42), and allopurinol (aOR = 2.74, 95%CI:1.43-5.25) were significantly associated with CA-AKI.

CONCLUSIONS

Identifying factors associated with CA-AKI in an emergency setting, such as age, comorbidities, and home medications, can help identify patients at low risk of developing CA-AKI.

Effect of N-acetylcysteine on antimicrobials induced nephrotoxicity: a meta-analysis

OBJECTIVE

N-acetylcysteine (NAC) has antioxidant effects in reducing acute kidney injury. This study systematically reviewed and assessed the efficacy of NAC in preventing antimicrobials induced nephrotoxicity.

METHODS

Pubmed, Embase, Web of Science, and the Cochrane Library were searched extensively for relevant studies that evaluating NAC on antimicrobials induced nephrotoxicity until June 1, 2024. Eligible records were screened according to the inclusion and exclusion criteria. The odds ratio (OR) was selected to evaluate the effect of NAC on nephrotoxicity. We pooled the extracted data using a random effects model.

RESULTS

Three randomized controlled trials were included in the analysis. The pooled results showed that NAC could reduce the incidence of antimicrobials induced nephrotoxicity (OR = 0.487, 95% CI = 0.258, 0.918, P = 0.03, I2 = 0%). Serum creatine (Scr) on Day 2 was significantly decreased in the NAC group compared to the placebo group (SMD, - 0.298; 95%CI, - 0.585 to - 0.010; I2 = 23%; P = 0.04). No difference was observed in blood urea nitrogen (BUN), and creatinine clearance (CrCl).

CONCLUSION

In this meta-analysis, NAC was associated with a benefit in the prevention of antimicrobials induced nephrotoxicity. However, large-scaled and well-designed RCTs are required in the future.

Oxidative stress and NRF2 signaling in kidney injury

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

Standardized Definitions of Changes in Kidney Function in Trials of Heart Failure: JACC Expert Panel From the HF-ARC

Perturbations in kidney function are frequently encountered in heart failure (HF) across its spectrum in both chronic and acute settings with distinct implications for patient management and prognosis. Lack of consensus on the threshold for clinically meaningful changes in kidney function has led to heterogeneity in the clinical characteristics and background therapies of individuals enrolled in clinical trials, and in multiple aspects of trial design. A meaningful and collaborative interaction among the disciplines of cardiology and nephrology, clinical trialists, industry sponsors, and regulatory agencies is vital to the development of standardized definitions of changes in kidney function across HF settings. To achieve this critically important objective, the Heart Failure Collaboratory assembled experts in HF and nephrology, including key stakeholders in the U.S. Food and Drug Administration and industry, with the goal of developing initial recommendations for improved standardization of design and conduct of clinical trials in HF. Recommendations included how and when to measure baseline and changes in kidney function, discouraging the use of the term "acute kidney injury," and the consideration of urinary markers in the assessment of kidney function.

Central Venous Pressure as a Predictor of Acute Kidney Injury in Cardiac Surgery: A Systematic Review of Observational Studies

Background/Objectives: Acute kidney injury (AKI) is a syndrome characterized by impaired kidney function, which is associated with reduced survival and increased morbidity. Central venous pressure (CVP) is a widely used hemodynamic parameter for assessing the volume status of patients and evaluating their response to fluid resuscitation. This systematic review aims to analyze various prospective and retrospective observational and controlled trials to determine the association between CVP and the risk of developing AKI in patients undergoing cardiac surgery. Additionally, it examines whether elevated CVP serves as an accurate predictor of AKI in this patient population. Methods: A systematic review was conducted following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, using PubMed as the primary database. The search focused on studies published after 2014 that included adult patients undergoing cardiac surgery with reported measurements of CVP and kidney function assessment. Studies conducted on animals, pediatric populations, those published before 2014, or in languages other than English were excluded from the review. Results: Through the analysis of 21 studies, a clear association between higher CVP and increased AKI risk emerged. The most critical CVP thresholds identified were 10 mmHg, 12 mmHg, 14 mmHg, and 20 mmHg, with risk increasing progressively beyond these values. CVP ≥ 10 mmHg was the most commonly reported cutoff for elevated AKI risk, showing 1.42 to 4.53 times increased odds. CVP ≥ 12 mmHg further amplified the risk, while CVP ≥ 14 mmHg was consistently associated with severe AKI and the need for RRT. The highest threshold (CVP ≥ 20 mmHg) showed the greatest risk escalation, linked to fluid overload, right heart failure, and mortality. Studies also suggest an optimal CVP range of 6-8 mmHg to minimize AKI incidence. Conclusions: Elevated CVP is an independent risk factor for the development of AKI in patients undergoing cardiac surgery. These findings suggest that CVP monitoring can play a significant role in predicting AKI and guiding perioperative management strategies.

Effect of restrictive fluid resuscitation on severe acute kidney injury in septic shock: a systematic review and meta-analysis

OBJECTIVES

Sepsis-associated hypotension or shock is a critical stage of sepsis, and a current clinical emergency that has high mortality and multiple complications. A new restrictive fluid resuscitation therapy has been applied, and its influence on patients' renal function remains unclear. The purpose of this study is to evaluate the influence of restrictive fluid resuscitation on incidence of severe acute kidney injury (AKI) in adult patients with sepsis hypotension and shock compared with usual care.

DESIGN

Systematic review and meta-analysis using the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach.

DATA SOURCES

PubMed, Embase, Web of Science and Cochrane Library were searched through 1 November 2024.

ELIGIBILITY CRITERIA

We included randomised controlled trials that compared restrictive fluid resuscitation with liberal fluid therapy on patients with sepsis-associated hypotension and shock, to find out their effect on the incidence of severe AKI. Severe AKI was defined as the AKI network score 2-3 or Kidney Disease Improving Global Outcomes stages 2 and 3.

DATA EXTRACTION AND SYNTHESIS

Two independent reviewers used standardised methods to search, screen and code included trials. Risk of bias was assessed using the Cochrane Systematic Review Handbook for randomised clinical trials. Meta-analysis was conducted using random effects models. Sensitivity and subgroup analyses, trial sequential analysis (TSA), Egger's test and the trim-and-fill method were performed. Findings were summarised in GRADE evidence profiles and synthesised qualitatively.

RESULTS

Nine trials (3718 participants) were included in this research and the analysis was conducted in random effects model. There was a significant difference in the incidence of severe AKI (risk ratio 0.87, 95% CI 0.79 to 0.96, p=0.006; I2=0%) and the duration of mechanical ventilation (mean difference -41.14, 95% CI -68.80 to -13.48; p=0.004; I2=74%) between patients receiving restrictive fluid resuscitation and patients receiving liberal fluid resuscitation. TSA showed that the cumulative amount of participants met the required information size, the positive conclusion had been confirmed. The GRADE assessment results demonstrated moderate confidence in the incidence of severe AKI, as well as the results of all second outcomes except the Intensive Care Unit length of stay (ICU LOS), which received limited confidence. The result of incidence of worse AKI was rated as of high certainty.

CONCLUSIONS

It is conclusive that fluid restriction strategy is superior to usual care when it comes to reducing the incidence of severe AKI in sepsis-associated hypotension and shock. Shorter duration of ventilation is concerned with fluid restriction as well, but the heterogeneity is substantial. GRADE assessments confirmed moderate and above certainty. Traditional fluid resuscitation therapy has the potential to be further explored for improvements to be more precise and appropriate for a better prognosis.

PROSPERO REGISTRATION NUMBER

CRD42023449239.

Metabolomics- and proteomics-based multi-omics integration reveals early metabolite alterations in sepsis-associated acute kidney injury

BACKGROUND

Sepsis-associated acute kidney injury (SA-AKI) is a frequent complication in patients with sepsis and is associated with high mortality. Therefore, early recognition of SA-AKI is essential for administering supportive treatment and preventing further damage. This study aimed to identify and validate metabolite biomarkers of SA-AKI to assist in early clinical diagnosis.

METHODS

Untargeted renal proteomic and metabolomic analyses were performed on the renal tissues of LPS-induced SA-AKI and sepsis mice. Glomerular filtration rate (GFR) monitoring technology was used to evaluate real-time renal function in mice. To elucidate the distinctive characteristics of SA-AKI, a multi-omics Spearman correlation network was constructed integrating core metabolites, proteins, and renal function. Subsequently, metabolomics analysis was used to explore the dynamic changes of core metabolites in the serum of SA-AKI mice at 0, 8, and 24 h. Finally, a clinical cohort (28 patients with SA-AKI vs. 28 patients with sepsis) serum quantitative metabolomic analysis was carried out to build a diagnostic model for SA-AKI via logistic regression (LR).

RESULTS

Thirteen differential renal metabolites and 112 differential renal proteins were identified through a multi-omics study of SA-AKI mice. Subsequently, a multi-omics correlation network was constructed to highlight five core metabolites, i.e., 3-hydroxybutyric acid, 3-hydroxymethylglutaric acid, creatine, myristic acid, and inosine, the early changes of which were then observed via serum time series experiments of SA-AKI mice. The levels of 3-hydroxybutyric acid, 3-hydroxymethylglutaric acid, and creatine increased significantly at 24 h, myristic acid increased at 8 h, while inosine decreased at 8 h. Ultimately, based on the identified core metabolites, we recruited 56 patients and constructed a diagnostic model named IC3, using inosine, creatine, and 3-hydroxybutyric acid, to early identify SA-AKI (AUC = 0.90).

CONCLUSIONS

We proposed a blood metabolite model consisting of inosine, creatine, and 3-hydroxybutyric acid for the early screening of SA-AKI. Future studies will observe the performance of these metabolites in other clinical populations to evaluate their diagnostic role.

Association of perfusate cytokine concentrations during liver graft ex situ normothermic perfusion to donor type and postoperative outcomes

The use of the so-called extended criteria donors increases the number of grafts available for transplantation. Many studies reported their good outcomes but their use is debated due to increased risk of complications. Ex situ liver perfusion has reduced graft discard rate and helped to test their function before implantation. Cytokines are known to be involved in ischemia-reperfusion injury, but their potential to predict liver function during normothermic machine perfusion (NMP) has not been fully investigated. The aim of this study was to compare cytokines levels during NMP in 3 different types of donors (donation after brain death, donation after circulatory death [DCD]-II, DCD-III) and correlate these data to postoperative clinical and biochemical outcomes. All donations after brain deaths older than 70 years and DCDs transplanted after NMP were included. IL-6, IL-10, and TNF-α were measured during NMP and correlated with clinical outcomes. Thirty liver grafts were transplanted after NMP: 16 donations after brain deaths, 7 DCD-II, and 7 DCD-III. There were 6 cases of early allograft dysfunction (20.0%), 10 of post-reperfusion syndrome (33.3%), and 11 cases of acute kidney injury (36.7%), with no major differences among groups. A positive correlation was found between perfusate IL-6 levels and the bilirubin peak within 7 days after liver transplantation, while IL-10 was associated with the intensive care unit stay and TNF-α to the international normalized ratio peak within 7 days. IL-6 was negatively associated with postoperative ALT levels and IL-10 to bilirubin peak. A correlation between higher IL-6 levels at 2 hours and graft loss was found. This is the first study to compare cytokines profile during NMP in 3 different types of donors and correlate it to clinical outcomes. A correlation between IL-6 concentration and graft failure was found. The role and significance of inflammatory markers in machine perfusion perfusate and their potential to assess graft viability and the risk of post-liver transplantation complications have to be further addressed.

Outcomes of Secondary Endovascular Aortic Repair After Frozen Elephant Trunk

OBJECTIVE

The aim of this study was to evaluate the midterm outcomes of secondary extension of frozen elephant trunk (FET) by means of thoracic endovascular aortic repair (TEVAR).

METHODS

This single-center prospective study was conducted in a tertiary aortic center on consecutive patients having undergone TEVAR with an endograft covering most of the 10 cm FET module with 2 to 4 mm oversizing. All patients were monitored by computerized tomography angiography (CTA) at sixth month and yearly thereafter.

RESULTS

From January 2015 to July 2022, among 159 patients who received FET, 30 patients (18.8%) underwent a TEVAR procedure (13 for a thoracoabdominal aneurysm, 11 for a chronic aortic dissection and 6 for an emergency procedure). All connections were successfully achieved with 2 postoperative deaths (6.6%) and 1 paraplegia (3.3%). At a median follow-up of 21 months (interquartile range [IQR], 4.2-34.7), 5 patients (25%) required a fenestrated-branched endovascular aortic repair (F-BEVAR) extension followed by 4 patients with 5 reinterventions, 3 for a Type 3 endoleak due to disconnection between FET and TEVAR endograft, and 2 unrelated to the FET for a secondary Type 1C endoleak. All reinterventions were successful, without mortality or morbidity.

CONCLUSIONS

In this series, FET connection with a TEVAR endograft was effective with low postoperative morbidity but with a risk of aortic reintervention related to disconnection between the FET and TEVAR endograft. These results suggest the need for annual CTA monitoring with no time limit in patients following connection of the FET with a TEVAR endograft.

CLINICAL IMPACT

In this series of 30 patients, midterm outcomes of secondary extension of frozen elephant trunk (FET) by thoracic endovascular repair (TEVAR) showed 3 disconnections (10%) with a Type 3 endoleak between FET and TEVAR. These findings suggest the need for annual CTA monitoring with no time limit. But so far, only a few studies provide some information after one year while the risk of disconnection increases over time and becomes a concern after 3 years. This is the new message brought by our study.

Perfusate Liver Arginase 1 Levels After End-Ischemic Machine Perfusion Are Associated with Early Allograft Dysfunction

Background/Objectives: The rising use of liver grafts from donation after circulatory death (DCD) has been enabled by advances in normothermic regional perfusion (NRP) and machine perfusion (MP) technologies. We aimed to identify predictive biomarkers in DCD grafts subjected to NRP, followed by randomization to either normothermic machine perfusion (NMP) or dual hypothermic oxygenated perfusion (D-HOPE). Methods: Among 57 DCD donors, 32 liver grafts were transplanted, and recipients were monitored for one week post-transplant. Biomarkers linked with oxidative stress, hepatic injury, mitochondrial dysfunction, inflammation, regeneration, and autophagy were measured during NRP, end-ischemic MP, and one week post-transplant. Results: Arginase-1 (ARG-1) levels were consistently higher in discarded grafts and in recipients who later developed early allograft dysfunction (EAD). Specifically, ARG-1 levels at the end of MP correlated with markers of hepatic injury. Receiver operating characteristic analysis indicated that ARG-1 at the end of MP had a good predictive accuracy for EAD (AUC = 0.713; p = 0.02). Lipid peroxidation (TBARS) elevated at the start of NRP, declined over time, with higher levels in D-HOPE than in NMP, suggesting a more oxidative environment in D-HOPE. Metabolites like flavin mononucleotide (FMN) and NADH exhibited significant disparities between perfusion types, due to differences in perfusate compositions. Inflammatory biomarkers rose during NRP and NMP but normalized post-transplantation. Regenerative markers, including osteopontin and hepatocyte growth factor, increased during NRP and NMP and normalized post-transplant. Conclusions: ARG-1 demonstrates strong potential as an early biomarker for assessing liver graft viability during perfusion, supporting timely and effective decision-making in transplantation.

Plasma neutrophil gelatinase-associated lipocalin as a single test rule out biomarker for acute kidney injury: A cross-sectional study in patients admitted to the emergency department

OBJECTIVES

Acute kidney injury (AKI) is a syndrome with high mortality and morbidity in part due to delayed recognition based on changes in creatinine. A marker for AKI based on a single measurement is needed and therefore the performance of a single measurement of plasma neutrophil gelatinase-associated lipocalin (pNGAL) to predict AKI in patients admitted to the emergency department was tested.

METHODS

Samples from the Triage study which included 6005 consecutive adult patients admitted to the emergency department were tested for pNGAL. The optimal cutoff for pNGAL was determined by the AUC and compared to AKI based on creatinine using different estimations of the premorbid kidney function.

RESULTS

In 4833 patients, two or more plasma creatinine (pCr) measurements were available allowing the detection of AKI. The highest prevalence of AKI (10%) was found when defining AKI as an increase in pCr ≥26.5 μmol/L from the prior year's mean pCr. At these conditions the AUC for pNGAL to predict AKI was 85% giving an optimal cutoff of 142.5 ng/mL with a negative predictive value of 0.96, a positive predictive value of 0.35, a specificity of 0.87 and a sensitivity of 0.70.

CONCLUSION

The study illustrates that the value of a single measurement of pNGAL is primarily in excluding AKI whereas it`s poorer in predicting the presence of AKI. When diagnosing AKI with pCr the optimal baseline pCr level is the mean of available pCr (mb-pCr) measurements from up to a year prior to the current event.

Proenkephalin improves cardio-renal risk prediction in acute coronary syndromes: the KID-ACS score

BACKGROUND AND AIMS

Circulating proenkephalin (PENK) is a stable endogenous polypeptide with fast response to glomerular dysfunction and tubular damage. This study examined the predictive value of PENK for renal outcomes and mortality in patients with acute coronary syndrome (ACS).

METHODS

Proenkephalin was measured in plasma in a prospective multicentre ACS cohort from Switzerland (n = 4787) and in validation cohorts from the UK (n = 1141), Czechia (n = 927), and Germany (n = 220). A biomarker-enhanced risk score (KID-ACS score) for simultaneous prediction of in-hospital acute kidney injury (AKI) and 30-day mortality was derived and externally validated.

RESULTS

On multivariable adjustment for established risk factors, circulating PENK remained associated with in-hospital AKI [per log2 increase: adjusted odds ratio 1.53, 95% confidence interval (CI) 1.13-2.09, P = .007] and 30-day mortality (adjusted hazard ratio 2.73, 95% CI 1.85-4.02, P < .001). The KID-ACS score integrates PENK and showed an area under the receiver operating characteristic curve (AUC) of .72 (95% CI .68-.76) for in-hospital AKI and .91 (95% CI .87-.95) for 30-day mortality in the derivation cohort. Upon external validation, KID-ACS achieved similarly high performance for in-hospital AKI (Zurich: AUC .73, 95% CI .70-.77; Czechia: AUC .75, 95% CI .68-.81; Germany: AUC .71, 95% CI .55-.87) and 30-day mortality (UK: AUC .87, 95% CI .83-.91; Czechia: AUC .91, 95% CI .87-.94; Germany: AUC .96, 95% CI .92-1.00), outperforming the contrast-associated AKI score and the Global Registry of Acute Coronary Events 2.0 score, respectively.

CONCLUSIONS

Circulating PENK offers incremental value for predicting in-hospital AKI and mortality in ACS. The simple six-item KID-ACS risk score integrates PENK and provides a novel tool for simultaneous assessment of renal and mortality risk in patients with ACS.

Effect and safety of sivelestat on acute severe pancreatitis with systemic inflammatory response syndrome: a retrospective study

The study was to explore the efficacy and safety of sivelestat (SV) in the treatment of severe acute pancreatitis (SAP) with systemic inflammatory response syndrome (SIRS). A total of 102 SAP patients diagnosed and treated in the Emergency Intensive Care Unit of the First Affiliated Hospital of Zhengzhou University from January 2021 to August 2024 were selected. The changes of disease outcome, hospital stays and mortality were compared between the two groups. A total of 102 patients were recruited to control group (n = 56) or SV group (n = 46) according to whether SV was applied or not. There was no significant difference in baseline data at admission between the two groups. After 1 week of treatment, all the indexes in both groups improved. The duration of ventilator use (p = 0.0400) and ICU stays (p  = 0.0495) in SV group was shorter than that in control group, but there was no significant difference in mortality between the two groups. Although SV did not reduce the mortality of patients with SAP, it reduced the length of ventilator use and ICU stay.

Changes in Microbiome in Patients with Kidney Injury after Allogeneic Hematopoietic Stem Cell Transplantation

Key Points

Changes in microbiome diversity index are common in patients with stem cell transplant. Changes in microbiome diversity do not explain the high incidence of AKI in patients with stem cell transplant.

Background

AKI is a common complication of allogeneic hematopoietic cell transplantation (allo-HCT) that increases the risk of mortality. By contrast, higher diversity of intestinal microbiota at the time of neutrophil engraftment has been associated with lower mortality. We aimed to better understand kidney outcomes in relation to changes in gut diversity in this patient population, hypothesizing that patients with lower microbiome diversity at baseline and at engraftment were at higher risk of developing kidney complications.

Methods

We performed a single-center retrospective study of 419 hematopoietic cell transplant recipients from 2014 to 2017 at our institution whose gut microbiota were analyzed. We defined AKI and CKD on the basis of Kidney Disease Improving Global Outcomes criteria and eGFR using the CKD Epidemiology Collaboration equation. We defined gut microbiome diversity using Shannon and Simpson reciprocal diversity indices, with higher levels indicating more diverse microbiota.

Results

Simpson reciprocal diversity index and Shannon diversity index were 21.8 (interquartile range [IQR], 13.7–35.2; range, 1.6–102.5) and 3.7 (IQR, 3.2–4.2; range, 0.7–5.2) in our cohort at baseline and 6.3 (IQR, 3.7–10.4) and 2.3 (IQR, 1.7–2.8) at periengraftment, respectively. Of the 419, 263 patients (63%) developed any grade AKI in 100 days after hematopoietic cell transplantation and 114 (27%) developed grade 2+ AKI. There were no significant differences in microbiome diversity at baseline or periengraftment in patients who developed post-transplant AKI or CKD, respectively, in comparison with those who did not develop kidney complications.

Conclusions

Our findings do not support the existence of a link between baseline or periengraftment gut diversity and the risk of development of AKI or CKD in patients undergoing allo-HCT. This study highlights the complex and multifactorial etiology of AKI in allo-HCT recipients and the need for additional prospective and mechanistic studies.

Anterior Transversus Abdominis Plane Block for Lower Extremity Revascularization

INTRODUCTION

Regional anesthesia remains underutilized in vascular surgery; therefore, we retrospectively reviewed and compared the usage of perioperative opioids in patients undergoing lower extremity revascularization surgery, who received the anterior transversus abdominis plane (TAP) block along with local anesthesia at the incision site versus who did not receive any regional anesthesia.

METHODS

We conducted a retrospective review of 107 patients undergoing open or hybrid lower extremity revascularization under general anesthesia at a single institution between 2017 and 2022. Patients were divided into two groups. Regional block group (n = 41 [38%]) (femoral endarterectomy 27%; femoral endarterectomy + endovascular intervention 51%; infrainguinal bypass 22%) received both an intraoperative anterior TAP block and local anesthesia at the incision site; No regional block group (n = 66 [62%]) (femoral endarterectomy 29%; femoral endarterectomy + endovascular intervention 13%; infrainguinal bypass 58%) did not receive either regional or local anesthesia.

RESULTS

There were no significant differences in either the procedural metrics or intraprocedural complications between the two groups. The in-hospital stay was shorter in the Regional group, 1 (1, 3) versus the No regional group, 3 (2, 7), P < 0.001. The median intraoperative morphine milliequivalents use was 20 (15, 25) in the Regional block group and 25 (20, 35) in the No regional block group, P = 0.008. The median postoperative opioids use at 24h was 75 (60, 98) in the Regional block group and 113 (83, 151) in the No regional block group, P < 0.001; at 48h was 103 (70, 118) in the Regional block group and 148 (90, 210) in the No regional block group, P = 0.027; at 72h was 105 (70, 138) in the Regional block group and 196 (113, 263) in the No regional block group, P = 0.010.

CONCLUSIONS

Anterior TAP block combined with local anesthesia at the incision site seems to be a safe postoperative analgesia option for patients undergoing lower extremity revascularization surgery that could potentially help reducing both intra and postoperative opioids requirement.

Lymphocytes and innate immune cells in acute kidney injury and repair

Acute kidney injury (AKI) is a common and serious disease entity that affects native kidneys and allografts but for which no specific treatments exist. Complex intrarenal inflammatory processes driven by lymphocytes and innate immune cells have key roles in the development and progression of AKI. Many studies have focused on prevention of early injury in AKI. However, most patients with AKI present after injury is already established. Increasing research is therefore focusing on mechanisms of renal repair following AKI and prevention of progression from AKI to chronic kidney disease. CD4+ and CD8+ T cells, B cells and neutrophils are probably involved in the development and progression of AKI, whereas regulatory T cells, double-negative T cells and type 2 innate lymphoid cells have protective roles. Several immune cells, such as macrophages and natural killer T cells, can have both deleterious and protective effects, depending on their subtype and/or the stage of AKI. The immune system not only participates in injury and repair processes during AKI but also has a role in mediating AKI-induced distant organ dysfunction. Targeted manipulation of immune cells is a promising therapeutic strategy to improve AKI outcomes.

Relationship between intra-operative urine output and postoperative acute kidney injury in paediatric cardiac surgery: A retrospective observational study

BACKGROUND

Intra-operative urine output (UO) has been shown to predict postoperative acute kidney injury (AKI) in adults; however, its significance in children undergoing cardiac surgery remains unknown.

OBJECTIVE

To explore the association between intra-operative UO and postoperative AKI in children with congenital heart disease.

DESIGN

A retrospective observational study.

SETTING

A tertiary hospital.

PATIENTS

Children aged >28 days and <6 years who underwent cardiac surgery at Fuwai Hospital from 1 April 2022 to 30 August 2022.

MAIN OUTCOME MEASURES

AKI was identified by the highest serum creatinine value within postoperative 7 days using Kidney Disease Improving Global Outcomes (KDIGO) criteria.

RESULTS

In total, 1184 children were included. The incidence of AKI was 23.1% (273/1184), of which 17.7% (209/1184) were stage 1, 4.2% (50/1184) were stage 2, and others were stage 3 (1.2%, 14/1184). Intra-operative UO was calculated by dividing the total intra-operative urine volume by the duration of surgery and the actual body weight measured before surgery. There was no significant difference in median [IQR] intra-operative UO between the AKI and non-AKI groups (2.6 [1.4 to 5.4] and 2.7 [1.4 to 4.9], respectively, P  = 0.791), and multivariate logistic regression analyses showed that intra-operative UO was not associated with postoperative AKI [adjusted odds ratio (OR) 0.971; 95% confidence interval (CI), 0.930 to 1.014; P  = 0.182]. Regarding the clinical importance of severe forms of AKI, we further explored the association between intra-operative UO and postoperative moderate-to-severe AKI (adjusted OR 0.914; 95% CI, 0.838 to 0.998; P  = 0.046).

CONCLUSIONS

Intra-operative UO was not associated with postoperative AKI during paediatric cardiac surgery. However, we found a significant association between UO and postoperative moderate-to-severe AKI. This suggests that reductions in intra-operative urine output below a specific threshold may be associated with postoperative renal dysfunction.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT05489263.

A promising application of kidney-specific cell-free DNA methylation markers in real-time monitoring sepsis-induced acute kidney injury

Sepsis-induced acute kidney injury (SI-AKI) is a common clinical syndrome that is associated with high mortality and morbidity. Effective timely detection may improve the outcome of SI-AKI. Kidney-derived cell-free DNA (cfDNA) may provide new insight into understanding and identifying SI-AKI. Plasma cfDNA from 82 healthy individuals, 7 patients with sepsis non-acute kidney injury (SN-AKI), and 9 patients with SI-AKI was subjected to genomic methylation sequencing. We deconstructed the relative contribution of cfDNA from different cell types based on cell-specific methylation markers and focused on exploring the association between kidney-derived cfDNA and SI-AKI.Based on the deconvolution of the cfDNA methylome: SI-AKI patients displayed the elevated cfDNA concentrations with an increased contribution of kidney epithelial cells (kidney-Ep) DNA; kidney-Ep derived cfDNA achieved high accuracy in distinguishing SI-AKI from SN-AKI (AUC = 0.92, 95% CI 0.7801-1); the higher kidney-ep cfDNA concentrations tended to correlate with more advanced stages of SI-AKI; strikingly, SN-AKI patients with potential kidney damage unmet by SI-AKI criteria showed higher levels of kidney-Ep derived cfDNA than healthy individuals. The autonomous screening of kidney-Ep (n = 24) and kidney endothelial (kidney-Endo, n = 12) specific methylation markers indicated the unique identity of kidney-Ep/kidney-Endo compared with other cell types, and its targeted assessment reproduced the main findings of the deconvolution of the cfDNA methylome. Our study first demonstrates that kidney-Ep- and kidney-Endo-specific methylation markers can serve as a novel marker for SI-AKI emergence, supporting further exploration of the utility of kidney-specific cfDNA methylation markers in the study of SI-AKI.

Acute kidney disease in hospitalized pediatric patients: risk prediction based on an artificial intelligence approach

BACKGROUND

Acute kidney injury (AKI) and acute kidney disease (AKD) are prevalent among pediatric patients, both linked to increased mortality and extended hospital stays. Early detection of kidney injury is crucial for improving outcomes. This study presents a machine learning-based risk prediction model for AKI and AKD in pediatric patients, enabling personalized risk predictions.

METHODS

Data from 2,346 hospitalized pediatric patients, collected between January 2020 and January 2023, were divided into an 85% training set and a 15% test set. Predictive models were constructed using eight machine learning algorithms and two ensemble algorithms, with the optimal model identified through AUROC. SHAP was used to interpret the model, and an online prediction tool was developed with Streamlit to predict AKI and AKD.

RESULTS

The incidence of AKI and AKD were 14.90% and 16.26%, respectively. Patients with AKD combined with AKI had the highest mortality rate, at 6.94%, when analyzed by renal function trajectories. The LightGBM algorithm showed superior predictive performance for both AKI and AKD (AUROC: 0.813, 0.744). SHAP identified top predictors for AKI as serum creatinine, white blood cell count, neutrophil count, and lactate dehydrogenase, while key predictors for AKD included proton pump inhibitor, blood glucose, hemoglobin, and AKI grade.

CONCLUSION

The high incidence of AKI and AKD among hospitalized children warrants attention. Renal function trajectories are strongly associated with prognosis. Supported by a web-based tool, machine learning models can effectively predict AKI and AKD, facilitating early identification of high-risk pediatric patients and potentially improving outcomes.

Outcomes of acute kidney injury continuum in children

BACKGROUND

Acute kidney injury (AKI) is associated with high morbidity and mortality. The continuum of kidney damage after an AKI episode is poorly explored in the paediatric population.

METHODS

We performed a retrospective cohort study on 2346 children with AKI from a tertiary care hospital in Romania over a 9-year period. The main objective was to evaluate the impact of AKI duration on mortality and the risk of new-onset chronic kidney disease (CKD).

RESULTS

Out of 2346 AKI patients, transient AKI was present in 655 patients (27.9%), persistent AKI in 1009 children (43%) and acute kidney disease in 682 patients (29.1%). In contrast to transient AKI, children who developed acute kidney disease were younger, with a higher degree of anaemia, lower number of platelets, higher procalcitonin, higher LDH, higher GGT, higher urea and higher serum creatinine levels. The pre-renal cause of AKI was the leading cause regardless of AKI duration. As kidney injury progressed over time, there was an increasing incidence of the intrinsic causes of AKI (11.1% in transient AKI, 13.2% in persistent AKI and 22.6% in acute kidney disease). Acute kidney disease patients had the highest mortality rate (16.42%), followed by transient AKI (14.66%) and persistent AKI (9.81%). Overall mortality increased in the presence of renal microvascular alterations, acute tubular necrosis, lower haemoglobin, serum proteins and platelets, and higher procalcitonin levels.

CONCLUSIONS

The continuum of AKI expressed as acute kidney disease resulted in an increased risk of new-onset CKD. CKD was influenced by the intrinsic cause of AKI and not by AKI severity.

Discovery of Propionic Acid Derivatives with a 5-THIQ Core as Potent and Orally Bioavailable Keap1-Nrf2 Protein-Protein Interaction Inhibitors for Acute Kidney Injury

Keap1 plays a crucial role in regulating the Nrf2-mediated cytoprotective response and is increasingly targeted for oxidative stress-related diseases. Using small molecules to disrupt the Keap1-Nrf2 protein-protein interaction (PPI) has emerged as a new strategy for developing Nrf2 activators. Through extensive structure-activity relationship studies, we identified compound 56, which features a unique 5-tetrahydroisoquinoline scaffold and acts as a potent inhibitor of the Keap1-Nrf2 PPI. Compound 56 exhibited significant inhibitory activity (IC50 = 16.0 nM) and tight Keap1 binding affinity (Kd = 3.07 nM), along with acceptable oral bioavailability (F = 20%). Notably, 56 enhanced antioxidant defenses in HK-2 renal tubular epithelial cells and significantly reduced plasma creatinine and blood urea nitrogen levels in acute kidney injury (AKI) mice. These findings collectively position compound 56 as a promising candidate for the treatment of AKI.

Mitochondrial Dysfunction-Evoked DHODH Acetylation is Involved in Renal Cell Ferroptosis during Cisplatin-Induced Acute Kidney Injury

Several studies have observed renal cell ferroptosis during cisplatin-induced acute kidney injury (AKI). However, the mechanism is not completely clear. In this study, oxidized arachidonic acid (AA) metabolites are increased in cisplatin-treated HK-2 cells. Targeted metabolomics showed that the end product of pyrimidine biosynthesis is decreased and the initiating substrate of pyrimidine biosynthesis is increased in cisplatin-treated mouse kidneys. Mitochondrial DHODH, a key enzyme for pyrimidine synthesis, and its downstream product CoQH2, are downregulated. DHODH overexpression attenuated but DHODH silence exacerbated cisplatin-induced CoQH2 depletion and lipid peroxidation. Mechanistically, renal DHODH acetylation is elevated in cisplatin-exposed mice. Mitochondrial SIRT3 is reduced in cisplatin-treated mouse kidneys and HK-2 cells. Both in vitro SIRT3 overexpression and in vivo NMN supplementation attenuated cisplatin-induced mitochondrial DHODH acetylation and renal cell ferroptosis. By contrast, Sirt3 knockout aggravated cisplatin-induced mitochondrial DHODH acetylation and renal cell ferroptosis, which can not be attenuated by NMN. Additional experiments showed that cisplatin caused mitochondrial dysfunction and SIRT3 SUMOylation. Pretreatment with mitochondria-target antioxidant MitoQ alleviated cisplatin-caused mitochondrial dysfunction, SIRT3 SUMOylation, and DHODH acetylation. MitoQ pretreatment protected against cisplatin-caused AKI and renal cell ferroptosis. Taken together, these results suggest that mitochondrial dysfunction-evoked DHODH acetylation partially contributes to renal cell ferroptosis during cisplatin-induced AKI.

Urinary GM2AP coincides with renal cortical damage and grades cisplatin nephrotoxicity severity in rats

Nephrotoxicity, including electrolytic disorders and acute kidney injury (AKI), limits the clinical dosage and utility of platinated antineoplastics such as cisplatin. Cisplatin nephrotoxicity embodies a tubulopathy involving the medullary S2 and S3 segments of the proximal and the distal tubules. Higher dosage extends damage over the cortical S1 segment and intensifies overall injury. However, the standard diagnosis based on plasma creatinine as well as novel injury biomarkers lacks enough pathophysiological specificity. Further granularity in the detection of renal injury would help understand the implications of individual damage patterns needed for personalized patient handling. In this article, we studied the association of urinary ganglioside GM2 activator protein (GM2AP) with the patterns of tubular damage produced by 5 and 10 mg/kg cisplatin in rats. Our results show that GM2AP appears in the urine only following damage to the cortical segment of the proximal tubule. The information provided by GM2AP is not redundant with but distinct and complementary to that provided by urinary neutrophil gelatinase-associated lipocalin (NGAL). Similarly, treatment with 150 mg/kg/day gentamicin damages the renal cortex and increases GM2AP urinary excretion; whereas renal ischemia, which does not affect the cortex, has no effect on GM2AP. Because of the key role of the cortical proximal tubule in renal function, we contend GM2AP as a potential diagnostic biomarker to stratify AKI patients according to the underlying damage and follow their evolution and prognosis. Prospectively, urinary GM2AP may help grade the severity of platinated antineoplastic nephrotoxicity by forming part of a non-invasive liquid biopsy.

Past, present, and future biomarkers of kidney function and injury: The relationship with antibiotics

Routinely used kidney biomarkers of injury and function such as serum creatinine and urine albumin to creatinine ratio, are neither sensitive nor specific. Future biomarkers are being developed for clinical use and have already been included in guidance from groups such as the U.S. Food and Drug Administration and the Predictive Safety Testing Consortium. These biomarkers have important implications for early identification of kidney injury and more accurate measurement of kidney function. Many antibiotics are either eliminated by the kidney or can cause clinically significant nephrotoxicity. As a result, clinicians should be familiar with new biomarkers of kidney function and injury, their place in clinical practice, and applications for antibiotic dosing.

Iodinated Contrast and Nephropathy: Does It Exist and What Is the Actual Evidence?

Iodinated contrast material (ICM) is a critical component for many radiologic examinations and procedures. However, ICM has often been withheld in the past out of concern for its potential nephrotoxicity and increased risk of morbidity and mortality, often at the expense of diagnostic accuracy and timely diagnosis. Evidence from controlled studies now suggest that most cases of acute kidney injury (AKI) caused by ICM were instead due to contrast-independent causes of AKI or normal variation in renal function. This study will discuss current knowledge of contrast-induced AKI, including the incidence, sequelae, risk factors, and prevention strategies of this potential complication.

Diagnostic accuracy of NT-proBNP to predict the incidence of CSA-AKI: A systematic review and meta-analysis

BACKGROUND

Cardiac surgery-associated acute kidney injury (CSA-AKI) is a severe complication following cardiac surgery. Early identification and diagnosis are critical. In this study, we aim to systematically assess the diagnostic value of N-terminal pro-B-type natriuretic peptide (NT-proBNP) for CSA-AKI.

METHODS

The PubMed, Embase, Web of Science, and Cochrane Library databases were searched from January 1971 to October 2023 to identify prospective observational and retrospective observational studies. Data extraction and study screening were carried out independently by 2 authors. The methodological quality of the included studies was evaluated by the Quality Assessment of Diagnostic Accuracy Studies 2 standards, and all statistical analyses were conducted by Stata 15.0.

RESULTS

Seven studies including 37,200 patients were identified. The pooled sensitivity of 0.67 (95% credible interval [CI] = 0.56-0.77), specificity of 0.55 (95% CI = 0.45-0.64), area under the summary receiver operating characteristic curve of 0.65 (95% CI = 0.60-0.69), positive likelihood ratio of 1.5 (95% CI = 1.2-1.8), negative likelihood ratio of 0.60 (95% CI = 0.46-0.79), and diagnostic odds ratio of 2 (95% CI = 2-4) suggested that patients with higher preoperative NT-proBNP levels (pg/mL) are at higher risk of developing acute kidney injury after cardiac surgery. However, NT-proBNP lacks sufficient sensitivity and specificity to reliably predict CSA-AKI.

CONCLUSION

Our findings suggest that the diagnostic accuracy of NT-proBNP to predict the incidence of CSA-AKI is limited. However, we provide novel perspectives on the early detection of CSA-AKI biomarkers, and it is urgent to identify more precise and practical biomarkers for the early diagnosis of CSA-AKI.

Features selection in a predictive model for cardiac surgery-associated acute kidney injury

BACKGROUND

Cardiac surgery-associated acute kidney injury (CSA-AKI) is related to increased morbidity and mortality. However, limited studies have explored the influence of different feature selection (FS) methods on the predictive performance of CSA-AKI. Therefore, we aimed to compare the impact of different FS methods for CSA-AKI.

METHODS

CSA-AKI is defined according to the kidney disease: Improving Global Outcomes (KDIGO) criteria. Both traditional logistic regression and machine learning methods were used to select the potential risk factors for CSA-AKI. The area under the receiver operating characteristic curve (AUC) was used to evaluate the performance of the models. In addition, the importance matrix plot by random forest was used to rank the features' importance.

RESULTS

A total of 1977 patients undergoing cardiac surgery at Fuwai hospital from December 2018 to April 2021 were enrolled. The incidence of CSA-AKI during the first postoperative week was 27.8%. We concluded that different enrolled numbers of features impact the final selected feature number. The more you input, the more likely its output with all FS methods. In terms of performance, all selected features by various FS methods demonstrated excellent AUCs. Meanwhile, the embedded method demonstrated the highest accuracy compared with the LR method, while the filter method showed the lowest accuracy. Furthermore, NT-proBNP was found to be strongly associated with AKI. Our results confirmed some features that previous studies have reported and found some novel clinical parameters.

CONCLUSIONS

In our study, FS was as suitable as LR for predicting CSA-AKI. For FS, the embedded method demonstrated better efficacy than the other methods. Furthermore, NT-proBNP was confirmed to be strongly associated with AKI.

Complex Hepatectomy Under Total Vascular Exclusion of the Liver Preserving the Caval Flow with Portal Hypothermic Perfusion and Temporary Portacaval Shunt: A Proof of Concept

BACKGROUND

Hypothermic liver perfusion decreases ischemia/reperfusion injury during hepatectomy under standard total vascular exclusion (TVE) of the liver. This surgery needs venovenous bypass and is hampered by high morbi-mortality. TVE preserving the inferior vena cava (IVC) flow is hemodynamically well tolerated but remains limited in duration when performed under liver normothermia. The objective of this study was to report the results of TVE preserving the caval flow, modified to allow hypothermic liver perfusion and obviate splanchnic congestion.

PATIENTS AND METHODS

The technique, indicated for tumors abutting large tributaries of the hepatic veins but sparing their roots in IVC and the latter, was applied when TVE was anticipated to last for ≥ 60 min. It combines continuous TVE preserving the IVC flow with hypothermic liver perfusion and temporary portacaval shunt (PCS). Results are given as median (range).

RESULTS

Vascular control was achieved in 13 patients with excellent hemodynamical tolerance. PCS was direct or via an interposed synthetic graft (five and eight cases, respectively). Liver temperature dropped to 16.5 (6-24) °C under perfusion of 2 (2-4) L of cold perfusate. TVE lasted 67 (54-125) min and 4.5 (0-8) blood units were transfused. Resection was major in nine cases and was complete in all cases. Five complications occurred in four patients, and the 90-day mortality rate was zero.

CONCLUSIONS

This technique maintains stable hemodynamics and combines the advantages of in situ or ex situ standard TVE with hypothermic liver perfusion, without their inherent prolongation of ischemia time and need for venovenous bypass.

Ammonia and urea metabolism in acute liver failure: A multicentre cohort study

BACKGROUND & AIMS

Ammonia is metabolized into urea in the liver. In acute liver failure (ALF), ammonia has been associated with survival. However, urea variation has been poorly studied.

METHODS

Observational cohort including ALF patients from Curry Cabral Hospital (Lisbon, Portugal) and Clinic Hospital (Barcelona, Spain) between 10/2010 and 01/2023. The United States ALF Study Group cohort was used for external validation. Primary exposures were serum ammonia and urea on ICU admission. Primary endpoint was 30-day transplant-free survival (TFS). Secondary endpoint was explanted liver weight.

RESULTS

Among 191 ALF patients, median (IQR) age was 46 (32; 57) years and 85 (44.5%) were males. Overall, 86 (45.0%) patients were transplanted and 75 (39.3%) died. Among all ALF patients, following adjustment for age, sex, body weight, and aetiology, higher ammonia or lower urea was independently associated with higher INR on ICU admission (p < .009). Among all ALF patients, following adjustment for sex, aetiology, and lactate, higher ammonia was independently associated with lower TFS (adjusted odds ratio (95% confidence interval [CI]) = 0.991 (0.985; 0.997); p = .004). This model predicted TFS with good discrimination (area under receiver operating curve [95% CI] = 0.78 [0.75; 0.82]) and reasonable calibration (R2 of 0.43 and Brier score of 0.20) after external validation. Among transplanted patients, following adjustment for age, sex, actual body weight, and aetiology, higher ammonia (p = .024) or lower (p < .001) urea was independently associated with lower explanted liver weight.

CONCLUSIONS

Among ALF patients, serum ammonia and urea were associated with ALF severity. A score incorporating serum ammonia predicted TFS reasonably well.

Latin American Surgical Outcomes Study in Paediatrics (LASOS-Peds): study protocol and statistical analysis plan for a multicentre international observational cohort study

INTRODUCTION

Surgery is a cost-effective public health intervention. Access to safe surgery is a basic human right. However, there are still significant disparities in the access to and safety of surgical and anaesthesia care between low-income and middle-income countries and high-income countries. The Latin American Surgical Outcomes Study in Paediatrics (LASOS-Peds) is an international, observational, 14-day cohort study to investigate the incidence of 30-day in-hospital complications following elective or emergency paediatric surgery in Latin American countries.

METHODS AND ANALYSIS

LASOS-Peds is a prospective, international, multicentre observational study of paediatric patients undergoing both elective and non-elective surgeries and procedures, inpatient and outpatient, including those performed outside the operating room. The primary outcome is the incidence of in-hospital postoperative complications up to 30 days after surgery. Secondary outcomes include intraoperative complications and the need for intensive care unit admission.

ETHICS AND DISSEMINATION

This study received approval from the Institutional Review Board of the coordinating centre (Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo) as well as from all the participating centres. The study results are expected to be published in peer-reviewed journals and disseminated at international conferences.

TRIAL REGISTRATION NUMBER

NCT05934682.

Polypharmacy and Guideline-Directed Medical Therapy Initiation Among Adults Hospitalized With Heart Failure

Background

Underprescribing of guideline-directed medical therapy (GDMT) for heart failure (HF) persists.

Objectives

The purpose of this study was to assess polypharmacy as a barrier to GDMT.

Methods

We examined participants hospitalized for HF with reduced ejection fraction and HF with mildly reduced ejection fraction between 2003 and 2017 from the Reasons for Geographic and Racial Differences in Stroke study. Participants were stratified by admission medication count-0 to 4, 5 to 9, and ≥10 medications. We examined GDMT use at admission, GDMT contraindications, and initiation of eligible indicated GDMT by medication count. We conducted a multivariable Poisson regression with robust standard errors to examine the association between medication count and GDMT initiation. GDMT included agents for HF with reduced ejection fraction/HF with mildly reduced ejection fraction, antiplatelet agents and statins for coronary artery disease, and anticoagulants for atrial fibrillation.

Results

Among 545 participants with HF, 34% were not taking a beta-blocker, 39% were not taking an angiotensin-converting enzyme inhibitor/angiotensin receptor blocker/angiotensin receptor-neprilysin inhibitor, or hydralazine-isosorbide dinitrate, and 90% were not taking a mineralocorticoid receptor antagonist at admission; among participants with coronary artery disease, 36% were not taking an antiplatelet agent, and 38% were not taking a statin; and among participants with atrial fibrillation, 49% were not taking an anticoagulant. Polypharmacy was inversely associated with initiation of at least one indicated medication (5-9 medications: relative risk [RR]: 0.67; 95% CI: 0.56-0.82; P < 0.001; ≥10 medications: RR: 0.50; 95% CI: 0.39-0.64; P < 0.001) and initiation of at least half of indicated medications (5-9 medications: RR: 0.64; 95% CI: 0.51-0.81; P < 0.001; ≥10 medications: RR: 0.50; 95% CI: 0.38-0.67; P < 0.001).

Conclusions

Polypharmacy is an important barrier to GDMT.

A wide scope, pan-comparative, systematic meta-analysis of the efficacy of prophylactic strategies for cardiac surgery-associated acute kidney injury

Acute kidney injury (AKI) is the most common complication of cardiac surgery. Cardiac surgery-associated AKI (CSA-AKI) is caused by systemic and renal hemodynamic impairment and parenchymal injury. Prophylaxis of CSA-AKI remains an unmet priority, for which preventive strategies based on drug therapies, hydration procedures, and remote ischemic preconditioning (RIPC) have been tested in pre-clinical and clinical studies, with variable success. Contradicting reports and scarce or insufficiently pondered information have blurred conclusions. Therefore, with an aim to contribute to consolidating the available information, we carried out a wide scope, pan-comparative meta-analysis including the accessible information about the most relevant nephroprotective approaches assayed. After a thorough examination of 1892 documents retrieved from PubMed and Web of Science, 150 studies were used for the meta-analysis. Individual odds ratios of efficacy at reducing AKI incidence, need for dialysis, and plasma creatinine elevation were obtained for each alleged protectant. Also, the combined class effect of drug families and protective strategies was also meta-analyzed. Our results show that no drug family or procedure affords substantial protection against CSA-AKI. Only, a mild but significant reduction in the incidence of CSA-AKI by preemptive treatment with dopaminergic and adrenergic drugs, vasodilators, and the RIPC technique. The integrated analysis suggests that single-drug approaches are unlikely to cope with the variety of individual pathophysiological scenarios potentially underlying CSA-AKI. Accordingly, a theragnostic approach involving the etiopathological diagnosis of kidney frailty is necessary to guide research towards the development of pharmacological combinations concomitantly and effectively addressing the key mechanisms of CSA-AKI.

Proton pump inhibitors may increase the risk of cisplatin-induced acute kidney injury in patients with nasopharyngeal carcinoma: a prospective cohort study

Cisplatin is the most commonly used platinum-based treatment for nasopharyngeal carcinoma (NPC). However, its clinical application is limited owing to its nephrotoxicity and gastrointestinal reactions. Proton pump inhibitors (PPIs) have been reported to increase nephrotoxicity risk in previous studies. We aimed to evaluate whether PPIs increase cisplatin-induced nephrotoxicity in patients with NPC. In total, 295 patients were included in this prospective cohort study: 145 in the PPIs group and 150 in the non-PPIs group. All patients underwent cisplatin-based induction chemotherapy, followed by cisplatin-based concurrent chemoradiotherapy. The PPIs group received 40 mg of intravenous esomeprazole sodium for 7 days in each chemotherapy cycle. Chi-squared test and logistic regression analyses with odds ratios and 95% confidence intervals were applied to assess the association between PPIs and the risk of acute kidney injury (AKI). AKI incidence in the PPIs group was significantly higher than that in the non-PPIs group (P = 0.005). After adjusting for various confounders including demographic features, clinical features, and renal function indices, PPIs use was significantly associated with a higher AKI risk (odds ratio: 2.775; 95% confidence interval 1.280-6.020; P = 0.010). The incidences of acute and chronic kidney diseases were similar between both groups (P > 0.05), whereas the incidence of nausea was lower in the PPIs group than in the non-PPIs group (P = 0.029). This study has shown that PPIs use may increase the risk of cisplatin-induced acute nephrotoxicity in patients with NPC.

Reframing acute kidney injury as a pathophysiological continuum of disrupted renal excretory function

Surrogate measures of glomerular filtration rate (GFR) continue to serve as pivotal determinants of the incidence, severity, and management of acute kidney injury (AKI), as well as the primary reference point underpinning knowledge of its pathophysiology. However, several clinically important deficits in aspects of renal excretory function during AKI other than GFR decline, including acid-base regulation, electrolyte and water balance, and urinary concentrating capacity, can evade detection when diagnostic criteria are built around purely GFR-based assessments. The use of putative markers of tubular injury to detect "sub-clinical" AKI has been proposed to expand the definition and diagnostic criteria for AKI, but their diagnostic performance is curtailed by ambiguity with respect to their biological meaning and context specificity. Efforts to devise new holistic assessments of overall renal functional compromise in AKI would foster the capacity to better personalize patient care by replacing biomarker threshold-based diagnostic criteria with a shift to assessment of compromise along a pathophysiological continuum. The term AKI refers to a syndrome of sudden renal deterioration, the severity of which is classified by precise diagnostic criteria that have unquestionable utility in patient management as well as blatant limitations. Particularly, the absence of an explicit pathophysiological definition of AKI curtails further scientific development and clinical handling, entrapping the field within its present narrow GFR-based view. A refreshed approach based on a more holistic consideration of renal functional impairment in AKI as the basis for a new diagnostic concept that reaches beyond the boundaries imposed by the current GFR threshold-based classification of AKI, capturing broader aspects of pathogenesis, could enhance AKI prevention strategies and improve AKI patient outcome and prognosis.

Effect of Serum Bilirubin Levels on Contrast-induced Acute Kidney Injury: A Systematic Evaluation and Meta-analysis

Contrast-induced acute kidney injury (CI-AKI) is an important complication following the use of iodinated contrast media. Bilirubin has a protective effect but may also aggravate CI-AKI. The purpose of this systematic review was to assess whether bilirubin is a risk factor for CI-AKI. We searched the databases PubMed, Embase, Web of Science, Cochrane Library, Scopus, Ovid Medline, CNKI (China National Knowledge Infrastructure), VPCS (Vip Paper Check System), Wanfang, and CBM (Chinese BioMedical Literature Database) from the initial date to May 6, 2023. We summarized the results by directly combining the effect-size odds ratio (OR) and 95% confidence interval (CI) and identified sources of heterogeneity through subgroup analysis, sensitivity analysis, and meta-regression analysis. A total of 10 studies (14 data sets) were included: 7 retrospective studies (10 data sets) and 3 prospective studies (4 data sets), involving 12776 participants. The incidence of CI-AKI of 16% (95% CI: 14-19%). Total bilirubin was positively associated with the occurrence of CI-AKI (OR = 1.80; 95% CI: 1.36-2.38). Both low and high bilirubin concentrations were risk factors for CI-AKI. The incidence of CI-AKI was higher in the low bilirubin group than in the high bilirubin group.

Predictive Value of Serum Soluble ST2 in Adult Patients Undergoing Cardiac Surgery for Acute Kidney Injury

INTRODUCTION

Cardiac surgery is related to an increased risk of postoperative acute kidney injury (AKI). Serum soluble ST2 (sST2) is highly predictive of several cardiovascular diseases and may also be involved in renal injury. This study explored the relationship between serum sST2 levels measured at intensive care unit (ICU) admission and the development of AKI after cardiac surgery.

METHODS

We prospectively conducted an investigation on consecutive patients who underwent cardiac surgery. sST2 was immediately measured at ICU admission. The relationship between the levels of sST2 and the development of AKI was explored using stepwise logistic regression.

RESULTS

Among the 500 patients enrolled, AKI was observed in 207 (41%) patients. Serum sST2 levels in AKI patients were higher than those without AKI (61.46 ng/mL [46.52, 116.25] vs. 38.91 ng/mL [28.74, 50.93], p < 0.001). Additionally, multivariable logistic regression analysis showed that as progressively higher tertiles of serum sST2, the odds ratios (ORs) of AKI gradually increased (adjusted ORs of 1.97 [95% CI, 1.13-3.45], and 4.27 [95% CI, 2.36-7.71] for tertiles 2 and 3, respectively, relative to tertile 1, p < 0.05). The addition of sST2 further improved reclassification (p < 0.001) and discrimination (p < 0.001) over the basic model, which included established risk factors.

CONCLUSION

Serum sST2 levels at ICU admission were associated with the development of postoperative AKI and improved the identification of AKI after cardiac surgery.

Urinary Extracellular Vesicles as a Readily Available Biomarker Source: A Simplified Stratification Method

Urine, a common source of biological markers in biomedical research and clinical diagnosis, has recently generated a new wave of interest. It has recently become a focus of study due to the presence of its content of extracellular vesicles (EVs). These uEVs have been found to reflect physiological and pathological conditions in kidney, urothelial, and prostate tissue and can illustrate further molecular processes, leading to a rapid expansion of research in this field In this work, we present the advantages of an immunoaffinity-based method for uEVs' isolation with respect to the gold standard purification approach performed by differential ultracentrifugation [in terms of purity and antigen presence. The immunoaffinity method was made feasible by combining specific antibodies with a functionalized polymethacrylate polymer. Flow cytometry indicated a significant fluorescence shift, validating the presence of the markers (CD9, CD63, CD81) and confirming the effectiveness of the isolation method. Microscopy evaluations have shown that the morphology of the vesicles remained intact and corresponded to the expected shapes and dimensions of uEVs. The described protocol is inexpensive, fast, easy to process, has good reproducibility, and can be applied to further biological samples.

Biomarker-guided detection of acute kidney injury in abdominal aortic surgery: the new and the old

Introduction

Acute kidney injury (AKI) is a common complication in patients undergoing major vascular surgery. Despite significant research efforts in this area, the incidence of AKI remains high, posing a significant challenge to healthcare systems, especially in situations where resources are limited. Early prediction of AKI severity and individualized postoperative care is therefore essential.

Methods

The primary objective of this exploratory study was to assess the diagnostic value of urine cell-cycle arrest biomarkers [(TIMP-2) × (IGFBP7)] and soluble urokinase plasminogen activator receptor (suPAR) for predicting moderate or severe AKI within 24 h after open aortic surgery, and compared to routine kidney biomarkers. Seventy-five patients undergoing elective aortic surgery were included. Clinical parameters, urine and blood samples were collected preoperatively, immediately postoperatively, and 24 h later. AKI was defined using KDIGO criteria. Individual and combined diagnostic performance of biomarkers were evaluated.

Results

Of the 75 patients, 61% developed AKI, of which 28% developed moderate or severe AKI within 24 h of surgery. Baseline demographics, comorbidities and kidney parameters did not differ between patients with moderate or severe AKI (AKI II/III) and none or mild AKI (AKI 0/I), except for higher preoperative suPAR levels in later AKI II/III patients. Urine osmolality, Cystatin C and serum creatinine had the highest predictive power for AKI II/III with AUCs of 0.75-0.72. (TIMP-2) × (IGFBP7), and neither (TIMP-2) × (IGFBP7) nor suPAR individually showed superior diagnostic value. Combining CysC or SCr with urine osmolality and 6 h urine output gave the best performance with AUCs of 0.86 (95% CI, 0.74-0.96) and 0.85 (95% CI, 0.75-0.95) respectively.

Conclusion

Our study suggests that routine parameters like urine osmolality, CysC, SCr and 6 h urine output perform best in predicting postoperative AKI after aortic surgery compared to the new biomarkers (TIMP-2) × (IGFBP7) and suPAR. Combining biomarkers, particularly CysC or SCr with urine output, urine osmolality, may enhance diagnostic accuracy. Further validation in larger cohorts and clinical settings is warranted to establish their clinical utility.

Long-term outcomes of acute kidney injury in acute decompensated heart failure: identifying true cardiorenal syndrome and unveiling prognostic significance

BACKGROUND

Cardiorenal syndrome (CRS) type 1 defined as acute kidney injury (AKI) in acute decompensated heart failure (ADHF), is complicated due to diverse definitions. Recently, a more precise CRS type 1 definition was proposed, mandating concurrent AKI and signs of unimproved heart failure (HF). Our study explores the incidence, predictors, and long-term outcomes of AKI in ADHF under this new definition.

METHODS

A prospective observation study of ADHF patients categorized into the CRS type 1, pseudo-CRS, and non-AKI groups, followed for 12 months. CRS type 1 involved AKI with clinical congestion, while pseudo-CRS included AKI with clinical decongestion (clinical congestion score <2). The primary outcome was a 1-year composite of mortality or HF rehospitalization.

RESULTS

Among 250 consecutive ADHF patients, 46.0% developed CRS type 1; chronic kidney disease (CKD) and blood urea nitrogen were significant risk factors (odds ratios, 1.37; p = 0.002 and OR, 1.05; p < 0.001, respectively). The CRS type 1 group exhibited shorter times to AKI development and peak serum creatinine than the pseudo-CRS group (1 day vs. 4 days and 2 days vs. 4 days, respectively). At 12 months, composite outcomes of mortality or HF rehospitalization and CKD progression were significantly higher in the CRS type 1 group than in the pseudo-CRS and non-AKI groups (63.5% vs. 31.7% vs. 36.1%, p < 0.001; 28.1% vs. 16.2% vs. 11.4%, p = 0.024, respectively).

CONCLUSION

Distinguishing between CRS type 1 and pseudo-CRS is vital, highlighting significant disparities in short-term and longterm outcomes. Notably, pseudo-CRS exhibits comparable long-term cardiovascular and renal outcomes to those without AKI.

Risk of Acute Kidney Injury Following IV Iodinated Contrast Media Exposure: 2023 Update, From the AJR Special Series on Contrast Media

Iodinated contrast material (ICM) has revolutionized the field of diagnostic radiology through improvements in diagnostic performance and the expansion of clinical indications for radiographic and CT examinations. Historically, nephrotoxicity was a feared complication of ICM use, thought to be associated with a significant risk of morbidity and mortality. Such fears often precluded the use of ICM in imaging evaluations, commonly at the expense of diagnostic performance and timely diagnosis. Over the past 20 years, the nephrotoxic risk of ICM has become a topic of debate, as more recent evidence from higher-quality studies now suggests that many cases of what was considered contrast-induced acute kidney injury (CI-AKI) likely were cases of mistaken causal attribution; most of these cases represented either acute kidney injury (AKI) caused by any of myriad other known factors that can adversely affect renal function and were coincidentally present at the time of contrast media exposure (termed "contrast-associated AKI" [CA-AKI]) or a manifestation of the normal variation in renal function that increases with worsening renal function. This Special Series Review discusses the current state of knowledge regarding CI-AKI and CA-AKI, including the incidence, risk factors, outcomes, and prophylactic strategies in the identification and management of these clinical conditions.

Acute Kidney Injury in Neonatal Intensive Care Unit: Epidemiology, Diagnosis and Risk Factors

Acute kidney injury (AKI) is associated with long-term consequences and poor outcomes in the neonatal intensive care unit. Its precocious diagnosis represents one of the hardest challenges in clinical practice due to the lack of sensitive and specific biomarkers. Currently, neonatal AKI is defined with urinary markers and serum creatinine (sCr), with limitations in early detection and individual treatment. Biomarkers and risk factor scores were studied to predict neonatal AKI, to early identify the stage of injury and not the damage and to anticipate late increases in sCr levels, which occurred when the renal function already began to decline. Sepsis is the leading cause of AKI, and sepsis-related AKI is one of the main causes of high mortality. Moreover, preterm neonates, as well as patients with post-neonatal asphyxia or after cardiac surgery, are at a high risk for AKI. Critical patients are frequently exposed to nephrotoxic medications, representing a potentially preventable cause of AKI. This review highlights the definition of neonatal AKI, its diagnosis and new biomarkers available in clinical practice and in the near future. We analyze the risk factors involving patients with AKI, their outcomes and the risk for the transition from acute damage to chronic kidney disease.

Sequential Normothermic Regional Perfusion and End-ischemic Ex Situ Machine Perfusion Allow the Safe Use of Very Old DCD Donors in Liver Transplantation

BACKGROUND

In Italy, 20 min of continuous, flat-line electrocardiogram are required for death declaration. Despite prolonged warm ischemia time, Italian centers reported good outcomes in controlled donation after circulatory death (cDCD) liver transplantation by combining normothermic regional and end-ischemic machine perfusion (MP). The aim of this study was to evaluate the safety and feasibility of the use of septuagenarian and octogenarian cDCD donors with this approach.

METHODS

All cDCD older than 70 y were evaluated during normothermic regional perfusion and then randomly assigned to dual hypothermic or normothermic MP.

RESULTS

In the period from April 2021 to December 2022, 17 cDCD older than 70 y were considered. In 6 cases (35%), the graft was not considered suitable for liver transplantation, whereas 11 (65%) were evaluated and eventually transplanted. The median donor age was 82 y, being 8 (73%) older than 80. Median functional warm ischemia and no-flow time were 36 and 28 min, respectively. Grafts were randomly assigned to ex situ dual hypothermic oxygenated MP in 6 cases (55%) and normothermic MP in 5 (45%). None was discarded during MP. There were no cases of primary nonfunction, 1 case of postreperfusion syndrome (9%) and 2 cases (18%) of early allograft dysfunction. At a median follow-up of 8 mo, no vascular complications or ischemic cholangiopathy were reported. No major differences were found in terms of postoperative hospitalization or complications based on the type of MP.

CONCLUSIONS

The implementation of sequential normothermic regional and end-ischemic MP allows the safe use of very old donation after circulatory death donors.

Double-negative T cells have a reparative role after experimental severe ischemic acute kidney injury

T cells mediate organ injury and repair. A proportion of unconventional kidney T cells called double-negative (DN) T cells (TCR+ CD4- CD8-), with anti-inflammatory properties, were previously demonstrated to protect from early injury in moderate experimental acute kidney injury (AKI). However, their role in repair after AKI has not been studied. We hypothesized that DN T cells mediate repair after severe AKI. C57B6 mice underwent severe (40 min) unilateral ischemia-reperfusion injury (IRI). Kidney DN T cells were studied by flow cytometry and compared with gold-standard anti-inflammatory CD4+ regulatory T cells (Tregs). In vitro effects of DN T cells and Tregs on renal tubular epithelial cell (RTEC) repair after injury were quantified with live-cell analysis. DN T cells, Tregs, CD4, or vehicle were adoptively transferred after severe AKI. Glomerular filtration rate (GFR) was measured using fluorescein isothiocyanate (FITC)-sinistrin. Fibrosis was assessed with Masson's trichrome staining. Profibrotic genes were measured with qRT-PCR. Percentages and the numbers of DN T cells substantially decreased during repair phase after severe AKI, as well as their activation and proliferation. Both DN T cells and Tregs accelerated RTEC cell repair in vitro. Post-AKI transfer of DN T cells reduced kidney fibrosis and improved GFR, as did Treg transfer. DN T cell transfer lowered transforming growth factor (TGF)β1 and α-smooth muscle actin (αSMA) expression. DN T cells reduced effector-memory CD4+ T cells and IL-17 expression. DN T cells undergo quantitative and phenotypical changes after severe AKI, accelerate RTEC repair in vitro as well as improve GFR and renal fibrosis in vivo. DN T cells have potential as immunotherapy to accelerate repair after AKI.NEW & NOTEWORTHY Double-negative (DN) T cells (CD4- CD8-) are unconventional kidney T cells with regulatory abilities. Their role in repair from acute kidney injury (AKI) is unknown. Kidney DN T cell population decreased during repair after ischemic AKI, in contrast to regulatory T cells (Tregs) which increased. DN T cell administration accelerated tubular repair in vitro, while after severe in vivo ischemic injury reduced kidney fibrosis and increased glomerular filtration rate (GFR). DN T cell infusion is a potential therapeutic agent to improve outcome from severe AKI.

Cardiac Surgery-Associated Acute Kidney Injury

AKI is a common and serious complication of cardiac surgery that has a significant impact on patient morbidity and mortality. The Kidney Disease Improving Global Outcomes definition of AKI is widely used to classify and identify AKI associated with cardiac surgery (cardiac surgery-associated AKI [CSA-AKI]) on the basis of changes in serum creatinine and/or urine output. There are various preoperative, intraoperative, and postoperative risk factors for the development of CSA-AKI which should be recognized and addressed as early as possible to expedite its diagnosis, reduce its occurrence, and prevent or ameliorate its devastating complications. Crucial issues are the inaccuracy of serum creatinine as a surrogate parameter of kidney function in the perioperative setting of cardiothoracic surgery and the necessity to discover more representative markers of the pathophysiology of AKI. However, except for the tissue inhibitor of metalloproteinase-2 and insulin-like growth factor binding protein 7 ratio, other diagnostic biomarkers with an acceptable sensitivity and specificity are still lacking. This article provides a comprehensive review of various aspects of CSA-AKI, including pathogenesis, risk factors, diagnosis, biomarkers, classification, prevention, and treatment management.