Mechanisms and treatment approaches for ACLF

Novel prognostic scoring models for hepatitis B virus-related acute-on-chronic liver failure: A comparison with classical models

Early diagnosis and accurate prognostic evaluation are important for guiding clinical treatment and reducing mortality in patients with hepatitis B virus (HBV)-related acute-on-chronic liver failure (ACLF). The present study established novel prognostic scoring models to guide the clinical treatment of patients with HBV-ACLF. We performed a retrospective analysis of clinical data from two cohorts of patients diagnosed with HBV-ACLF. By comparing differences in baseline characteristics and clinical indicators between the survival (n = 102) and dead (n = 64) groups in the derivation cohort(n = 166), four laboratory indicators (age, INR, TBIL, and HBeAg status) and three clinical signs (extrahepatic infection, ascites, and hepatic encephalopathy) were identified as independent risk factors. Logistic regression and nomogram models were used to construct three novel predictive models. By comparing the death and survival groups, we found that the three new models had higher predictions for AUROC (average of 0.856) than the three old models (average of 0.773). Model 1 had the strongest predictive power for the short-term survival rate of HBV-ACLF patients. Finally, we verified the predictive value of the new models for HBV-ACLF in a validation cohort (n = 42), and the Model 2 demonstrated good predictive accuracy for the 30-day survival rate of patients. The novel model based on seven predictors could accurately predict short-term mortality in patients with HBV-ACLF, which is promising for guiding clinical management and addressing the aetiological differences in Asian populations.

Comparison of Open Albumin Dialysis (OPAL) With Prometheus Fractionated Plasma Separation and Adsorption (FPSA) and Standard Medical Treatment for Acute-On-Chronic Liver Failure

BACKGROUND

Acute-on-chronic liver failure (ACLF) is associated with high short-term mortality of up to 40%. Albumin dialysis is a therapeutic option that can be used to bridge patients with ACLF to liver transplantation or recovery.

METHODS

This retrospective cohort study was conducted to determine the effectiveness and adverse effects of open albumin dialysis (OPAL) by comparing the biochemical and clinical variables of model for end-stage liver disease (MELD)-matched ACLF patients who received one of three treatments: OPAL plus standard medical treatment (SMT; 22 patients), Prometheus dialysis fractionated plasma separation and adsorption (FPSA) plus SMT (41 patients), or hemodialysis plus SMT (24 patients) at the University Hospital Essen.

RESULTS

OPAL treatment significantly reduced liver function tests such as bilirubin (p = 0.0001) and creatinine levels (p = 0.049). Therefore, OPAL therapy significantly reduced the MELD score (p = 0.001) and the Chronic Liver Failure Consortium (CLIF-C) ACLF (p = 0.0005) score. In both extracorporeal liver support groups, the decrease in MELD score was significantly stronger than that achieved with SMT (OPAL vs. SMT, p = 0.002; Prometheus vs. SMT, p = 0.0001; OPAL vs. Prometheus p = 0.90). In comparison to the SMT group, survival rates after 14 and 30 days were significantly higher in the Prometheus group (p = 0.0008 and 0.03) and tended to be better in the OPAL group, although statistical significance was not reached (p = 0.06 and p = 0.11).

CONCLUSIONS

Our analysis revealed OPAL is an efficient method of albumin dialysis yielding a reduction of bilirubin and creatinine levels and improving clinical scoring in ACLF patients. OPAL as well as Prometheus were associated with a stronger reduction of relevant biochemical variables of liver function and amelioration in clinical scoring in comparison to SMT. However, it should be considered that patients from the SMT group were older and experienced progressive ACLF with high mortality risks compared to the patients from the OPAL and Prometheus groups. Thus, when interpreting the study results, several limitations including small sample size and heterogeneity of the treatment groups due to the lack of randomization should be taken into account.

The Kidney and Extracorporeal Therapies in Acute-on-Chronic Liver Failure: What the Nephrologist Needs to Know

In this review, we discuss the pathophysiology and management of acute kidney injury (AKI) in the setting of acute-on-chronic liver failure (ACLF). ACLF is characterised by the occurrence of acute hepatic and/or extrahepatic organ failure, induced by immune dysregulation and systemic inflammation in patients with chronic liver disease. Kidney involvement is common, with AKI occurring in 30% to > 95% of ACLF patients, depending on the definition used. Since there is a lack of kidney biopsy data in these patients, the underlying pathophysiological basis of AKI remains incompletely understood, and systemic inflammation is believed to be the primary driver of organ injury. The management of AKI has been largely extrapolated from studies in decompensated cirrhosis, and there is little data specifically in the ACLF setting. However, available evidence suggests that structural kidney injury is more common in ACLF than in decompensated CLD, and therefore, AKI in ACLF is less likely to respond to volume repletion and vasopressors. Treatment options remain limited for those who are non-responsive to intravenous fluids and vasopressors. Liver transplantation (LT), with or without kidney transplantation, is the definitive treatment for these patients. At present, extracorporeal therapies such as therapeutic plasma exchange and kidney replacement therapies play a supportive role in ACLF as a bridge to LT; however, the optimal timing and dosing remain unclear. While theoretically, extracorporeal therapies have the potential to reverse or halt progression of organ damage in ACLF, there is limited evidence currently.

Acute-on-Chronic Liver Failure: Steps Towards Consensus

Acute-on-chronic liver failure (ACLF) is a clinical syndrome characterized by organ failure and high short-term mortality. Since its first definition in 2013, many international organizations have defined this syndrome and, till now, there has been no agreement regarding definitions and diagnostic criteria. Although the precise mechanism of ACLF is unknown, precipitant factors and the systemic inflammation response play a major role. Specific management of this high-mortality syndrome is still under development, but a general consensus in the diagnosis and management of ACLF is needed.

Single-Cell Transcriptome Identifies a Proinflammatory B-Cell Subset in Hepatitis B Virus Associated Acute-on-Chronic Liver Failure

Acute-on-chronic liver failure (ACLF) is a severe clinical condition with high short-term mortality, in part due to the dysfunctional immune response. Identifying immune mechanism under ACLF is critical to understand its pathogenesis and to develop novel targeted therapeutics. Among the immune cells, how are B cells involved in ACLF remains largely unknown. We performed scRNA-seq on peripheral blood mononuclear cells from clinical ACLF patients and healthy controls. Integrated analysis was performed to identify the role of B cells in ACLF. Subsequently, different subsets of B cells in ACLF were validated through flow cytometry based on their highlighted markers. Six B-cell subgroups, including naive B cells, naive B2 cells, nonclass-switched memory B cells, class-switched memory B cells, autoimmune-related B cells and plasma B cells were identified. The proportions of naive B cells significantly expand in ACLF, compared with healthy control. Function enrichment analysis revealed the activation of inflammatory response in naive B cells. Further flow cytometry confirmed the elevated circulating naive B cells in ACLF. Our study uncovered the altered immune landscape of circulating B cells after ACLF. The proportion dynamics and functional perturbation indicate the potential of naive B cells as intervention targets in the future ACLF therapy.

A nomogram model based on albumin-bilirubin score for predicting 90-day prognosis in patients with acute-on-chronic liver failure

Objective

To develop a nomogram model based on the albumin-bilirubin (ALBI) score for predicting the 90-day prognosis of patients with acute-on-chronic liver failure (ACLF) and to evaluate its predictive efficacy.

Methods

Clinical data of 290 ACLF patients at the Third People's Hospital of Nantong City, collected from December 2020 to December 2023, were analyzed. The data were divided into a training set (n = 200) and a validation set (n = 90), with August 2022 as the cut-off date. Patients in the training set were categorized into an improvement group (n = 133) and a mortality group (n = 67) based on their 90-day outcomes. The predictive power of baseline parameters was assessed using univariate and multivariate logistic regression to construct model. Model performance was assessed using receiver operating characteristic (ROC) curves, calibration curves, decision curve analysis (DCA) and the Hosmer-Lemeshow test.

Results

Creatinine (CR) [odds ratio (OR) = 1.013, 95% confidence interval (CI): 1.004-1.022], ALBI (OR = 10.831, 95% CI: 4.009-33.247), Gender (OR = 1.931, 95% CI: 0.973-3.870) and ascites (OR = 3.032, 95% CI: 1.249-8.178) were identified as independent prognostic factors. The prognostic model formula was derived as prognostic index (PI) = -0.591 + 0.658 × Gender + 1.109 × ascites + 0.012 × CR + 2.382 × ALBI. The area under the curve (AUC) was 0.804 (95% CI: 0.741-0.866), with a specificity of 85.0% and a sensitivity of 65.7% at a cut-off of 0.425. The AUC of the validation set was 0.811 (95% CI: 0.697-0.926). The Hosmer-Lemeshow test indicated a good model fit with a p-value of 0.287 for the training set and 0.423 for the validation set. Calibration curves demonstrated the accuracy of the model, and DCA results suggested that the model was clinically useful when the threshold was below 0.6.

Conclusion

The nomogram model incorporating ALBI with CR, Gender and ascites can predict the 90-day prognosis of ACLF patients, potentially helping to optimize treatment strategies and improve patient outcomes.

Mechanisms and implications of recompensation in cirrhosis

Decompensated cirrhosis has long been considered the irreversible end stage of liver disease, characterised by further decompensating events until death or liver transplantation. However, the observed clinical improvements after effective antiviral treatments for HBV and HCV and after sustained alcohol abstinence have changed this paradigm, leading to the concept of "recompensation" of cirrhosis. Recompensation of cirrhosis was recently defined by Baveno VII as (i) cure of the primary liver disease aetiology; (ii) disappearance of signs of decompensation (ascites, encephalopathy and portal hypertensive bleeding) off therapy; and (iii) stable improvement of liver function tests (bilirubin, international normalised ratio and albumin). Achieving these recompensation criteria is linked to a significant survival benefit. However, apart from aetiological therapies, no interventions/treatments that facilitate recompensation are available, the molecular mechanisms underlying recompensation remain incompletely understood, and early predictors of recompensation are lacking. Moreover, current recompensation criteria are based on expert opinion and may be refined in the future. Herein, we review the available evidence on cirrhosis recompensation, provide guidance on the clinical management of recompensated patients and discuss future challenges related to cirrhosis recompensation.

Evidence-based incorporation of key parameters into MELD score for acute-on-chronic liver failure

BACKGROUND

The model for end-stage liver disease (MELD) score is widely used for the prognostication in end-stage liver disease but has limited performance in acute-on-chronic liver failure (ACLF). In this study, we identified additional predictive parameters and reformed the MELD score to predict ACLF more accurately.

METHODS

A meta-analysis was performed on relevant studies to identify the predictive factors of 28-day/90-day outcomes of ACLF, which were validated in two large prospective cohorts. A prognostic score was developed by incorporating predictive parameters into the MELD score. The model was evaluated with a focus on discrimination and calibration.

RESULTS

The meta-analysis incorporated 32 cohort studies with a total of 13 939 patients, of which 13 risk factors were identified, and 3 risk factors (age, neutrophil count and hepatic encephalopathy (HE) grade) besides MELD score were validated in 751 patients with ACLF derived from two prospective cohorts. A new model (Chinese Acute-on-Chronic Liver Failure Consortium (CATCH-LIFE)-MELD score) was developed as follows: 0.028×age+0.3×HE grade+0.039×neutrophil count+0.079×MELD score. CATCH-LIFE-MELD score achieved a concordance index of 0.791/0.788 for 28-day/90-day outcomes, which is superior to other traditional scores. Other discrimination indices, including net reclassification improvement, integrated discrimination improvement and probability density function, and calibration including Nagelkerke's R2 and Brier scores confirmed its superiority. Moreover, the accuracy of CATCH-LIFE-MELD score remained stable. It was highest in patients with or without hepatitis B virus infection, cirrhosis, liver failure or under the Chinese Group on the Study of Severe Hepatitis B (COSSH) criteria or European Association for the Study of the Liver (EASL) criteria. All results were substantiated by an evaluation using an external cohort.

CONCLUSIONS

CATCH-LIFE-MELD score, a modified MELD score exhibited improved accuracy in predicting the short-term prognosis of ACLF than other traditional scores.

Hypermethylation of the glutathione peroxidase 4 promoter predicts poor prognosis in patients with hepatitis B virus-associated acute-on-chronic liver failure

BACKGROUND

Hepatitis B virus-associated acute-on-chronic liver failure (HBV-ACLF) is a syn-drome with a high short-term mortality rate, and its prognosis is critical in clinical management. This study aimed to investigate the clinical significance of glutathione peroxidase 4 (GPX4) in the occurrence and development of HBV-ACLF and its prognostic value for 90-day mortality.

METHODS

The expression levels of GPX4, oxidative stress-related molecules and inflammatory cytokines in serum or peripheral blood mononuclear cells (PBMCs) of 289 participants were determined by RT-qPCR or ELISA, and the methylation level of GPX4 promoter in PBMCs was determined by MethyLight.

RESULTS

The expression levels of GPX4 in the PBMCs and serum of HBV-ACLF patients were lower than those in non-HBV-associated acute-on-chronic liver failure (non-HBV ACLF) patients, patients with chronic hepatitis B (CHB) and healthy control (HC) individuals, while the methylation level of the GPX4 promoter was greater. In HBV-ACLF patients, the methylation level of the GPX4 promoter is correlated with oxidative stress, inflammation-related molecules, and some clinicopathological indicators. The methylation level of the GPX4 promoter was identified as an independent risk factor for 90-day mortality in HBV-ACLF patients and yielded a larger area under the receiver operating characteristic curve (AUROC) than the model for end-stage liver disease (MELD) score in predicting 90-day mortality.

CONCLUSION

The GPX4 promoter methylation level has promising potential as a predictor of 90-day mortality in patients with HBV-ACLF.

Baicalein upregulates macrophage TREM2 expression via TrKB-CREB1 pathway to attenuate acute inflammatory injury in acute-on-chronic liver failure

OBJECTIVE

Acute-on-chronic liver failure (ACLF) is a syndrome characterized by a high short-term mortality rate, and effective interventions are still lacking. This study aims to investigate whether the small molecule baicalein can mitigate ACLF and elucidate the molecular mechanisms.

METHODS

The ACLF mouse model was induced through chronic liver injury using carbon tetrachloride, followed by acute inflammation induction with lipopolysaccharide (LPS). Baicalein was administered through intraperitoneal injection to explore its therapeutic effects. In vitro experiments utilized the iBMDM macrophage cell line to investigate the underlying mechanisms. Peripheral blood was collected from clinical ACLF patients for validation.

RESULTS

In the LPS-induced ACLF mouse model, baicalein demonstrated a significant reduction in acute inflammation and liver damage, as evidenced by histopathological evaluation, liver function analysis, and inflammatory marker measurements. Transcriptomic analysis, coupled with molecular biology experiments, uncovered that baicalein exerts its effects in ACLF by activating the TrKB-CREB1 signaling axis to upregulate the surface expression of the TREM2 receptor on macrophages. This promotes M2 macrophage polarization and activates efferocytosis, thereby inhibiting inflammation and alleviating liver damage. Furthermore, we observed a substantial negative correlation between postoperative peripheral blood plasma soluble TREM2 (sTREM2) levels and inflammation, as well as adverse outcomes in clinical ACLF patients.

CONCLUSION

Baicalein plays a protective role in ACLF by enhancing the surface expression of the TREM2 receptor on macrophages, leading to the suppression of inflammation, mitigation of liver damage, and a reduction in mortality. Additionally, plasma sTREM2 emerges as a critical indicator for predicting adverse outcomes in ACLF patients.

Acute decompensation of cirrhosis versus acute-on-chronic liver failure: What are the clinical implications?

It is essential to identify the subgroup of patients who experience poorer outcomes in order to adapt clinical management effectively. In the context of liver disease, the earlier the identification occurs, the greater the range of therapeutic options that can be offered to patients. In the past, patients with acute decompensation (AD) of chronic liver disease were treated as a homogeneous group, with emphasis on identifying those at the highest risk of death. In the last 15 years, a differentiation has emerged between acute-on-chronic liver failure syndrome (ACLF) and AD, primarily due to indications that the latter is linked to a less favorable short-term prognosis. Nevertheless, the definition of ACLF varies among the different knowledge societies, making it challenging to assess its true impact compared with AD. Therefore, the purpose of this review is to provide a detailed analysis emphasizing the critical importance of identifying ACLF in the field of advanced liver disease. We will discuss the differences between Eastern and Western approaches, particularly in relation to the occurrence of liver failure and disease onset. Common characteristics, such as the dynamic nature of the disease course, will be highlighted. Finally, we will focus on two key clinical implications arising from these considerations: the prevention of ACLF before its onset and the clinical management strategies once it develops, including liver transplantation and withdrawal of care.