Acute renal failure and sepsis

H-151 attenuates lipopolysaccharide-induced acute kidney injury by inhibiting the STING-TBK1 pathway

Sepsis is a severe systemic infectious disease that often leads to multi-organ dysfunction. One of the common and serious complications of sepsis is renal injury. In this study, we aimed to investigate the potential mechanistic role of a novel compound called H-151 in septic kidney injury. We also examined its impact on renal function and mouse survival rates. Initially, we confirmed abnormal activation of the STING-TBK1 signaling pathway in the kidneys of septic mice. Subsequently, we treated the mice with H-151 and observed significant improvement in sepsis-induced renal dysfunction. This was evidenced by reductions in blood creatinine and urea nitrogen levels, as well as a marked decrease in inflammatory cytokine levels. Furthermore, H-151 substantially improved the seven-day survival rate of septic mice, indicating its therapeutic potential. Importantly, H-151 also exhibited an inhibitory effect on renal apoptosis levels, further highlighting its mechanism of protecting against septic kidney injury. These study findings not only offer new insights into the treatment of septic renal injury but also provide crucial clues for further investigations into the regulatory mechanisms of the STING-TBK1 signaling pathway and potential drug targets.

The REPERFUSE study protocol: The effects of vasopressor therapy on renal perfusion in patients with septic shock-A mechanistically focused randomised control trial

INTRODUCTION

Acute kidney injury (AKI) is a common complication of septic shock and together these conditions carry a high mortality risk. In septic patients who develop severe AKI, renal cortical perfusion is deficient despite normal macrovascular organ blood flow. This intra-renal perfusion abnormality may be amenable to pharmacological manipulation, which may offer mechanistic insight into the pathophysiology of septic AKI. The aim of the current study is to investigate the effects of vasopressin and angiotensin II on renal microcirculatory perfusion in a cohort of patients with septic shock.

METHODS AND ANALYSIS

In this single centre, mechanistically focussed, randomised controlled study, 45 patients with septic shock will be randomly allocated to either of the study vasopressors (vasopressin or angiotensin II) or standard therapy (norepinephrine). Infusions will be titrated to maintain a mean arterial pressure (MAP) target set by the attending clinician. Renal microcirculatory assessment will be performed for the cortex and medulla using contrast-enhanced ultrasound (CEUS) and urinary oxygen tension (pO2), respectively. Renal macrovascular flow will be assessed via renal artery ultrasound. Measurement of systemic macrovascular flow will be performed through transthoracic echocardiography (TTE) and microvascular flow via sublingual incident dark field (IDF) video microscopy. Measures will be taken at baseline, +1 and +24hrs following infusion of the study drug commencing. Blood and urine samples will also be collected at the measurement time points. Longitudinal data will be compared between groups and over time.

DISCUSSION

Vasopressors are integral to the management of patients with septic shock. This study aims to further understanding of the relationship between this therapy, renal perfusion and the development of AKI. In addition, using CEUS and urinary pO2, we hope to build a more complete picture of renal perfusion in septic shock by interrogation of the constituent parts of the kidney. Results will be published in peer-reviewed journals and presented at academic meetings.

TRIAL REGISTRATION

The REPERFUSE study was registered on Clinical Trials.gov (NCT06234592) on the 30th Jan 24.

The role of thromboinflammation in acute kidney injury among patients with septic coagulopathy

Inflammation and coagulation are critical self-defense mechanisms for mitigating infection that can nonetheless induce tissue injury and organ dysfunction. In severe cases, like sepsis, a dysregulated thromboinflammatory response may result in multiorgan dysfunction. Sepsis-associated acute kidney injury (AKI) is a significant contributor to patient morbidity and mortality. The connection between AKI and thromboinflammation is largely due to unique aspects of the renal vasculature. Specifically, the interaction between blood cells with the endothelial, glomerular, and peritubular capillary systems during thromboinflammation reduces oxygen supply to tubular epithelial cells. Previous studies have focused on tubular epithelial cell damage due to hypoxia, oxidative stress, and nephrotoxins. Although these factors are pivotal in acute tubular injury or necrosis, recent studies have demonstrated that AKI in sepsis encompasses a mixture of tubular and glomerular damage subtypes. In cases of sepsis-induced coagulopathy, thromboinflammation within the glomerulus and peritubular capillaries is an important pathogenic mechanism for AKI. Unfortunately, and despite the use of renal replacement therapy, the development of AKI in sepsis continues to be associated with high morbidity, mortality, and clinical challenges requiring alternative approaches. This review introduces the important role of thromboinflammation in AKI pathogenesis and details innovative vascular-targeting therapeutic strategies.

EARLY FLUID PLUS NOREPINEPHRINE RESUSCITATION DIMINISHES KIDNEY HYPOPERFUSION AND INFLAMMATION IN SEPTIC NEWBORN PIGS

ABSTRACT

Sepsis is the most frequent risk factor for acute kidney injury (AKI) in critically ill infants. Sepsis-induced dysregulation of kidney microcirculation in newborns is unresolved. The objective of this study was to use the translational swine model to evaluate changes in kidney function during the early phase of sepsis in newborns and the impact of fluid plus norepinephrine resuscitation. Newborn pigs (3-7-day-old) were allocated randomly to three groups: 1) sham, 2) sepsis (cecal ligation and puncture) without subsequent resuscitation, and 3) sepsis with lactated Ringer plus norepinephrine resuscitation. All animals underwent standard anesthesia and mechanical ventilation. Cardiac output and glomerular filtration rate were measured noninvasively. Mean arterial pressure, total renal blood flow, cortical perfusion, medullary perfusion, and medullary tissue oxygen tension (mtPO 2 ) were determined for 12 h. Cecal ligation and puncture decreased mean arterial pressure and cardiac output by more than 50%, with a proportional increase in renal vascular resistance and a 60-80% reduction in renal blood flow, cortical perfusion, medullary perfusion, and mtPO 2 compared to sham. Cecal ligation and puncture also decreased glomerular filtration rate by ~79% and increased AKI biomarkers. Isolated foci of tubular necrosis were observed in the septic piglets. Except for mtPO 2 , changes in all these parameters were ameliorated in resuscitated piglets. Resuscitation also attenuated sepsis-induced increases in the levels of plasma C-reactive protein, proinflammatory cytokines, lactate dehydrogenase, alanine transaminase, aspartate aminotransferase, and renal NLRP3 inflammasome. These data suggest that newborn pigs subjected to cecal ligation and puncture develop hypodynamic septic AKI. Early implementation of resuscitation lessens the degree of inflammation, AKI, and liver injury.

Acute Kidney Injury in Sepsis

Sepsis-associated kidney injury is common in critically ill patients and significantly increases morbidity and mortality rates. Several complex pathophysiological factors contribute to its presentation and perpetuation, including macrocirculatory and microcirculatory changes, mitochondrial dysfunction, and metabolic reprogramming. Recovery from acute kidney injury (AKI) relies on the evolution towards adaptive mechanisms such as endothelial repair and tubular cell regeneration, while maladaptive repair increases the risk of progression to chronic kidney disease. Fundamental management strategies include early sepsis recognition and prompt treatment, through the administration of adequate antimicrobial agents, fluid resuscitation, and vasoactive agents as needed. In septic patients, organ-specific support is often required, particularly renal replacement therapy (RRT) in the setting of severe AKI, although ongoing debates persist regarding the ideal timing of initiation and dosing of RRT. A comprehensive approach integrating early recognition, targeted interventions, and close monitoring is essential to mitigate the burden of SA-AKI and improve patient outcomes in critical care settings.

Andrographolide attenuates sepsis-induced acute kidney injury by inhibiting ferroptosis through the Nrf2/FSP1 pathway

Sepsis is a systemic inflammatory response syndrome caused by infection, which causes renal dysfunction known as sepsis-associated acute kidney injury (S-AKI). Ferroptosis is a form of lipid peroxidation dependent on iron and reactive oxygen species that differs from other forms of programmed cell death at the morphological and biochemical levels. Andrographolide (AG), a natural diterpenoid lactone compound extracted from Andrographis paniculata, has been shown to have therapeutic effects in kidney disease. In this study, we investigated the novel mechanism by which AG attenuates septic acute kidney injury by inhibiting ferroptosis in renal tubular epithelial cells (HK-2) through the Nrf2/FSP1 pathway. Cecum ligation and puncture (CLP)-induced septic rats and lipopolysaccharide (LPS)-induced HK-2 cells were used for in vivo and in vitro experiments. Firstly, in septic rats and HK-2 cells, AG effectively decreased the levels of kidney injury indicators, including blood creatinine, urea nitrogen, and markers of kidney injury such as neutrophil gelatinase-associated lipid transport protein and kidney injury molecule-1 (KIM-1). In addition, AG prevented ferroptotosis, by avoiding the accumulation of iron and lipid peroxidation, and an increase in SLC7A11 and GPX4 in AG-treated HK-2 cells. Furthermore, AG attenuated mitochondrial damage, including mitochondrial swelling, outer membrane rupture, and a reduction in mitochondrial cristae in LPS-treated HK-2 cells. Ferrostatin-1 (Fer-1), a ferroptosis inhibitor, significantly inhibited LPS-induced ferroptosis in HK-2 cells. Importantly, our results confirm that Nrf2/FSP1 is an important pathway for ferroptosis resistance. Nrf2 siRNA hindered the effect of AG in attenuating acute kidney injury and inhibiting ferroptosis. These findings demonstrate that Nrf2/FSP1-mediated HK-2 ferroptosis is associated with AG, alleviates septic acute kidney injury, and indicates a novel avenue for therapeutic interventions in the treatment of acute kidney injury in sepsis.

Thiamine administration in septic shock: a post hoc analysis of two randomized trials

BACKGROUND

This is a post hoc analysis of combined cohorts from two previous Phase II clinical trials to assess the effect of thiamine administration on kidney protection and mortality in patients with septic shock.

METHODS

Patient-level data from the Thiamine in Septic Shock Trial (NCT01070810) and the Thiamine for Renal Protection in Septic Shock Trial (NCT03550794) were combined in this analysis. The primary outcome for the current study was survival without the receipt of renal replacement therapy (RRT). Analyses were performed on the overall cohort and the thiamine-deficient cohort (thiamine < 8 nmol/L).

RESULTS

Totally, 158 patients were included. Overall, thiamine administration was associated with higher odds of being alive and RRT-free (adjusted odds ratio [aOR]: 2.05 [95% confidence interval (CI) 1.08-3.90]) and not needing RRT (aOR: 2.59 [95% CI 1.01-6.62]). In the thiamine-deficient group, thiamine administration was associated with higher odds of being alive and RRT-free (aOR: 8.17 [95% CI 1.79-37.22]) and surviving to hospital discharge (aOR: 6.84 [95% CI 1.54-30.36]). There was a significant effect modification by baseline thiamine deficiency for alive and RRT-free (interaction, p = 0.016) and surviving to hospital discharge (p = 0.019).

CONCLUSION

In the combined analysis of two previous randomized trials, thiamine administration was associated with higher odds of being alive and RRT-free at hospital discharge in patients with septic shock. This signal was stronger in patients with thiamine deficiency.

Acute kidney injury comorbidity analysis based on international classification of diseases-10 codes

OBJECTIVE

Acute kidney injury (AKI) is a clinical syndrome that occurs as a result of a dramatic decline in kidney function caused by a variety of etiological factors. Its main biomarkers, serum creatinine and urine output, are not effective in diagnosing early AKI. For this reason, this study provides insight into this syndrome by exploring the comorbidities of AKI, which may facilitate the early diagnosis of AKI. In addition, organ crosstalk in AKI was systematically explored based on comorbidities to obtain clinically reliable results.

METHODS

We collected data from the Medical Information Mart for Intensive Care-IV database on patients aged [Formula: see text] 18 years in intensive care units (ICU) who were diagnosed with AKI using the criteria proposed by Kidney Disease: Improving Global Outcomes. The Apriori algorithm was used to mine association rules on the diagnoses of 55,486 AKI and non-AKI patients in the ICU. The comorbidities of AKI mined were validated through the Electronic Intensive Care Unit database, the Colombian Open Health Database, and medical literature, after which comorbidity results were visualized using a disease network. Finally, organ diseases were identified and classified from comorbidities to investigate renal crosstalk with other distant organs in AKI.

RESULTS

We found 579 AKI comorbidities, and the main ones were disorders of lipoprotein metabolism, essential hypertension, and disorders of fluid, electrolyte, and acid-base balance. Of the 579 comorbidities, 554 were verifiable and 25 were new and not previously reported. In addition, crosstalk between the kidneys and distant non-renal organs including the liver, heart, brain, lungs, and gut was observed in AKI with the strongest heart-kidney crosstalk, followed by lung-kidney crosstalk.

CONCLUSION

The comorbidities mined in this study using association rules are scientific and may be used for the early diagnosis of AKI and the construction of AKI predictive models. Furthermore, the organ crosstalk results obtained through comorbidities may provide supporting information for the management of short- and long-term treatment practices for organ dysfunction.

Nephrotoxic drug burden and predictors of exposure among patients with renal impairment in Ethiopia: A multi-center study

Background

Nephrotoxic drugs may hasten the decline in kidney function and worsen the progression of renal impairment as a result; these drugs should be avoided or used with caution in patients with pre-existing renal insufficiency. The purpose of this study was to assess the burden of nephrotoxic medication use and its predictors among patients with underlying renal impairment.

Methods

A multicenter, institution-based, cross-sectional study was conducted from May 30, 2021 to July 30, 2021, at medical wards. Renal impaired patients admitted during the data collection period who took at least one medication were enrolled in the study. A simple random sampling technique was used to select the study participants. Data was collected through an interview and a medical card review. Both bivariable and multivariable binary logistic regression analyses were fitted to identify factors associated with nephrotoxic drug use.

Results

Among the 422 participants, more than half of them (53.6 %) were male. The mean patient's age was 47.5 (±16.7) years. A total of 1310 drugs were prescribed for 422 patients with renal impairment, of which 80.15 % were nephrotoxic. Nephrotoxic drugs were prescribed for 66.4 % of patients. The burden of nephrotoxic medication prescription was significantly associated with variables like the presence of comorbidity (AOR = 6.31, 95 % CI: 2.01-19.79), the number of medications prescribed (AOR = 1.43, 95 % CI: 1.05-1.93), and the age of participants (AOR = 1.12, 95 % CI: 1.07-1.17).

Conclusion

The present study demonstrated that two-third of the patients with renal impairment were exposed to nephrotoxic medications. Furosemide, Enalapril, and vancomycin were the most frequently prescribed nephrotoxic medications. The study suggests that prescribers need to give special attention to older patients who have underlying renal insufficiency, a comorbid condition, and polypharmacy regarding exposure to contraindicated nephrotoxic medication.

The Apelin/APJ System: A Potential Therapeutic Target for Sepsis

Apelin is the native ligand for the G protein-coupled receptor APJ. Numerous studies have demonstrated that the Apelin/APJ system has positive inotropic, anti-inflammatory, and anti-apoptotic effects and regulates fluid homeostasis. The Apelin/APJ system has been demonstrated to play a protective role in sepsis and may serve as a promising therapeutic target for the treatment of sepsis. Better understanding of the mechanisms of the effects of the Apelin/APJ system will aid in the development of novel drugs for the treatment of sepsis. In this review, we provide a brief overview of the physiological role of the Apelin/APJ system and its role in sepsis.

Assessing the impact of transfusion thresholds in patients with septic acute kidney injury: a retrospective study

Background

Sepsis is a severe condition that often leads to complications such as acute kidney injury, which significantly increases morbidity and mortality rates. Septic AKI (S-AKI) is common in ICU patients and is associated with poor outcomes. However, there is no consensus on the optimal transfusion threshold for achieving the best clinical results. This retrospective study aims to investigate the relationship between different transfusion thresholds during hospitalization and the prognosis of septic AKI.

Methods

Data from patients with S-AKI was extracted from MIMIC-IV. Based on the lowest hemoglobin level 24 h before transfusion, patients were divided into high-threshold (≥7 g/L) and low-threshold (<7 g/L) groups. We compared the outcomes between these two groups, including hospital and ICU mortality rates as primary outcomes, and 30 days, 60 days, and 90 days mortality rates, as well as duration of stay in ICU and hospital as secondary outcomes.

Results

A total of 5,654 patients were included in our study. Baseline characteristics differed significantly between the two groups, with patients in the low-threshold group generally being younger and having higher SOFA scores. After performing propensity score matching, no significant differences in survival rates were found between the groups. However, patients in the low-threshold group had a longer overall hospital stay.

Conclusion

A lower transfusion threshold does not impact the mortality rate in S-AKI patients, but it may lead to a longer hospital stay.

Urinary cell cycle biomarkers for the prediction of renal non-recovery in patients with septic acute kidney injury: a prospective study

BACKGROUND

Poor prognosis has been associated with the absence of renal recovery after acute kidney injury (AKI). This study aimed to investigate whether urinary biomarkers at 0 and 24 h could be used independently or in conjunction with a clinical model to predict renal non-recovery in septic AKI.

METHODS

A prospective observational study was conducted to measure the urinary levels of insulin-like growth factor-binding protein 7 (IGFBP7) and tissue inhibitor of metalloproteinase-2 (TIMP-2) at the time of AKI diagnosis (0 h) and 24 h later. Renal non-recovery within 7 days was defined as the outcome. The predictive value of urinary biomarkers for renal non-recovery in septic AKI was assessed using the area under the curve (AUC).

RESULTS

A total of 198 individuals with septic AKI were included in the final analysis. Among them, 38.9% (n = 77) did not experience renal recovery within 7 days. The combination of urinary IGFBP7 and TIMP-2 at the initial time point demonstrated prognostic value for non-recovery of renal function, with an AUC of 0.782. When [TIMP-2]*[IGFBP7] was measured at 0 h, the clinical prognostic model, incorporating AKI stage 2-3 and the non-renal sequential organ failure assessment score, showed an improved AUC of 0.822 (with a sensitivity of 88.3% and specificity of 59.5%).

CONCLUSIONS

The combination of urinary [TIMP-2]*[IGFBP7] at 0 h exhibited moderate predictive ability for renal non-recovery in cases of septic AKI. However, there is potential to enhance the prognostic capabilities of the [TIMP-2]*[IGFBP7]-clinical prediction model.

Acetyl-11-Keto-β-Boswellic Acid and Incensole Acetate Attenuate Lipopolysaccharide-Induced Acute Kidney Injury by Inhibiting Inflammation and Oxidative Stress

Boswellia serrata has been used in traditional medicine to treat various inflammatory diseases. Acetyl-11-keto-β-boswellic acid (AKBA) and incensole acetate (IA) are two active ingredients of B. serrata that possess anti-inflammatory and antioxidant activities. The present study aimed to investigate the protective effects of AKBA and IA against lipopolysaccharide (LPS)- induced acute kidney injury (AKI) in rats. Wistar rats were intraperitoneally pretreated with AKBA or IA for 2 weeks. After 30 min, an LPS injection was applied to induce AKI. Blood samples and kidney tissues were collected and used for biochemical assays. AKBA and IA not only significantly decreased interleukin-6 as a marker of renal inflammation but also attenuated the oxidative stress markers in kidney tissues. AKBA and IA also remarkably decreased serum creatinine and blood urea nitrogen. These results suggest that AKBA and IA have protective effects against AKI in rats through regulating inflammation and oxidative stress.

Effects of low-dose furosemide combined with aminophylline on the renal function in septic shock patients

BACKGROUND

To investigate the effects of low-dose furosemide and aminophylline on the renal function in patients with septic shock.

METHODS AND RESULTS

A total of 109 eligible septic shock patients in the intensive care unit were randomly divided into a control group (n = 55) and an intervention group (n = 54). The control group received normal saline, and the intervention group received low-dose furosemide (0.048 mg/kg.h^-1) with aminophylline (0.3 mg/kg.h^-1). The primary outcomes included the levels of serum creatinine (Scr), creatinine clearance rate (Ccr), blood urea nitrogen (BUN), glomerular filtration rate (GFR), and urine output on admission and on days 3, 7 and 14. The secondary outcomes were the sequential organ failure assessment (SOFA) scores, continuous renal replacement therapy (CRRT) time and intensive care unit (ICU) mortality, hospital mortality and 28-day mortality. There were no significant differences in the levels of Scr, Ccr, BUN, or GFR between the two groups, while the urine output was higher in the intervention group on days 3, 7, and 14. Compared with the control group, the SOFA scores, ICU mortality, hospital mortality and 28-day mortality were significantly lower in the intervention group on days 3, 7, and 14, the CRRT time was shorter, and the cumulative fluid balance was lower on days 3 and 7 in the intervention group.

CONCLUSIONS

Although low-dose furosemide and aminophylline have fewer protective effects on the renal function in septic shock patients, they could reduce the CRRT time and improve the prognosis.

Disseminated intravascular coagulation is strongly associated with severe acute kidney injury in patients with septic shock

BACKGROUND

Disseminated intravascular coagulation (DIC) worsens the prognosis of septic shock and contributes to multiple organ failure. To date, no data linking DIC and acute kidney injury (AKI) occurrence, severity, and evolution in this setting are available. We aimed at analyzing the association between AKI occurrence, severity and evolution in patients with septic shock-induced DIC. In a prospective monocentric cohort study, consecutive patients, 18 years and older, admitted in the ICU of Strasbourg University Hospital in the setting of systemic hypotension requiring vasopressor related to an infection, without history of terminal chronic kidney disease were eligible. AKI was defined according to the KDIGO classification. DIC diagnosis was based on the International Society on Thrombosis and Haemostasis (ISTH) score. Evolution of AKI was evaluated through the composite endpoint of major adverse kidney events. Only patients with DIC that occurred before or at the time of AKI diagnosis were considered. Univariate and multivariate analysis were performed to determine factors associated with renal outcomes.

RESULTS

350 patients were included, of whom 129 experienced DIC. Patients with DIC were more seriously ill (median SAPS II 64 vs. 56, p < 0.001), and had higher 28-day mortality (43.3% vs. 26.2%, p < 0.001). AKI was more frequent in patients with DIC (86.8% vs. 74.2%, p < 0.005), particularly for the more severe stage of AKI [KDIGO 3 in 58.1% of patients with DIC vs. 30.8% of patients without DIC, p < 0.001, AKI requiring renal replacement therapy (RRT) in 47.3% of patients with DIC vs. 21.3% of patients without DIC, p < 0.001]. After adjustment for confounding factors, DIC occurrence remained associated with the risk of having the more severe stage of AKI with an odds ratio (OR) of 2.74 [IC 95% (1.53-4.91), p < 0.001], and with the risk of requiring RRT during the ICU stay [OR 2.82 (1.53-5.2), p < 0.001].

CONCLUSION

DIC appears to be strongly associated with the risk of developing the more severe form of AKI (stage 3 of the KDIGO classification, RRT requirement), even after adjustment for severity and other relevant factors.

CHIP protects against septic acute kidney injury by inhibiting NLRP3-mediated pyroptosis

Septic acute kidney injury (S-AKI), the most common type of acute kidney injury (AKI), is intimately related to pyroptosis and oxidative stress in its pathogenesis. Carboxy-terminus of Hsc70-interacting protein (CHIP), a U-box E3 ligase, modulates oxidative stress by degrading its targeted proteins. The role of CHIP in S-AKI and its relevance with pyroptosis have not been investigated. In this study, we showed that CHIP was downregulated in renal proximal tubular cells in lipopolysaccharide (LPS)-induced S-AKI. Besides, the extent of redox injuries in S-AKI was attenuated by CHIP overexpression or activation but accentuated by CHIP gene disruption. Mechanistically, our work demonstrated that CHIP interacted with and ubiquitinated NLRP3 to promote its proteasomal degradation, leading to the inhibition of NLRP3/ACS inflammasome-mediated pyroptosis. In summary, this study revealed that CHIP ubiquitinated NLRP3 to alleviate pyroptosis in septic renal injuries, suggesting that CHIP might be a potential therapeutic target for S-AKI.

Thiamine for Renal Protection in Septic Shock (TRPSS): A Randomized, Placebo-controlled, Clinical Trial

Rationale: Kidney injury is common and associated with worse outcomes in patients with septic shock. Mitochondrial resuscitation with thiamine (vitamin B1) may attenuate septic kidney injury. Objectives: To assess whether thiamine supplementation attenuates kidney injury in septic shock. Methods: The TRPSS (Thiamine for Renal Protection in Septic Shock) trial was a multicenter, randomized, placebo-controlled trial of thiamine versus placebo in septic shock. The primary outcome was change in serum creatinine between enrollment and 72 hours after enrollment. Measurements and Main Results: Eighty-eight patients were enrolled (42 patients received the intervention, and 46 received placebo). There was no significant between-groups difference in creatinine at 72 hours (mean difference, -0.57 mg/dl; 95% confidence interval, -1.18, 0.04; P = 0.07). There was no difference in receipt of kidney replacement therapy (14.3% vs. 21.7%, P = 0.34), acute kidney injury (as defined by stage 3 of the Kidney Disease: Improving Global Outcomes acute kidney injury scale; 54.7% vs. 73.9%, P = 0.07), or mortality (35.7% vs. 54.3%, P = 0.14) between the thiamine and placebo groups. Patients who received thiamine had more ICU-free days (median [interquartile range]: 22.5 [0.0-25.0] vs. 0.0 [0.0-23.0], P < 0.01). In the thiamine-deficient cohort (27.4% of patients), there was no difference in rates of kidney failure (57.1% thiamine vs. 81.5% placebo) or in-hospital mortality (28.6% vs. 68.8%) between groups. Conclusions: In the TRPSS trial, there was no statistically significant difference in the primary outcome of change in creatinine over time. Patients who received thiamine had more ICU-free days, but there was no difference in other secondary outcomes. Clinical trial registered with www.clinicaltrials.gov (NCT03550794).

OCE-205, A Novel, Selective Vasopressin Receptor Mixed Agonist-Antagonist: Safety, Tolerability, and Pharmacokinetics/Pharmacodynamics from a Phase 1 Study in Healthy Volunteers

BACKGROUND

OCE-205, a novel, selective vasopressin V1a receptor mixed agonist/antagonist with no V2 receptor activity, may treat the portal hypertension-related complications of end-stage liver disease with an improved therapeutic profile over currently utilized nonselective full-agonist vasopressin analogs.

OBJECTIVES

This Phase 1, double-blind, placebo-controlled, within-dose-group randomized trial investigated the safety, tolerability, and pharmacokinetic/pharmacodynamic profiles of OCE-205 in healthy adults.

METHODS

Subjects received a single intravenous dose of OCE-205 0.1, 0.3, 0.45, 0.6, or 0.9 mg, or placebo infused over 6 h. Safety and tolerability were assessed, and blood samples were obtained for pharmacokinetic analyses. Sixty-four subjects were randomized and treated.

RESULTS

Area under the concentration-time curve (AUC) and maximum plasma concentrations (Cmax) were approximately dose-proportional across doses from 0.1 to 0.9 mg. OCE-205 terminal half-life was ~ 1.5 h. Diastolic, and to a lesser extent systolic, blood pressure increased in all OCE-205 dose groups; pulse rate decreased. Overall changes in mean arterial pressure were similar to changes in diastolic blood pressure. Absolute changes in cardiac output, by echocardiogram, were somewhat dose-dependent, with mean reductions of 3-12% after the 0.9 mg dose, and individual reductions ≤ 20 to 25% across all doses. The most frequent adverse events were abdominal pain, abnormal gastrointestinal sounds, and diarrhea, with no reported cases of mesenteric ischemia. Adverse events were generally mild or moderate in severity.

CONCLUSION

OCE-205 was safe and well tolerated, with a pharmacodynamic profile achieving submaximal partial agonism consistent with mixed agonism-antagonism of the V1a receptor. OCE-205 shows promise as a treatment for some complications of end-stage liver disease.

Eupatilin Ameliorates Lipopolysaccharide-Induced Acute Kidney Injury by Inhibiting Inflammation, Oxidative Stress, and Apoptosis in Mice

Acute kidney injury (AKI) is a common complication of sepsis. Eupatilin (EUP) is a natural flavone with multiple biological activities and has beneficial effects against various inflammatory disorders. However, whether EUP has a favorable effect on septic AKI remains unknown. Here, we examined the effect of EUP on lipopolysaccharide (LPS)-evoked AKI in mice. LPS-evoked renal dysfunction was attenuated by EUP, as reflected by reductions in serum creatinine and blood urea nitrogen levels. LPS injection also induced structural damage such as tubular cell detachment, tubular dilatation, brush border loss of proximal tubules, and upregulation of tubular injury markers. However, EUP significantly ameliorated this structural damage. EUP decreased serum and renal cytokine levels, prevented macrophage infiltration, and inhibited mitogen-activated protein kinase and NF-κB signaling cascades. Lipid peroxidation and DNA oxidation were increased after LPS treatment. However, EUP mitigated LPS-evoked oxidative stress through downregulation of NPDPH oxidase 4 and upregulation of antioxidant enzymes. EUP also inhibited p53-mediated apoptosis in LPS-treated mice. Therefore, these results suggest that EUP ameliorates LPS-evoked AKI through inhibiting inflammation, oxidative stress, and apoptosis.

OCE-205 in rats and non-human primates: Pharmacokinetic and pharmacodynamic analysis

Treatment for complications associated with the hemodynamic consequences of decompensated cirrhosis remains suboptimal. Terlipressin, the latest pharmacological management of hepatorenal syndrome-acute kidney injury (HRS-AKI), targets the vasopressin system but has serious side effects. OCE-205 is a novel peptide designed to target the vasopressin receptor system as a mixed V1a agonist/antagonist, resulting in effective partial agonism without V2 agonism. We examined the in vivo pharmacokinetic/pharmacodynamic properties of OCE-205 in healthy rats and cynomolgus monkeys. OCE-205 was administered by IV or SC bolus injection; arginine vasopressin (AVP) or terlipressin were comparators. After IV OCE-205 administration in rats, mean plasma concentration decreased in a mostly linear manner to 2 mg/mL after 120 min, and for SC administration, slowly decreased to ∼50 ng/mL after 300 min. Compared with pre-test values, arterial blood pressure values significantly increased after all OCE-205 doses tested. For monkeys, the concentration after IV OCE-205 administration was mostly linear to 5 ng/mL after 180 min, and for SC administration, ∼3 ng/mL after 480 min. Subcutaneous OCE-205 administration increased mean arterial pressure (MAP) versus baseline, with ΔMAP in OCE-205-treated animals marked and long-lasting while terlipressin induced an increase from baseline in MAP, with negligible ΔMAP, on average, by 150 min after administration in all groups. AVP, but not OCE-205, significantly increased blood lactate concentrations. OCE-205 was well tolerated in adult male rats and cynomolgus monkeys following single-dose bolus administration. The preclinical results of OCE-205, with its demonstrated V1a selective partial agonist activity and potentially tolerable safety profile, suggest its potential utility for treatment of the cardiovascular complications of cirrhosis.

Institutional protocol number

Procedures were approved by the Ferring Research Institute (FRI) Institutional Animal Care and Use Committee (IACUC) on November 27, 2006 under protocol FRI 06-011, and by the Sinclair Research Center IACUC under protocol S11177.

OCE-205, a Selective V1a Partial Agonist, Reduces Portal Pressure in Rat Models of Portal Hypertension

Purpose

Management of decompensated cirrhosis may include the use of vasoconstrictors that can lead to serious adverse events. OCE-205 was designed as a highly selective V1a receptor partial agonist, intended to have a wider therapeutic window than full vasopressin agonists.

Methods

We aimed to characterize the activity of OCE-205 treatment in two rat models of portal hypertension (PHT). For both models, OCE-205 was administered as a subcutaneous bolus injection. Thirty male Wistar rats were fed a methionine/choline-deficient (MCD) diet to model PHT. Animals received OCE-205 (10, 25, 100, or 500 µg/kg) or intra-arterial terlipressin (100 µg/kg). In a more severe model of PHT, 11 male Sprague Dawley rats had the common bile duct surgically ligated (BDL) and received OCE-205. Portal pressure (PP) and mean arterial pressure (MAP) were measured.

Results

For PP in the MCD model, MAP increased while PP decreased in rats treated with OCE-205 or terlipressin; the peak changes to MAP were 14.7 and 33.5 mmHg, respectively. Changes in MAP began to plateau after 10 min in the OCE-205 groups, whereas in the terlipressin group, MAP rapidly increased and peaked after 20 min. Across all treatment groups in the BDL model, a dose-related decrease from baseline in PP was observed following OCE-205, plateauing as the dose increased. In all treatment groups, PP change remained negative throughout the 30-min testing period. In both PHT rat models, a reduction in PP was coupled to an increase in MAP, with both plateauing in dose-response curves.

Conclusion

Data support OCE-205 as a promising candidate for further development.

Institutional Protocol Number

Procedures were approved by the Ferring Research Institute (FRI) Institutional Animal Care and Use Committee on July 13, 2011, under protocol FRI-07-0002.

Contrast-Enhanced Ultrasonography for Acute Kidney Injury: A Systematic Review and Meta-Analysis

OBJECTIVE

The aim of the work described here was to provide an evidence-based evaluation of contrast-enhanced ultrasonography (CEUS) in acute kidney injury (AKI) and assess variations in renal microperfusion with CEUS quantitative parameters in patients at a high risk of developing AKI.

METHODS

A meta-analysis and systematic review were conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and the Embase, MEDLINE, Web of Science and the Cochrane Library databases were used to search the relevant articles systematically (2000-2022). Studies using CEUS to assess renal cortical microcirculation in AKI were included.

RESULTS

Six prospective studies (374 patients) were included. The overall quality of included studies was moderate to high. CEUS measures, maximum intensity (standard mean difference [SMD]: -1.37, 95% confidence interval [CI]: -1.64 to -1.09) and wash-in rate (SMD: -0.77, 95% CI: -1.09 to -0.45) were lower in the AKI+ group than in the AKI- group, and mean transit time (SMD: 0.76, 95% CI: 0.11-1.40) and time to peak (SMD: 1.63, 95% CI: 0.99-2.27) were higher in the AKI+ group. Moreover, maximum intensity and wash-in rate values changed before creatinine changed in the AKI+ group.

CONCLUSION

Patients with AKI had reduced microcirculatory perfusion, prolonged perfusion time and a reduced rising slope in the renal cortex, which occurred before serum creatinine changes. And they could be measured using CEUS, indicating that CEUS could help in the diagnosis of AKI.

Acute Kidney Injury as a Leading Cause of Papal Deaths in the Years 1277 to 2005: A Review of 21 Cases

OBJECTIVES

This study was devised to investigate papal deaths due to acute kidney injury, a topic for which scarce data exist.

MATERIALS AND METHODS

We studied all popes between John XXI, who died in 1277 of crush syndrome, and John Paul II, who died of anuria and urinary sepsis in 2005.

RESULTS

Between pontification years from 1277 to 2005, 21 of 78 popes (26.9%) died of acute kidney injury. Sepsis was identified as the leading cause of acute kidney injury and death in 20 of 21 popes (95.2%). Mean ± SE age at death of the 21 popes was 69.4 ± 2.26 years. Six popes (28.6%) died of stroke.

CONCLUSIONS

Sepsis-associated acute kidney injury, a syndrome with a complex pathogenesis and poor prognosis, which is far from being fully understood, contributed to a high number of papal deaths.

Renal mitochondrial dysfunction in ovine experimental sepsis-associated acute kidney injury

Sheep develop sepsis-associated acute kidney injury (SA-AKI) during experimental sepsis despite normal to increased renal oxygen delivery. A disturbed relation between oxygen consumption (V̇o2) and renal Na+ transport has been demonstrated in sheep and in clinical studies of AKI, which could be explained by mitochondrial dysfunction. We investigated the function of isolated renal mitochondria compared with renal oxygen handling in an ovine hyperdynamic model of SA-AKI. Anesthetized sheep were randomized to either an infusion of live Escherichia coli with resuscitative measures (sepsis group; n = 13 animals) or served as controls (n = 8 animals) for 28 h. Renal V̇o2 and Na+ transport were repeatedly measured. Live cortical mitochondria were isolated at baseline and at the end of the experiment and assessed in vitro with high-resolution respirometry. Sepsis markedly reduced creatinine clearance, and the relation between Na+ transport and renal V̇o2 was decreased in septic sheep compared with control sheep. Cortical mitochondrial function was altered in septic sheep with a reduced respiratory control ratio (6.0 ± 1.5 vs. 8.2 ± 1.6, P = 0.006) and increased complex II-to-complex I ratio during state 3 (1.6 ± 0.2 vs. 1.3 ± 0.1, P = 0.0014) mainly due to decreased complex I-dependent state 3 respiration (P = 0.016). However, no differences in renal mitochondrial efficiency or mitochondrial uncoupling were found. In conclusion, renal mitochondrial dysfunction composed of a reduction of the respiratory control ratio and an increased complex II/complex I relation in state 3 was demonstrated in an ovine model of SA-AKI. However, the disturbed relation between renal V̇o2 and renal Na+ transport could not be explained by a change in renal cortical mitochondrial efficiency or uncoupling.NEW & NOTEWORTHY We studied the function of renal cortical mitochondria in relation to oxygen consumption in an ovine model of sepsis with acute kidney injury. We demonstrated changes in the electron transport chain induced by sepsis consisting of a reduced respiratory control ratio mainly by a reduced complex I-mediated respiration. Neither an increase in mitochondrial uncoupling nor a reduction in mitochondrial efficiency was demonstrated and cannot explain why oxygen consumption was unaffected despite reduced tubular transport.

Clinico-Etiological Spectrum and Outcome in Patients With Septic Acute Kidney Injury and Its Comparison With Non-septic Acute Kidney Injury: A Hospital-Based Prospective Study Conducted in a Tertiary Care Hospital in North India

Background Acute kidney injury (AKI) is a heterogenous syndrome defined by the impairment of kidney filtration and excretory function over days to weeks, resulting in the retention of nitrogenous and other waste products normally cleared by the kidneys. In addition, AKI is frequently recognized to be associated with sepsis and contributes to an unfavorable outcome in sepsis. This study was undertaken to study and compare the etiology and clinical profile of patients with septic and non-septic AKI and to study and compare the outcome in both groups. Materials and methods This is a prospective, observational, and comparative study with a total sample size of 200 patients selected randomly having sustained an acute kidney injury. Data was collected, recorded, analyzed, and compared for two groups of patients with septic and non-septic AKI. Results A total of 200 cases of AKI were enrolled, out of which 120 (60%) were due to non-septic etiology and 80 (40%) were of septic etiology. Urosepsis (37.5%) due to various urinary tract infections including pyelonephritis and chest sepsis (18.75%) including community-acquired pneumonia (CAP) and aspiration pneumonia were the predominant causes of sepsis. AKI secondary to nephrotoxic agents (27.5%) was the commonest cause in the non-septic group, followed by glomerulonephritis (13.3%), vitamin D intoxication-related hypercalcemia (12.5%), acute gastroenteritis (10.8%), etc. Patients of septic AKI had a significantly higher mean of maximum urea and creatinine than their non-septic AKI counterparts. In addition to having an increased duration of hospital stay, mortality was significantly higher in patients with septic AKI (27.5%) than in patients with non-septic AKI (4.1%). However, sepsis had no effect on renal functions, measured by urea and creatinine, at discharge. In patients with AKI, certain factors were found to increase the risk of mortality. These factors include being over 65 years old, needing mechanical ventilation or vasopressors, requiring renal replacement therapy (RRT), and having multiorgan dysfunction syndrome (MODS), septic shock, or acute coronary syndrome (ACS). However, pre-existing conditions such as diabetes, hypertension, malignancy, previous stroke, chronic kidney disease (CKD), and chronic liver disease (CLD) did not affect the overall mortality risk. Conclusion In the septic AKI group, urosepsis was the most frequent etiology of AKI, while the most frequent etiology of AKI in the non-septic group was nephrotoxin exposure. Patients with septic AKI had considerably longer hospital stays and greater in-hospital mortality rates than patients with non-septic AKI. The renal functions as determined by urea and creatinine at discharge were unaffected by sepsis. Finally, death was significantly impacted by age of >65 years, the necessity for mechanical ventilation, the use of vasopressors and RRT, and the presence of MODS, septic shock, and ACS.

Machine learning algorithm to predict mortality in critically ill patients with sepsis-associated acute kidney injury

This study aimed to establish and validate a machine learning (ML) model for predicting in-hospital mortality in patients with sepsis-associated acute kidney injury (SA-AKI). This study collected data on SA-AKI patients from 2008 to 2019 using the Medical Information Mart for Intensive Care IV. After employing Lasso regression for feature selection, six ML approaches were used to build the model. The optimal model was chosen based on precision and area under curve (AUC). In addition, the best model was interpreted using SHapley Additive exPlanations (SHAP) values and Local Interpretable Model-Agnostic Explanations (LIME) algorithms. There were 8129 sepsis patients eligible for participation; the median age was 68.7 (interquartile range: 57.2-79.6) years, and 57.9% (4708/8129) were male. After selection, 24 of the 44 clinical characteristics gathered after intensive care unit admission remained linked with prognosis and were utilized developing ML models. Among the six models developed, the eXtreme Gradient Boosting (XGBoost) model had the highest AUC, at 0.794. According to the SHAP values, the sequential organ failure assessment score, respiration, simplified acute physiology score II, and age were the four most influential variables in the XGBoost model. Individualized forecasts were clarified using the LIME algorithm. We built and verified ML models that excel in early mortality risk prediction in SA-AKI and the XGBoost model performed best.

Correlation between perioperative dexmedetomidine administration and postoperative acute kidney injury in hypertensive patients undergoing non-cardiac surgery

Background: Previous studies have suggested that dexmedetomidine may have a protective effect on renal function. However, it is currently unclear whether perioperative dexmedetomidine administration is associated with postoperative acute kidney injury (AKI) incidence risk in hypertensive patients undergoing non-cardiac surgery.

Methods: This investigation was a retrospective cohort study. Hypertensive patients undergoing non-cardiac surgery in Third Xiangya Hospital of Central South University from June 2018 to December 2019 were included. The relevant data were extracted through electronic cases. The univariable analysis identified demographic, preoperative laboratory, and intraoperative factors associated with acute kidney injury. Multivariable stepwise logistic regression was used to assess the association between perioperative dexmedetomidine administration and postoperative acute kidney injury after adjusting for interference factors. In addition, we further performed sensitivity analyses in four subgroups to further validate the robustness of the results.

Results: A total of 5769 patients were included in this study, with a 7.66% incidence of postoperative acute kidney injury. The incidence of postoperative acute kidney injury was lower in the dexmedetomidine-administered group than in the control group (4.12% vs. 8.06%, p &lt; 0.001). In the multivariable stepwise logistic regression analysis, perioperative dexmedetomidine administration significantly reduced the risk of postoperative acute kidney injury after adjusting for interference factors [odds ratio (OR) = 0.56, 95% confidence interval (CI): 0.36–0.87, p = 0.010]. In addition, sensitivity analysis in four subgroups indicated parallel findings: i) eGRF &lt;90 mL/min·1.73/m2 subgroup (OR = 0.40, 95% CI: 0.19–0.84, p = 0.016), ii) intraoperative blood loss &lt;1000 mL subgroup (OR = 0.58, 95% CI: 0.36–0.94, p = 0.025), iii) non-diabetes subgroup (OR = 0.51, 95% CI: 0.29–0.89, p = 0.018), and iv) older subgroup (OR = 0.55, 95% CI: 0.32–0.93, p = 0.027).

Conclusion: In conclusion, our study suggests that perioperative dexmedetomidine administration is associated with lower risk and less severity of postoperative acute kidney injury in hypertensive individuals undergoing non-cardiac surgery. Therefore, future large-scale RCT studies are necessary to validate this benefit.

Identification of Biomarkers for the Diagnosis of Sepsis-Associated Acute Kidney Injury and Prediction of Renal Recovery in the Intensive Care Unit

PURPOSE

Acute kidney injury (AKI) following sepsis is associated with higher mortality; however, reliable biomarkers for AKI development and recovery remain to be elucidated.

MATERIALS AND METHODS

Patients with sepsis admitted to the medical intensive care unit (ICU) of Severance Hospital between June 2018 and May 2019 were prospectively analyzed. Patients were divided into those with and without AKI within 48 hours. Patients with septic AKI were subdivided into AKI-recovery and non-recovery groups based on whether their kidney injury recovered within 7 days.

RESULTS

A total of 84 patients were enrolled. The baseline creatinine (2.9 mg/dL vs. 0.8 mg/dL vs. 1.2 mg/dL, p<0.001), Charlson Comorbidity Index (4.5 vs. 2.0 vs. 3.0, p=0.002), Sequential Organ Failure Assessment (10.0 vs. 6.5 vs. 8.0, p<0.001), and Acute Physiology and Chronic Health Evaluation II scores (32.0 vs. 21.5 vs. 30.5, p=0.004) were higher in the non-recovery AKI group compared to the non-AKI and AKI-recovery groups. The Kaplan-Meier curves revealed that non-recovery from AKI was associated with lower survival (p<0.001). High-lactate (p≤0.05) and kynurenine levels (p≤0.05) were associated with non-recovery of renal function following AKI. The areas under the curve for predicting non-recovery from AKI were 0.693 and 0.721 for lactate and kynurenine, respectively. The survival rate was lower in the high-kynurenine (p=0.040) and high-lactate (p=0.010) groups.

CONCLUSION

The mortality of patients who recovered from AKI was comparable to that of patients without AKI. Lactate and kynurenine could be useful biomarkers for the diagnosis and recovery of AKI following sepsis.

Early effects of bone marrow-derived mononuclear cells on lung and kidney in experimental sepsis

BACKGROUND

In experimental sepsis, functional and morphological effects of bone marrow-derived mononuclear cell (BMDMC) administration in lung tissue have been evaluated 1 and 7 days after therapy. However, to date no study has evaluated the early effects of BMDMCs in both lung and kidney in experimental polymicrobial sepsis.

MATERIAL AND METHODS

Twenty-five female C57BL/6 mice were randomly divided into the following groups: 1) cecal ligation and puncture (CLP)-induced sepsis; and 2) Sham (surgical procedure without CLP). After 1 h, CLP animals received saline (NaCl 0.9%) (CLP-Saline) or 10⁶ BMDMCs (CLP-Cell) via the jugular vein. At 6, 12, and 24 h after saline or BMDMC administration, lungs and kidneys were removed for histology and molecular biology analysis.

RESULTS

In lungs, CLP-Saline, compared to Sham, was associated with increased lung injury score (LIS) and keratinocyte chemoattractant (KC) mRNA expression at 6, 12, and 24 h. BMDMCs were associated with reduced LIS and KC mRNA expression regardless of the time point of analysis. Interleukin (IL)- 10 mRNA content was higher in CLP-Cell than CLP-Saline at 6 and 24 h. In kidney tissue, CLP-Saline, compared to Sham, was associated with tubular cell injury and increased neutrophil gelatinase-associated lipocalin (NGAL) levels, which were reduced after BMDMC therapy at all time points. Surface high-mobility-group-box (HMGB)- 1 levels were higher in CLP-Saline than Sham at 6, 12, and 24 h, whereas nuclear HMGB-1 levels were increased only at 24 h. BMDMCs were associated with decreased surface HMGB-1 and increased nuclear HMGB-1 levels. Kidney injury molecule (KIM)- 1 and IL-18 gene expressions were reduced in CLP-Cell compared to CLP-Saline at 12 and 24 h.

CONCLUSION

In the present experimental polymicrobial sepsis, early intravenous therapy with BMDMCs was able to reduce lung and kidney damage in a time-dependent manner. BMDMCs thus represent a potential therapy in well-known scenarios of sepsis induction.

PURPOSE

To evaluate early bone marrow-derived mononuclear cell (BMDMC) therapy on lung and kidney in experimental polymicrobial sepsis.

METHODS

Twenty-five female C57BL/6 mice were randomly divided into the following groups: cecal ligation and puncture (CLP)-induced sepsis; and sham (surgical procedure without CLP). After 1 h, CLP animals received saline (CLP-saline) or 10⁶ BMDMCs (CLP-cell) via the jugular vein. Lungs and kidneys were evaluated for histology and molecular biology after 6, 12, and 24 h.

RESULTS

In lungs, BMDMCs reduced the lung injury score and keratinocyte chemoattractant mRNA expression regardless of the time point of analysis; interleukin-10 mRNA content was higher in CLP-cell than CLP-saline at 6 and 24 h. In kidneys, BMDMCs reduced neutrophil gelatinase-associated lipocalin levels at all time points. BMDMCs decreased surface high mobility group box (HMGB)- 1 but increased nuclear HMGB-1 levels.

CONCLUSION

Early BMDMC therapy reduced lung and kidney damage in a time-dependent manner.

Endocrine sequelae of hematopoietic stem cell transplantation: Effects on mineral homeostasis and bone metabolism

Hematopoietic stem cell transplantation (HSCT) is an established therapeutic strategy for the treatment of malignant (leukemia and lymphoma) and non-malignant (thalassemia, anemia, and immunodeficiency) hematopoietic diseases. Thanks to the improvement in patient care and the development of more tolerable conditioning treatments, which has extended the applicability of therapy to the elderly, a growing number of patients have successfully benefited from HSCT therapy and, more importantly, HSCT transplant-related mortality has consistently reduced in recent years. However, concomitantly to long term patient survival, a growing incidence of late HSCT-related sequelae has been reported, being variably associated with negative effects on quality of life of patients and having a non-negligible impact on healthcare systems. The most predominantly observed HSCT-caused complications are chronic alterations of the endocrine system and metabolism, which endanger post-operative quality of life and increase morbidity and mortality of transplanted patients. Here, we specifically review the current knowledge on HSCT-derived side-effects on the perturbation of mineral metabolism; in particular, the homeostasis of calcium, focusing on current reports regarding osteoporosis and recurrent renal dysfunctions that have been observed in a percentage of HSC-transplanted patients. Possible secondary implications of conditioning treatments for HSCT on the physiology of the parathyroid glands and calcium homeostasis, alone or in association with HSCT-caused renal and bone defects, are critically discussed as well.

Acute Kidney Injury: Medical Causes and Pathogenesis

Acute kidney injury (AKI) is a common clinical syndrome characterized by a sudden decline in or loss of kidney function. AKI is not only associated with substantial morbidity and mortality but also with increased risk of chronic kidney disease (CKD). AKI is classically defined and staged based on serum creatinine concentration and urine output rates. The etiology of AKI is conceptually classified into three general categories: prerenal, intrarenal, and postrenal. Although this classification may be useful for establishing a differential diagnosis, AKI has mostly multifactorial, and pathophysiologic features that can be divided into different categories. Acute tubular necrosis, caused by either ischemia or nephrotoxicity, is common in the setting of AKI. The timely and accurate identification of AKI and a better understanding of the pathophysiological mechanisms that cause kidney dysfunction are essential. In this review, we consider various medical causes of AKI and summarize the most recent updates in the pathogenesis of AKI.

Incidence, risk factors and clinical outcomes of septic acute renal injury in cancer patients with sepsis admitted to the ICU: A retrospective study

Background

The purpose of this study was to clarify the incidence, risk factors, and clinical outcomes of septic acute kidney injury (AKI) in cancer patients with sepsis admitted to the intensive care unit (ICU).

Methods

A total of 356 cancer patients admitted to the ICU due to sepsis from January 2016 to October 2021 were analyzed retrospectively. According to the incidence of septic AKI, all patients were divided into the non-AKI group (n = 279) and the AKI group (n = 77). The clinical data after ICU admission were compared between the above two groups, and the risk factors and the clinical outcomes of septic AKI in the ICU were identified.

Results

The incidence of septic AKI in all patients was 21.6% (77/356). LASSO regression and logistic regression all showed that lactate, sequential organ failure assessment (SOFA) score and septic shock were closely related to the occurrence of septic AKI. In terms of clinical outcomes after ICU admission, the rate of mechanical ventilation (MV) and continuous renal replacement therapy (CRRT), MV time, hospitalization time and 28-day mortality in the ICU were significantly higher in the septic AKI group than in the non-septic AKI group. Among the three subgroups of septic AKI (AKI combined with septic shock, septic cardiac dysfunction or acute respiratory failure), the mortality of patients in the subgroup of AKI combined with septic shock was significantly higher than others. CRRT has no significant effect on the short-term outcome of these patients.

Conclusion

Lactate level, SOFA score and septic shock were closely related to the occurrence of septic AKI in the ICU. The clinical outcomes within 28 days after ICU admission of cancer patients with septic AKI were worse than those without septic AKI. The short-term outcome was worse in patients with septic AKI complicated with septic shock. CRRT does not have any significant effect on the short-term prognosis of cancer patients with septic AKI in the ICU.

Effects of changes in inspired oxygen fraction on urinary oxygen tension measurements

BACKGROUND

Continuous measurement of urinary PO₂ (PuO₂) is being applied to indirectly monitor renal medullary PO₂. However, when applied to critically ill patients with shock, its measurement may be affected by changes in FiO₂ and PaO₂ and potential associated O₂ diffusion between urine and ureteric or bladder tissue. We aimed to investigate PuO₂ measurements in septic shock patients with a fiberoptic luminescence optode inserted into the urinary catheter lumen in relation to episodes of FiO₂ change. We also evaluated medullary and urinary oxygen tension values in Merino ewes at two different FiO₂ levels.

RESULTS

In 10 human patients, there were 32 FiO₂ decreases and 31 increases in FiO₂. Median pre-decrease FiO₂ was 0.36 [0.30, 0.39] and median post-decrease FiO₂ was 0.30 [0.23, 0.30], p = 0.006. PaO₂ levels decreased from 83 mmHg [77, 94] to 72 [62, 80] mmHg, p = 0.009. However, PuO₂ was 23.2 mmHg [20.5, 29.0] before and 24.2 mmHg [20.6, 26.3] after the intervention (p = 0.56). The median pre-increase FiO₂ was 0.30 [0.21, 0.30] and median post-increase FiO₂ was 0.35 [0.30, 0.40], p = 0.008. PaO₂ levels increased from 64 mmHg [58, 72 mmHg] to 71 mmHg [70, 100], p = 0.04. However, PuO₂ was 25.0 mmHg [IQR: 20.7, 26.8] before and 24.3 mmHg [IQR: 20.7, 26.3] after the intervention (p = 0.65). A mixed linear regression model showed a weak correlation between the variation in PaO₂ and the variation in PuO₂ values. In 9 Merino ewes, when comparing oxygen tension levels between FiO₂ of 0.21 and 0.40, medullary values did not differ (25.1 ± 13.4 mmHg vs. 27.9 ± 15.4 mmHg, respectively, p = 0.6766) and this was similar to urinary oxygen values (27.1 ± 6.17 mmHg vs. 29.7 ± 4.41 mmHg, respectively, p = 0.3192).

CONCLUSIONS

Changes in FiO₂ and PaO₂ within the context of usual care did not affect PuO₂. Our findings were supported by experimental data and suggest that PuO₂ can be used as biomarker of medullary oxygenation irrespective of FiO₂.

Factors associated with occurrence and severity of acute kidney injury in patients with Sepsis - A retrospective database study

PURPOSE

Sepsis remains the most common cause of acute kidney injury (AKI) and is associated with a high mortality. This study aims to identify laboratory, clinical and demographic factors that are associated with the different stages of AKI in sepsis.

METHODS

We studied patients >18 years who met Sepsis-3 criteria between July 10, 2009 and September 7, 2019 using ordinal logistic regression to determine the factors associated with different stages of AKI. Sensitivity analyses for development of any stage vs no AKI and, separately, the factors associated with receipt of kidney replacement therapy were also done.

RESULTS

Of 31,228 patients meeting Sepsis-3 criteria, 4684 (15%) developed AKI. Of the AKI patients, 53% were KDIGO stage 1, 9% stage 2, and 37% stage 3, with 27% of AKI patients receiving kidney replacement therapy (Stage 3b). Several comorbidities, mechanical ventilation, and pre-sepsis creatinine levels were associated with AKI occurrence and severity. Positive blood culture was associated with a higher risk (OR 1.10 [1.06, 1.15], p < 0.001), while positive respiratory, urine, and wound cultures were associated with lower risks of developing AKI and with lower severity.

CONCLUSION

Presepsis creatinine levels, mechanical ventilation, comorbidities, and positive blood cultures were associated with AKI.

Prospective cohort study to identify prevalence, risk factors and outcomes of infection associated kidney disease in a regional hospital in Malawi

OBJECTIVES

Acute kidney injury (AKI) is a common and severe complication of community acquired infection, but data on impact in sub-Saharan Africa (SSA) are lacking. We determined prevalence, risk factors and outcomes of infection associated kidney disease in adults in Malawi.

DESIGN

A prospective cohort study of adults admitted to hospital with infection, from February 2021 to June 2021, collecting demographic, clinical, laboratory and ultrasonography data.

SETTING

Adults admitted to a regional hospital in Southern Region, Malawi.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcomes were prevalence of kidney disease and mortality by Cox proportional hazard model. AKI was defined according to Kidney Disease Improving Global Outcomes (KDIGO) guidelines. Secondary outcomes were risk factors for AKI identified by logistic regression and prevalence of chronic kidney disease at 3 months.

RESULTS

We recruited 101 patients presenting to hospital with infection. Median age was 38 years (IQR: 29-48 years), 88 had known HIV status of which 53 (60%) were living with HIV, and of these 42 (79%) were receiving antiretroviral therapy. AKI was present in 33/101 at baseline, of which 18/33 (55%) cases were severe (KDIGO stage 3). At 3 months, 28/94 (30%) participants had died, while 7/61 (11%) of survivors had chronic kidney disease. AKI was associated with older age (age: 60 years vs 40 years, OR: 3.88, 95% CI 1.82 to 16.64), and HIV positivity (OR: 4.08, 95% CI 1.28 to 15.67). Living with HIV was independently associated with death (HR: 3.97, 95% CI 1.07 to 14.69).

CONCLUSIONS

Kidney disease is common among hospitalised adults with infection in Malawi, with significant kidney impairment identified at 3 months. Our study highlights the difficulty in diagnosing acute and chronic kidney disease, and the need for more accurate methods than creatinine based estimated glomerular filtration rate (eGFR) equations for populations in Africa. Patients with kidney impairment identified in hospital should be prioritised for follow-up.

Prognostic value of serum levels of multiple adhesion factors in patients with sepsis-induced acute kidney injury

Background

Acute kidney injury (AKI) is common in patients with sepsis and septic shock. Urine output and serum creatinine (SCr) levels are the criteria for diagnosing AKI. However, the application of these levels in the diagnosis of AKI has limitations.

Objective

To detect the expression of various adhesion factors in different stages of AKI as defined by Kidney Disease: Improving Global Outcomes (KDIGO) and to analyse their relationship with the prognosis of patients with sepsis-induced AKI (S-AKI).

Methods

Adult patients with sepsis who were admitted to the hospital between June 2019 and May 2020 were included. Of 90 adult patients with sepsis, 58 had S-AKI. Sixty-seven subjects without sepsis were used as controls. Enzyme-linked immunosorbent assay kits were used to measure E-selectin (CD62E), L-selectin (CD62L), P-selectin, intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1), and their relationship with the prognosis of patients with S-AKI patients was analysed. Receiver operating characteristic curves were used to analyse the predictive value of different adhesion factors on renal resistance index and renal function recovery. Multivariate logistic regression analysis was used to identify factors associated with renal recovery.

Results

The expression of CD62L was significantly higher in S-AKI patients than in non-AKI patients with sepsis. Compared with the non-AKI group, Acute Physiology and Chronic Health Evaluation II and Sequential Organ Failure Assessment scores were significantly higher in the AKI group than in the non-AKI group (P < 0.05). Mean blood pressure, SCr levels and procalcitonin levels were higher in the AKI group than in the non-AKI group (P < 0.05 for all). The CD62L levels decreased with increasing S-AKI stage. The CD62E levels were highest in S-AKI stage 2, and the VCAM-1 levels were highest in S-AKI stage 3. All patients with S-AKI were followed up with for 28 days. The results found that VCAM-1 was the best predictor of renal recovery in patients with S-AKI.

Conclusion

CD62L is an indicator of S-AKI stage1, and CD62E is an indicator of S-AKI stage 2. In addition, VCAM-I demonstrated satisfactory performance in predicting early recovery of renal function in patients with S-AKI.

SENP3 Aggravates Renal Tubular Epithelial Cell Apoptosis in Lipopolysaccharide-Induced Acute Kidney Injury via deSUMOylation of Drp1

BACKGROUND

Sepsis causes acute kidney injury (AKI) in critically ill patients, although the mechanisms underlying the pathophysiology are not fully understood. SUMO-specific proteases 3 (SENP3), a member of the deSUMOylating enzyme family, is known as a redox sensor and could regulate multiple cellular signaling pathways. However, the role of SENP3 in septic AKI remains unclear.

OBJECTIVES

The purpose of this study was to investigate the role of SENP3 in lipopolysaccharide (LPS)-induced AKI model.

METHODS

C57BL/6 mice were given intraperitoneal injection of LPS (10 mg/kg). NRK-52E cells were treated with LPS in vitro. The SENP3 protein expression was analyzed by Western blotting. The levels of reactive oxygen species (ROS) in cells were measured using DCFH-DA. SENP3-siRNA or SENP3-plasmid was, respectively, transfected into NRK-52E cells to knock down or overexpress the SENP3 expression. Western blotting was performed to analyze the protein expression of cleaved caspase 3, cytochrome c, and dynamin-related protein 1 (Drp1). The mitochondrial membrane potential was measured using JC-1 assay kit. Co-immunoprecipitation was used to determine the interaction of Drp1 and SMUO2/3.

RESULTS

SENP3 protein expression was obviously increased in renal tissues from the mouse model of LPS-induced AKI. Accordingly, SENP3 expression was upregulated in NRK-52E cells treated with LPS in a ROS-dependent manner in vitro. Knockdown of SENP3 dramatically ameliorated LPS-induced apoptosis of NRK-52E cells, whereas overexpression of SENP3 further aggravated LPS-induced apoptosis of NRK-52E cells. Mechanistically, SENP3 triggered Drp1 recruitment to mitochondria by increasing the deSUMOylation of Drp1.

CONCLUSION

SENP3 aggravated renal tubular epithelial cell apoptosis in LPS-induced AKI via Drp1 deSUMOylation manner.

Prevention of LPS-Induced Acute Kidney Injury in Mice by Bavachin and Its Potential Mechanisms

Acute kidney injury (AKI) is a serious complication of sepsis with a rapid onset and high mortality rate. Bavachin, an active component of Psoralea corylifolia L., reportedly has antioxidant, anti-apoptotic, and anti-inflammatory effects; however, its beneficial effects on AKI remain undetermined. We investigated the protective effect of bavachin on lipopolysaccharide (LPS)-induced AKI in mice and elucidated the underlying mechanism in human renal tubular epithelial HK-2 cells. Increased serum creatinine and blood urea nitrogen levels were observed in LPS-injected mice; however, bavachin pretreatment significantly inhibited this increase. Bavachin improved the kidney injury score and decreased the expression level of tubular injury markers, such as neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1), in both LPS-injected mice and LPS-treated HK-2 cells. LPS-induced oxidative stress via phosphorylated protein kinase C (PKC) β and upregulation of the NADPH oxidase (NOX) 4 pathway was also significantly decreased by treatment with bavachin. Moreover, bavachin treatment inhibited the phosphorylation of MAPKs (P38, ERK, and JNK) and nuclear factor (NF)-κB, as well as the increase in inflammatory cytokine levels in LPS-injected mice. Krüppel-like factor 5 (KLF5) expression was upregulated in the LPS-treated HK-2 cells and kidneys of LPS-injected mice. However, RNAi-mediated silencing of KLF5 inhibited the phosphorylation of NF-kB, consequently reversing LPS-induced KIM-1 and NGAL expression in HK-2 cells. Therefore, bavachin may ameliorate LPS-induced AKI by inhibiting oxidative stress and inflammation via the downregulation of the PKCβ/MAPK/KLF5 axis.

Predicting the risk of acute kidney injury after hematopoietic stem cell transplantation: development of a new predictive nomogram

The purpose was to predict the risk of acute kidney injury (AKI) within 100 days after hematopoietic stem cell transplantation (HSCT) in patients with hematologic disease by using a new predictive nomogram. Collect clinical data of patients with hematologic disease undergoing HSCT in our hospital from August 2012 to March 2018. Parameters with non-zero coefficients were selected by the Least Absolute Selection Operator (LASSO). Then these parameters were selected to build a new predictive nomogram model. Receiver operating characteristic (ROC) curve, calibration curve, C-index, and decision curve analysis (DCA) were used for the validation of the evaluation model. Finally, the nomogram was further evaluated by internal verification. According to 2012 Kidney Disease Improving Global Guidelines (KDIGO) diagnostic criteria, among 144 patients, the occurrence of AKI within 100 days after HSCT The rate was 29.2% (42/144). The C-index of the nomogram was 0.842. The C-value calculated by the internal verification was 0.809. The AUC was 0.842, and The DCA range of the predicted nomogram was from 0.01 to 0.71. This article established a high-precision nomogram for the first time for predicting the risk of AKI within 100 days after HSCT in patients with hematologic diseases. The nomogram had good clinical validity and reliability. For clinicians, it was very important to prevent AKI after HSCT.

Developing an ensemble machine learning model for early prediction of sepsis-associated acute kidney injury

Sepsis-associated acute kidney injury (S-AKI) is very common and early prediction is beneficial. This study aiming to develop an accurate ensemble model to predict the risk of S-AKI based on easily available clinical information. Patients with sepsis from the United States (US) database Medical Information Mart for Intensive Care-IV were used as a modeling cohort to predict the occurrence of AKI by combining Support Vector Machine, Random Forest, Neural Network, and Extreme Gradient Boost as four first-level learners via stacking algorithm. The external validation databases were the eICU Collaborative Research Database from US and Critical Care Database comprising infection patients at Zigong Fourth People’s Hospital from China, whose AUROC values for the ensemble model 48–12 h before the onset of AKI were 0.774–0.788 and 0.756–0.813, respectively. In this study, an ensemble model for early prediction of S-AKI onset was developed and it demonstrated good performance in multicenter external datasets.

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We developed an ensemble model to predict sepsis-associated AKI early.

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The model was constructed by stacking algorithm with high discriminative power.

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External tests from US and China showed evidence of generalizability.

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We constructed easy-to-access website calculator for clinicians.

Analysis of exosome-derived microRNAs as early biomarkers of lipopolysaccharide-induced acute kidney injury in rats

Sepsis contributes to the high prevalence of acute kidney injury (AKI), which mainly occurs in hospitalized patients. The delay in AKI detection is a risk factor for death and chronicity; thus, early diagnosis is essential for initiating proper treatment strategies. Although serum creatinine is used as biomarker, it is increased in plasma serum creatinine only at late stages of AKI. MicroRNAs (miRNAs), a class of noncoding RNAs responsible for gene regulation, can be found in biological fluids within vesicles such as exosomes and may be promising tools for the early detection of AKI. We aimed to identify potential blood miRNAs that can be used as early biomarkers of sepsis-induced AKI in rats. Adult male Wistar rats received a single dose of lipopolysaccharide (LPS). The earliest significant increase in serum creatinine was detected 4 h after LPS administration. To evaluate whether miRNAs could act as early biomarkers, blood samples were collected before and 2 h after LPS infusion. Serum NGAL levels were used as a comparative marker. Serum miRNAs were derived from exosomes, and their expression were evaluated by the PCR array. miR-181a-5p and miR-23b-3p showed higher expression in LPS-treated rats than in the control animals (p < 0.05). Bioinformatics analysis showed that both miRNAs target molecules associated with transcription factors that regulate genes related to proinflammatory cytokines. Considering that LPS activates transcription factors that lead to the production of proinflammatory cytokines, possible premature changes in the serum levels of miR-181a-5p and miR-23b-3p may be used to identify sepsis-induced AKI earlier.

Restrictive intraoperative fluid intake in liver surgery and postoperative renal function: A propensity score matched study

BACKGROUND

Postoperative acute kidney injury (AKI) is a common complication in hepatic surgery. In hepatic surgery, relative hypovolemia may help to limit blood loss, but the consequences of restrictive fluid intake are unknown. The goal of this study was to determine the influence of intraoperative fluid intake on the incidence of AKI and its consequences.

METHODS

Data from 397 consecutive patients who underwent liver resection were prospectively recorded and retrospectively analyszed. We compared the incidence of postoperative acute kidney failure in patients given restrictive (≤ 5 mL/kg/h) versus liberal (> 5 mL/kg/h) fluid therapy. We calculated a 1:1 match propensity score using logistic regression to estimate the likelihood of patients receiving restrictive or liberal intraoperative fluid intakes. The association between the intraoperative fluid intake strategy and occurrence of postoperative AKI were tested using a Cox frailty model on the database of matched patients.

RESULTS

Postoperative AKI was diagnosed in 133 of the 397 patients. Fluid intake strategy was restrictive for 121 patients and liberal for 276 patients. After propensity score matching to balance confounding factors, the liberal strategy was associated with a significantly lower risk for postoperative AKI compared to the restrictive strategy (Hazard Ratio 0.40 [0.29; 0.56], P<0.001). Patients with postoperative AKI had longer hospital stays and higher mortality. There were no cases of further blood loss in the liberal fluid intake group.

CONCLUSIONS

A restrictive fluid intake strategy is a risk factor for developing postoperative AKI, with serious consequences, without reducing blood loss in liver surgery.

Kynurenine Pathway-An Underestimated Factor Modulating Innate Immunity in Sepsis-Induced Acute Kidney Injury?

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection, and it accounts for about half of the cases of acute kidney injury (AKI). Although sepsis is the most frequent cause of AKI in critically ill patients, its pathophysiological mechanisms are not well understood. Sepsis has the ability to modulate the function of cells belonging to the innate immune system. Increased activity of indoleamine 2,3-dioxygenase 1 (IDO1) and production of kynurenines are the major metabolic pathways utilized by innate immunity cells to maintain immunological tolerance. The activation of the kynurenine pathway (KP) plays a dual role in sepsis—in the early stage, the induction of IDO1 elicits strong proinflammatory effects that may lead to tissue damage and septic shock. Afterwards, depletion of tryptophan and production of kynurenines contribute to the development of immunosuppression that may cause the inability to overpower opportunistic infections. The presented review provides available data on the various interdependencies between elements of innate immunity and sepsis-induced AKI (SAKI) with particular emphasis on the immunomodulatory significance of KP in the above processes. We believe that KP activation may be one of the crucial, though underestimated, components of a deregulated host response to infection during SAKI.

Melatonin: A window into the organ-protective effects of sepsis

Sepsis is an uncontrolled host response to infection. In some cases, it progresses to multi-organ insufficiency, leading to septic shock and increased risk of mortality. Various organ support strategies are currently applied clinically, but they are still inadequate in terms of reducing mortality. Melatonin is a hormone that regulates sleep and wakefulness, and it is associated with a reduced risk of death in patients with sepsis. Evidence suggests that melatonin may help protect organ function from sepsis-related damage. Here, we review information related to the role of melatonin in protecting organ function during sepsis and explore its potential clinical applications, with the aim of providing an effective therapeutic strategy for treating sepsis-induced organ insufficiency.

Aminoglycoside-mimicking carbonized polymer dots for bacteremia treatment

Bacteremia and associated bacterial sepsis are potentially fatal and occur when the host response to microbial invasion is impaired or compromised. This motivated us to develop carbonized polymer dots (CPDs_Man/AA) from a mixture of mannose (Man) and positively charged amino acids [AAs; lysine, arginine (Arg), or histidine] through a one-step mild pyrolysis procedure, which effectively inhibited drug-resistant bacterial strains isolated from septic patients. The as-prepared CPDs_Man/AA showed broad-spectrum antibacterial activity, including multidrug-resistant bacteria, even in human plasma. The minimal inhibitory concentration of CPDs_Man/Arg is ca. 1.0 μg mL^-1, which is comparable to or lower than those of other tested antibiotics (e.g., ampicillin, gentamicin, and vancomycin). In addition to directly disrupting bacterial membranes, the CPDs_Man/Arg feature a structure similar to aminoglycoside antibiotics that could bind to 16S rRNA, thereby blocking bacterial protein synthesis. In vitro cytotoxic and hemolytic assays demonstrated the high biocompatibility of the CPDs_Man/AA. In addition, in vivo studies on methicillin-resistant Staphylococcus aureus-infected mice treated with the CPDs_Man/Arg showed a significant decrease in mortality-even better than that of antibiotics. Overall, the synthesis of the CPDs_Man/AA is cost-efficient, straightforward, and effective for treating bacteremia. The polymeric features of the CPDs_Man/Arg, including cationic charges and specific groups, can be recognized as a safe and broad-spectrum biocide to lessen our reliance on antibiotics to treat systemic bacterial infections in the future.

Burn-Induced Acute Kidney Injury-Two-Lane Road: From Molecular to Clinical Aspects

Severe burn injuries lead to acute kidney injury (AKI) development, increasing the mortality risk up to 28-100%. In addition, there is an increase in hospitalization days and complications appearance. Various factors are responsible for acute or late AKI debut, like hypovolemia, important inflammatory response, excessive load of denatured proteins, sepsis, and severe organic dysfunction. The main measure to improve the prognosis of these patients is rapidly recognizing this condition and reversing the underlying events. For this reason, different renal biomarkers have been studied over the years for early identification of burn-induced AKI, like neutrophil gelatinase-associated lipocalin (NGAL), cystatin C, kidney injury molecule-1 (KIM-1), tissue inhibitor of metalloproteinase-2 (TIMP-2), interleukin-18 (IL-18), and insulin-like growth factor-binding protein 7 (IGFBP7). The fundamental purpose of these studies is to find a way to recognize and prevent acute renal injury progression early in order to decrease the risk of mortality and chronic kidney disease (CKD) onset.

Circular RNAs in Acute Kidney Injury: Roles in Pathophysiology and Implications for Clinical Management

Acute kidney injury (AKI) is a common clinical condition, results in patient morbidity and mortality, and incurs considerable health care costs. Sepsis, ischaemia-reperfusion injury (IRI) and drug nephrotoxicity are the leading causes. Mounting evidence suggests that perturbations in circular RNAs (circRNAs) are observed in AKI of various aetiologies, and have pathogenic significance. Aberrant circRNA expressions can cause altered intracellular signalling, exaggerated oxidative stress, increased cellular apoptosis, excess inflammation, and tissue injury in AKI due to sepsis or IRI. While circRNAs are dysregulated in drug-induced AKI, their roles in pathogenesis are less well-characterised. CircRNAs also show potential for clinical application in diagnosis, prognostication, monitoring, and treatment. Prospective observational studies are needed to investigate the role of circRNAs in the clinical management of AKI, with special focus on the safety of therapeutic interventions targeting circRNAs and the avoidance of untoward off-target effects.

The Clinical Impact of Platelets on Post-Injury Serum Creatinine Concentration in Multiple Trauma Patients: A Retrospective Cohort Study

Background and objective: Platelets contribute to the immunological response after multiple trauma. To determine the clinical impact, this study analyzes the association between platelets and creatinine concentration as an indicator of kidney function in polytraumatized patients. Methods: We investigated all patients presenting an Injury Severity Score (ISS) ≥16 for a 2-year period at our trauma center. Platelet counts and creatinine concentrations were analyzed, and correlation analysis was performed within 10 days after multiple trauma. Results: 83 patients with a median ISS of 22 were included. Platelet count was decreased on day 3 (p ≤ 0.001) and increased on day 10 (p ≤ 0.001). Platelet count was elevated on day 10 in younger patients and diminished in severely injured patients (ISS ≥35) on day 1 (p = 0.012) and day 3 (p = 0.011). Creatinine concentration was decreased on day 1 (p = 0.003) and day 10 (p ≤ 0.001) in female patients. Age (p = 0.01), male sex (p = 0.004), and injury severity (p = 0.014) were identified as factors for increased creatinine concentration on day 1, whereas platelets (p = 0.046) were associated with decreased creatinine concentrations on day 5 after multiple trauma. Conclusions: Kinetics of platelet count and creatinine concentration are influenced by age, gender, and trauma severity. There was no clear correlation between platelet counts and creatinine concentration. However, platelets seem to have a modulating effect on creatinine concentrations in the vulnerable phase after trauma.

The Pathophysiology of Sepsis-Associated AKI

Sepsis-associated AKI is a life-threatening complication that is associated with high morbidity and mortality in patients who are critically ill. Although it is clear early supportive interventions in sepsis reduce mortality, it is less clear that they prevent or ameliorate sepsis-associated AKI. This is likely because specific mechanisms underlying AKI attributable to sepsis are not fully understood. Understanding these mechanisms will form the foundation for the development of strategies for early diagnosis and treatment of sepsis-associated AKI. Here, we summarize recent laboratory and clinical studies, focusing on critical factors in the pathophysiology of sepsis-associated AKI: microcirculatory dysfunction, inflammation, NOD-like receptor protein 3 inflammasome, microRNAs, extracellular vesicles, autophagy and efferocytosis, inflammatory reflex pathway, vitamin D, and metabolic reprogramming. Lastly, identifying these molecular targets and defining clinical subphenotypes will permit precision approaches in the prevention and treatment of sepsis-associated AKI.