Immunopathogenesis of acute on chronic liver failure.

Acute-on-chronic liver failure is a well-established description of a high-mortality syndrome of chronic liver disease (usually cirrhosis) with organ failure. While the exact definition is under refinement, the accepted understanding of this entity is in patients with chronic liver disease and various organs in failure and where systemic inflammation is a major component of the pathobiology. There are limited therapies for a disease with such a poor prognosis, and while improvements in the critical care management and for very few patients, liver transplantation, mean 50% can survive to hospital discharge, rapid application of new therapies is required. Here we explain the current understanding of the immunologic abnormalities seen in acute-on-chronic liver failure across the innate and adaptive immune systems, the role of the hepatic cell death and the gut-liver axis, and recommendations for future research and treatment paradigms.

Common definitions and variables are needed for the United States to join the conversation on acute-on-chronic liver failure.

Acute-on-chronic liver failure (ACLF) is a variably defined syndrome characterized by acute decompensation of cirrhosis with organ failures. At least 13 different definitions and diagnostic criteria for ACLF have been proposed, and there is increasing recognition that patients with ACLF may face disadvantages in the current United States liver allocation system. There is a need, therefore, for more standardized data collection and consensus to improve study design and outcome assessment in ACLF. In this article, we discuss the current landscape of transplantation for patients with ACLF, strategies to optimize organ utility, and data opportunities based on emerging technologies to facilitate improved data collection.

Long-term outcome following liver transplantation of patients with ACLF grade 3.

BACKGROUND AND AIMS: Utility, a major principle for allocation in the context of transplantation, is questioned in patients with acute-on chronic liver failure grade 3 (ACLF-3) who undergo liver transplantation (LT). We aimed to explore long-term outcomes of patients included the three-center retrospective French experience published in 2017. METHOD: All patients with ACLF-3 (n=73) as well as their transplanted matched controlled with ACLF-2 (n=145), 1 (n=119) and no ACLF (n=292) that have participated in the princeps study published in 2017 were included. We explored 5- and 10-year patient and graft survivals, causes of death and their predictive factors. RESULTS: Median follow-up of patients ACLF-3 patients was 7.5 years. At LT, median MELD was 40. In patients with ACLF-3, 2, 1 and no ACLF, 5-year patients' survivals were respectively 72.6% vs. 69.7% vs. 76.4% vs. 77.0% (p=0.31). Ten-year patients' survival ACLF-3 was 56.8% and was not different other groups (p=0.37) Leading causes of death in ACLF-3 patients were infections (33.3%), and cardiovascular events (23.3%). After exclusion of early death, UCLA futility risk score, age-adjusted Charlson comorbidity index and Chronic Liver Failure Consortium ACLF score were independently associated with 10-year patients' survival. Long-term grafts' survivals were not different across the groups. Clinical frailty scale and WHO performance status improved over time in patients alive after 5 years. CONCLUSION: 5- and 10-year patients' and grafts' survivals in ACLF-3 patients were not different from their controls. 5-year patients' survival is higher than that of the 50%-70% threshold defining the utility of liver graft. Efforts should focus on candidates' selection based on comorbidities as well as the prevention of infection and cardiovascular events standing as the main cause of death. IMPACT AND IMPLICATIONS: While short-term outcomes following liver transplantation in the most severely ill cirrhotic patients (ACLF-3) are known, long-term data are limited, raising questions about the utility of graft allocation in the context of scarce medical resources. This study provides a favorable long-term update, confirming no differences in 5- and 10-year patient and graft survival following liver transplantation in ACLF-3 patients compared to matched ACLF-2, ACLF-1, and no-ACLF patients. The study highlights the risk of dying from infection and cardiovascular causes in the long-term and identifies scores including comorbidities evaluation, such as the age-adjusted Charlson Comorbidity Index, as independently associated with long-term survival. Therefore, physicians should consider the cumulative burden of comorbidities when deciding to transplant these patients. Additionally, after transplantation, the study encourages mitigating infectious risk with tailored immunosuppressive regimens and managing tightly cardiovascular risk over time.

One-year transplant-free survival following hospital discharge after ICU admission for ACLF in the Netherlands.

BACKGROUND & AIMS: Patients with acute decompensation of cirrhosis or acute-on-chronic liver failure (ACLF) often require intensive care unit (ICU) admission for organ support. Existing research, mostly from specialized liver transplant centers, largely addresses short-term outcomes. Our aim was to evaluate in-hospital mortality and 1-year transplant-free survival after hospital discharge in the Netherlands. METHODS: We conducted a nationwide observational cohort study, including patients with a history of cirrhosis or first complications of cirrhotic portal hypertension admitted to ICUs in the Netherlands between 2012 and 2020. The influence of ACLF grade at ICU admission on 1-year transplant-free survival after hospital discharge among hospital survivors was evaluated using unadjusted Kaplan-Meier survival curves and an adjusted Cox proportional hazard model. RESULTS: Out of the 3,035 patients, 1,819 (59.9%) had ACLF-3. 1,420 patients (46.8%) survived hospitalization after ICU admission. The overall probability of 1-year transplant-free survival after hospital discharge was 0.61 (95% CI 0.59-0.64). This rate varied with ACLF grade at ICU admission, being highest in patients without ACLF (0.71; 95% CI 0.66-0.76) and lowest in those with ACLF-3 (0.53 [95% CI 0.49-0.58]) (log-rank p <0.0001). However, after adjusting for age, malignancy status and MELD score, ACLF grade at ICU admission was not associated with an increased risk of liver transplantation or death within 1 year after hospital discharge. CONCLUSION: In this nationwide cohort study, ACLF grade at ICU admission did not independently affect 1-year transplant-free survival after hospital discharge. Instead, age, presence of malignancy and the severity of liver disease played a more prominent role in influencing transplant-free survival after hospital discharge. IMPACT AND IMPLICATIONS: Patients with acute-on-chronic liver failure often require intensive care unit (ICU) admission for organ support. In these patients, short-term mortality is high, but long-term outcomes of survivors remain unknown. Using a large nationwide cohort of ICU patients, we discovered that the severity of acute-on-chronic liver failure at ICU admission does not influence 1-year transplant-free survival after hospital discharge. Instead, age, malignancy status and overall severity of liver disease are more critical factors in determining their long-term survival.

Thrombospondin 1 enhances systemic inflammation and disease severity in acute-on-chronic liver failure.

BACKGROUND: The key role of thrombospondin 1 (THBS1) in the pathogenesis of acute-on-chronic liver failure (ACLF) is unclear. Here, we present a transcriptome approach to evaluate THBS1 as a potential biomarker in ACLF disease pathogenesis. METHODS: Biobanked peripheral blood mononuclear cells (PBMCs) from 330 subjects with hepatitis B virus (HBV)-related etiologies, including HBV-ACLF, liver cirrhosis (LC), and chronic hepatitis B (CHB), and normal controls (NC) randomly selected from the Chinese Group on the Study of Severe Hepatitis B (COSSH) prospective multicenter cohort underwent transcriptome analyses (ACLF = 20; LC = 10; CHB = 10; NC = 15); the findings were externally validated in participants from COSSH cohort, an ACLF rat model and hepatocyte-specific THBS1 knockout mice. RESULTS: THBS1 was the top significantly differentially expressed gene in the PBMC transcriptome, with the most significant upregulation in ACLF, and quantitative polymerase chain reaction (ACLF = 110; LC = 60; CHB = 60; NC = 45) was used to verify that THBS1 expression corresponded to ACLF disease severity outcome, including inflammation and hepatocellular apoptosis. THBS1 showed good predictive ability for ACLF short-term mortality, with an area under the receiver operating characteristic curve (AUROC) of 0.8438 and 0.7778 at 28 and 90 days, respectively. Enzyme-linked immunosorbent assay validation of the plasma THBS1 using an expanded COSSH cohort subjects (ACLF = 198; LC = 50; CHB = 50; NC = 50) showed significant correlation between THBS1 with ALT and γ-GT (P = 0.01), and offered a similarly good prognostication predictive ability (AUROC = 0.7445 and 0.7175) at 28 and 90 days, respectively. ACLF patients with high-risk short-term mortality were identified based on plasma THBS1 optimal cut-off value (< 28 µg/ml). External validation in ACLF rat serum and livers confirmed the functional association between THBS1, the immune response and hepatocellular apoptosis. Hepatocyte-specific THBS1 knockout improved mouse survival, significantly repressed major inflammatory cytokines, enhanced the expression of several anti-inflammatory mediators and impeded hepatocellular apoptosis. CONCLUSIONS: THBS1 might be an ACLF disease development-related biomarker, promoting inflammatory responses and hepatocellular apoptosis, that could provide clinicians with a new molecular target for improving diagnostic and therapeutic strategies.

Mesenchymal stromal cell-derived extracellular vesicles therapy openings new translational challenges in immunomodulating acute liver inflammation.

Inflammation plays a critical role in conditions such as acute liver failure, acute-on-chronic liver failure, and ischemia-reperfusion-induced liver injury. Various pathogenic pathways contribute to liver inflammation, involving inflammatory polarization of macrophages and Küpffer cells, neutrophil infiltration, dysregulation of T cell subsets, oxidative stress, and activation of hepatic stellate cells. While mesenchymal stromal cells (MSCs) have demonstrated beneficial properties, their clinical translation is limited by their cellular nature. However, MSC-derived extracellular vesicles (MSC-EVs) have emerged as a promising cell-free therapeutic approach for immunomodulation. MSC-EVs naturally mirror their parental cell properties, overcoming the limitations associated with the use of MSCs. In vitro and in vivo preclinical studies have demonstrated that MSC-EVs replicate the beneficial effects of MSCs in liver injury. This includes the reduction of cell death and oxidative stress, improvement of hepatocyte function, induction of immunomodulatory effects, and mitigation of cytokine storm. Nevertheless, MSC-EVs face challenges regarding the necessity of defining consistent isolation methods, optimizing MSCs culture conditions, and establishing quality control measures for EV characterization and functional assessment. By establishing standardized protocols, guidelines, and affordable cost mass production, clinicians and researchers will have a solid foundation to conduct further studies, validate the therapeutic efficacy of MSC-EVs, and ultimately pave the way for their clinical implementation in acute liver injury.

From hepatitis B virus infection to acute-on-chronic liver failure: The dynamic role of hepatic macrophages.

Acute-on-chronic liver failure (ACLF) is a progressive disease that is associated with rapid worsening of clinical symptoms and high mortality. A multicentre prospective study from China demonstrated that patients with hepatitis B virus-related ACLF (HBV-ACLF) exhibited worse clinical characteristics and higher mortality rates compared to non-HBV-ACLF patients. Immune dysregulation is closely linked to the potential mechanisms of initiation and progression of ACLF. Innate immune response, which is represented by monocytes/macrophages, is up-regulated across ACLF development. This suggests that monocytes/macrophages play an essential role in maintaining the immune homeostasis of ACLF. Information that has been published in recent years shows that the immune status and function of monocytes/macrophages vary in ACLF precipitated by different chronic liver diseases. Monocytes/macrophages have an immune activation effect in hepatitis B-precipitated-ACLF, but they exhibit an immune suppression in cirrhosis-precipitated-ACLF. Therefore, this review aims to explain whether this difference affects the clinical outcome in HBV-ACLF patients as well as the mechanisms involved. We summarize the novel findings that highlight the dynamic polarization phenotype and functional status of hepatic macrophages from the stage of HBV infection to ACLF development. Moreover, we discuss how different HBV-related liver disease tissue microenvironments affect the phenotype and function of hepatic macrophages. In summary, increasing developments in understanding the differences in immune phenotype and functional status of hepatic macrophages in ACLF patients will provide new perspectives towards the effective restoration of ACLF immune homeostasis.

Severe acute liver disease in adults: Contemporary role of histopathology.

Liver biopsies have consistently contributed to our understanding of the pathogenesis and aetiologies of acute liver disease. As other diagnostic modalities have been developed and refined, the role of biopsy in the management of patients with acute liver failure (ALF), acute-on-chronic liver failure (ACLF) and acute hepatitis, including acute liver injury (ALI), has changed. Liver biopsy remains particularly valuable when first-line diagnostic algorithms fail to determine aetiology. Despite not being identified as a mandatory diagnostic tool in recent clinical guidelines for the management of ALF or ACLF, many centres continue to undertake biopsies given the relative safety of transjugular biopsy in this setting. Several studies have demonstrated that liver biopsy can provide prognostic information, particularly in the context of so-called indeterminate hepatitis, and is extremely useful in excluding conditions such as metastatic tumours that would preclude transplantation. In addition, its widespread use of percutaneous biopsies in cases of less severe acute liver injury, for example in the establishment of a diagnosis of acute presentation of autoimmune hepatitis or confirmation of a probable or definite drug-induced liver injury (DILI), has meant that many centres have seen a shift in the ratio of specimens they are receiving from patients with chronic to acute liver disease. Histopathologists therefore need to be equipped to deal with these challenging specimens. This overview provides an insight into the contemporary role of biopsies (as well as explant and autopsy material) in diagnosing acute liver disease. It outlines up-to-date clinical definitions of liver injury and considers recent recommendations for the diagnosis of AIH and drug-induced, autoimmune-like hepatitis (DI-AIH).

Mesenchymal Stem Cells Promote Polarization of M2 Macrophages in Mice with Acute-On-Chronic Liver Failure via Mertk/JAK1/STAT6 Signaling.

Acute-on-chronic liver failure (ACLF) is a severe disease with a high mortality. Macrophage-related inflammation plays a crucial role in ACLF development. Mesenchymal stem cells (MSCs) treatment was demonstrated to be beneficial in ACLF in our previous study; however, the underlying mechanisms remain unknown. Therefore, mouse bone marrow-derived MSCs were used to treat an ACLF mouse model or cocultured with RAW264.7/J774A.1 macrophages that were stimulated with LPS. Histological and serological parameters and survival were analyzed to evaluate efficacy. We detected changes of Mer tyrosine kinase (Mertk), JAK1/STAT6, inflammatory cytokines, and markers of macrophage polarization in vitro and in vivo. In ACLF mice, MSCs improved liver function and 48-h survival of ACLF mice and alleviated inflammatory injury by promoting M2 macrophage polarization and elevated Mertk expression levels in macrophages. This is significant, as Mertk regulates M2 macrophage polarization via the JAK1/STAT6 signaling pathway.

Prognosis algorithms for acute decompensation of cirrhosis and ACLF.

Accurate prediction of survival in patients with cirrhosis is crucial, as patients who are unlikely to survive in the short-term need to be oriented to liver transplantation and to novel therapeutic approaches. Patients with acute decompensation of cirrhosis without or with organ dysfunction/failure, the so-called acute-on-chronic liver failure (ACLF), have a particularly high short-term mortality. Recognizing the specificity of this clinical situation, dedicated classifications and scores have been developed over the last 15 years, including variables (e.g. organ failures and systemic inflammation) not part of the formerly available cirrhosis severity scores, namely Child-Pugh score or MELD. For patients with acute decompensation of cirrhosis, it led to the development of a dedicated score, the Clif-C-AD score, independently validated. For more severe patients, three different scoring systems have been proposed, by European, Asian and North American societies namely Clif-C-ACLF, AARC score and NASCELD-ACLF respectively. These scores have been validated, and are widely used across the world. The differences and similarities between these scores, as well as their validation and limitations are discussed here. Even if these scores and classifications have been a step forward in favouring homogeneity between studies, and in helping making decisions for individual patients, their predictive value for mortality can still be improved as their area under the ROC curve does not exceed .8. Novel scores including biomarkers reflecting the pathophysiology of acute decompensation of cirrhosis might help reach that goal.

Acute and non-acute decompensation of liver cirrhosis (47/130).

In the traditional view, the occurrence of cirrhosis-related complications, such as hepatic encephalopathy, formation of ascites or variceal haemorrhage, marks the transition to the decompensated stage of cirrhosis. Although the dichotomous stratification into a compensated and decompensated state reflects a prognostic water-shed moment and remains to hold its prognostic validity, it represents an oversimplification of clinical realities. A broadening understanding of pathophysiological mechanisms underpinning decompensation have led to the identification of distinct prognostic subgroups, associated with different clinical courses following decompensation. Data provided by the PREDICT study uncovered three distinct sub-phenotypes of acute decompensation (AD). Moreover, acute-on-chronic liver failure (ACLF) has been established as a distinct clinical entity for many years, which is associated with a high short-term mortality. Recently, non-acute decompensation (NAD) has been proposed as a distinct pathway of decompensation, complementing current concepts of the spectrum of decompensation. In contrast to AD, NAD is characterized by a slow and progressive development of complications, which are often presented at first decompensation and/or in patients in an earlier stage of chronic liver disease. Successful treatment of AD or NAD may lead to a clinical stabilization or even the concept of recompensation. This review aims to provide an overview on current concepts of decompensation and to delineate recent advances in our clinical and pathophysiological understanding.

Predictors of clinical trajectories of patients with acutely decompensated cirrhosis. An external validation of the PREDICT study.

BACKGROUND AND AIMS: The PREDICT study recently showed that acutely decompensated (AD) patients with cirrhosis can present three different clinical phenotypes in the 90 days after admission: (1) pre-ACLF, developing acute-on-chronic liver failure (ACLF); (2) unstable decompensated cirrhosis (UDC), being re-admitted for AD without ACLF and (3) stable decompensated cirrhosis (SDC), not presenting readmission or ACLF. This study aimed to externally validate the existence of these three distinct trajectories and to identify predictors for the occurrence of each trajectory. METHODS: Baseline data, 3-month ACLF and readmission incidence and 1-year survival were analysed in a prospective cohort of patients admitted for AD. A multinomial multivariable model was used to evaluate the association between baseline features and clinical trajectories. RESULTS: Of the 311 patients enrolled, 55% met the criteria for SDC, 18% for UDC and 27% for pre-ACLF, presenting a significantly different 1-year mortality: pre-ACLF 65%, UDC 46%, SDC 21% (p < .001). The presence of hepatic encephalopathy (HE) was associated with UDC (p = .043), while the absence of ascites to SDC (p = .017). Among laboratory parameters, an increase in MELD-Na (p = .001) and C-reactive protein (p = .009) and a decrease in haemoglobin (p = .004) and albumin (p = .008) levels were associated with pre-ACLF. CONCLUSION: The present study confirms that AD patients have three different clinical trajectories with different mortality rates. Besides the severity of cirrhosis, the association with C-reactive protein supports the predominant role of systemic inflammation in ACLF pathophysiology. Finally, HE is associated with the UDC phenotype highlighting the need for better management of this complication after discharge.

Histological characteristics in patients admitted to the hospital with alcoholic hepatitis complicated by acute-on-chronic liver failure.

OBJECTIVES: Alcoholic hepatitis (AH) is a frequent precipitating event for the development of acute-on-chronic liver failure (ACLF), a syndrome characterised by organ failures due to immune dysfunction. The histological features of this complication are not well characterized. We investigated whether ACLF has specific histological characteristics. METHODS: Prospective cohort study in consecutive adult patients admitted between 03-2008 and 04-2021 to a tertiary referral centre with suspected AH. Diagnosis of AH was based on clinical presentation and confirmed by transjugular liver biopsy. All biopsies were assessed by a dedicated liver pathologist, blinded for clinical data and outcome. Diagnosis of ACLF was based on EASL-CLIF criteria. Histological and clinical characteristics of patients with and without ACLF at baseline were compared. RESULTS: 184 patients with biopsy-proven AH were enrolled. Median time from hospital admission to transjugular biopsy was 4.5 days (IQR 2-8). At baseline, ACLF was present in 73 patients (39.7%). Out of the 110 patients without ACLF at baseline, 30 (27.3%) developed ACLF within 28 days (median 7.5 days (IQR 2-20)). At baseline, ductular bilirubinostasis (DB) was the only histological feature significantly more frequently present in patients with ACLF compared to patients without ACLF (50.7% vs. 30.6%, p = 0.003). No clear association between histological features and the development of ACLF later on could be demonstrated. CONCLUSIONS: In this well-defined cohort of patients with biopsy-proven AH, DB was associated with the presence of ACLF. This finding fits with the pathophysiology of this syndrome, which is characterized by systemic inflammation and an increased risk of infections.

Weighted thyroid-stimulating hormone disturbance in prognosis of hepatitis B virus-related acute-on-chronic liver failure.

AIM: To weight the prognostic value of thyroid hormones in catastrophic acute-on-chronic liver failure (ACLF). METHODS: A retrospective cohort (n = 635) and two prospective cohorts (n = 353, and 198) were enrolled in this study. The performance of a novel developed prognostic score was assessed from aspects of reliability, discrimination, and clinical net benefit. RESULTS: Thyroid-stimulating hormone (TSH) was identified to have the most potential as a prognostic predictor for hepatitis B virus-related ACLF among thyroid hormones. The novel score (modified chronic liver failure-organ failure score [mCLIF-OFs]) was developed with weighted TSH and other scored organs in the CLIF-OFs using the retrospective cohort (n = 635). The predicted risk and observed probabilities of death were comparable across the deciles of mCLIF-OFs (Hosmer-Lemeshow χ2  = 4.28, p = 0.83; Brier scaled = 11.9). The C-index of mCLIF-OFs (0.885 [0.883-0.887]) for 30-day mortality was significantly higher than that of the CLIF-OFs, chronic liver failure-sequential organ failure assessment score (CLIF-SOFAs), CLIF-C ACLFs, Model of End-stage Liver Disease (MELD), and Child-Pugh (all p < 0.001). The absolute improvements of prediction error rates of the mCLIF-OFs compared to the above five scores were from 19.0% to 61.1%. After the analysis of probability density function, the mCLIF-OFs showed the least overlapping coefficients (27.9%) among the above prognostic scores. Additionally, the mCLIF-OFs showed greater net benefit than the above five prognostic scores over a wide range of risk threshold of death. Similar results were validated in two prospective ACLF cohorts with HBV and non-HBV etiologies. CONCLUSION: Weighted TSH portended the outcome of ACLF patients, which could be treated as a "damaged organ" of the hypothalamic-pituitary-thyroid axis. The novel mCLIF-OFs is a reliable prognostic score with better discrimination power and clinical net benefit than CLIF-OFs, CLIF-SOFAs, CLIF-C ACLFs, MELD, and Child-Pugh.

Cytokine adsorption in patients with acute-on-chronic liver failure (CYTOHEP)-A single center, open-label, three-arm, randomized, controlled intervention pilot trial.

BACKGROUND: To investigate the efficacy of bilirubin reduction by hemoadsorption with CytoSorb® in patients with acute-on-chronic liver failure (ACLF) receiving continuous renal replacement therapy (CRRT). METHODS: A prospective, randomized, single-center, open-label, controlled pilot trial. Patients with ACLF, acute kidney injury, and serum bilirubin ≥5 mg/dL were assigned 1:1:1 to one of three study groups (CRRT with or without hemoadsorption, no CRRT). In the hemoadsorption group, the CytoSorb adsorber was incorporated into the CRRT system, replaced after 12, 24, and 48 h, and removed after 72 h. The primary endpoint was the serum bilirubin level after 72 h. RESULTS: CYTOHEP was terminated early due to difficulties in recruiting patients and ethical concerns. Three of 9 patients (33%) were treated in each group. Comparing the three groups, mean bilirubin levels after 72 h were lower by -8.0 mg/dL in the "CRRT with hemoadsorption" group compared to "CRRT without hemoadsorption" (95% CI, -21.3 to 5.3 mg/dL; p = 0.17). The corresponding mean difference between "CRRT without hemoadsorption" and "no CRRT" was -1.4 mg/dL (95% CI, -14.2 to 11.5 mg/dL; p = 0.78). Comparing "CRRT with hemoadsorption" and "no CRRT," it was -9.4 mg/dL (95% CI, -20.8 to 2.1 mg/dL; p = 0.0854). Only 1/9 patients (11%, "no CRRT" group) survived day 30 after study inclusion but died on day 89. IL-6, liver function parameters, and clinical scores were similar between the study groups. CONCLUSIONS: CYTOHEP failed to demonstrate that extracorporeal hemoadsorption combined with CRRT can reduce serum bilirubin in ACLF patients with acute kidney failure.

Mesenchymal stem cell-regulated miRNA-mRNA landscape in acute-on-chronic liver failure.

BACKGROUND: Acute-on-chronic liver failure (ACLF) is a major challenge in the field of hepatology. While mesenchymal stem cell (MSC) therapy can improve the prognosis of patients with ACLF, the molecular mechanisms through which MSCs attenuate ACLF remain poorly understood. We performed global miRNA and mRNA expression profiling via next-generation sequencing of liver tissues from MSC-treated ACLF mice to identify important signaling pathways and major factors implicated in ACLF alleviation by MSCs. METHODS: Carbon tetrachloride-induced ACLF mice were treated with saline or mouse bone marrow-derived MSCs. Mouse livers were subjected to miRNA and mRNA sequencing. Related signal transduction pathways were obtained through Gene Set Enrichment Analysis. Functional enrichment, protein-protein interaction, and immune infiltration analyses were performed for the differentially expressed miRNA target genes (DETs). Hub miRNA and mRNA associated with liver injury were analyzed using LASSO regression. The expression levels of hub genes were subjected to Pearson's correlation analysis and verified using RT-qPCR. The biological functions of hub genes were verified in vitro. RESULTS: The tricarboxylic acid cycle and peroxisome proliferator-activated receptor pathways were activated in the MSC-treated groups. The proportions of liver-infiltrating NK resting cells, M2 macrophages, follicular helper T cells, and other immune cells were altered after MSC treatment. The expression levels of six miRNAs and 10 transcripts correlated with the degree of liver injury. miR-27a-5p was downregulated in the mouse liver after MSC treatment, while its target gene E2f2 was upregulated. miR-27a-5p inhibited E2F2 expression, suppressed G1/S phase transition and proliferation of hepatocytes, in addition to promoting their apoptosis. CONCLUSIONS: This is the first comprehensive analysis of miRNA and mRNA expression in the liver tissue of ACLF mice after MSC treatment. The results revealed global changes in hepatic pathways and immune subpopulations. The miR-27a-5p/E2F2 axis emerged as a central regulator of the MSC-induced attenuation of ACLF. The current findings improve our understanding of the molecular mechanisms through which MSCs alleviate ACLF.

The Immunoregulatory and Regenerative Potential of Activated Human Stem Cell Secretome Mitigates Acute-on-Chronic Liver Failure in a Rat Model.

Acute-on-chronic liver failure (ACLF) is a syndrome marked by sudden liver function decline and multiorgan failure, predominantly acute kidney injury (AKY), in patients with chronic liver disease. Unregulated inflammation is a hallmark of ACLF; however, the key drivers of ACLF are not fully understood. This study explores the therapeutic properties of human mesenchymal stem cell (MSC) secretome, particularly focusing on its enhanced anti-inflammatory and pro-regenerative properties after the in vitro preconditioning of the cells. We evaluated the efficacy of the systemic administration of MSC secretome in preventing liver failure and AKI in a rat ACLF model where chronic liver disease was induced using by the administration of porcine serum, followed by D-galN/LPS administration to induce acute failure. After ACLF induction, animals were treated with saline (ACLF group) or MSC-derived secretome (ACLF-secretome group). The study revealed that MSC-secretome administration strongly reduced liver histological damage in the ACLF group, which was correlated with higher hepatocyte proliferation, increased hepatic and systemic anti-inflammatory molecule levels, and reduced neutrophil and macrophage infiltration. Additionally, renal examination revealed that MSC-secretome treatment mitigated tubular injuries, reduced apoptosis, and downregulated injury markers. These improvements were linked to increased survival rates in the ACLF-secretome group, endorsing MSC secretomes as a promising therapy for multiorgan failure in ACLF.

Evolution of Liver Transplantation Indications: Expanding Horizons.

Liver transplantation (LT) has significantly transformed the prognosis of patients with end-stage liver disease and hepatocellular carcinoma (HCC). The traditional epidemiology of liver diseases has undergone a remarkable shift in indications for LT, marked by a decline in viral hepatitis and an increase in metabolic dysfunction-associated steatotic liver disease (MASLD), along with expanded indications for HCC. Recent advancements in surgical techniques, organ preservation and post-transplant patients' management have opened new possibilities for LT. Conditions that were historically considered absolute contraindications have emerged as potential new indications, demonstrating promising results in terms of patient survival. While these expanding indications provide newfound hope, the ethical dilemma of organ scarcity persists. Addressing this requires careful consideration and international collaboration to ensure equitable access to LT. Multidisciplinary approaches and ongoing research efforts are crucial to navigate the evolving landscape of LT. This review aims to offer a current overview of the primary emerging indications for LT, focusing on acute-on-chronic liver failure (ACLF), acute alcoholic hepatitis (AH), intrahepatic and perihilar cholangiocarcinoma (i- and p-CCA), colorectal liver metastasis (CRLM), and neuroendocrine tumor (NET) liver metastases.

[Epidemiological characteristics of inpatients with liver failure at the Beijing You'an Hospital from 2012 to 2021].

Objective: To elucidate the epidemiological characteristics and changing trends of liver failure in order to provide evidence-based strategies for prevention and treatment. Methods: The epidemiological information of inpatients with liver failure admitted and treated at Beijing You'an Hospital from 2012 to 2021 was retrospectively collected. The trend test was used to analyze age, gender, as well as the year-by-year changes in the underlying acute and chronic etiology of acute liver failure (ALF), sub-acute liver failure (SALF), acute-on-chronic liver failure (ACLF), and chronic liver failure (CLF). Results: During the study period, information on a total of 8512 inpatients, aged 51.3±13.5 years and mainly male (71.9%) with liver failure, was collected. The highest to lowest proportions of liver failure types were ACLF 4 023 (47.3%), CLF 3 571(42.0%), SALF 670 (7.9%), and ALF 248 (2.9%). The top five causes of liver failure in the overall population, accounting for 87.6% of the total, were hepatitis B 3 199 (37.58%), alcoholic liver disease 2 237 (26.28%), cryptogenic liver disease 906(10.61%), hepatitis B + alcoholic liver disease 603 (7.08%), drugs 488 (5.73%), The top three etiologies of patients with different types of liver failure were acute etiologies for acute liver failure (ALF), followed by drugs 107 (43.1%), hepatitis B 47(19.0%), and unknown etiology 36 (14.5%); sub-acute liver failure (SALF), followed by drugs 381(56.9%), unknown etiology 106 (15.8%), and sepsis 56 (8.4%); and acute-on-chronic liver failure (ACLF), followed by drugs 2 092(52.0%), alcoholic liver disease 813(20.2%), and cryptogenic liver disease 398(9.9%); and chronic etiologies for chronic liver failure (CLF), followed by alcoholic liver disease 1 410(39.5%), hepatitis B 1 028(28.8%), and cryptogenic liver disease 364(10.2%). Longitudinal analysis showed that the average age of patients with liver failure increased year by year, but the sex ratio trend did not change significantly, with male patients predominating throughout. The proportion of drug-induced liver failure in patients with ALF and SALF increased year by year, and the difference in the trend test was statistically significant (P < 0.05). The proportion of patients with chronic etiologies of ACLF and CLF decreased year by year among hepatitis B, while the proportion of alcoholic liver disease, autoimmune liver disease, and cryptogenic liver disease increased year by year (the difference was statistically significant, P < 0.05). Conclusion: The etiological spectrum of liver failure is changing in our country. Although hepatitis B is still the main cause of liver failure, its proportion shows a decreasing trend year by year, with the exception of ACLF, which is no longer the primary etiology of other types of liver failure, while drug-induced liver disease, alcoholic liver disease, autoimmune liver disease, and cryptogenic liver disease are increasing year by year and will become the focus of liver disease prevention and treatment in the future.

[Experimental study on the inhibition of the NLRP3 signaling pathway with Shengsan Jiedu Huayu decoction to alleviate inflammatory injury in rats with acute-on-chronic liver failure].

Objective: To observe the therapeutic effect of Shengsan Jiedu Huayu decoction in alleviating inflammatory liver injury in rats with acute-on-chronic liver failure (ACLF) and its effect on the activation intensity for the NLRP3 signaling pathway. Methods: 63 SD rats were randomly divided into a blank group, a model group, and low-, medium-, and high-dose groups of Shengsan Jiedu Huayu decoction (7.29 g/kg/d, 14.58 g/kg/d, and 29.16 g/kg/d). The ACLF rat model was replicated using carbon tetrachloride combined with d-galactosamine and lipopolysaccharide. Different dose gradients of the Shengsan Jiedu Huayu decoction were used for a five-day intervention treatment, and then rat serum and tissue samples were collected. A biochemical analyzer was used to detect the serum levels of ALT, AST, and TBIL in rats. ELISA was used to detect serum IL-18 and IL-1ß content. HE staining was used to observe histomorphological changes in liver tissue. Immunohistochemistry was used to detect GSDMD expression in liver tissue. Western blot and PCR were used to detect NLRP3, Caspase1, ASC, TLR4, IL-1ß, IL-18 protein, and mRNA expression levels.The groups were compared using analysis of variance and the rank-sum test. Results: Compared with the blank group, the model group's rat liver tissue was severely injured. Serum levels of ALT, AST, and TBIL, inflammatory factors IL-1ß and IL-18, and the GSDMD protein expression level, NLRP3 expression level, TLR4, caspase 1, ASC, IL-1ß, IL-18 protein, and mRNA (P<0.01) were all significantly increased in the model than the blank group (P<0.01). Additionally, compared with the model group, the low-, medium-, and high-dose groups of Shengsan Jiedu Huayu decoction had improved liver tissue injury in ACLF rats, while the serum levels of ALT, AST, TBIL, IL-1ß, IL-18, liver tissue GSDMD protein, NLRP3, TLR4, caspase 1, and ASC expressions were all lower in the different dose gradients of the Shengsan Jiedu Huayu decoction than the model group, with the most evident reduction in the high-dose group (P<0.01). Conclusion: Shengsan Jiedu Huayu decoction can weaken the activation intensity of the NLRP3 signaling pathway, alleviate liver tissue pathological injury, reduce inflammatory factor release, and alleviate inflammatory liver injury in ACLF rats.