Acute-on-Chronic Liver Failure: Pathophysiological Mechanisms and Management

Hepatofugal portal flow is highly predictive of acute-on-chronic liver failure: A new hemodynamic patho-physiological hypothesis

BACKGROUND AND AIMS

Acute-on-chronic liver failure (ACLF) is a severe complication of advanced liver disease. A significant number of ACLF patients have not clear precipitating factors. The aim of the study was to investigate the role of alterations in porto-hepatic hemodynamics, especially non-forward portal flow (NFPF), in ACLF and liver-related mortality.

METHODS

233 cirrhotic patients were included in the study with a median follow-up of 24 months. Color-Doppler ultrasound was used to assess portal vein patency, flow direction and significant porto-systemic collaterals (>8 mm). Patients with active cancer, both at baseline and during follow-up and severe non liver-related comorbidities were excluded. ACLF and liver-related mortality were recorded during follow-up.

RESULTS

Fifty-six patients (24%) developed ACLF; 24 (10,3%) had baseline NFPF. In survival analysis, NFPF, but not portal vein thrombosis, was independently associated with ACLF development (HR 2.85 95% C.I. [1.49-5.42], p = 0.001) and liver-related mortality (HR 2.24 95% C.I. [1.16-4.28], p = 0.015), even after adjustment for liver disease severity scores, age and etiology of liver disease.

CONCLUSION

NFPF is independently associated with ACLF development and liver-related mortality, regardless of etiology, severity disease scores and portal vein thrombosis. Although there is no specific measure to reverse NFPF, patients with NFPF should receive prompt intensive management and urgent prioritization for liver transplantation.

CLINICAL TRIAL NUMBER

2730 CESC.

HSPB1 alleviates acute-on-chronic liver failure via the P53/Bax pathway

The mortality rate of acute-on-chronic liver failure (ACLF) remains significantly elevated; hence, this study aimed to investigate the impact of heat shock protein family B (small) member 1 (HSPB1) on ACLF in vivo and in vitro and the underlying mechanism. This study used the ACLF mouse model, and liver damage extent was studied employing Masson trichrome, hematoxylin and eosin (H&E), Sirius red staining, and serum biochemical indices. Similarly, hepatocyte injury in lipopolysaccharide (LPS)-induced L02 cells was evaluated using cell counting kit-8 assay, enzymatic activity, flow cytometry, and TUNEL assay, while the underlying mechanism was investigated using western blot. Results showed that the morphology of liver tissue in ACLF mice was changed and was characterized by cirrhosis, fibrosis, collagen fiber deposition, inflammatory cell infiltration, and elevated liver injury indices. Moreover, HSPB1 was upregulated in both ACLF patients and mice, where overexpressing HSPB1 was found to inhibit ACLF-induced liver damage. Similarly, the HSPB1 expression in LPS-treated L02 cell lines was also increased, where overexpressing HSPB1 was found to promote cell viability, inhibit liver injury-related enzyme activity, and suppress apoptosis. Mechanistic investigations revealed that HSPB1 was responsible for inhibiting p-P53 and Bax protein levels, where activated P53 counteracted HSPB1's effects on cellular behaviors. In conclusion, HSPB1 attenuated ACLF-induced liver injury in vivo and inhibited LPS-induced hepatocyte damage in vitro, suggesting that HSPB1 may be a novel target for ACLF therapy.

Prognostic Value of Platelet-to-Monocyte Ratio for Mortality in HBV-Related Acute-on-Chronic Liver Failure

Purpose

Hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) is a critical condition associated with unfavorable survival rates. Recent studies have indicated that the platelet-to-monocyte ratio (PMR) is considered an effective prognostic marker in several diseases. However, there has been no study to evaluate the prognostic value of PMR in HBV-ACLF patients. Therefore, this study aimed to investigate the association between PMR and 28-day survival in these patients.

Methods

In this retrospective study, data, including clinical and laboratory parameters, were collected for 184 HBV-ACLF patients. Disease severity was assessed using the Model for End-Stage Liver Disease (MELD) score. Logistic regression analyses were conducted to identify predictors influencing 28-day survival. Receiver-operating characteristic curve (ROC) analyses were performed to assess the predictive abilities of the identified predictors.

Results

During the 28-day follow-up period, 56 (30.4%) HBV-ACLF patients died. PMR was significantly lower in non-survivors than in survivors (P <0.001). Logistic regression demonstrated that PMR (Odds ratio, 0.983; 95% Confidence interval, 0.976-0.990; P=0.001) and MELD score (Odds ratio, 1.317; 95% Confidence interval, 1.200-1.446; P <0.001) were independent risk factors for mortality in HBV-ACLF patients. The area under ROC curve for PMR was 0.760 (sensitivity=0.840, specificity=0.620, P=0.001) at a cut-off value of 140.6, and the area under ROC curve for MELD score was 0.819 (sensitivity=0.700, specificity=0.860, P=0.001) at a cut-off value of 23.1. PMR and MELD score exhibited similar predictive performances (Z=1.229; P=0.219). Furthermore, the combined use of PMR and MELD score further increased the area under the ROC curve to 0.858, which more accurate prognosis prediction than use of either factor alone (both P< 0.05).

Conclusion

The PMR could serve as a reliable tool for predicting mortality in HBV-ACLF patients. Additionally, combining the PMR with the MELD score could improve prognostic accuracy for predicting 28-day mortality in these patients. However, further and larger studies are needed to confirm our findings.

Nucleic acid-based nanotherapeutics for treating sepsis and associated organ injuries

In recent years, gene therapy has been made possible with the success of nucleic acid drugs against sepsis and its related organ dysfunction. Therapeutics based on nucleic acids such as small interfering RNAs (siRNAs), microRNAs (miRNAs), messenger RNAs (mRNAs), and plasmid DNAs (pDNAs) guarantee to treat previously undruggable diseases. The advantage of nucleic acid-based therapy against sepsis lies in the development of nanocarriers, achieving targeted and controlled gene delivery for improved efficacy with minimal adverse effects. Entrapment into nanocarriers also ameliorates the poor cellular uptake of naked nucleic acids. In this study, we discuss the current state of the art in nanoparticles for nucleic acid delivery to treat hyperinflammation and apoptosis associated with sepsis. The optimized design of the nanoparticles through physicochemical property modification and ligand conjugation can target specific organs-such as lung, heart, kidney, and liver-to mitigate multiple sepsis-associated organ injuries. This review highlights the nanomaterials designed for fabricating the anti-sepsis nanosystems, their physicochemical characterization, the mechanisms of nucleic acid-based therapy in working against sepsis, and the potential for promoting the therapeutic efficiency of the nucleic acids. The current investigations associated with nanoparticulate nucleic acid application in sepsis management are summarized in this paper. Noteworthily, the potential application of nanotherapeutic nucleic acids allows for a novel strategy to treat sepsis. Further clinical studies are required to confirm the findings in cell- and animal-based experiments. The capability of large-scale production and reproducibility of nanoparticle products are also critical for commercialization. It is expected that numerous anti-sepsis possibilities will be investigated for nucleic acid-based nanotherapeutics in the future.

Chishao - Fuzi herbal pair restore the macrophage M1/M2 balance in acute-on-chronic liver failure

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional herbal pair Paeoniae Radix Rubra (roots of Paeonia lactiflora Pall., Chishao in Chinese) and Aconiti Lateralis Radix Praeparata (lateral roots of Aconitum carmichaelii Debeaux, Fuzi in Chinese) are widely used for the treatment of liver diseases, demonstrating clinical efficacy against acute-on-chronic liver failure (ACLF). As the core drug pair representing the "clearing method" and "warming method" in traditional Chinese medicine (TCM), they align with the TCM syndromic characteristics of ACLF, characterized by a mixture of deficiencies and realities. However, the molecular mechanisms underlying the anti-ACLF effects of Chishao - Fuzi herbal pair remain unclear.

AIM OF THE STUDY

To reveal the immunoinflammatory status of patients with hepatitis B virus-related ACLF (HBV-ACLF) based on macrophage polarization and to explore the mechanism of action of Chishao - Fuzi herbal pair in regulating macrophage polarization against ACLF.

MATERIALS AND METHODS

Peripheral blood samples were prospectively obtained from patients with HBV-ACLF, patients with chronic hepatitis B (CHB) in the immunoactive phase and healthy individuals. Flow cytometry, qRT-qPCR, and ELISA were used to reveal the activation status of monocyte-macrophages and the expression differences in related cytokines in the peripheral blood of patients with HBV-ACLF. Then, an ACLF rat model and a macrophage inflammation model in vitro were established. Hematoxylin-eosin staining, immunohistochemical staining, transmission electron microscopy, flow cytometry, western blotting, RT-qPCR, and ELISA were used to observe changes in the expression of M1/M2 macrophage markers and related inflammatory factors after Chishao - Fuzi herbal pair intervention, both in vivo and in vitro.

RESULTS

Patients with HBV-ACLF exhibited an imbalance in M1/M2 macrophage polarization, showing a tendency to activate M1 macrophages with high expression of CD86 and iNOS. This imbalance led to an increase in relevant pro-inflammatory factors (IL-1β, IL-6, TNF-α) and a decrease in anti-inflammatory factors (IL-10, TGF-β, VEGF), exacerbating the uncontrolled immune-inflammatory response. Chishao - Fuzi herbal pair intervention improved liver function, coagulation function, and histopathological injury in ACLF rats. It also partially ameliorated endotoxemia and inflammatory injury in ACLF. The mechanism was to restore the immune-inflammatory imbalance and prevent the exacerbation of inflammatory response to liver failure by promoting macrophage polarization toward M2 anti-inflammatory direction, inhibiting M1 macrophage activation, and increasing the levels of anti-inflammatory factors and decreasing pro-inflammatory factors.

CONCLUSION

Chishao - Fuzi herbal pair can reduce the systemic inflammatory burden of liver failure by modulating macrophage polarization and restoring ACLF immune-inflammatory imbalance. This study provides new perspectives and strategies for studying HBV-ACLF immune reconstitution and inflammatory response control.

Acute-on-chronic liver failure: a retrospective review of cases at a transplantation center in Brazil

PURPOSE

Acute-on-chronic liver failure (ACLF) is a leading cause of death in cirrhotic patients. This study aims to describe the outcomes of in-patients with ACLF at a liver transplantation (LT) center in Brazil.

METHODS

Retrospective study analyzing patient data from 2017 to 2022. Re-transplant cases and patients without previous chronic liver disease were excluded. The ACLF diagnosis was based on the European Association for the Study of the Liver-Chronic Liver Failure criteria and assessments repeated on days 3 and 7 after the initial diagnosis.

RESULTS

Among 381 patients, 10.49% (n = 40) were diagnosed with ACLF. Bacterial infection was the most common precipitating factor (45%). Kidney failure occurred in 65% of the cases. The 28-day mortality rate was 35% and varied according to ACLF severity at diagnosis, from single organ failure (ACLF-1) at 22% to three organ failures (ACLF-3) at 60%. Eighteen patients (45%) were transplanted with a 100% 28-day survival rate. For ACLF-3 cases at diagnosis (n = 15), the 28-day and 1-year survival rates with a transplant (n = 4) were 100% and 80%, respectively, and without transplant (n = 11), 10 and 0%, respectively.

CONCLUSIONS

ACLF was associated with high mortality rates. LT was an effective therapeutic option, particularly for ACLF-3 cases.

A Clinical Course of Repeated Supratherapeutic Ingestion of Acetaminophen

Acute liver failure (ALF) exemplifies a rapid decline in liver function among individuals with previously healthy livers, often manifesting through symptoms such as jaundice, confusion, and potentially life-threatening complications. Timely medical intervention, and, in severe instances, liver transplantation, are essential for enhancing outcomes and averting further deterioration. While the causes of ALF are multifaceted, in developed nations, it predominantly arises from drug-induced liver injury. Treatment primarily revolves around supportive measures, with severe cases necessitating liver transplantation. In instances where acute overdose with acetaminophen serves as the instigating factor, N-acetylcysteine (NAC) emerges as a pivotal component of management, as indicated by the Rumack-Matthew nomogram. The Rumack-Matthew nomogram guides treatment for acetaminophen overdose by correlating serum levels with the risk of liver damage. If levels exceed a set threshold, NAC is administered to prevent toxicity by replenishing glutathione. The decision to administer NAC is typically guided by this clinical tool, which aids healthcare providers in determining the appropriate course of action. NAC assumes a critical role in ameliorating the detrimental effects of acetaminophen overdose, particularly in averting liver damage, thus holding significant importance in patient care and recovery. While chronic acetaminophen overdose cases leading to ALF may also benefit from NAC, the supporting evidence remains weak. In this context, we present a case of ALF stemming from chronic acetaminophen ingestion, managed with NAC when liver transplantation was not a viable option.

Changes in TNF-α, IL-33, and MIP-1α before and after artificial liver support treatment and their prognostic value

OBJECTIVE

To investigate the effect of ALST (artificial liver support treatment) on inflammatory factors and prognosis in patients with ACLF (acute-on-chronic liver failure).

METHODS

Data of ACLF patients admitted to the No. 2 People's Hospital of Lanzhou from June 2020 to January 2023 were retrospectively analyzed. Patients were compared before and after ALST in terms of ALT (Alanine Aminotransferase), AST (Aspartate Aminotransferase), TBil (Total Bilirubin), Cr (Creatinine), INR (International Normalized Ratio), MELD (Model for End-Stage Liver Disease) scores, as well as TNF-α (Tumor Necrosis Factor-α), IL-33 (Interleukin-33), and MIP-1α (Macrophage Inflammatory Protein-1 α) levels. The ROC (receiver operating characteristic) curve was used to analyze the efficacy of the above indicators in predicting 90-day mortality in patients.

RESULTS

After the treatment, the levels of ALT, AST, TBil, Cr, INR, and MELD score were significantly lower than those before treatment (all P<0.001). Also, the levels of TNF-α, IL-33, and MIP-1α were substantially lower than those before treatment (all P<0.001). TNF-α, IL-33, and MIP-1α were positively correlated with MELD score before and after the treatment (all P<0.01). TNF-α, IL-33, MIP-1α, and MELD score were significantly higher in the death group than in the survival group (all P<0.01). The ROC curves showed that MELD (AUC=0.857), TNF-α (AUC=0.836), IL-33 (AUC=0.749), and MIP-1α (AUC=0.746) had high efficacy in predicting patients' 90-day mortality.

CONCLUSION

ALST can significantly reduce TNF-α, IL-33, and MIP-1α levels in patients with ACLF, and postoperative TNF-α, IL-33, and MIP-1α levels have a high predictive value for patients' prognosis.

Acute-on-Chronic Liver Failure: Causes, Clinical Parameters, and Predictors of Mortality

Objectives This study aimed to identify the causes, clinical characteristics, and 28-day in-hospital mortality predictors in patients with acute-on-chronic liver failure (ACLF). Methods A cross-sectional study enrolled sixty-four patients aged 18-70 years with acute-on-chronic liver failure. The study was conducted at the Gastroenterology Department, Lahore General Hospital. The study classified ACLF according to the criteria of the European Association for the Study of the Liver - Chronic Liver Failure (EASL-CLIF). Patients were followed for 28 days for mortality outcomes. The outcomes between Survivor and Non-survivor groups were compared using the Chi-Square/Fisher's Exact Test for categorical variables and the Mann-Whitney U test for continuous variables. Results In this study, age and duration of chronic liver disease were not significantly different between survivors and non-survivors. The etiology of liver disease and ACLF causes had no impact on 28-day mortality. Non-survivors had lower mean arterial pressure, and higher mortality was linked with lower Glasgow Coma Scale scores, upper gastrointestinal bleeding, and Grade IV hepatic encephalopathy. Significant differences in bilirubin, serum creatinine, urea, and C-reactive protein levels were observed at 28 days. Survival rates were highest with single organ failure (35.94%) and decreased with multiple organ failures. The overall survival rate was 51.56%. Predictive validity for mortality was assessed using the Area Under the Curve (AUC), with Child-Turcotte-Pugh (CTP) at 0.679, Model for End-Stage Liver Disease (MELD) at 0.819, and Chronic Liver Failure-Sequential Organ Failure Assessment (CLIF-SOFA) at 0.771. Conclusion This study concludes that in acute-on-chronic liver failure, factors like age, gender, and disease etiology do not significantly predict 28-day mortality. Key mortality indicators include clinical parameters such as lower Glasgow Coma Scale scores, hepatic encephalopathy Grade IV, and laboratory findings like elevated bilirubin and serum creatinine. The MELD score is the most compelling prognostic tool.

Interprofessional Therapeutic Drug Monitoring of Carbapenems Improves ICU Care and Guideline Adherence in Acute-on-Chronic Liver Failure

(1) Background: Acute-on-chronic liver failure (ACLF) is a severe, rapidly progressing disease in patients with liver cirrhosis. Meropenem is crucial for treating severe infections. Therapeutic drug monitoring (TDM) offers an effective means to control drug dosages, especially vital for bactericidal antibiotics like meropenem. We aimed to assess the outcomes of implementing TDM for meropenem using an innovative interprofessional approach in ACLF patients on a medical intensive care unit (ICU). (2) Methods: The retrospective study was conducted on a medical ICU. The outcomes of an interprofessional approach comprising physicians, hospital pharmacists, and staff nurses to TDM for meropenem in critically ill patients with ACLF were examined in 25 patients. Meropenem was administered continuously via an infusion pump after the application of an initial loading dose. TDM was performed weekly using high-performance liquid chromatography (HPLC). Meropenem serum levels, implementation of the recommendations of the interprofessional team, and meropenem consumption were analyzed. (3) Results: Initial TDM for meropenem showed a mean meropenem serum concentration of 20.9 ± 9.6 mg/L in the 25 analyzed patients. Of note, in the initial TDM, only 16.0% of the patients had meropenem serum concentrations within the respective target range, while 84.0% exceeded this range. Follow-up TDM showed serum concentrations of 15.2 ± 5.7 mg/L (9.0-24.6) in Week 2 and 11.9 ± 2.3 mg/L (10.2-13.5) in Week 3. In Week 2, 41.7% of the patients had meropenem serum concentrations that were within the respective target range, while 58.3% of the patients were above this range. In Week 3, 50% of the analyzed serum concentrations of meropenem were within the targeted range, and 50% were above the range. In total, 100% of the advice given by the interprofessional team regarding meropenem dosing or a change in antibiotic therapy was implemented. During the intervention period, the meropenem application density was 37.9 recommended daily doses (RDD)/100 patient days (PD), compared to 42.1 RDD/100 PD in the control period, representing a 10.0% decrease. (4) Conclusions: Our interprofessional approach to TDM significantly reduced meropenem dosing, with all the team's recommendations being implemented. This method not only improved patient safety but also considerably decreased the application density of meropenem.

Efficacy and safety of tenofovir disoproxil fumarate versus entecavir in the treatment of acute-on-chronic liver failure with hepatitis B: a systematic review and meta-analysis

BACKGROUND

Oral nucleoside (acid) analogues (NAs) are recommended for patients with acute-on-chronic liver failure (ACLF) associated with hepatitis B virus (HBV-ACLF). The efficacy and safety of tenofovir (TDF) and entecavir (ETV) in these patients remain unclear.

METHODS

A comprehensive literature search in PubMed, Web of Science, The Cochrane Library, and Embase database was conducted to select studies published before December 2022 on TDF or ETV for HBV-ACLF. The primary outcomes were survival rates at 4, 12, and 48 weeks. Secondary outcomes were virologic and biochemical responses, serum antigen conversion, liver function score, and safety.

RESULTS

Four prospective and one retrospective cohort studies were selected. The overall analysis showed comparable survival rates at 4, 12, and 48 weeks for all patients receiving TDF or ETV (4-week: RR = 1.17, 95% CI: 0.90-1.51, p = 0.24; 12-week: RR = 1.00, 95% CI: 0.88-1.13, p = 0.94; 48-week: RR = 0.96, 95% CI: 0.58-1.57, p = 0.86). Child-Turcotte-Pugh (CTP) score and model for end-stage liver disease (MELD) score at 12 weeks were comparable in both groups but lower than baseline (CTP: SMD = -0.75, 95% CI:-2.81-1.30, p = 0.47; MELD: SMD = -1.10, 95% CI:-2.29-0.08, p = 0.07). At 48 weeks, estimated glomerular filtration rate (eGFR) levels were found to decrease to different degrees from baseline in both the TDF and ETV groups, and the decrease was greater in the TDF group than in the ETV group. No significant differences were found in biochemical, virologic response, and serum antigen conversion between the two groups during the observation period.

CONCLUSION

TDF treatment of HBV-ACLF is similar to ETV in improving survival, liver function, and virologic response but the effects on renal function in two groups in the long term remain unclear. More and larger long-term clinical trials are required to confirm these findings.

Resolvin D1 promotes the resolution of inflammation in the ACLF rat model by increasing the proportion of Treg cells

OBJECTIVE

Acute-on-chronic liver failure (ACLF) causes organ system failures in patients and increases the risk of mortality. One of the main predictors of ACLF development in patients is the severity of systemic inflammation. The purpose of this study was to explore the effects of resolvin D1 (RvD1) on the rat model of ACLF.

METHODS

The ACLF rats were induced by first intraperitoneally (ip) injecting CCl4 and porcine serum for 6 weeks to establish the chronic liver injury, followed by once administration (ip) of lipopolysaccharide and d-galactose d-GalN to cause acute liver injury (ALI). An hour before the ALI-induced treatment, rats were administrated (ip) with 0.9% saline or different doses of RvD1 (0.3 or 1 µg/kg). Afterward, the control and treated rats were killed and samples were collected. Biochemical analysis, hematoxylin-eosin and Sirius red staining, flow cytometry assay, and real-time polymerase chain reaction were used to assess the rat liver histopathological injury, the percentage of Treg cells in the spleen, and the messenger RNA (mRNA) levels of transcription factors and immunologic cytokines in liver.

RESULTS

The necroinflammatory scores and the serum levels of transaminase significantly increased in ACLF rats compared with those in control rats. These impaired changes observed in ACLF rats could be attenuated by the administration of a low dose of RvD1 before the induction of ALI, which was associated with the increased proportion of regulatory T cells (Treg) in the spleen together with the increased gene expression ratio of Foxp3/RORγt and decreased mRNA level of Il-17a and Il-6 in the liver.

CONCLUSION

A low dose of RvD1 can promote the resolution of inflammation in ACLF rats by increasing the proportion of Treg cells. RvD1, therefore, may be used as a potential drug for the treatment of patients with ACLF.

Identification of oxidative stress-related biomarkers associated with the development of acute-on-chronic liver failure using bioinformatics

Acute-on-chronic liver failure (ACLF) is a serious stage of chronic liver disease with high short-term mortality and no definitely effective treatment. Oxidative stress (OS) is involved in the development of ACLF. OS-related genes targeted therapy may provide additional assistance for the treatment of ACLF. ACLF related gene sets and oxidative stress-related genes (OSGs) were respectively downloaded from gene expression omnibus (GEO) database and GeneCards database for integrated bioinformatics analyses (functional enrichment, weighted gene co-expression network and immune cells infiltration). Immune-related differentially expressed oxidative stress-related genes (DEOSGs) in ACLF were used for construction of protein-protein interaction (PPI) network in which hub genes were screened out. Hub genes with consistently good diagnostic or prognostic value for ACLF in four gene sets were named as key genes. DEOSGs were significantly enriched in biological process and signaling pathways related to inflammation, immune response and oxidative stress. Six key genes (MPO, CCL5, ITGAM, TLR2, TLR4, and TIMP1) were identified and found to be highly correlated with immune response and metabolic process. This study deepened our understanding of the impact of oxidative stress on the pathogenesis and prognosis of ACLF and provided more insights into the prediction of prognosis and molecular targeted therapy in ACLF.

Serum interleukin-6 level predicts the prognosis for patients with alcohol-related acute-on-chronic liver failure

AIM

Heavy alcohol consumption is the most common etiology of acute-on-chronic liver failure (ACLF) in Japan. In some patients, ACLF is associated with a fatal outcome in less than 6 months. We evaluated the prognosis of patients with alcohol-related ACLF in our cohort and explored the prognostic factors.

METHODS

Forty-six patients with alcoholic liver cirrhosis who fulfilled the Japanese diagnostic criteria for ACLF, including those classified as extended and/or probable, were enrolled in this study. Serum concentrations of inflammatory cytokines (interleukin [IL]-1β, IL-6, IL-8, IL-10, IL-12p70 and TNFα) were measured. We assessed prognosis and identified factors associated with survival.

RESULTS

During the median 33-day observation period, 19 patients died, and 3 patients underwent living donor liver transplantation. Cumulative survival rates of patients treated without liver transplantation were 69, 48, 41, and 36% at 1, 3, 6, and 12 months, respectively. Eighteen of the 19 deceased patients died within 6 months after ACLF diagnosis. Serum concentrations of inflammatory cytokines were significantly elevated, and patients who underwent liver transplantation or who died within 6 months after admission had significantly higher serum IL-6 levels than the survival group. Multivariate analysis identified IL-6 > 23.3 pg/mL at admission and model for end-stage liver disease (MELD) score ≥ 25 on day 4 of admission as significant independent factors for mortality within 6 months.

CONCLUSION

Serum IL-6 level and Day-4 MELD were prognostic factors for alcohol-related ACLF. Early liver transplantation is a potential treatment option for patients whose prognosis is expected to be poor.

Acute on Chronic Liver Failure in Patients with Alcohol-Associated Hepatitis: A Review

Acute on chronic liver failure (ACLF) is a unique disease process associated with significant short-term mortality wherein patients with either chronic liver disease or cirrhosis suffer rapid decompensation in hepatic function accompanied by extrahepatic organ failures. Alcohol-associated hepatitis (AH) is a common precipitant of ACLF and has been shown to uniquely affect the pathophysiology of systemic and hepatic immune responses in patients with ACLF. Treatment of AH-associated ACLF includes supportive measures as well as treatment directed at AH; however, AH-directed therapies unfortunately remain limited and are of suboptimal efficacy.

Liver Regeneration in Acute on Chronic Liver Failure

Liver regeneration is a multifaceted process by which the organ regains its original size and histologic organization. In recent decades, substantial advances have been made in our understanding of the mechanisms underlying regeneration following loss of hepatic mass. Liver regeneration in acute liver failure possesses several classic pathways, while also exhibiting unique differences in key processes such as the roles of differentiated cells and stem cell analogs. Here we summarize these unique differences and new molecular mechanisms involving the gut-liver axis, immunomodulation, and microRNAs with an emphasis on applications to the patient population through stem cell therapies and prognostication.

Challenges in Diagnosis and Therapeutic Approach of Acute on Chronic Liver Failure-A Review of Current Evidence

Acute-on-chronic liver failure (ACLF) is a syndrome characterized by acute and severe decompensation of chronic liver disease (CLD) correlated with multiple organ failure, poor prognosis, and increased mortality. In 40-50% of ACLF cases, the trigger is not recognized; for many of these patients, bacterial translocation associated with systemic inflammation is thought to be the determining factor; in the other 50% of patients, sepsis, alcohol consumption, and reactivation of chronic viral hepatitis are the most frequently described trigger factors. Other conditions considered precipitating factors are less common, including acute alcoholic hepatitis, major surgery, TIPS insertion, or inadequate paracentesis without albumin substitution. Host response is likely the primary factor predicting ACLF severity and prognosis, the host immune response having a particular significance in this syndrome, together with the inflammatory cascade. The management of ACLF includes both the prevention of the precipitating factors that lead to acute liver decompensation and the support of vital functions, the prevention and management of complications, the estimation of prognosis, and the opportunity for liver transplantation.

Risk stratification based on acute-on-chronic liver failure in cirrhotic patients hospitalized for acute variceal bleeding

BACKGROUND AND AIMS

Acute variceal bleeding (AVB) is a life-threatening complication of cirrhosis. Acute-on-chronic liver failure (ACLF) is a syndrome characterized by acute decompensation of cirrhosis, multiple organ failures and high short-term mortality. This study aimed to evaluate the role of ACLF in the risk stratification of cirrhotic patients with AVB.

METHODS

Prospective data of 335 cirrhotic patients hospitalized for AVB were retrospectively extracted from Medical Information Mart for Intensive Care (MIMIC)-IV database. ACLF was defined by European Association for the Study of Liver-Chronic Liver Failure Consortium and diagnosed/graded with chronic liver failure-organ failure (CLIF-OF) score. Cox-proportional hazards regression analysis was performed to identify the risk factors for 6-week morality in AVB patients. Discrimination and calibration of prognostic scores were evaluated by plotting the receiver operating characteristics (ROC) curve and calibration curve, respectively. Overall performance was assessed by calculating the Brier score and R² value.

RESULTS

A total of 181 (54.0%) patients were diagnosed with ACLF (grade 1: 18.2%, grade 2: 33.7%, grade 3: 48.1%) at admission. The 6-week mortality in patients with ACLF was significantly higher than that in patients without ACLF (43.6% vs. 8.4%, P < 0.001) and increased in line with the severity of ACLF (22.5%, 34.2% and 63.8% for ACLF grade 1, 2 and 3, P < 0.001). In multivariate analysis, presence of ACLF remained as an independent risk factor for 6-week mortality after adjusting for confounding factors (HR = 2.12, P = 0.03). The discrimination, calibration and overall performance of CLIF-C ACLF and CLIF-C AD were superior to the traditional prognostic scores (CTP, MELD and MELD-Na) in the prediction of 6-week mortality of patients with and without ACLF, respectively.

CONCLUSION

The prognosis of cirrhotic patients with AVB is poor when accompanied by ACLF. ACLF at admission is an independent predictor for the 6-week mortality in cirrhotic patients with AVB. CLIF-C ACLF and CLIF-C AD are the best prognostic scores in AVB patients with and without ACLF, respectively, and can be used for the risk stratification of these two distinct entities.

A novel nomogram to predict 90-day mortality in patients with hepatitis B virus-related acute-on-chronic liver failure: a single-center retrospective study

BACKGROUND

Acute-on-chronic liver failure (ACLF) is a critical illness with high mortality. Herein, we developed and validated a new and simple prognostic nomogram to predict 90-day mortality in hepatitis B virus-related ACLF (HBV-ACLF) patients.

METHODS

This single-center retrospective study collected data from 181 HBV-ACLF patients treated between June 2018 and March 2020. The correlation between clinical data and 90-day mortality in patients with HBV-ACLF was assessed using univariate and multivariate logistic regression analyses.

RESULTS

Multivariate logistic regression analysis showed that age (p = 0.011), hepatic encephalopathy (p = 0.001), total bilirubin (p = 0.007), international normalized ratio (p = 0.006), and high-density lipoprotein cholesterol (p = 0.011) were independent predictors of 90-day mortality in HBV-ACLF patients. A nomogram was created to predict 90-day mortality using these risk factors. The C-index for the prognostic nomogram was calculated as 0.866, and confirmed to be 0.854 via bootstrapping verification. The area under the curve was 0.870 in the external validation cohort. The predictive value of the nomogram was similar to that of the Chinese Group on the Study of Severe Hepatitis B score, and exceeded the performance of other prognostic scores.

CONCLUSION

The prognostic nomogram constructed using the factors identified in multivariate regression analysis might serve as a beneficial tool to predict 90-day mortality in HBV-ACLF patients.

The progress to establish optimal animal models for the study of acute-on-chronic liver failure

Acute-on-chronic liver failure (ACLF) defines a complicated and multifaceted syndrome characterized by acute liver dysfunction following an acute insult on the basis of chronic liver diseases. It is usually concurrent with bacterial infection and multi-organ failure resulting in high short-term mortality. Based on the cohort studies in ACLF worldwide, the clinical course of ACLF was demonstrated to comprise three major stages including chronic liver injury, acute hepatic/extrahepatic insult, and systemic inflammatory response caused by over-reactive immune system especially bacterial infection. However, due to the lack of optimal experimental animal models for ACLF, the progress of basic study on ACLF is limping. Though several experimental ACLF models were established, none of them can recapitulate and simulate the whole pathological process of ACLF patients. Recently, we have developed a novel mouse model for ACLF combining chronic liver injury [injection of carbon tetrachloride (CCl₄) for 8 weeks], acute hepatic insult (injection of a double dose CCl₄), and bacterial infection (intraperitoneal injection of Klebsiella pneumoniae), which could recapitulate the major clinical features of patients with ACLF worsened by bacterial infection.

Research progress on short-term prognosis of acute-on-chronic liver failure

INTRODUCTION

Acute-on-chronic liver failure (ACLF) is a clinical syndrome characterized as a severe condition with rapid progression, poor therapeutic response and poor prognosis. Early and timely evaluation of the prognosis is helpful for providing appropriate clinical intervention and prolonging patient survival.

AREAS COVERED

Currently, there are no specific dynamic and comprehensive approaches to assess the prognosis of patients with ACLF. This article reviews the progress in evaluating the short-term prognosis of ACLF to provide future directions for more dynamic prospective large-scale multicenter studies and a basis for individualized and precise treatment for ACLF patients. We searched PubMed and Web of Science with the term 'acute on chronic liver failure' and 'prognosis.' There was no date or language restriction, and our final search was on 26 October 2022.

EXPERT OPINION

ACLF is a dynamic process, and the best prognostic marker is the clinical evolution of organ failure over time. New prognostic markers are developing not only in the fields of genetics and histology but also toward diversification combined with imaging. Determining which patients will benefit from continued advanced life support is a formidable challenge, and accurate short-term prognostic assessments of ACLF are a good approach to addressing this issue.

Current and future perspectives on acute-on-chronic liver failure: Challenges of transplantation, machine perfusion, and beyond

Acute-on-chronic liver failure (ACLF) is a syndrome that occurs in patients with chronic liver disease and is characterized by acute decompensation, organ failure and high short-term mortality. Partially due to the lack of universal diagnostic criteria, the actual ACLF prevalence remains unclear; nevertheless, it is expected to be a highly prevalent condition worldwide. Earlier transplantation is an effective protective measure for selected ACLF patients. Besides liver trans-plantation, diagnosing and treating precipitant events and providing supportive treatment for organ failures are currently the cornerstone of ACLF therapy. Although new clinical specific therapies have been researched, more studies are necessary to assess safety and efficacy. Therefore, future ACLF management strategies must consider measures to improve access to liver transplantation because the time window for this life-saving therapy is frequently narrow. Thus, an urgent and global discussion about allocation and prioritization for transplantation in critically ill ACLF patients is needed because there is evidence suggesting that the current model may not portray their waitlist mortality. In addition, while donor organ quality is meant to be a prognostic factor in the ACLF setting, recent evidence suggests that machine perfusion of the liver may be a safe tool to improve the donor organ pool and expedite liver transplantation in this scenario.

The Mechanisms of Systemic Inflammatory and Immunosuppressive Acute-on-Chronic Liver Failure and Application Prospect of Single-Cell Sequencing

Acute-on-chronic liver failure (ACLF) is a complex clinical syndrome, and patients often have high short-term mortality. It occurs with intense systemic inflammation, often accompanied by a proinflammatory event (such as infection or alcoholic hepatitis), and is closely related to single or multiple organ failure. Liver inflammation begins when innate immune cells (such as Kupffer cells (KCs)) are activated by binding of pathogen-associated molecular patterns (PAMPs) from pathogenic microorganisms or damage-associated molecular patterns (DAMPs) of host origin to their pattern recognition receptors (PRRs). Activated KCs can secrete inflammatory factors as well as chemokines and recruit bone marrow-derived cells such as neutrophils and monocytes to the liver to enhance the inflammatory process. Bacterial translocation may contribute to ACLF when there are no obvious precipitating events. Immunometabolism plays an important role in the process (including mitochondrial dysfunction, amino acid metabolism, and lipid metabolism). The late stage of ACLF is mainly characterized by immunosuppression. In this process, the dysfunction of monocyte and macrophage is reflected in the downregulation of HLA-DR and upregulation of MER tyrosine kinase (MERTK), which weakens the antigen presentation function and reduces the secretion of inflammatory cytokines. We also describe the specific function of bacterial translocation and the gut-liver axis in the process of ACLF. Finally, we also describe the transcriptomics in HBV-ACLF and the recent progress of single-cell RNA sequencing as well as its potential application in the study of ACLF in the future, in order to gain a deeper understanding of ACLF in terms of single-cell gene expression.

Hepatic perfusion as a new predictor of prognosis and mortality in critical care patients with acute-on-chronic liver failure

Background and aims

Liver diseases are frequent causes of morbidity and mortality worldwide. Liver diseases can lead to cirrhosis, with the risk of acute-on-chronic liver failure (ACLF). For the detection of changes in hepatic hemodynamics, Doppler ultrasonography is a well-established method. We investigated hepatic hemodynamics via serial Doppler ultrasonography to determine the predictive value of changes in hepatic perfusion for the outcome in patients with severe liver diseases compared to established prognostic models such as the MELD (Model for End-Stage Liver Disease) or CLIF-C (Chronic Liver Failure-Consortium) ACLF score.

Methods

In this prospective cohort study, hepatic perfusion was quantified at baseline before the initiation of treatment and every third day by means of serial measurements of the hepatic artery resistance index (HARI) and the maximum portal vein velocity (PVv) using Doppler ultrasonography in 50 consecutive patients with severe liver diseases admitted to a medical intensive care unit (MICU). The recorded hemodynamic parameters were compared to the MELD score, and the CLIF-C ACLF score to analyze their utility for the prediction of the outcome of patients with severe liver diseases, liver cirrhosis, and ACLF.

Results

The changes (delta) obtained by serial measurements of the MELD score, HARI, and PVv were analyzed through scatter plots. Bivariate correlation analysis yielded a new positive linear correlation between the delta-HARI and the delta-MELD score (r = 0.469; p < 0.001). In addition, our data revealed a new negative linear correlation between delta-PVv and the delta-MELD score (r = -0.279, p = 0.001). The leading cause of MICU mortality was acute-on-chronic liver failure (ACLF). A subgroup analysis of patients with liver cirrhosis revealed a positive linear correlation between the delta-HARI and the delta-CLIF-C-ACLF score (r = 0.252, p = 0.005). Of clinical relevance, non-survivors of ACLF exhibited a significantly higher mean value for the delta-HARI (0.010 vs. -0.005; p = 0.015) and a lower mean value for the delta-PVv (-0.7 vs. 1.9 cm/s; p = 0.037) in comparison to survivors of ACLF.

Conclusion

This study shows the prognostic value of the assessment of hepatic perfusion in critical care patients with severe liver diseases by bedside Doppler ultrasound examination and its utility as an accurate predictor of the outcome in patients with ACLF. Increasing HARI and a decreasing PVv are predictors of an adverse outcome. Delta-HARI and delta-PVv are new biomarkers of prognosis and ACLF-related mortality in patients with liver diseases. Delta-HARI and delta-PVv may be helpful in guiding clinical decision-making, especially in catecholamine and fluid management.

Hepatorenal Syndrome: Pathophysiology

Hepatorenal syndrome (HRS) is defined as a functional renal failure without major histologic changes in individuals with severe liver disease and it is associated with a high mortality rate. Renal hypoperfusion due to marked vasoconstriction as a result of complex circulatory dysfunction has been suggested to be the cornerstone of HRS. Splanchnic and peripheral arterial vasodilation and cirrhotic cardiomyopathy result in effective arterial hypovolemia and compensatory activation of vasoconstrictor mechanisms. The efficacy of current therapeutic strategies targeting this circulatory dysfunction is limited. Increasing evidence suggests a substantial role of systemic inflammation in HRS via either vascular or direct renal effects. Here we summarize the current understanding of HRS pathophysiology.