Analysis of the high incidence of acute kidney injury associated with acute-on-chronic liver failure

Glycyrrhizin attenuates renal inflammation in a mouse Con A-hepatitis model via the IL-25/M2 axis

Glycyrrhizin (GL) has immunoregulatory effects on various inflammatory diseases including hepatitis and nephritis. However, the mechanisms underlying the anti-inflammatory effect of GL on renal inflammation are not fully understood. Hepatorenal syndrome (HRS) is a functional acute renal impairment that occurs in severe liver disease, and we found that kidney injury also occurs in Con A-induced experimental hepatitis in mice. We previously found that GL can alleviate Con A-induced hepatitis by regulating the expression of IL-25 in the liver. We wanted to investigate whether GL can alleviate Con A-induced nephritis by regulating IL-25. IL-25 regulates inflammation by modulating type 2 immune responses, but the mechanism by which IL-25 affects kidney disease remains unclear. In this study, we found that the administration of GL enhanced the expression of IL-25 in renal tissues; the latter promoted the generation of type 2 macrophages (M2), which inhibited inflammation in the kidney caused by Con A challenge. IL-25 promoted the secretion of the inhibitory cytokine IL-10 by macrophages but inhibited the expression of the inflammatory cytokine IL-1β by macrophages. Moreover, IL-25 downregulated the Con A-mediated expression of Toll-like receptor (TLR) 4 on macrophages. By comparing the roles of TLR2 and TLR4, we found that TLR4 is required for the immunoregulatory effect of IL-25 on macrophages. Our data revealed that GL has anti-inflammatory effects on Con A-induced kidney injury and that the GL/IL-25/M2 axis participates in the anti-inflammatory process. This study suggested that GL is a potential therapeutic for protecting against acute kidney injury.

Incidence and risk factors of acute kidney injury in cirrhosis: a systematic review and meta-analysis of 5,202,232 outpatients, inpatients, and ICU-admitted patients

INTRODUCTION

Acute kidney injury (AKI) is a commonly seen condition in the natural course of cirrhosis. The aim of this study was to evaluate the pooled incidence and risk factors of AKI in different clinical stages and situations in patients with cirrhosis.

METHODS

Search was conducted on 13 December 2023 across MEDLINE (PubMed), Embase, and Cochrane databases. Meta-analysis was performed using a generalized linear mixed model.

RESULTS

In total, 73 studies with 5,202,232 patients were finally enrolled in the meta-analysis. AKI commonly occurs among hospitalized cirrhotics experiencing any decompensation event (29%) as well as among stable outpatients (28%) throughout a 1-year follow-up period. On admission, patients with infection or sepsis/septic shock had the highest AKI rate (47%), followed by those with hepatic encephalopathy (41%). Furthermore, the severity of liver disease proved to be a substantial driver for AKI development, while patients at intensive care unit had the greatest AKI incidence (61%).

CONCLUSIONS

Both hospitalized patients and stable outpatients with cirrhosis exhibited an elevated susceptibility to AKI. Patients at intensive care unit and those with severe liver disease, infection, sepsis/septic shock, hepatic encephalopathy, or acute on chronic liver failure upon admission are at higher risk for AKI.

TRIAL REGISTRATION

PROSPERO, registered 09/12/23, CRD42023487736.

Definitions, Etiologies, and Outcomes of Acute on Chronic Liver Failure: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Acute-on-chronic liver failure (ACLF) is a major public health concern. We aimed to assess the definitions, etiologic spectrum, organ failure (OF), and outcomes of ACLF globally.

METHODS

Three databases were searched for studies on ACLF from 1990 until September 2022. Information regarding definitions, acute precipitants, underlying chronic liver disease (CLD), OF, and mortality were extracted. Meta-analyses were performed for pooled prevalence rates (95% confidence interval [CI]) using random-effects model for each definition of ACLF.

RESULTS

Of the 11,451 studies identified, 114 articles (142 cohorts encompassing 210,239 patients) met the eligibility criteria. Most studies (53.2%) used the European Association for the Study of the Liver (EASL) definition, followed by Asia-Pacific Association for the Study of the Liver (APASL) (33.3%). Systemic infection was the major acute precipitant, and alcohol use was the major cause of CLD in EASL-defined studies, whereas alcohol was both the major acute precipitant and cause of CLD in APASL-defined studies. Liver failure was the major OF in APASL-based studies, whereas renal failure was predominant in EASL-based studies. Thirty-day mortality varied across definitions: APASL: 38.9%, 95% CI, 31.2%-46.9%; EASL: 47.9%, 95% CI, 42.2%-53.5%; and NACSELD: 52.2%, 95% CI, 51.9%-52.5%. Diagnostic overlap between definitions ranged from 7.7% to 80.2%. Meta-regression suggested that the World Health Organization region influenced 30-day mortality in studies using EASL definition.

CONCLUSIONS

Heterogeneity in the definition of ACLF proposed by different expert societies and regional preferences in its use result in differences in clinical phenotype and outcomes. A uniform definition would enhance the comparability and interpretation of global data.

Exploiting urine-derived induced pluripotent stem cells for advancing precision medicine in cell therapy, disease modeling, and drug testing

The field of regenerative medicine has witnessed remarkable advancements with the emergence of induced pluripotent stem cells (iPSCs) derived from a variety of sources. Among these, urine-derived induced pluripotent stem cells (u-iPSCs) have garnered substantial attention due to their non-invasive and patient-friendly acquisition method. This review manuscript delves into the potential and application of u-iPSCs in advancing precision medicine, particularly in the realms of drug testing, disease modeling, and cell therapy. U-iPSCs are generated through the reprogramming of somatic cells found in urine samples, offering a unique and renewable source of patient-specific pluripotent cells. Their utility in drug testing has revolutionized the pharmaceutical industry by providing personalized platforms for drug screening, toxicity assessment, and efficacy evaluation. The availability of u-iPSCs with diverse genetic backgrounds facilitates the development of tailored therapeutic approaches, minimizing adverse effects and optimizing treatment outcomes. Furthermore, u-iPSCs have demonstrated remarkable efficacy in disease modeling, allowing researchers to recapitulate patient-specific pathologies in vitro. This not only enhances our understanding of disease mechanisms but also serves as a valuable tool for drug discovery and development. In addition, u-iPSC-based disease models offer a platform for studying rare and genetically complex diseases, often underserved by traditional research methods. The versatility of u-iPSCs extends to cell therapy applications, where they hold immense promise for regenerative medicine. Their potential to differentiate into various cell types, including neurons, cardiomyocytes, and hepatocytes, enables the development of patient-specific cell replacement therapies. This personalized approach can revolutionize the treatment of degenerative diseases, organ failure, and tissue damage by minimizing immune rejection and optimizing therapeutic outcomes. However, several challenges and considerations, such as standardization of reprogramming protocols, genomic stability, and scalability, must be addressed to fully exploit u-iPSCs' potential in precision medicine. In conclusion, this review underscores the transformative impact of u-iPSCs on advancing precision medicine and highlights the future prospects and challenges in harnessing this innovative technology for improved healthcare outcomes.

Early diagnostic biomarkers for acute kidney injury using cisplatin-induced nephrotoxicity in rat model

Chronic kidney diseases (CKD) caused by acute kidney injury (AKI) results rapid and reversible loss in renal function. A real-time, highly accurate, and sensitive acute kidney injury biomarker is urgently required in order to keep these patients alive and prevent end stage renal disease and related complications that include hypertension, fluid and electrolyte retention, metabolic acidosis, anemia, stroke etc. This study was designed to develop a specific and sensitive model for the early identification of renal damage in male albino rats. Using a single intraperitoneal dose of cisplatin (10 mg/kg body weight) to the rats, the various duration-dependent nephrotoxic activities were compared using multiple physiological, biochemical, genomic, and histopathological markers. We looked into when renal dysfunction would start occurring after receiving a single high dose of cisplatin while blood urea nitrogen (BUN) and serum creatinine (sCr) remained normal. Following a single cisplatin injection, various measurements were taken in plasma, urine, and/or kidney tissues of rats euthanized on days 1, 2, 3, 5, and 7. When the urine kidney injury molecule (KIM-1), interleukine 18 (IL-18), nephrin, neutrophil gelatinase-associated lipocalin (NGAL) and serum cystatin C (Cys C) levels are greatly raised on day 3 after cisplatin treatment, BUN and sCr levels remain normal. Nephrotoxicity of cisplatin is also indicated by the upregulated mRNA expression of KIM-1, IL-18, Cys C, and NGAL and downregulated expression of nephrin in kidney tissue at very initial stage. Protein expression of KIM-1, IL-18 and NGAL level of kidney tissues was upregulated indicated confirmatory results done by western blot. Utilising an array of kidney impairment indicators has emerged as an earlier, more effective, and more reliable technique to diagnose AKI when compared to the most sophisticated signs now available.

Hirsutidin Prevents Cisplatin-Evoked Renal Toxicity by Reducing Oxidative Stress/Inflammation and Restoring the Endogenous Enzymatic and Non-Enzymatic Level

Recent research has shown that phytocomponents may be useful in the treatment of renal toxicity. This study was conducted to evaluate the renal disease hirsutidin in the paradigm of renal toxicity induced by cisplatin. Male Wistar rats were given cisplatin (3 mg/kg body weight/day, for 25 days, i.p.) to induce renal toxicity. Experimental rats were randomly allocated to four different groups: group I received saline, group II received cisplatin, group III received cisplatin + hirsutidin (10 mg/kg)and group IV (per se)received hirsutidin (10 m/kg)for 25 days. Various biochemical parameters were assessed, oxidative stress (superoxide dismutase (SOD), glutathione transferase (GSH), malonaldehyde (MDA) and catalase (CAT)), blood-chemistry parameters (blood urea nitrogen (BUN) and cholesterol), non-protein-nitrogenous components (uric acid, urea, and creatinine), and anti-inflammatory-tumor necrosis factor-α (TNF-α), interleukin-1β(IL-1β). IL-6 and nuclear factor-kB (NFκB) were evaluated and histopathology was conducted. Hirsutidin alleviated renal injury which was manifested by significantly diminished uric acid, urea, urine volume, creatinine, and BUN, compared to the cisplatin group. Hirsutidin restored the activities of several antioxidant enzyme parameters—MDA, CAT, GSH, and SOD. Additionally, there was a decline in the levels of inflammatory markers—TNF-α, IL-1β, IL-6, and NFκB—compared to the cisplatin group. The current research study shows that hirsutidin may act as a therapeutic agent for the treatment of nephrotoxicity induced by cisplatin.

Rosinidin Protects against Cisplatin-Induced Nephrotoxicity via Subsiding Proinflammatory and Oxidative Stress Biomarkers in Rats

BACKGROUND

Rosinidin is a flavonoid anthocyanin pigmentation found in shrub flowers such as Catharanthus roseus and Primula rosea. The molecular docking studies predicted that rosinidin has adequate structural competency, making it a viable medicinal candidate for the treatment of a wide range of disorders. The current study intends to assess rosinidin nephroprotective efficacy against nephrotoxicity induced by cisplatin in rats.

MATERIALS AND METHODS

Oral acute toxicity tests of rosinidin were conducted to assess potential toxicity in animals, and it was shown to be safe. The nephroprotective effect of rosinidin 10, and 20 mg/kg were tested in rats for 25 days with concurrent administration of cisplatin. Several biochemical parameters were measured to support enzymatic and non-enzymatic oxidative stress such as superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GSH). Likewise, changes in several non-protein-nitrogenous components and blood chemistry parameters were made to support the theory linked with the pathogenesis of chemical-induced nephrotoxicity.

RESULTS

Cisplatin caused significant changes in biochemical, enzymatic, and blood chemistry, which rosinidin efficiently controlled.

CONCLUSIONS

The present investigation linked rosinidin with nephroprotective efficacy in experimental models.

Drug-Induced Nephrotoxicity Assessment in 3D Cellular Models

The kidneys are often involved in adverse effects and toxicity caused by exposure to foreign compounds, chemicals, and drugs. Early predictions of these influences are essential to facilitate new, safe drugs to enter the market. However, in current drug treatments, drug-induced nephrotoxicity accounts for 1/4 of reported serious adverse reactions, and 1/3 of them are attributable to antibiotics. Drug-induced nephrotoxicity is driven by multiple mechanisms, including altered glomerular hemodynamics, renal tubular cytotoxicity, inflammation, crystal nephropathy, and thrombotic microangiopathy. Although the functional proteins expressed by renal tubules that mediate drug sensitivity are well known, current in vitro 2D cell models do not faithfully replicate the morphology and intact renal tubule function, and therefore, they do not replicate in vivo nephrotoxicity. The kidney is delicate and complex, consisting of a filter unit and a tubular part, which together contain more than 20 different cell types. The tubular epithelium is highly polarized, and maintaining cellular polarity is essential for the optimal function and response to environmental signals. Cell polarity depends on the communication between cells, including paracrine and autocrine signals, as well as biomechanical and chemotaxis processes. These processes affect kidney cell proliferation, migration, and differentiation. For drug disposal research, the microenvironment is essential for predicting toxic reactions. This article reviews the mechanism of drug-induced kidney injury, the types of nephrotoxicity models (in vivo and in vitro models), and the research progress related to drug-induced nephrotoxicity in three-dimensional (3D) cellular culture models.

Individual mortality risk predictive system of patients with acute-on-chronic liver failure based on a random survival forest model

Background:

The basis of individualized treatment should be individualized mortality risk predictive information. The present study aimed to develop an online individual mortality risk predictive tool for acute-on-chronic liver failure (ACLF) patients based on a random survival forest (RSF) algorithm.

Methods:

The current study retrospectively enrolled ACLF patients from the Department of Infectious Diseases of The First People's Hospital of Foshan, Shunde Hospital of Southern Medical University, and Jiangmen Central Hospital. Two hundred seventy-six consecutive ACLF patients were included in the present study as a model cohort (n = 276). Then the current study constructed a validation cohort by drawing patients from the model dataset based on the resampling method (n = 276). The RSF algorithm was used to develop an individual prognostic model for ACLF patients. The Brier score was used to evaluate the diagnostic accuracy of prognostic models. The weighted mean rank estimation method was used to compare the differences between the areas under the time-dependent ROC curves (AUROCs) of prognostic models.

Results:

Multivariate Cox regression identified hepatic encephalopathy (HE), age, serum sodium level, acute kidney injury (AKI), red cell distribution width (RDW), and international normalization index (INR) as independent risk factors for ACLF patients. A simplified RSF model was developed based on these previous risk factors. The AUROCs for predicting 3-, 6-, and 12-month mortality were 0.916, 0.916, and 0.905 for the RSF model and 0.872, 0.866, and 0.848 for the Cox model in the model cohort, respectively. The Brier scores were 0.119, 0.119, and 0.128 for the RSF model and 0.138, 0.146, and 0.156 for the Cox model, respectively. The nonparametric comparison suggested that the RSF model was superior to the Cox model for predicting the prognosis of ACLF patients.

Conclusions:

The current study developed a novel online individual mortality risk predictive tool that could predict individual mortality risk predictive curves for individual patients. Additionally, the current online individual mortality risk predictive tool could further provide predicted mortality percentages and 95% confidence intervals at user-defined time points.

Protective Effects of Taraxacum officinale L. (Dandelion) Root Extract in Experimental Acute on Chronic Liver Failure

BACKGROUND

Taraxacum officinale (TO) or dandelion has been frequently used to prevent or treat different liver diseases because of its rich composition in phytochemicals with demonstrated effect against hepatic injuries. This study aimed to investigate the possible preventing effect of ethanolic TO root extract (TOERE) on a rat experimental acute on chronic liver failure (ACLF) model.

METHODS

Chronic liver failure (CLF) was induced by human serum albumin, and ACLF was induced in CLF by D-galactosamine and lipopolysaccharide (D-Gal-LPS). Five groups (n = 5) of male Wistar rats (200-250 g) were used: ACLF, ACLF-silymarin (200 mg/kg b.w./day), three ACLF-TO administered in three doses (200 mg, 100 mg, 50 mg/kg b.w./day).

RESULTS

The in vivo results showed that treatment with TOERE administered in three chosen doses before ACLF induction reduced serum liver injury markers (AST, ALT, ALP, GGT, total bilirubin), renal tests (creatinine, urea), and oxidative stress tests (TOS, OSI, MDA, NO, 3NT). Histopathologically, TOERE diminished the level of liver tissue injury and 3NT immunoexpression.

CONCLUSIONS

This paper indicated oxidative stress reduction as possible mechanisms for the hepatoprotective effect of TOERE in ACLF and provided evidence for the preventive treatment.

Infection deteriorating hepatitis B virus related acute-on-chronic liver failure: a retrospective cohort study

Background

Infection is common in acute-on-chronic liver failure (ACLF), which may worsen the clinical condition and prognosis. However, the characteristics of infection and its influence on prognosis in hepatitis B virus related ACLF (HBV-ACLF) as defined by the European Association for the Study of the Liver (EASL) have not been clarified. We aimed to investigate the characteristics of infection and its influence on mortality in patients with HBV-ACLF defined by EASL in China.

Methods

We performed a retrospective cohort study in patients with HBV-ACLF defined by EASL in a single center from January 2015 to December 2017. These patients were divided into two groups with and without infection. The incidence, sites of infection, isolated strains, and risk factors associated with mortality were evaluated.

Results

A total of 289 patients were included, among them 185 (64.0%) were diagnosed with an infection. The most common type of infection was pneumonia (55.7%), followed by spontaneous bacterial peritonitis (47.6%) and others. The gram-negative bacteria were the most frequent (58.3%). Patients with one, two, and three or more infection sites had a gradually increasing incidence of sepsis (P < 0.01), septic shock (P < 0.001), and ACLF-3 (P < 0.05). Also, patients with infection isolated one, two, and three or more strains showed a growing incidence of sepsis (P < 0.01) and septic shock (P < 0.001). Patients with infection showed a significantly higher 28-day mortality than those without (P < 0.01), especially in patients with ACLF-3. Infection was identified as an independent risk factor for 28-day mortality in all HBV-ACLF patients. Pneumonia and sepsis were identified as independent predictors of 28-day mortality for patients with infection.

Conclusions

Infection is associated with severe clinical course and high mortality in HBV-ACLF defined by EASL. The increased number of infection sites or isolated strains was associated with the occurrence of sepsis and septic shock. Pneumonia and sepsis were independent predictors for mortality in HBV-ACLF patients with infection.

Kidney-based in vivo model for drug-induced nephrotoxicity testing

The need is critical and urgent for a real-time, highly specific, and sensitive acute kidney injury biomarker. This study sought to establish a sensitive and specific Miox-NanoLuc transgenic mouse for early detection of drug-induced nephrotoxicity. We generated Miox-NanoLuc transgenic mice with kidney-specific NanoLuc overexpression. Our data showed that Miox-NanoLuc-produced luminescence was kidney-specific and had good stability at room temperature, 4 °C, − 20 °C, and repeated freeze–thaw cycles. Serum levels of BUN and creatinine were significantly increased at day 2 or 3 in cisplatin-treated mice and at day 5 in aristolochic acid (AAI)-treated mice. Particularly, the serum and urine Miox-NanoLuc luminescence levels were significantly increased at day 1 in cisplatin-treated mice and at day 3 in AAI-treated mice. Renal pathological analysis showed that the kidney sections of cisplatin-treated mice at day 5 and AAI-treated mice at day 13 showed cytolysis and marked vacuolization of tubular cells. In conclusion, we developed a new platform to early quantify drug-induced nephrotoxicity before serum BUN and creatinine levels increased and pathological tubular cell injury occurred. This model may serve as an early detection for drug- and food-induced nephrotoxicity and as an animal model to investigate tubular cell injury.

Prevalence and short-term outcome of acute kidney injury in patients with acute-on-chronic liver failure: A meta-analysis

Acute kidney injury (AKI) in patients with acute-on-chronic liver failure (ACLF) is a distinct syndrome to that in patients with cirrhosis, yet is less characterized. The aim of this meta-analysis was to investigate the impact of AKI on outcome of ACLF. We searched PubMed, Web of Science and Cochrane Library for original articles that evaluated the impact of AKI on outcome of ACLF from 2011 to 2019. Odds ratio (OR) with 95% confidence interval (CI) for 1-month and 3-month mortality was calculated. The response rate of vasoconstrictor for hepatorenal syndrome (HRS)-AKI was assessed. Eight relevant articles with 3610 patients were included. The prevalence of AKI in ACLF patients was 41% (95% CI 32%-50%). The presence of AKI was significantly associated with 1-month mortality of ACLF (OR 3.98, 95% CI 3.09-5.12; P < .001) and 3-month mortality (OR 4.98, 95% CI 3.59-6.92; P < .001). Additionally, patients with AKI stage ≥2 showed a higher 3-month mortality than stage 1 (OR 3.89, 95% CI 2.60-5.82; P < .001), and those of stage 3 had a higher mortality than stage ≤2 (OR 3.77, 95% CI 2.10-6.77; P < .001). The pooled response rate of vasoconstrictors was 32% (95% CI 26%-37%). This meta-analysis indicated that about 40% of ACLF patients complicated with AKI and the presence of AKI substantially increased the short-term mortality, together with a poor response rate of vasoconstrictors for HRS-AKI.

Schmidt-Ott K. The Incidence of Acute Kidney Injury and Associated Hospital Mortality

BACKGROUND

Studies from multiple countries have shown that acute kidney injury (AKI) in hospitalized patients is associated with mortality and morbidity. There are no reliable data at present on the incidence and mortality of AKI episodes among hospitalized patients in Germany. The utility of administrative codings of AKI for the identification of AKI episodes is also unclear.

METHODS

In an exploratory approach, we retrospectively analyzed all episodes of AKI over a period of 3.5 years (2014-2017) on the basis of routinely obtained serum creatinine measurements in 103 161 patients whose creatinine had been measured at least twice and who had been in the hospital for at least two days. We used the "Kidney Disease: Improving Global Outcomes" (KDIGO) criteria for AKI. In parallel, we assessed the administrative coding of discharge diagnoses of the same patients with codes from the International Classification of Diseases (ICD-10-GM).

RESULTS

Among 185 760 hospitalizations, stage 1 AKI occurred in 25 417 cases (13.7%), stage 2 in 8503 cases (4.6%), and stage 3 in 5881 cases (3.1%). AKI cases were associated with length of hospital stay, renal morbidity, and overall mortality, and this association was stage-dependent. The in-hospital mortality was 5.1% for patients with stage 1 AKI, 13.7% for patients with stage 2 AKI, and 24.8% for patients with stage 3 AKI. An administrative coding for acute kidney injury (N17) was present in only 28.8% (11 481) of the AKI cases that were identified by creatinine criteria. Like the AKI cases overall, those that were identified by creatinine criteria but were not coded as AKI had significantly higher mortality, and this association was stage-dependent.

CONCLUSION

AKI episodes are common among hospitalized patients and are associated with considerable morbidity and mortality, yet they are inadequately documented and probably often escape the attention of the treating physicians.

Acute Liver Failure: From Textbook to Emergency Room and Intensive Care Unit With Concomitant Established and Modern Novel Therapies

Acute liver failure is a rare hepatic emergent situation that affects primarily young people and has often a catastrophic or even fatal outcome. Definition of acute liver failure has not reached a universal consensus and the interval between the appearance of jaundice and hepatic encephalopathy for the establishment of the acute failure is a matter of debate. Among the wide variety of causes, acetaminophen intoxication in western societies and viral hepatitis in the developing countries rank at the top of the etiology list. Identification of the clinical appearance and initial management for the stabilization of the patient are of vital significance. Further advanced therapies, that require intensive care unit, should be offered. The hallmark of treatment for selected patients can be orthotopic liver transplantation. Apart from well-established treatments, novel therapies like hepatocyte or stem cell transplantation, additional new therapeutic strategies targeting acetaminophen intoxication and/or hepatic encephalopathy are mainly experimental, and some of them do not belong, yet, to clinical practice. For clinicians, it is substantial to have the alertness to timely identify the patient and transfer them to a specialized center, where more treatment opportunities are available.