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Acute-on-chronic liver failure: Terminology, mechanisms and management
Abstract
Acute-on-chronic liver failure (ACLF) is a distinct clinical entity and differs from acute liver failure and decompensated cirrhosis in timing, presence of acute precipitant, course of disease and potential for unaided recovery. The definition involves outlining the acute and chronic insults to include a homogenous patient group with liver failure and an expected outcome in a specific timeframe. The pathophysiology of ACLF relates to persistent inflammation, immune dysregulation with initial wide-spread immune activation, a state of systematic inflammatory response syndrome and subsequent sepsis due to immune paresis. The disease severity and outcome can be predicted by both hepatic and extrahepatic organ failure(s). Clinical recovery is expected with the use of nucleoside analogues for hepatitis B, and steroids for severe alcoholic hepatitis and, possibly, severe autoimmune hepatitis. Artificial liver support systems help remove toxins and metabolites and serve as a bridge therapy before liver transplantation. Hepatic regeneration during ongoing liver failure, although challenging, is possible through the use of growth factors. Liver transplantation remains the definitive treatment with a good outcome. Pre-emptive antiviral agents for hepatitis B before chemotherapy to prevent viral reactivation and caution in using potentially hepatotoxic drugs can prevent the development of ACLF.
... Currently, medical therapy, including pharmacological treatment and artificial liver therapy, is the main treatment for patients with ACLF. For those who do not respond to routine medical treatment, liver transplantation is the only curative treatment [1]. However, the use of liver transplantation is limited by the number of donors and the high cost of the procedure. ...
... Early diagnosis and treatment of potential precipitating events are crucial in preventing ACLF [9]. These precipitating events include hepatitis B infection, acute viral hepatitis, alcohol consumption, hepatotoxic drugs, and acute variceal bleeding [1]. Based on the CANONIC study in 2011, the TIPS procedure, as an invasive transhepatic treatment strategy, may increase the risk of ACLF [3]. ...
BACKGROUND
Transjugular intrahepatic portosystemic shunt (TIPS) is a cause of acute-on-chronic liver failure (ACLF).
AIM
To investigate the risk factors of ACLF within 1 year after TIPS in patients with cirrhosis and construct a prediction model.
METHODS
In total, 379 patients with decompensated cirrhosis treated with TIPS at Nanjing Drum Tower Hospital from 2017 to 2020 were selected as the training cohort, and 123 patients from Nanfang Hospital were included in the external validation cohort. Univariate and multivariate logistic regression analyses were performed to identify independent predictors. The prediction model was established based on the Akaike information criterion. Internal and external validation were conducted to assess the performance of the model.
RESULTS
Age and total bilirubin (TBil) were independent risk factors for the incidence of ACLF within 1 year after TIPS. We developed a prediction model comprising age, TBil, and serum sodium, which demonstrated good discrimination and calibration in both the training cohort and the external validation cohort.
CONCLUSION
Age and TBil are independent risk factors for the incidence of ACLF within 1 year after TIPS in patients with decompensated cirrhosis. Our model showed satisfying predictive value.
... [1][2][3] Patients with ACLF commonly manifest functional failures in the liver, kidneys, brain, coagulation, circulation, respiratory system and other systems, with 90-day mortality rate reaching up to 58%. [4][5][6] Currently, effective treatments for ACLF are lacking. [7][8][9][10] Liver transplantation stands as the definitive treatment, significantly improving long-term survival. ...
Introduction
Acute-on-chronic liver failure (ACLF) is a prevalent and life-threatening liver disease with high short-term mortality. Although recent clinical trials on the use of mesenchymal stem cells (MSCs) for ACLF treatment have shown promising results, multicentre randomised controlled phase II clinical trials remain uncommon. The primary aim of this trial is to assess the safety and efficacy of different MSCs treatment courses for ACLF.
Methods and analysis
This is a multicentre, double-blind, two-stage, randomised and placebo-controlled clinical trial. In the first stage, 150 patients with ACLF will be enrolled and randomly assigned to either a control group (50 cases) or an MSCs treatment group (100 cases). They will receive either a placebo or umbilical cord-derived MSCs (UC-MSCs) treatment three times (at weeks 0, 1 and 2). In the second stage, 28 days after the first UC-MSCs infusion, surviving patients in the MSCs treatment group will be further randomly divided into MSCs-short and MSCs-prolonged groups at a 1:1 ratio. They will receive two additional rounds of placebo or UC-MSCs treatment at weeks 4 and 5. The primary endpoints are the transplant-free survival rate and the incidence of treatment-related adverse events. Secondary endpoints include international normalised ratio, total bilirubin, serum albumin, blood urea nitrogen, model for end-stage liver disease score and Child-Turcotte-Pugh score.
Ethics and dissemination
Ethical approval of this study has been obtained from the Fifth Medical Center of the Chinese PLA General Hospital (KY-2023-3-19-1). All results of the study will be submitted to international journals and international conferences for publication on completion of the study.
Trial registration number
NCT05985863 .
... In this context, the activated immune cells seem to be dysfunctional, paralyzed and energy-depleted, rendering individuals more susceptible to infections. 21 Speci cally, MER receptor tyrosine kinase (MERTK) expressed by monocytes and macrophages was reported as a critical protein greatly increased in patients with liver failure and contributed to down-regulation of innate immune response to microbes. 22 Accordingly, the reduced cellular immune function in subjects with liver failure might contribute to the increased infectious morbidity of these patients and provide a rational basis for prevention strategies. ...
Background/Aims
Organ transplant recipients with hepatitis E virus (HEV) infection bears high risk to develop chronic hepatitis, which is generally associated with immunosuppressive therapies. This study aimed to identify the incidence and predictors of de novo HEV infection in patients after receiving transplantation.
Methods
We performed a large retrospective study to investigate the prevalence of anti-HEV at baseline, incidence of de novo HEV infection after transplantation, and the risk factors of HEV infection among patients with liver transplant in China. A total of 407 liver transplant recipients were examined for the presence of anti-HEV immunoglobulin G (IgG), IgM antibodies, and HEV RNA in serum. Basal indexes in individuals with evidence of post-transplant HEV infection were compared with those without evidence of that, and risk factors associated with HEV infection were assessed.
Results
The prevalence of anti-HEV at pre-transplant in liver transplant recipients was 25.8% (105/407). Serum-negative conversion occurred in 34 (32.38%) of 105 liver transplant patients. Sixty-five out of 302 patients had de novo HEV infection after transplantation, with a cumulative incidence of 42.74% during follow-up. After transplantation, HEV infection was associated with liver failure (P = 0.012), hypoproteinemia (P = 0.030) and higher level of r-glutamyl transferase (GGT) (P = 0.022) before transplantation. Graft rejection (OR 0.075; P = 0.045) was negatively associated with serum-negative conversion in patients who had positive anti-HEV antibody before transplantation.
Conclusions
The incidence of de novo HEV infection after transplantation were higher in China. Liver failure, hypoproteinemia, and GGT elevation may be associated with HEV infection after liver transplantation. This study suggests that prevention and control of HEV infection after liver transplantation should be paid attention in patients bearing these risk factors.
... Liver failure (LF) is a seriously life-threatening hepatic syndrome associated with numerous serious complications characterized by organ failure and high clinical mortality (1,2). There is no specific treatment for LF, and the current treatment consists of general management, artificial liver support system therapy, and liver transplantation. ...
Background and objectives
The prognosis of liver failure treated with non-bioartificial liver support systems is poor. Detecting its risk factors and developing relevant prognostic models still represent the top priority to lower its death risk.
Methods
All 215 patients with liver failure treated with non-bioartificial liver support system were retrospectively analyzed. Potential prognostic factors were investigated, and the Nomogram and the Random Survival Forests (RSF) models were constructed, respectively. Notably, we evaluated the performance of models and calculated the risk scores to divide patients into low-risk and high-risk groups.
Results
In the training set, multifactorial Cox regression analysis showed that etiology, hepatic encephalopathy, total bilirubin, serum alkaline phosphatase, platelets, and MELD score were independent factors of short-term prognosis. The RSF model (AUC: 0.863, 0.792) performed better in prediction than the Nomogram model (AUC: 0.816, 0.756) and MELD (AUC: 0.658, 0.700) in the training and validation groups. On top of that, patients in the low-risk group had a significantly better prognosis than those in the high-risk group.
Conclusion
We constructed the RSF model with etiology, hepatic encephalopathy, total bilirubin, serum alkaline phosphatase, platelets, and MELD score, which showed better prognostic power than the Nomogram model and MELD score and could help physicians make optimal treatment decisions.
Drug repurposing involves the investigation of existing drugs for new indications. It offers a great opportunity to quickly identify a new drug candidate at a lower cost than novel discovery and development. Despite the importance and potential role of drug repurposing, there is no specific definition that healthcare providers and the World Health Organization credit. Unfortunately, many similar and interchangeable concepts are being used in the literature, making it difficult to collect and analyze uniform data on repurposed drugs. This research was conducted based on understanding general criteria for drug repurposing, concentrating on liver diseases. Many drugs have been investigated for their effect on liver diseases even though they were originally approved (or on their way to being approved) for other diseases. Some of the hypotheses for drug repurposing were first captured from the literature and then processed further to test the hypothesis. Recently, with the revolution in bioinformatics techniques, scientists have started to use drug libraries and computer systems that can analyze hundreds of drugs to give a short list of candidates to be analyzed pharmacologically. However, this study revealed that drug repurposing is a potential aid that may help deal with liver diseases. It provides available or under-investigated drugs that could help treat hepatitis, liver cirrhosis, Wilson disease, liver cancer, and fatty liver. However, many further studies are needed to ensure the efficacy of these drugs on a large scale.
Background & Aims
Hepatitis B virus (HBV) infection is a major etiology of acute-on-chronic liver failure (ACLF). At present, the pattern and regulation of hepatocyte death during HBV-ACLF progression are still undefined. Evaluating the mode of cell death and its inducers will provide new insights for developing therapeutic strategies targeting cell death. In this study, we aimed to elucidate whether and how immune landscapes trigger hepatocyte death and lead to the progression of HBV-related ACLF.
Approach & Results
We identified that pyroptosis represented the main cell death pattern in the liver of patients with HBV-related ACLF. Deficiency of MHC-I in HBV-reactivated hepatocytes activated cytotoxic NK cells, which in turn operated in a perforin/granzyme-dependent manner to trigger GSDMD/caspase-8-dependent pyroptosis of hepatocytes. Neutrophils selectively accumulated in pyroptotic liver, and HMGB1 derived from pyroptotic liver constituted an important factor triggering generation of pathogenic extracellular traps in neutrophils (NETs). Clinically, elevated plasma levels of MPO-DNA complexes were a promising prognostic biomarker for HBV-related ACLF. More importantly, targeting GSDMD pyroptosis-HMGB1 release in the liver abrogates NETs that intercept the development of HBV-related ACLF.
Conclusions
Studying the mechanisms that selectively modulate GSDMD-dependent pyroptosis, as well as its immune landscapes, will provide a novel strategy for restoring liver function of HBV-related ACLF patients.
Background
Since boosting stem cell resilience in stressful environments is critical for the therapeutic efficacy of stem cell-based transplantations in liver disease, this study aimed to establish the efficacy of a transient plasmid-based preconditioning strategy for boosting the capability of mesenchymal stromal cells (MSCs) for anti-inflammation/antioxidant defenses and paracrine actions in recipient hepatocytes.
Methods
Human adipose mesenchymal stem cells (hADMSCs) were subjected to transfer, either with or without the nuclear factor erythroid 2-related factor 2 (Nrf2)/Dickkopf1 (DKK1) genes, followed by exposure to TNF-α/H2O2. Mouse models were subjected to acute chronic liver failure (ACLF) and subsequently injected with either transfected or untransfected MSCs. These hADMSCs and ACLF mouse models were used to investigate the interaction between Nrf2/DKK1 and the hepatocyte receptor cytoskeleton-associated protein 4 (CKAP4).
Results
Activation of Nrf2 and DKK1 enhanced the anti-stress capacity of MSCs in vitro. In a murine model of ACLF, transient co-overexpression of Nrf2 and DKK1 via plasmid transfection improved MSC resilience against inflammatory and oxidative assaults, boosted MSC transplantation efficacy, and promoted recipient liver regeneration due to a shift from the activation of the anti-regenerative IFN-γ/STAT1 pathway to the pro-regenerative IL-6/STAT3 pathway in the liver. Importantly, the therapeutic benefits of MSC transplantation were nullified when the receptor CKAP4, which interacts with DKK1, was specifically removed from recipient hepatocytes. However, the removal of the another receptor low-density lipoprotein receptor-related protein 6 (LRP6) had no impact on the effectiveness of MSC transplantation. Moreover, in long-term observations, no tumorigenicity was detected in mice following transplantation of transiently preconditioned MSCs.
Conclusions
Co-stimulation with Nrf2/DKK1 safely improved the efficacy of human MSC-based therapies in murine models of ACLF through CKAP4-dependent paracrine mechanisms.
Introduction: In patients with autoimmune hepatitis efficient immunosuppressive therapy is essential to avoid progression to cirrhosis. There is no established second line therapy for patients failing standard therapy with steroids and azathioprine. The aim of this study was to examine the possible role of Mycophenolate mofetil (MMF) as second line treatment of autoimmune hepatitis (AIH). Patients and methods: We were able to identify 36 patients (28 women, 8 men) with AIH proven according to International Autoimmune Hepatitis Group-criteria who failed standard therapy. 27 of 36 patients had experienced side effects necessitating stop of treatment. One patient stopped azathioprine due to pregnancy. 8 patients did not respond sufficiently to azathioprine. Results: 3 patients were excluded due to MMF intolerance or noncompliance. Of the remaining 33 patients 15 patients (45%) experienced remission being defined as AST< twice UNL. 18 patients (55%) did not respond sufficiently to MMF. The response rate to MMF was dependent on the cause of treatment cessation of azathioprine. Of 8 patients with prior nonresponse to azathioprine, 6 (75%) did not respond to MMF and only two (25%) reached a biochemical remission. Of 25 patients with azathioprine intolerance in 12 (48%) patients the response to MMF was insufficient and in 13 patients (52%) remission was reached. The difference did not reach statistical significance due to the relatively small numbers included. Conclusion: In the light of its good tolerability MMF seems to be an alternative for patients who could not tolerate azathioprine previously. However, our data suggest that a majority of patients fail MMF particularly if they are switched because of an insufficient response to azathioprine
Illustration of patient distribution
Mycophenolate mofetil - autoimmune hepatitis
Objective: Only 30% of alcoholics develop cirrhosis, suggesting that the development of alcohol-induced liver injury requires one or more additional factors. Animal studies have shown that gut-derived endotoxin is one such factor. Because increased intestinal permeability has been shown to cause endotoxemia, we hypothesized that increased gastrointestinal permeability contributes to the pathogenesis of alcoholic liver disease. This study aimed to measure gastroduodenal and intestinal permeability in alcoholics with and without chronic liver disease and in nonalcoholic subjects with chronic liver disease. Methods: Gastroduodenal permeability was assessed by measurement of urinary excretion of sucrose after oral administration. Intestinal permeability was assessed by measurement of urinary lactulose and mannitol after oral administration of these sugars. Results: Alcoholics with no liver disease showed a small but significant increase in sucrose excretion. Alcoholics with chronic liver disease demonstrated a marked and highly significant increase in urinary sucrose excretion relative to the controls, to the alcoholics with no liver disease, and to the nonalcoholics with liver disease. Alcoholics with chronic liver disease demonstrated a marked and highly significant increase in both lactulose absorption and in the urinary lactulose/mannitol ratio (alcoholics 0.703 vs controls 0.019, p = 0.01). In contrast, alcoholics with no liver disease and nonalcoholics with liver disease showed normal lactulose absorption and normal lactulose/mannitol ratio. Conclusion: Because only the alcoholics with chronic liver disease had increased intestinal permeability, we conclude that a “leaky” gut may be a necessary cofactor for the development of chronic liver injury in heavy drinkers.
Malnutrition is prevalent in patients with hepatic failure; it is also an independent risk factor for morbidity and mortality in these patients. Factors that contribute to malnutrition in patients with hepatic failure include altered metabolic rate, fat malabsorption, early satiety and impaired gastric emptying, as well as frequent hospitalizations and overzealous diet therapy. Providing increased nutrition improves nitrogen balance, increases lean body mass, and some indices of hepatic function. Although restricting dietary protein is still practiced in some institutions, most patients tolerate normal, or increased, levels of protein without exacerbation of encephalopathy when adequate medical therapy is provided. The following article addresses strategies for the clinician to overcome some of the obstacles that prevent adequate nutrition delivery in this population.
Hepatitis E virus (HEV) is yearly responsible for approximately 20 million infections worldwide. Although most infections occur in developing countries, HEV appears to be an emerging problem in several industrialized countries, where it is mostly associated with either traveling to an HEV endemic area or contact with pigs, which represent a major reservoir of HEV. The major risk groups for HEV infection and its ensuing complications are elderly men, pregnant women, young children, immunocompromised patients, patients with preexisting liver disease, and workers that come into close contact with HEV-infected animals. Whereas HEV mainly causes acute self-limiting infections, chronic infections may occur among immunocompromised patients (e.g., transplant recipients and human immunodeficiency virus [HIV]-infected patients. Accordingly, HEV-HIV coinfection leads to accelerated liver cirrhosis and increased mortality rates compared to HEV infection alone, which is, except during pregnancy, usually associated with only low mortality. In the Western world, the most common genotype (gt) causing HEV infection is gt 3. Ribavirin (RBV) and interferon have been used successfully for treatment of HEV, but this treatment is contraindicated in certain patient groups. Therefore, novel antiviral compounds are highly needed, especially given that viral isolates with RBV resistance have been recently identified. Moreover, eradication of HEV is hampered by long-term environmental persistence of the virus, which represents a continuous source of the virus. In 2011, the first prophylactic HEV vaccine, Hecolin, was approved in China, but it is not yet globally available. In this review, we will discuss the molecular virology of HEV, mode of transmission in industrialized countries, and potential implications for different specific patient populations. © 2015 by the American Association for the Study of Liver Diseases
Acute-on-chronic liver failure combines an acute deterioration in liver function in an individual with pre-existing chronic liver disease and hepatic and extrahepatic organ failures, and is associated with substantial short-term mortality. Common precipitants include bacterial and viral infections, alcoholic hepatitis, and surgery, but in more than 40% of patients, no precipitating event is identified. Systemic inflammation and susceptibility to infection are characteristic pathophysiological features. A new diagnostic score, the Chronic Liver Failure Consortium (CLIF-C) organ failure score, has been developed for classification and prognostic assessment of patients with acute-on-chronic liver failure. Disease can be reversed in many patients, and thus clinical management focuses upon the identification and treatment of the precipitant while providing multiorgan-supportive care that addresses the complex pattern of physiological disturbance in critically ill patients with liver disease. Liver transplantation is a highly effective intervention in some specific cases, but recipient identification, organ availability, timing of transplantation, and high resource use are barriers to more widespread application. Recognition of acute-on-chronic liver failure as a clinically and pathophysiologically distinct syndrome with defined diagnostic and prognostic criteria will help to encourage the development of new management pathways and interventions to address the unacceptably high mortality.
Compensatory proliferation triggered by hepatocyte loss is required for liver regeneration and maintenance but also promotes development of hepatocellular carcinoma (HCC). Despite extensive investigation, the cells responsible for hepatocyte restoration or HCC development remain poorly characterized. We used genetic lineage tracing to identify cells responsible for hepatocyte replenishment following chronic liver injury and queried their roles in three distinct HCC models. We found that a pre-existing population of periportal hepatocytes, located in the portal triads of healthy livers and expressing low amounts of Sox9 and other bile-duct-enriched genes, undergo extensive proliferation and replenish liver mass after chronic hepatocyte-depleting injuries. Despite their high regenerative potential, these so-called hybrid hepatocytes do not give rise to HCC in chronically injured livers and thus represent a unique way to restore tissue function and avoid tumorigenesis. This specialized set of pre-existing differentiated cells may be highly suitable for cell-based therapy of chronic hepatocyte-depleting disorders.
Copyright © 2015 Elsevier Inc. All rights reserved.