Artificial and bioartificial support systems for acute and acute-on-chronic liver failure: a systematic review

First Application of a Mixed Porcine-Human Repopulated Bioengineered Liver in a Preclinical Model of Post-Resection Liver Failure

In this study, a mixed porcine-human bioengineered liver (MPH-BEL) was used in a preclinical setup of extracorporeal liver support devices as a treatment for a model of post-resection liver failure (PRLF). The potential for human clinical application is further illustrated by comparing the functional capacity of MPH-BEL grafts as assessed using this porcine PRLF model with fully human (FH-BEL) grafts which were perfused and assessed in vitro. BEL grafts were produced by reseeding liver scaffolds with HUVEC and primary porcine hepatocytes (MPH-BEL) or primary human hepatocytes (FH-BEL). PRLF was induced by performing an 85% liver resection in domestic white pigs and randomized into the following three groups 24 h after resection: standard medical therapy (SMT) alone, SMT + extracorporeal circuit (ECC), and SMT + MPH-BEL. The detoxification and metabolic functions of the MPH-BEL grafts were compared to FH-BEL grafts which were perfused in vitro. During the 24 h treatment interval, INR values normalized within 18 h in the MPH-BEL therapy group and urea synthesis increased as compared to the SMT and SMT + ECC control groups. The MPH-BEL treatment was associated with more rapid decline in hematocrit and platelet count compared to both control groups. Histological analysis demonstrated platelet sequestration in the MPH-BEL grafts, possibly related to immune activation. Significantly higher rates of ammonia clearance and metabolic function were observed in the FH-BEL grafts perfused in vitro than in the MPH-BEL grafts. The MPH-BEL treatment was associated with improved markers of liver function in PRLF. Further improvement in liver function in the BEL grafts was observed by seeding the biomatrix with human hepatocytes. Methods to reduce platelet sequestration within BEL grafts is an area of ongoing research.

Dengue-related acute liver failure-A scoping review

Infection by dengue virus is common in tropical countries. Hepatic involvement in dengue can range from asymptomatic elevation of transaminases to life-threatening acute liver failure (ALF). Dengue-related ALF (DALF) is responsible for significant morbidity and mortality, especially in Southeast Asia. However, there is a scarcity of literature on DALF, necessitating a thorough examination of its clinical determinants and management strategies. All relevant studies related to DALF were reviewed until December 2023. Case reports, case series and studies reporting ALF in dengue infection were included. Demographics, clinical profiles, management and outcomes of DALF cases were analyzed, which revealed a predominance of DALF incidence in pediatric patients (1.1% to 15.8%) and an upward trend over the years, particularly in India. The proportion of ALF cases attributable to dengue was also higher among pediatric ALF patients (6.7% to 34.3%). Age ≤ 40 years, persistent nausea, vomiting and elevated serum bilirubin and alkaline phosphatase (ALP) with aspartate aminotransferase (AST) > 1000 IU/mL within the first five days of illness, more than 10% of atypical lymphocytes in peripheral blood, platelet count of < 50,000/cu·mm, severe hepatitis at presentation and baseline model for end-stage liver disease (MELD) > 15 were the risk factors for the development of DALF. Histopathological features of DALF included multi-lobular hepatic necrosis, steatosis and occasional cholestasis. Mortality in DALF ranged from 0% to 80%; admission pH and lactate strongly predicted mortality, while mortality was found to be significantly higher in patients with cirrhosis. N-Acetyl cysteine (NAC) has been used as a treatment modality with varying results. There is limited evidence regarding the use of extra-corporeal support systems, while candidate selection for liver transplantation (LT) in DALF remains poorly defined.

Transjugular intrahepatic portosystemic shunts for adults with hepatorenal syndrome

BACKGROUND

Hepatorenal syndrome is a condition that occurs in people with chronic liver disease (such as alcoholic hepatitis, advanced cirrhosis, or fulminant liver failure) and portal hypertension. The prognosis is dismal, often with a survival of weeks to months. Hepatorenal syndrome is characterised by the development of intense splanchnic vasodilation favouring ascites and hypotension leading to renal vasoconstriction and acute renal failure. Therefore, treatment attempts focus on improving arterial pressure through the use of vasopressors, paracentesis, and increasing renal perfusion pressure. Several authors have reported that the placement of transjugular intrahepatic portosystemic shunts (TIPS) may be a therapeutic option because it decreases portal pressure and improves arterial and renal pressures. However, the evidence is not clearly documented and TIPS may cause adverse events. Accordingly, it is necessary to evaluate the evidence of the benefits and harms of TIPS to assess its value in people with hepatorenal syndrome.

OBJECTIVES

To evaluate the benefits and harms of transjugular intrahepatic portosystemic shunts (TIPS) in adults with hepatorenal syndrome compared with sham, no intervention, conventional treatment, or other treatments.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 2 June 2023.

SELECTION CRITERIA

We included only randomised clinical trials with a parallel-group design, which compared the TIPS placement with sham, no intervention, conventional therapy, or other therapies, in adults aged 18 years or older, regardless of sex or ethnicity, diagnosed with chronic liver disease and hepatorenal syndrome. We excluded trials of adults with kidney failure due to causes not related to hepatorenal syndrome, and we also excluded data from quasi-randomised, cross-over, and observational study designs as we did not design a separate search for such studies.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were 1. all-cause mortality, 2. morbidity due to any cause, and 3. serious adverse events. Our secondary outcomes were 1. health-related quality of life, 2. non-serious adverse events, 3. participants who did not receive a liver transplant, 4. participants without improvement in kidney function, and 5. length of hospitalisation. We performed fixed-effect and random-effects meta-analyses using risk ratio (RR) or Peto odds ratio (Peto OR), with 95% confidence intervals (CI) for the dichotomous outcomes and mean difference (MD) or standardised mean difference (SMD) for the continuous outcomes. We used GRADE to assess certainty of evidence.

MAIN RESULTS

We included two randomised clinical trials comparing TIPS placement (64 participants) versus conventional treatment (paracentesis plus albumin 8 g/L of removed ascites) (66 participants). The co-interventions used in the trials were dietary treatment (sodium less than 60 mmoL/day), spironolactone (300 mg/day to 400 mg/day), and furosemide (120 mg/day). Follow-up was up to 24 months. Both were multicentre trials from Spain and the USA, and Germany, conducted between 1993 and 2002. Most participants were men (aged 18 to 75 years). We are uncertain about the effect of TIPS placement compared with conventional treatment, during the first 24 months of follow-up, on all-cause mortality (RR 0.88, 95% CI 0.55 to 1.38; 2 trials, 130 participants; I2 = 58%; very low-certainty evidence) and on the development of any serious adverse event (RR 1.60, 95% CI 0.10 to 24.59; 2 trials, 130 participants; I2 = 78%; very low-certainty evidence). The use of TIPS may or may not result in a decrease in overall morbidity such as bacterial peritonitis, encephalopathy, or refractory ascites, during the first 24 months of follow-up, compared with the conventional treatment (RR 0.95, 95% CI 0.77 to 1.18; 2 trials, 130 participants; I2 = 0%; low-certainty evidence). We are uncertain about the effect of TIPS placement versus conventional treatment on the number of people who did not receive a liver transplant (RR 1.03, 95% CI 0.93 to 1.14; 2 trials, 130 participants; I2 = 0%; very low-certainty evidence) or on the length of hospitalisation (MD -20.0 days, 95% CI -39.92 to -0.08; 1 trial, 60 participants; very low-certainty evidence). Kidney function may improve in participants with TIPS placement (RR 0.53, 95% CI 0.27 to 1.02; 1 trial, 70 participants; low-certainty evidence). No trials reported health-related quality of life, non-serious adverse events, or number of participants with improvement in liver function associated with the TIPS placement. Funding No trials reported sources of commercial funding or conflicts of interest between researchers. Ongoing studies We found one ongoing trial comparing TIPS with conventional therapy (terlipressin plus albumin) and listed one study as awaiting classification as no full-text article could be found.

AUTHORS' CONCLUSIONS

TIPS placement was compared with conventional treatment, with a follow-up of 24 months, in adults with hepatorenal syndrome type 2. Based on two trials with insufficient sample size and trial limitations, we assessed the overall certainty of evidence as low or very low. We are unsure if TIPS may decrease all-cause mortality, serious adverse events, the number of people who did not receive a liver transplant, and the days of hospitalisation because of the very low-certainty evidence. We are unsure if TIPS, compared with conventional treatment, has better effects on overall morbidity (bacterial peritonitis, encephalopathy, or refractory ascites). TIPS may improve kidney function, but the certainty of evidence is low. The trials included no data on health-related quality of life, non-serious adverse events, and liver function associated with the TIPS placement. We identified one ongoing trial and one study awaiting classification which may contribute to the review when information becomes available.

The assessment in patients with acute fatty liver of pregnancy (AFLP) treated with plasma exchange: a cohort study of 298 patients

BACKGROUND

To assess the prevalence, risk factors, clinical characteristics of Acute fatty liver of pregnancy (AFLP) patients, and outcomes of AFLP patients treated with plasma exchange (PE).

METHODS

We retrospectively reviewed the AFLP patients admitted to the First Affiliated Hospital of Xi'an Jiaotong University and Xijing Hospital of Air Force Medical University from January 2012 to May 2022. Final prediction model for death among AFLP by means of stepwise backward elimination with p value < 0.05. Patients treated with and without PE were compared by propensity-matched cohort study.

RESULTS

Two hundred ninety eight patients with the diagnosis of AFLP, and finally 290 patients were enrolled in the cohort study, 50 of whom (17.2%) were dead. Compared with AFLP patients alive, the dead of patients were more likely to be combined encephalopathy (p < 0.01), postpartum hemorrhage (p < 0.01), and found significantly higher frequency of fetal distress (p = 0.04), fetal death (p < 0.01). we developed a predicted probability value and with an area under the receiver operating characteristics (ROC) curve of 0.94 (95%CI 0.87 to 1.00), indicating AFLP patients' death. The patients treated with PE had a significantly lower 60-day mortality rate (OR 0.42, 95% CI 0.29 to 2.64, p = 0.04), and significantly shorter duration of hospital-free days at day 28 (p = 0.01).

CONCLUSIONS

In conclusion, our study indicated that liver function were risk factors for maternal mortality, and PE was a protective factor for maternal 60-day mortality and hospital-free days at day 28 in AFLP patients.

MicroRNA-124 expression in Kupffer cells modulates liver injury by targeting IL-6/STAT3 signaling

MicroRNA-124 (miR-124) is related to liver injury due to chronic hepatitis B (CHB) and hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF). However, the mechanism whereby miR-124 regulates liver inflammation remains unknown. In this study, we show that serum miR-124 serves as a compensatory predictive factor for organ failure and the 28-day prognosis of patients with HBV-ACLF. Moreover, within a mouse model of concanavalin A-induced acute liver injury, miR-124 is highly expressed in Kupffer cells. Overexpression of miR-124 significantly decreases interleukin-6 (IL-6) secretion, and relieves pathological liver necrosis to a great extent. Mechanistically, miR-124 directly targets the 3'-untranslated region of signal transducer and activator of transcription 3 (STAT3) and inhibits IL-6/STAT3 signaling, which reduces pro-inflammatory Kupffer cell polarization. Collectively, our findings suggest that miR-124 can potentially serve as a predictive biomarker for HBV-ACLF prognosis and may represent a promising therapeutic target for relieving severe liver injury resulting from cytokine storms.

Extracorporeal blood purification in patients with liver failure: Considerations for the low-and-middle income countries of Latin America

Severe liver failure is common in Low-and-Medium Income Countries (LMIC) and is associated with a high morbidity, mortality and represents an important burden to the healthcare system. In its most severe state, liver failure is a medical emergency, that requires supportive care until either the liver recovers or a liver transplant is performed. Frequently the patient requires intensive support until their liver recovers or they receive a liver transplant. Extracorporeal blood purification techniques can be employed as a strategy for bridging to transplantation or recovery. The most common type of extracorporeal support provided to these patients is kidney replacement therapy (KRT), as acute kidney injury is very common in these patients and KRT devices more readily available. However, because most of the substances that the liver clears are lipophilic and albumin-bound, they are not cleared effectively by KRT. Hence, there has been much effort in developing devices that more closely resemble the clearance function of the liver. This article provides a review of various non-biologic extracorporeal liver support devices that can be used to support these patients, and our perspective keeping in mind the needs and unique challenges present in the LMIC of Latin America.

A non-human primate model of acute liver failure suitable for testing liver support systems

Acute hepatic failure is associated with high morbidity and mortality for which the only definitive therapy is liver transplantation. Some fraction of those who undergo emergency transplantation have been shown to recover native liver function when transplanted with an auxiliary hepatic graft that leaves part of the native liver intact. Thus, transplantation could have been averted with the development and use of some form of hepatic support. The costs of developing and testing liver support systems could be dramatically reduced by the availability of a reliable large animal model of hepatic failure with a large therapeutic window that allows the assessment of efficacy and timing of intervention. Non-lethal forms of hepatic injury were examined in combination with liver-directed radiation in non-human primates (NHPs) to develop a model of acute hepatic failure that mimics the human condition. Porcine hepatocyte transplantation was then tested as a potential therapy for acute hepatic failure. After liver-directed radiation therapy, delivery of a non-lethal hepatic ischemia-reperfusion injury reliably and rapidly generated liver failure providing conditions that can enable pre-clinical testing of liver support or replacement therapies. Unfortunately, in preliminary studies, low hepatocyte engraftment and over-immune suppression interfered with the ability to assess the efficacy of transplanted porcine hepatocytes in the model. A model of acute liver failure in NHPs was created that recapitulates the pathophysiology and pathology of the clinical condition, does so with reasonably predictable kinetics, and results in 100% mortality. The model allowed preliminary testing of xenogeneic hepatocyte transplantation as a potential therapy.

Inventing Engineered Organoids for end-stage liver failure patients

End-stage liver disease (ESLD) is a term used clinically in reference to a group of liver diseases with liver transplantation as the choice of treatment. Due to the limitations of liver transplantation, alternative treatments are needed. The use of primary human hepatocytes represents a valid alternative treatment, but the limitations related to hepatocyte quality, viability, function, conservation, and storage need to be overcome. Transplanted hepatocytes have only been followed for 6–9 months. Therefore, long-term causes of failures are not yet established, including rejection, apoptosis, or other causes. Other alternative therapies to replace liver transplantation include plasmapheresis, hemodiafiltration, and artificial livers. Unfortunately, these methods are highly limited due to availability, high cost, anaphylaxis reaction, development-deposition of immune-complexes, and restricted functionality. Liver organoids, which utilize stem cells instead of ‘impractical’ adult hepatocytes, may be a solution for the development of a complex bioartificial liver. Recent studies have explored the benefits of differentiating mature hepatocytes from stem cells inside a bioreactor. When the use of human-induced Hepatocytes (hiHeps) was investigated in mouse and pig models of liver failure, liver failure markers were decreased, hepatocyte function indicated by albumin synthesis improved, and survival time increased. Bioartificial liver treatment may decrease the infiltration of inflammatory cells into liver tissue by down-regulating pro-inflammatory cytokines.

Wenyang Huazhuo Tuihuang Formula Inhibits the Th17/Treg Cell Imbalance and Protects against Acute-on-Chronic Liver Failure

Objective

Acute-on-chronic liver failure (ACLF) is a group of chronic liver diseases and caused by acute internal and external liver injury. Wenyang Huazhuo Tuihuang (WYHZTH) formula had a good clinical effect on promoting the resolution of jaundice. The aim of this study is to further investigate the mechanism of the WYHZTH formula in the ACLF rat model.

Methods

The ACLF rat model was constructed by combining human serum albumin with LPS and D-gal. WYHZTH was used to intervene and treat. The cytokines IL-17, IL-23, IL-10, and TGF-β were detected by ELISA and fluorescence-quantitative PCR. Flow cytometry was used to detect the percentage of Th17 and Treg cells in the peripheral blood and liver tissues of each group of rats. The pathological changes in the liver tissue were detected by hematoxylin-eosin staining, immunohistochemistry, and electron microscopy.

Results

Compared with the ACLF group, the WYHZTH formula and Thy significantly decreased the levels of ALT, AST, and CHE in the ACLF group. After drug intervention, apoptosis was significantly reduced. The PCNA expression decreased in the ACLF model group but increased in the WYHZTH or Thy group. Under transmission electron microscope, hepatocytes in the ACLF group showed obvious necrosis. After drug intervention, hepatocyte necrosis was reduced with most of the structure returning to normal.

Conclusion

This present study demonstrated that WYHZTH formula may protect against acute-on-chronic liver failure, which may be related to the inhibition of Th17/Treg cell imbalance.

The therapeutic potential of exosomes derived from different cell sources in liver diseases

Exosomes are small nanovesicles with a size of approximately 40-120 nm that are secreted from cells. They are involved in the regulation of cell homeostasis and mediate intercellular communication. In addition, they carry proteins, nucleic acids, and lipids that regulate the biological activity of receptor cells. Recent studies have shown that exosomes perform important functions in liver diseases. This review will focus on liver diseases (drug-induced liver injury, hepatic ischemia-reperfusion injury, liver fibrosis, acute liver failure, and hepatocellular carcinoma) and summarize the therapeutic potential of exosomes from different cell sources in liver disease.

Acute-on-chronic liver failure in children

Although various complex definitions of acute-on-chronic liver failure (ACLF) have been suggested in relation to adult patients, there is currently no universal definition of the syndrome in pediatric patients. In simplified terms, ACLF is characterized by the acute deterioration of the liver functions due to the effects of a precipitating factor on the basis of a chronic liver disease. Acute events and underlying liver diseases are very different in children from those seen in adults. Moreover, acute events and underlying chronic liver diseases vary among geographical regions, although it seems that the most common such diseases and acute events are autoimmune hepatitis, Wilson’s disease, and their flares. ACLF is associated with a poor prognosis. While no scoring systems have been developed to predict the prognosis for children with ACLF, modified versions of the Asian Pacific Association for the Study of the liver’s acute-on-chronic liver failure scoring system and the Chronic Liver Failure-Sequential Organ Failure Assessment criteria can be used in children until specific and validated scoring systems are available. Aside from liver transplantation, there is no proven treatment for ACLF. Thus, the early recognition of ACLF prior to the development of extrahepatic organ failure is important.

Treatment of Severe Acute on Chronic Liver Failure: Management of Organ Failures, Investigational Therapeutics, and the Role of Liver Transplantation

Acute on chronic liver failure (ACLF) is a unique syndrome that afflicts patients with chronic liver disease and results in high short-term mortality, in the setting of organ system failures. Given this prognosis, there is an urgent need to understand risk factors for this condition, for appropriate medical management of organ failures, and for selection criteria for patients who may benefit from liver transplantation (LT). Although several definitions exist to identify ACLF, all of them are designed to identify patients with uniquely high mortality. Currently, management of severe ACLF relies on best supportive care for specific organ failures. Thromboelastography should guide the evaluation of coagulation pathways and hyperfibrinolysis in ACLF; prophylactic blood product transfusions and thrombopoetin agonists are not recommended. Combination therapy with terlipressin and albumin has been shown to be efficacious in the management of the hepatorenal syndrome but should be administered with caution in patients with ACLF-3. Recent data have characterized the role of beta-blockers and transjugular intrahepatic portosystemic shunt placement in the management of ACLF. Investigational therapies such as extracorporeal liver support and hepatocyte stem cell therapies have shown promise; larger scale studies may better define the subpopulations of patients with ACLF mostly likely to benefit from these evolving therapeutics. Regarding LT in ACLF, data suggest that even patients with 3 or more organ system failures may have a 1-year survival >80%. However, further efforts are needed to understand the predictors of post-LT survival to facilitate LT criteria for this condition.

Hierarchical core-shell nanoplatforms constructed from Fe3O4@C and metal-organic frameworks with excellent bilirubin removal performance

Hemoperfusion has become the third-generation treatment strategy for patients suffering from hyperbilirubinemia, but adsorbents used for bilirubin removal mostly face intractable problems, such as unsatisfactory adsorption performance and poor hemocompatibility. Metal-organic frameworks (MOFs) are promising adsorbents for hemoperfusion due to their high specific surface areas and easily modified organic ligands. However, their microporous properties and separation have hampered their application. Here, a novel hierarchical core-shell nanoplatform (named Double-PEG) with tailored binding sites and pore sizes based on Fe3O4@C and Uio66-NH2 was constructed. Notably, Double-PEG showed excellent bilirubin uptake of up to 1738.30 mg g-1 and maintained excellent bilirubin removal efficiency in simulated biological solutions. A study on the adsorption mechanism showed that the adsorption of Double-PEG towards bilirubin tended to be chemical adsorption and in accordance with the Langmuir model. Besides, the good separability, recyclability, cytotoxicity and hemocompatibility of Double-PEG show great potential in hemoperfusion therapy. The finding of this study may provide a novel insight into the application of MOF materials in the field of hemoperfusion.

Extracorporeal Albumin Dialysis in Liver Failure with MARS and SPAD: A Randomized Crossover Trial

INTRODUCTION

Liver failure is associated with hepatic and extrahepatic organ failure leading to a high short-term mortality rate. Extracorporeal albumin dialysis (ECAD) aims to reduce albumin-bound toxins accumulated during liver failure. ECAD detoxifies blood using albumin dialysis through an artificial semipermeable membrane with recirculation (molecular adsorbent recirculating system, MARS) or without (single-pass albumin dialysis, SPAD).

METHODS

We performed a randomized crossover open trial in a surgical intensive care unit. The primary outcome of the study was total bilirubin reduction during MARS and during SPAD therapies. The secondary outcomes were conjugated bilirubin and bile acid level reduction during MARS and SPAD sessions and tolerance of dialysis system devices. Inclusion criteria were adult patients presenting liver failure with factor V activity <50% associated with bilirubin ≥250 μmol/L and a complication (either hepatic encephalopathy, severe pruritus, or hepatorenal syndrome). For MARS and SPAD, the dialysis flow rate was equal to 1,000 mL/h.

RESULTS

Twenty crossovers have been performed. Baseline biochemical characteristics (bilirubin, ammonia, bile acids, creatinine, and urea) were not statistically different between MARS and SPAD. Both ECAD have led to a significant reduction in total bilirubin (-83 ± 67 μmol/L after MARS; -122 ± 118 μmol/L after SPAD session), conjugated bilirubin (-82 ± 61 μmol/L after MARS; -105 ± 96 μmol/L after SPAD session), and bile acid levels (-64 ± 75 μmol/L after MARS; -56 ± 56 μmol/L after SPAD session), all nondifferent comparing MARS to SPAD.

CONCLUSION

A simple-to-perform SPAD therapy with equal to MARS dialysate flow parameters provides the same efficacy in bilirubin and bile acid removal. However, clinically relevant endpoints have to be evaluated in randomized trials to compare MARS and SPAD therapies and to define the place of SPAD in the liver failure care program.

Bilirubin adsorption for the treatment of severe hyperbilirubinemia after cardiac surgery: A retrospective cohort study

OBJECTIVE

Severe hyperbilirubinemia after cardiac surgery increases in-hospital and 1-year mortality. Our present study aimed to analyze the safety and efficacy of bilirubin adsorption (BA) in patients with post-cardiac-surgery severe hyperbilirubinemia.

METHODS

We retrospectively included patients who underwent BA due to severe hyperbilirubinemia after cardiac surgery in our center between January 2015 and December 2018. The change of serum bilirubin, alanine aminotransferase, aspartate aminotransferase, and 30-day and 1-year mortality were assessed as endpoints. Univariate and multivariate analyses were employed to identify the risk factors of patient 30-day mortality.

RESULT

A total of 25 patients with 44 BA treatments were included. One BA treatment reduced total bilirubin (TB) concentration from 431.65 ± 136.34 to 324.83 ± 129.44 µmol/L (p < 0.001), with a reduction rate of 24.8%. No clinically relevant thrombosis of the extracorporeal circuit occurred during the BA treatment. The 30-day and 1-year mortality rates were 68% (n = 18) and 84% (n = 21), respectively. Multivariate analysis identified that TB level before BA treatment (odds ratio [OR] 1.010, 95% confidence interval [CI] 1.000-1.019; p = 0.043) was an independent risk factor of 30-day mortality.

CONCLUSIONS

BA treatment should be considered as an effective and safe method for the reduction of serum bilirubin in patients with post-cardiac-surgery severe hyperbilirubinemia. Patients with higher TB level before BA treatment had a relatively increased risk of 30-day mortality. Further studies are needed to evaluate the timing of BA for severe hyperbilirubinemia after cardiac surgery.

Efficacy and safety of liver support devices in acute and hyperacute liver failure: a systematic review and network meta-analysis

Acute liver failure (ALF) is a potentially life-threatening condition. Liver support therapies can be applied as a bridging-to-transplantation or bridging-to-recovery; however, results of clinical trials are controversial. Our aim was to compare liver support systems in acute and hyperacute liver failure with network meta-analysis. After systematic search, randomized controlled trials (RCT) comparing liver support therapies in adults with acute or hyperacute liver failure were included. In-hospital mortality was the primary outcome, the secondary outcomes were hepatic encephalopathy and mortality-by-aetiology. A Bayesian-method was used to perform network meta-analysis and calculate surface under the cumulative ranking curve (SUCRA) values to rank interventions. Eleven RCTs were included. BioLogic-DT and molecular adsorbent recirculating system (MARS) resulted in the lowest mortality (SUCRAs: 76% and 73%, respectively). In non-paracetamol-poisoned patients, BioLogic-DT, charcoal hemoperfusion and MARS may be equally efficient regarding mortality (SUCRAs: 53%, 52% and 52%, respectively). Considering hepatic encephalopathy, extracorporeal liver assist device (ELAD) may be the most effective option (SUCRA: 78%). However, in pairwise meta-analysis, there were no statistically significant differences between the interventions in the outcomes. In conclusion, MARS therapy seems to be the best available option in reducing mortality. Further research is needed on currently available and new therapeutic modalities. (CRD42020160133).

A bioartificial liver support system integrated with a DLM/GelMA-based bioengineered whole liver for prevention of hepatic encephalopathy via enhanced ammonia reduction

Although bioartificial liver support systems (BLSSs) play an essential role in maintaining partial liver functions and detoxification for liver failure patients, hepatocytes are unanimously seeded in biomaterials, which lack the hierarchal structures and mechanical cues of native liver tissues. To address this challenge, we developed a new BLSS by combining a decellularized liver matrix (DLM)/GelMA-based bioengineered whole liver and a perfusion-based, oxygenated bioreactor. The novel bioengineered whole liver was fabricated by integrating photocrosslinkable gelatin (GelMA) and hepatocytes into a DLM. The combination of GelMA and the DLM not only provided a biomimetic extracellular microenvironment (ECM) for enhanced cell immobilization and growth with elevated hepatic functions (e.g., albumin secretion and CYP activities), but also provided biomechanical support to maintain the native structure of the liver. In addition, the perfusion-based, oxygenated bioreactor helped deliver oxygen to the interior tissues of the bioengineered liver, which was of importance for long-term culture. Most importantly, this new bioengineered whole liver decreased ammonia concentration by 45%, whereas direct seeding of hepatocytes in a naked DLM showed no significant reduction. Thus, the developed BLSS integrated with the DLM/GelMA-based bioengineered whole liver can potentially help elevate liver functions and prevent HE in liver failure patients while waiting for liver transplantation.

Effect of Granulocyte Colony-stimulating Factor and Erythropoietin on Patients with Acute-on-chronic Liver Failure

Introduction

Patients with acute-on-chronic liver failure (ACLF) have low survival without liver transplantation. Granulocyte colony-stimulating factor (G-CSF) improves survival in ACLF and erythropoietin (EPO) promotes hepatic regeneration in animal studies. The aim of this study is to determine whether coadministration of G-CSF and EPO improves the outcome in ACLF.

Methods

The study was conducted in the Department of Hepatology, Bangabandhu Sheikh Mujib Medical University, Dhaka. Consecutive patients with ACLF were randomly assigned into group A and group B. Group A patients received subcutaneous G-CSF (5 mcg/kg/d) for 6 days and subcutaneous EPO (40 mcg/wk) for 4 weeks and group B patients received only standard medical care (control group). All patients were followed up for 3 months. The primary end point was to see survival at 3 months.

Results

Patients had comparable baseline characteristics; hepatitis B virus infection was the commonest etiology of ACLF as both acute and chronic events. A higher proportion of patients were male in both groups. The survival was higher in group A than in group B at the end of 3 months (36.4% vs 29.4%; p = 0.457), but this was not statistically significant. Regarding complications, hepatorenal syndrome was higher in group B than in group A (36.7% vs 41.7%). In both the groups, Child-Turcotte-Pugh score and model for end-stage liver disease scores were similar before treatment and improved during follow-up.

Conclusion

This is one of the early human studies that demonstrate potential hepatic regeneration using EPO in ACLF patients. Further study with a larger cohort will be needed to reproduce the results of the present work.

How to cite this article

Haque Md N, Al-Mahtab M, Das DC, et al. Effect of Granulocyte Colony-stimulating Factor and Erythropoietin on Patients with Acute-on-chronic Liver Failure. Euroasian J Hepato-Gastroenterol 2020;10(2):64-67.

Uncertainty in the impact of liver support systems in acute-on-chronic liver failure: a systematic review and network meta-analysis

BACKGROUND

The role of artificial and bioartificial liver support systems in acute-on-chronic liver failure (ACLF) is still controversial. We aimed to perform the first network meta-analysis comparing and ranking different liver support systems and standard medical therapy (SMT) in patients with ACLF.

METHODS

The study protocol was registered with PROSPERO (CRD42020155850). A systematic search was conducted in five databases. We conducted a Bayesian network meta-analysis of randomized controlled trials assessing the effect of artificial or bioartificial liver support systems on survival in patients with ACLF. Ranking was performed by calculating the surface under cumulative ranking (SUCRA) curve values. The RoB2 tool and a modified GRADE approach were used for the assessment of the risk of bias and quality of evidence (QE).

RESULTS

In the quantitative synthesis 16 trials were included, using MARS®, Prometheus®, ELAD®, plasma exchange (PE) and BioLogic-DT®. Overall (OS) and transplant-free (TFS) survival were assessed at 1 and 3 months. PE significantly improved 3-month OS compared to SMT (RR 0.74, CrI: 0.6-0.94) and ranked first on the cumulative ranking curves for both OS outcomes (SUCRA: 86% at 3 months; 77% at 1 month) and 3-month TFS (SUCRA: 87%) and second after ELAD for 1-month TFS (SUCRA: 76%). Other comparisons did not reach statistical significance. QE was moderate for PE concerning 1-month OS and both TFS outcomes. Other results were of very low certainty.

CONCLUSION

PE seems to be the best currently available liver support therapy in ACLF regarding 3-month OS. Based on the low QE, randomized trials are needed to confirm our findings for already existing options and to introduce new devices.

MARS: Should I Use It?

Severe liver failure, including acute liver failure and acute-on-chronic liver failure, is associated with high mortality, and many patients die despite aggressive medical therapy. While liver transplantation is a viable treatment option for liver failure patients, a large proportion of these patients die given the shortage in the liver donation and the severity of illness, leading to death while waiting for a liver transplant. Extracorporeal liver support devices, including molecular adsorbent recirculating system (MARS), have been developed as bridge to transplantation (bridge for patients who are decompensating while waiting for liver transplantation) and bridge to recovery (for whom recovery is deemed reasonable). In addition to its uses in acute liver failure and acute-on-chronic liver failure, the MARS system has also been applied in various clinical settings, such as drug overdosing and poisoning and intractable cholestatic pruritus refractory to pharmacological treatment. This review aims to discuss the controversies, potential benefits, practicalities, and disadvantages of using MARS in clinical practice.

Application value of artificial liver support system in the treatment of cytokine storm in patients with COVID-19

Objective

To explore the application value of artificial liver support system in the clinical treatment of coronavirus disease 2019 (COVID-19) patients with cytokine storm.

Methods

Six cases of severe or critically severe COVID-19 patients treated in The First Affiliated Hospital, College of Medicine, Zhejiang University from January 22 to February 4, 2020 were recruited, and all of them received artificial liver support treatment. Statistical analysis was carried out on the change of cytokines (TNF-α, IL-10, IL-6, IFN-γ, IL-2, IL-4), inflammation-related indicators (white blood cell, neutrophil, lymphocyte, C-reactive protein and procalcitonin), immune-related indicators (B lymphocyte percentage, natural killer cell percentage, CD3⁺CD4⁺CD8 T cell percentage), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the 6 patients before and after treatment, and the proportions of patients with abnormal indicators were analyzed as well. In addition, computed tomography (CT) was used to observe the absorption of pulmonary lesions before and after the artificial liver support treatment.

Results

The levels of cytokines (IL-6 and IL-10) were effectively reduced in the 6 patients after treatment with the artificial liver support system. Meanwhile, the proportions of patients with abnormal TNF-α, IL-10, IL-6 and IFN-γ were all decreased (p < 0.05). The levels of inflammation-related indicators including white blood cell, C-reactive protein and procalcitonin, and the proportions of patients with these abnormal indicators were both significantly reduced (p < 0.05). The level of neutrophil was not effectively reduced before and after the treatment, but the proportion was significantly reduced (p < 0.05). However, the abnormality of lymphocyte in the patients was not improved. There was no significant difference in immune-related indicators, AST and ALT before and after the treatment (p > 0.05). CT imaging showed that the artificial liver support treatment contributed to absorption of pulmonary lesions.

Conclusions

The artificial liver support system had a great clinical effect in the treatment of cytokine storm and inflammation in COVID-19 patients, and it could promote the absorption of infected lesions.

Post hepatectomy liver failure (PHLF) - Recent advances in prevention and clinical management

BACKGROUND

Posthepatectomy liver failure (PHLF) is a relatively rare but feared complication following liver surgery, and associated with high morbidity, mortality and cost implications. Significant advances have been made in detailed preoperative assessment, particularly of the liver function in an attempt to predict and mitigate this complication.

METHODS

A detailed search of PubMed and Medline was performed using keywords "liver failure", "liver insufficiency", "liver resection", "postoperative", and "post-hepatectomy". Only full texts published in English were considered. Particular emphasis was placed on literature published after 2015. A formal systematic review was not found feasible hence a pragmatic review was performed.

RESULTS

The reported incidence of PHLF varies widely in reported literature due to a historical absence of a universal definition. Incorporation of the now accepted definition and grading of PHLF would suggest the incidence to be between 8 and 12%. Major risk factors include background liver disease, extent of resection and intraoperative course. The vast majority of mortality associated with PHLF is related to sepsis, organ failure and cerebral events. Despite multiple attempts, there has been little progress in the definitive and specific management of liver failure. This review article discusses recent advances made in detailed preoperative evaluation of liver function and evidence-based targeted approach to managing PHLF.

CONCLUSION

PHLF remains a major cause of mortality following liver resection. In absence of a specific remedy, the best approach is mitigating the risk of it happening by detailed assessment of liver function, patient selection and general care of a critically ill patient.

Late-onset acute liver failure due to Wilson's disease managed by plasmapheresis and hemodiafiltration successfully serving as a bridge for deceased donor liver transplantation: a case report and literature review

Late-onset acute liver failure due to Wilson's disease (WD-ALF) is rare. A 44-year-old female patient presenting acute hepatic decompensation with extreme coagulopathy was transferred to our hospital for evaluation for liver transplantation (LT). Alveolar hemorrhage and Coombs-negative acute hemolysis occurred during workup. Mechanical ventilation, plasmapheresis, and hemodiafiltration with zinc and chelation were started immediately before placing the patient on the waitlist for deceased donor LT (DDLT), with a tentative diagnosis of WD-ALF using the Leipzig score and quick diagnostic criteria suggested by the Acute Liver Failure Study Group Registry. The peak MELD score was 40, and the revised version of King's score for WD was 13. Serum free copper levels and the patient's overall general condition were stabilized with artificial support systems, although triphasic wave on electroencephalogram and liver atrophy were noted. She successfully underwent emergent DDLT approximately 2 weeks after suffering from acute hemolysis and survived. The genetic tests confirmed mutations at 2 loci in the ATP7B gene and, therefore, the diagnosis of WD. This is the first and oldest patient reported in Japan to present late-onset WD-ALF that was successfully treated with emergent DDLT.

Metal-Organic Framework Traps with Record-High Bilirubin Removal Capacity for Hemoperfusion Therapy

Adsorption-based hemoperfusion has been widely used to remove toxins from the blood of patients suffering acute liver failure (ALF). However, its detoxification effect has been severely hampered by the unsatisfactory adsorption performance of clinically used porous adsorbents, such as activated carbon (AC) and adsorption resin. Herein, two cage-based metal-organic frameworks (MOFs), PCN-333 (constructed from 4,4,4-s-triazine-2,4,6-triyl-tribenzoic acid (H₃TATB) ligands and Al₃ metal clusters) and MOF-808 (constructed from 1,3,5-benzenetricarboxylic acid (H₃BTC) ligands and Zr₆ metal clusters), are introduced for highly efficient hemoperfusion. They possess negligible hemolytic activity and can act as "bilirubin traps" to achieve outstanding adsorption performance toward bilirubin, a typical toxin related to ALF. Notably, PCN-333 shows a record-high adsorption capacity (∼1003.8 mg g^-1) among various bilirubin adsorbents previously reported. More importantly, they can efficiently adsorb bilirubin in bovine serum albumin (BSA) solution or even in 100% fetal bovine serum (FBS) due to their high selectivity. Strikingly, the adsorption rate and capacity of PCN-333 in biological solutions are approximately four times faster and 69 times higher than those of clinical AC, respectively. Findings in this work pave a new avenue to overcome the challenge of low adsorption efficiency and capacity in hemoperfusion therapy.

Risk factors and associated outcomes of early acute kidney injury in pediatric liver transplant recipients: A retrospective study

BACKGROUND

Acute kidney injury (AKI) may contribute to high mortality rates after liver transplantation. Few studies have investigated AKI in pediatric liver transplantation. This retrospective study was conducted to investigate the risk factors for and associated outcomes of AKI in pediatric liver transplant recipients.

METHODS

Eighty pediatric liver transplant patients were included. The occurrence of AKI was defined by the KDIGO Clinical Practice Guidelines for Acute Kidney Injury. A multivariate regression analysis model was used to investigate risk factors for AKI in the pediatric liver recipients.

RESULTS

The final multivariable regression model showed that biliary atresia (odds ratio [OR] = 0.097, p = 0.03), increased time of the anhepatic phase (OR = 0.871, p = 0.005) and lower postoperative jaundice clearance (OR = 13.936, p = 0.02) were independently associated with the development of AKI in pediatric patients. Additionally, cumulative 3-year patient (p = 0.15) and graft (p = 0.26) survival rates between the non-acute kidney injury (NAKI) and AKI groups were 95.2% vs 86.8% and 90.5% vs 84.2%, respectively.

CONCLUSION

Pediatric liver transplant recipients with a presence of biliary atresia, increased time of anhepatic phase, and a lower postoperative jaundice clearance had an increased risk of AKI. The long-term outcomes of patients who developed AKI appears to be worse compared with those having NAKI.

TYPE OF STUDY

Prognosis study.

LEVEL OF EVIDENCE

Level III.

Alcohol-related liver diseases

This educational article/narrative review reflects the European Association for the Study of the Liver (EASL) clinical practice guidelines: management of alcohol-related liver disease. An important change contrasting with the 2012 guidelines is the new terminology of alcohol-related liver diseases. Another important outcome is the strong emphasis on prevention of alcohol use disorder which may be performed at all stages of public health care.

Artificial Liver Support System Improves Short-Term Outcomes of Patients with HBV-Associated Acute-on-Chronic Liver Failure: A Propensity Score Analysis

Background

Hepatitis B virus-associated acute-on-chronic liver failure (HBV-ALCF) is a complicated syndrome with extremely high short-term mortality. The artificial liver support system (ALSS) may improve the liver function for patients with HBV-ACLF, but the data on its short-term outcomes are insufficient in China.

Methods

We recruited HBV-ACLF patients in this nationwide, multicenter, retrospective study. Patients with HBV-ACLF were diagnosed by the COSSH-ACLF criteria. Propensity score matching (PSM) analysis was used to generate compared pairs. The short-term (28/90 days) survival rates between the standard medical therapy (SMT) group and ALSS group were calculated using a Kaplan–Meier graph.

Result

In total, 790 patients with HBV-ACLF were included in this retrospective study; 412 patients received SMT only (SMT group), and 378 patients received SMT and ALSS treatment (ALSS group). PSM generated 310 pairs and eliminated the baseline differences between the two groups (p > 0.05 for all baseline variables). The probabilities of survival on day 28 were 65.2% (205/310) in the ALSS group and 59.0% (185/310) in the SMT group; on day 90, they were 51.0% (163/310) and 42.3% (136/310). The short-term (28/90 days) survival rates of the ALSS group were significantly higher than those of the SMT group (p=0.0452 and p=0.0187, respectively). Compared to receiving SMT alone, treatment with ALSS was associated with a significant reduction in serum bilirubin levels and the model for end-stage liver disease (MELD) scores at day 7 and day 28. Multivariate logistic regression analysis revealed that older age, high total bilirubin (T-Bil), low albumin, high ALT, high MELD scores, and high COSSH-ACLF grade were independent baseline factors associated with poor prognosis.

Conclusions

This retrospective study found that compared to SMT, the ALSS improved the short-term (28/90 days) survival rates and laboratory parameters in HBV-ACLF patients. The ALSS had a better therapeutic effect than SMT for patients with HBV-ACLF in China.

Systematic review and meta-analysis of thrombocytopenia as a predictor of post-hepatectomy liver failure

BACKGROUND

We performed a systematic review and meta-analysis to assess whether thrombocytopenia constituted a risk factor for post-hepatectomy liver failure (PHLF).

METHODS

We searched MEDLINE and EMBASE from inception until February the 17th, 2018 for studies reporting cases of PHLF in patients with and without thrombocytopenia (defined as a platelet count below 100 or 150 (G/l)) and/or platelet counts in patients with and without PHLF. Pooled odd ratios for PHLF, as well as mean difference in platelet counts between patients with and without PHLF, were obtained by random effects models. Robustness was tested by subgroups and leave-one out sensitivity analyses. Heterogeneity was assessed using the Q-test and quantified based on I² value.

RESULTS

We included 15 studies representing 3966 patients. Pooled odds ratio for PHLF in thrombocytopenic patients was 3.71 (95% CI: 2.51 to 5.48; I² = 0%). Pooled odds ratio was 5.53 (95% CI: 2.85 to 10.48) when pooling only studies based on preoperative platelet count, and 3.13 (95% CI: 1.75 to 5.58) when pooling studies including only patients without liver cirrhosis. The pooled mean difference in platelet counts between patients with and without PHLF was -21.2 (G/l) (95% CI: -36.1 to 6.4) in disfavor of patients with PHLF. When pooling only patients with various qualities of liver tissue, the pooled mean difference was 0.6 (G/l) (95% CI: -21.1 to 22.2).

CONCLUSION

Preoperative and/or postoperative thrombocytopenia constitute significant risk factors for PHLF in cirrhotic and non-cirrhotic patients.

Extracorporeal liver support in patients with liver failure: a systematic review and meta-analysis of randomized trials

PURPOSE

Acute liver failure (ALF) and acute on chronic liver failure (ACLF) are associated with significant mortality and morbidity. Extracorporeal liver support (ECLS) devices have been used as a bridge to liver transplant; however, the efficacy and safety of ECLS are unclear. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to examine the efficacy and safety of ECLS in liver failure.

METHODS

We searched MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials from inception through March 13, 2019. RCTs comparing ECLS to usual care in ALF or ACLF were included. We used the Grading of Recommendations Assessment, Development and Evaluation approach to assess the certainty of the evidence.

RESULTS

We identified 25 RCTs (1796 patients). ECLS use was associated with reduction in mortality (RR 0.84; 95% CI 0.74, 0.96, moderate certainty) and improvement in hepatic encephalopathy (HE) (RR 0.71; 95% CI 0.60, 0.84, low certainty) in patients with ALF or ACLF. The effect of ECLS on hypotension (RR 1.46; 95% CI 0.98, 2.2, low certainty), bleeding (RR 1.21; 95% CI 0.88, 1.66, moderate certainty), thrombocytopenia (RR 1.62; 95% CI 1.0, 2.64, very low certainty) and line infection (RR 1.92; 95% CI 0.11, 33.44, low certainty) was uncertain.

CONCLUSIONS

ECLS may reduce mortality and improve HE in patients with ALF and ACLF. The effect on other outcomes is uncertain. However, the evidence is limited by risk of bias and imprecision, and larger trials are needed to better determine the effect of ECLS on patient-important outcomes.

The immunological roles in acute-on-chronic liver failure: An update

BACKGROUND

Acute-on-chronic liver failure (ACLF) refers to the acute deterioration of liver function that occurs in patients with chronic liver disease. ACLF is characterized by acute decompensation, organ failure and high short-term mortality. Numerous studies have been conducted and remarkable progress has been made regarding the pathophysiology and pathogenesis of this disease in the last decade. The present review was to summarize the advances in this field.

DATA SOURCES

A comprehensive search in PubMed and EMBASE was conducted using the medical subject words "acute-on-chronic liver failure", "ACLF", "pathogenesis", "predictors", and "immunotherapy" combined with free text terms such as "systemic inflammation" and "immune paralysis". Relevant papers published before October 31, 2018, were included.

RESULTS

ACLF has two marked pathophysiological features, namely, excessive systemic inflammation and susceptibility to infection. The systemic inflammation is mainly manifested by a significant increase in the levels of plasma pro-inflammatory factors, leukocyte count and C-reactive protein. The underlying mechanisms are unclear and may be associated with decreased immune inhibitory cells, abnormal expression of cell surface molecules and intracellular regulatory pathways in immune cells and increased damage-associated molecular patterns in circulation. However, the main cause of susceptibility to infection is immune paralysis. Immunological paralysis is characterized by an attenuated activity of immune cells. The mechanisms are related to elevations of immune inhibitory cells and the concentration of plasma anti-inflammatory molecules. Some immune biological indicators, such as soluble CD163, are used to explore the pathogenesis and prognosis of the disease, and some immunotherapies, such as glucocorticoids and granulocyte colony-stimulating factor, are effective on ACLF.

CONCLUSIONS

Overwhelming systemic inflammation and susceptibility to infection are two key features of ACLF. A better understanding of the state of a patient's immune system will help to guide immunotherapy for ACLF.

Bioartificial liver support systems for acute liver failure: A systematic review and meta-analysis of the clinical and preclinical literature

BACKGROUND

Acute liver failure (ALF) has a high mortality varying from 80% to 85% with rapid progress in multi-organ system failure. Bioartificial liver (BAL) support systems have the potential to provide temporary support to bridge patients with ALF to liver transplantation or spontaneous recovery. In the past decades, several BAL support systems have been conducted in clinical trials. More recently, concerns have been raised on the renovation of high-quality cell sources and configuration of BAL support systems to provide more benefits to ALF models in preclinical experiments.

AIM

To investigate the characteristics of studies about BAL support systems for ALF, and to evaluate their effects on mortality.

METHODS

Eligible clinical trials and preclinical experiments on large animals were identified on Cochrane Library, PubMed, and EMbase up to March 6, 2019. Two reviewers independently extracted the necessary information, including key BAL indicators, survival and indicating outcomes, and adverse events during treatment. Descriptive analysis was used to identify the characteristics of the included studies, and a meta-analysis including only randomized controlled trial (RCT) studies was done to calculate the overall effect of BAL on mortality among humans and large animals, respectively.

RESULTS

Of the 30 selected studies, 18 were clinical trials and 12 were preclinical experiments. The meta-analysis result suggested that BAL might reduce mortality in ALF in large animals, probably due to the recent improvement of BAL, including the type, cell source, cell mass, and bioreactor, but seemed ineffective for humans [BAL vs control: relative risk (95% confidence interval), 0.27 (0.12-0.62) for animals and 0.72 (0.48-1.08) for humans]. Liver and renal functions, hematologic and coagulative parameters, encephalopathy index, and neurological indicators seemed to improve after BAL, with neither meaningful adverse events nor porcine endogenous retrovirus infection.

CONCLUSION

BAL may reduce the mortality of ALF by bridging the gap between preclinical experiments and clinical trials. Clinical trials using improved BAL must be designed scientifically and conducted in the future to provide evidence for transformation.

Hemocompatible hemoadsorbent for effective removal of protein-bound toxin in serum

Resin hemoperfusion is a life-saving treatment for drug intoxication or hepatic failure of patients. However, current resin adsorbents exhibit a limited hemocompatibility or low adsorption efficiency, representing a major roadblock to successful clinical applications. In this work, we developed a hemocompatible and effective hemoadsorbent based on polystyrene resin (H103) microparticles encapsulated in anti-biofouling zwitterionic poly(carboxybetaine) (PCB) hydrogels. Apart from a strong mechanical stability, this PCB-based adsorbent (PCB-H103) exhibited excellent hemocompatibility (hemolysis ratio was ∼0.64%), which was attributed to the anti-biofouling property of PCB hydrogel. In addition, it can efficiently adsorb both small and middle molecular weight molecules in phosphate-buffered saline, and the efficiencies were significantly higher than poly(ethylene glycol) methacrylate-based and poly(2-hydroxyethyl methacrylate)-based adsorbent counterparts, indicating the favorable permeability of PCB hydrogel coating. More importantly, PCB-H103 could effectively remove protein-bound toxins including phenol red and bilirubin in bovine serum albumin solution or even in 100% fetal bovine serum (FBS). In 100% FBS, the adsorption capacity of PCB-H103 towards bilirubin was 8.3 times higher than that of pristine clinical-scale resin beads. Findings in this work may provide a new strategy for the development of modern resin hemoperfusion technology.

Development of liposome as a novel adsorbent for artificial liver support system in liver failure

Artificial liver support systems (ALSS), represented by albumin dialysis, are designed to replace the liver detoxification function and to serve as supportive therapy until liver transplantation or liver regeneration. We introduce liposome, which is majorly formed by soybean lecithin as the adsorbent nanomaterial in dialysate for the removal of protein-bound and liver failure-related solutes. The binding rate was detected by ultrafiltration column. In vitro and in vivo dialysis was performed in a recirculation system. Unconjugated bilirubin (52.83-99.87%) and bile salts (50.54-94.75%) were bound by liposomes (5-80 g/L) in a dose-response relationship. The in vitro haemodialysis model showed that the concentration of unconjugated bilirubin (45.64 ± 0.90 μmol/L vs. 54.47 ± 3.48 μmol/L, p < 0.05) and bile salts (153.75 ± 7.72 μmol/L vs. 180.72 ± 7.95 μmol/L, p < 0.05) were significantly decreased in the liposome dialysis group than in the phosphate buffer saline group. The in vivo haemodialysis model showed that 40 g/L liposome-containing dialysate led to a significant higher reduction ratio in total bilirubin (6.56 ± 5.72% vs. -1.86 ± 5.99%, p < 0.05) and more total bile acids (7.63 ± 5.27 μmol vs. 2.13 ± 2.32 μmol, p < 0.05) extracted in the dialysate in comparison with the conventional dialysate. In conclusion, the liposome-added dialysate proved to impose good extraction effects on the unconjugated bilirubin and bile salts. These findings indicate that conventional dialysate supported by this nanomaterial can markedly improve the removal of protein-bound and liver failure-related solutes, thus suggesting a novel and promising liver dialysis system.

Acute-on-chronic liver failure: consensus recommendations of the Asian Pacific association for the study of the liver (APASL): an update

The first consensus report of the working party of the Asian Pacific Association for the Study of the Liver (APASL) set up in 2004 on acute-on-chronic liver failure (ACLF) was published in 2009. With international groups volunteering to join, the "APASL ACLF Research Consortium (AARC)" was formed in 2012, which continued to collect prospective ACLF patient data. Based on the prospective data analysis of nearly 1400 patients, the AARC consensus was published in 2014. In the past nearly four-and-a-half years, the AARC database has been enriched to about 5200 cases by major hepatology centers across Asia. The data published during the interim period were carefully analyzed and areas of contention and new developments in the field of ACLF were prioritized in a systematic manner. The AARC database was also approached for answering some of the issues where published data were limited, such as liver failure grading, its impact on the 'Golden Therapeutic Window', extrahepatic organ dysfunction and failure, development of sepsis, distinctive features of acute decompensation from ACLF and pediatric ACLF and the issues were analyzed. These initiatives concluded in a two-day meeting in October 2018 at New Delhi with finalization of the new AARC consensus. Only those statements, which were based on evidence using the Grade System and were unanimously recommended, were accepted. Finalized statements were again circulated to all the experts and subsequently presented at the AARC investigators meeting at the AASLD in November 2018. The suggestions from the experts were used to revise and finalize the consensus. After detailed deliberations and data analysis, the original definition of ACLF was found to withstand the test of time and be able to identify a homogenous group of patients presenting with liver failure. New management options including the algorithms for the management of coagulation disorders, renal replacement therapy, sepsis, variceal bleed, antivirals and criteria for liver transplantation for ACLF patients were proposed. The final consensus statements along with the relevant background information and areas requiring future studies are presented here.

Artificial liver research output and citations from 2004 to 2017: a bibliometric analysis

Background

Researches on artificial livers greatly contribute to the clinical treatments for liver failure. This study aimed to evaluate the research output of artificial livers and citations from 2004 to 2017 through a bibliometric analysis.

Methods

A list of included articles on artificial livers were generated after a comprehensive search of the Web of Science Core Collection (from 2004 to 2017) with the following basic information: number of publications, citations, publication year, country of origin, authors and authorship, funding source, journals, institutions, keywords, and research area.

Results

A total of 968 included articles ranged from 47 citations to 394 citations with a fluctuation. The publications were distributed in 12 countries, led by China (n = 212) and the US (n = 207). There were strong correlations of the number of citations with authors (r ² = 0.133, p < 0.001), and countries (r ² = 0.275, p < 0.001), while no correlations of the number of citations with the years since publication (r ² = 0.016, p = 0.216), and funding (r ² < 0.001, p = 0.770) were identified. Keyword analysis demonstrated that with the specific change of "acute liver failure," decrease in "bioartificial livers" and "hepatocyte," and increase in "tissue engineering" were identified. The top 53 cited keyword and keyword plus (including some duplicates counts) were identified, led by bioartificial liver (405 citations) and hepatocyte (248 citations). The top 50 cited keywords bursts were mainly "Blood" (2004-2008), "hepatocyte like cell" (2008-2015), and "tissue engineering" (2014-2017). All keywords could be classified into four categories: bioartificial livers (57.40%), blood purification (25.00%), clinical (14.81%), and other artificial organs (2.78%).

Discussion

This study shows the process and tendency of artificial liver research with a comprehensive analysis on artificial livers. However, although it seems that the future of artificial livers seems brighter for hepatocyte transplantation, the systems of artificial livers now are inclined on focusing on blood purification, plasma exchange, etc.

Randomized Trial of Spheroid Reservoir Bioartificial Liver in Porcine Model of Posthepatectomy Liver Failure

Acute liver failure (ALF) is a catastrophic condition that can occur after major liver resection. The aim of this study was to determine the effects of the spheroid reservoir bio-artificial liver (SRBAL) on survival, serum chemistry, and liver regeneration in posthepatectomy ALF pigs. Wild-type large white swine (20 kg-30 kg) underwent intracranial pressure (ICP) probe placement followed by 85% hepatectomy. Computed tomography (CT) volumetrics were performed to measure the extent of resection, and at 48 hours following hepatectomy to assess regeneration of the remnant liver. Animals were randomized into three groups based on treatment delivered 24-48 hours after hepatectomy: Group1-standard medical therapy (SMT, n = 6); Group2-SMT plus bio-artificial liver treatment using no hepatocytes (0 g, n = 6); and Group3-SMT plus SRBAL treatment using 200 g of primary porcine hepatocyte spheroids (200 g, n = 6). The primary endpoint was survival to 90 hours following hepatectomy. Death equivalent was defined as unresponsive grade 4 hepatic encephalopathy or ICP greater than 20 mmHg with clinical evidence of brain herniation. All animals in both (SMT and 0 g) control groups met the death equivalent before 51 hours following hepatectomy. Five of 6 animals in the 200-g group survived to 90 hours (P < 0.01). The mean ammonia, ICP, and international normalized ratio values were significantly lower in the 200-g group. CT volumetrics demonstrated increased volume regeneration at 48 hours following hepatectomy in the 200-g group compared with the SMT (P < 0.01) and 0-g (P < 0.01) groups. Ki-67 staining showed increased positive staining at 48 hours following hepatectomy (P < 0.01). Conclusion: The SRBAL improved survival, reduced ammonia, and accelerated liver regeneration in posthepatectomy ALF. Improved survival was associated with a neuroprotective benefit of SRBAL therapy. These favorable results warrant further clinical testing of the SRBAL.

Novel spheroid reservoir bioartificial liver improves survival of nonhuman primates in a toxin-induced model of acute liver failure

This study aims to evaluate the effectiveness and safety of the spheroid reservoir bioartificial liver (SRBAL) with porcine hepatocyte organoids in a preclinical nonhuman primate model of acute liver failure (ALF). Methods: Thirty healthy rhesus monkeys were infused with α-amanitin and lipopolysaccharide and randomized into five groups (ALF alone control group; sham no-cell SRBAL treatment group; groups A, B and C with SRBAL treatment started at 12 h, 24 h and 36 h after induction of ALF, respectively). Animals were continuously treated with the SRBAL device for 6 h and followed for up to 336 h. Results: Survival of ALF monkeys improved with hepatocyte SRBAL treatment compared to control groups. Blood ammonia and total bilirubin were lower, and albumin levels were higher in all hepatocyte SRBAL treatment groups. No evidence of porcine endogenous retrovirus was identified in monkey liver or blood after SRBAL treatment. Titers of monkey antibody (IgG, IgM) did not rise after SRBAL treatment. In survival cases, the proportion of necrotic and apoptotic hepatocytes was lower in SRBAL-treated groups, with earlier liver regeneration leading to recovery. Cytokines TNF-α, IL-6, IL-12, IL-1β, IL-8, IFN-γ and IL-2 were ameliorated by the SRBAL treatment, while levels of M-CSF; HGF, EGF and VEGF; IL-1RA and MIF rose on priming, proliferation and the late phase of liver regeneration. Conclusions: The benefit of SRBAL therapy included preventive effects and therapeutic effects. SRBAL improved survival rate and prolonged median survival time in a nonhuman primate model of drug-induced ALF, and these benefits declined with a delay in the initiation of therapy. Improved survival and recovery of ALF monkeys was associated with a reduction in blood ammonia levels, inhibition of the pro-inflammatory response of ALF, and provided a microenvironment more suitable for regeneration of the injured liver.

Human mesenchymal stem cells for hepatitis B virus-related acute-on-chronic liver failure: a systematic review with meta-analysis

BACKGROUND AND AIM

Acute-on-chronic liver failure (ACLF) is a condition with high mortality. New strategies are urgently required. The present review aims to provide a comprehensive understanding of the efficacy and safety of mesenchymal stem cells (MSC) treatment in patients with ACLF associated with hepatitis B virus infection.

MATERIALS AND METHODS

The MEDLINE, Embase, and Cochrane Library databases were searched for the relevant publications. If appropriate, a meta-analysis was carried out for the following outcomes: survival rate, model for end-stage liver disease score, and liver function.

RESULTS

Three studies were eligible for the present systematic review. A total of 198 hepatitis B virus-ACLF patients were enrolled for this review. Ninety-one patients were treated with MSC and 107 patients were treated with standard medical therapy (SMT) as controls. Pooled results showed that MSC treatment could significantly reduce the mortality rate at week 12 [risk ratio: 0.50; 95% confidence interval (CI): 0.33, 0.76; P=0.00009] and the mortality rate at the final follow-up (risk ratio: 0.54; 95%CI: 0.37, 0.78; P=0.001) compared with the SMT group. Furthermore, pooled estimates showed that MSC treatment could significantly reduce the total bilirubin level at week 4 (mean difference: 58.89; 95%CI: 14.47, 103.32; P=0.009) compared with the SMT group. No severe complication associated with MSC treatment was observed.

CONCLUSION

Our pooled results suggested that MSC treatment could significantly reduce the mortality rate, without increasing the incidence of severe complications.

Bilirubin detoxification using different phytomaterials: characterization and in vitro studies

BACKGROUND

Activated carbon (AC) is a common adsorbent that is used in both artificial and bioartificial liver devices.

METHODS

Three natural materials - date pits of Phoenix dactylifera (fruit), Simmondsia chinensis (jojoba) seeds, and Scenedesmus spp. (microalgae) - were used in the present investigation as precursors for the synthesis of AC using physical activation. The chemical structures and morphology of AC were analyzed. Then, AC's bilirubin adsorption capacity and its cytotoxicity on normal liver (THLE2) and liver cancer (HepG2) cells were characterized.

RESULTS

Compared with the other raw materials examined, date-pit AC was highly selective and showed the most effective capacity of bilirubin adsorption, as judged by isotherm-modeling analysis. MTT in vitro analysis indicated that date-pit AC had the least effect on the viability of both THLE2 and HepG2 cells compared to jojoba seeds and microalgae. All three biomaterials under investigation were used, along with collagen and Matrigel, to grow cells in 3D culture. Fluorescent microscopy confirmed date-pit AC as the best to preserve liver cell integrity.

CONCLUSION

The findings of this study introduce date-pit-based AC as a novel alternative biomaterial for the removal of protein-bound toxins in bioartificial liver devices.

Alpha-Fetoprotein as a Predictive Marker for Patients with Hepatitis B-Related Acute-on-Chronic Liver Failure

BACKGROUND AND AIMS

The value of alpha-fetoprotein (AFP) in hepatitis B-related acute-on-chronic liver failure (HBACLF) is not fully understood. The present study aimed to evaluate the prognostic effect of AFP on the prediction of HBACLF outcomes.

METHODS

We investigated a cohort of patients with HBACLF admitted from January 2013 to May 2017. The endpoint of followup was 180 days, death, or liver transplantation. AFP concentrations were estimated on admission. To make statistical comparisons, we used chi-squared test, receiver operating characteristic (ROC) curve analysis, survivorship curve analysis, and Cox proportional-hazards model.

RESULTS

A total of 92 patients (81.5% male, median age of 46 years) were included. Overall survival rate within 180 days was 43.48%, and the value of log₁₀^AFP⁡  ≥ 2.04 indicated a better prognosis with 76.9% specificity and 62.5% sensitivity for patients with HBACLF. Age (HR 1.041), total bilirubin (HR 1.004), log₁₀^AFP⁡  (HR 2.155), and INR (HR 1.446) were found to be risk factors of survival.

CONCLUSION

AFP could be a useful marker to predict outcomes of acute-on-chronic liver failure.

Future Approaches and Therapeutic Modalities for Acute Liver Failure

The current gold standard for the management of acute liver failure is liver transplantation. However, because of organ shortages, other modalities of therapy are necessary as a possible bridge. This article discusses the current modalities as well as the future management of acute liver failure. Liver assist devices, hepatocyte transplantation, stem cell transplant, organogenesis, and repopulation of decellularized organs are discussed.

An experimental pilot study on controlled portal vein arterialization with an extracorporeal device in the swine model of partial liver resection and ischemia

AIM

To determine whether the physiologically oxygenated arterial blood reversed in the portal system by means of portal vein arterialization (PVA) through an extracorporeal device which we have called L.E.O2.NARDO (Liver Extracorporeal Oxygen. NARDO) is effective in treating swine with subtotal hepatectomy leading to acute liver failure (ALF).

METHODS

Ten swine with ALF induced by 85-90% liver resection and five minutes of ischemia-reperfusion injury were randomly divided into two groups: five animals received PVA extracorporeal treatment and five swine were not-treated (control group). Blood was withdrawn from the iliac artery and reversed in the portal venous system. An extracorporeal device was interposed between the outflow and the inflow in order to monitoring the hemodynamic parameters. Each treatment lasted 6 hours. Serum and liver samples were collected in both groups. The survival was assessed at 1 week.

RESULTS

The PVA-extracorporeal treatment yielded beneficial effects for subtotal hepatectomy-induced ALF swine with decreased serum ammonia, transaminases and total bilirubin as compared with the untreated group. INR recovered rapidly in the PVA-extracorporeal group remaining significantly lower than in untreated animals. The 7-day survival of PVA-extracorporeal group swine was significantly higher than that of untreated animals, with a statistically significant difference (p<0.05). Four swine in the PVA-extracorporeal group survived at 1 week while none of the swine in the control group were alive at that time; an average time of 144h+/-13h and 24.4h+/-5h was observed in the PVA-extracorporeal and control groups, respectively.

CONCLUSIONS

Arterial blood supply in the portal system through the extracorporeal device is easily applicable, efficacious, safe and may represent a novel approach for ALF swine induced by subtotal liver resection.

The Curative Effect of ALSS on 1-month Mortality in AoCLF Patients after 72 to 120 Hours

Background

Hepatitis B virus (HBV)-related acute-on-chronic liver failure (AoCLF) is associated with a high mortality rate. An artificial liver support system (ALSS) creates a better environment for the self-regeneration of retained hepatocytes.

Aim and Patients

We investigated the curative effect of ALSS on 1-month mortality at 72–120 h post-ALSS in 289 AoCLF patients.

Methods

Of the 289 patients, 117 who survived for at least 1 month post-ALSS comprised the survival group; the remaining cases who died within 1 month served as controls. The improvements in laboratory data and clinical syndromes at 72–120 h post-ALSS were compared with those at 24 h.

Results

Total bilirubin, international normalized ratio, and creatinine levels, and encephalopathy were significantly improved at 24 h post-ALSS in both the groups (p<0.05); however, these variables showed deterioration at 72–120 h; a rebound occurred in the nonsurvivors (p>0.05). The improvements in these variables in the nonsurvivors were considerably smaller than those in the survivors (p<0.05), particularly at 72–120 h. One-month mortality was more accurately predicted by the logistic regression model at 72–120 h than at 24 h.

Conclusions

The prognosis of AoCLF patients was highly dependent on the improvement in encephalopathy, total bilirubin, international normalized ratio, and creatinine levels at 72–120 h post-ALSS. These variables are useful, therefore, as disease severity indexes to determine organ allocation priorities for liver transplant.

Evaluation of an ADVanced Organ Support (ADVOS) system in a two-hit porcine model of liver failure plus endotoxemia

Background

Novel extracorporeal procedures are constantly being developed and evaluated for use in patients with sepsis. Preclinical evaluation of such procedures usually requires testing in large animal models. In the present work, the safety and efficacy of a recently developed ADVanced Organ Support (ADVOS) system in a newly developed large animal two-hit model of liver failure combined with endotoxemia were tested.

Methods

After establishing the model in more than 50 animals, a randomized study was performed. An inflammatory cholestatic liver injury was initially provoked in pigs. Three days after surgery, endotoxin was gradually administered during 7½ h. Animals were randomized to receive standard medical treatment either with (ADVOS group, n = 5) or without ADVOS (control group, n = 5). The ADVOS treatment was started 2½ h after endotoxemia and continued for 7 h. Survival, cardiovascular, respiratory, renal, liver, coagulation, and cerebral parameters were analyzed.

Results

Three days after surgery, cholestatic injury resulted in hyperbilirubinemia [5.0 mg/dl (IQR 4.3–5.9 mg/dl)], hyperammonemia [292 μg/dl (IQR 291–296 μg/dl)], leukocytosis [20.2 10³/μl (IQR 17.7–21.8 10³/μl)], and hyperfibrinogenemia [713 mg/dl (IQR 654–803 mg/dl)]. After endotoxemia, the ADVOS procedure stabilized cardiovascular, respiratory, and renal parameters and eliminated surrogate markers as bilirubin [2.3 (IQR 2.3–3.0) vs. 5.5 (IQR 4.6–5.6) mg/dl, p = 0.001] and creatinine [1.4 (IQR 1.1–1.7) vs. 2.3 (IQR 2.1–3.1) mg/dl, p = 0.01]. Mortality: All animals in the ADVOS group survived, while all animals in the control group expired during the 10-h observation period (p = 0.002). No adverse events related to the procedure were observed.

Conclusions

The ADVOS procedure showed a promising safety and efficacy profile and improved survival in a sepsis-like animal model with dysfunction of multiple organs. An amelioration of major organ functions (heart and lung) combined with removal of markers for kidney and liver function was observed.

Electronic supplementary material

The online version of this article (doi:10.1186/s40635-017-0144-3) contains supplementary material, which is available to authorized users.

Current Evidence for Extracorporeal Liver Support Systems in Acute Liver Failure and Acute-on-Chronic Liver Failure

Artificial (nonbiological) extracorporeal liver support devices aim to remove albumin-bound and water-soluble toxins to restore and preserve hepatic function and mitigate or limit the progression of multiorgan failure while hepatic recovery or liver transplant occurs. The following beneficial effects have been documented: improvement of jaundice, amelioration of hemodynamic instability, reduction of portal hypertension, and improvement of hepatic encephalopathy. The only randomized prospective multicenter controlled trial to show an improvement in transplant-free survival was for high-volume plasmapheresis. Biological (cell-based) extracorporeal liver support systems aim to support the failing liver through detoxification and synthetic function and warrant further study for safety and benefit.

Molecular adsorbent recirculating system (MARS) in acute liver injury and graft dysfunction: Results from a case-control study

Background

The primary therapeutic goals in the treatment of liver injury are to support liver regeneration or bridge the gap to liver transplantation (LT). Molecular adsorbent recirculating system (MARS) therapy has shown beneficial effects for specific symptoms of liver failure; however, general survival advantages have not yet been demonstrated.

Aim

We studied the effects of MARS therapy compared to standard medical treatment (SMT) in two patient cohorts: in patients with an acute liver injury and in those with graft dysfunction (GD).

Methods

We report on our experience over a 6.5-year period with 73 patients treated with SMT or with SMT and MARS (MARS group). In total, 53 patients suffered from acute liver injury in their native liver without a preexisting liver disease (SMT: n = 31, MARS: n = 22), and 20 patients showed a severe GD after LT (SMT: n = 10, MARS: n = 10).

Results

The entire cohort was predominantly characterized by hemodynamically and respiratorily stable patients with a low hepatic encephalopathy (HE) grade and a model of end-stage liver disease (MELD) score of 20.57 (MARS) or 22.51 (SMT, p = 0.555). Within the MARS group, the median number of extracorporeal therapy sessions was four (range = 3–5 sessions). Independent of the underlying etiology, MARS improved the patients’ bilirubin values in the short term compared to SMT alone. In patients with acute liver injury, this response was sustained even after the end of MARS therapy. By contrast, the majority of patients with GD and an initial response to MARS therapy experienced worsened hyperbilirubinemia. No differences in 28-day mortality were observed with respect to acute liver injury (MARS 5.3% (95% CI: 0–15.3); SMT 3.3% (95% CI: 0–9.8), p = 0.754) or GD (MARS 20.0% (95% CI: 0–44.7), SMT 11.1% (95% CI: 0–31.7), p = 0.478).

Conclusions

Although it did not improve 28-day mortality, MARS therapy improved the short-term response in patients with acute liver injury as well as in those with GD. In cases of acute hepatic injury, the use of MARS therapy resulted in the sustained stabilization of liver function and improved liver regeneration. A short-term response to MARS may predict the future course of the disease.

Effectiveness and Safety Assessment of Citrate Anticoagulation During Albumin Dialysis in Comparison to Other Methods of Anticoagulation

Liver failure is a serious and often deadly disease often requiring MARS (Molecular Adsorbent Recirculating System) therapy. Choosing the safe and effective method of anticoagulation during artificial liver support systems seems to be very difficult and extremely important. The aim of this study was to assess effectiveness and safety of regional anticoagulation with citrate in liver failure patients during MARS. We used a single center observational study. We analyzed 158 MARS sessions performed in 65 patients: 105 (66.5%) sessions in 41 patients with heparin anticoagulation, 40 (25.3%) sessions in 19 patients with citrate, and 13 (8%) sessions in only five patients without anticoagulation, that were excluded from part of the analysis. To determine the effectiveness of regional anticoagulation with citrate, probability of filter survival and changes in laboratory parameters were analyzed according to the applied method of anticoagulation. The safety of citrate was determined by Ca/Ca²⁺ ratio, acid-base balance, bleeding complications, and the need for blood product transfusions. The probability of filter survival in the citrate group was 94% and in the heparin group 82% (P = 0.204). There was no relationship between the method of anticoagulation and effectiveness of MARS therapy in lowering the levels of the analyzed parameters. Only one patient had a Ca/Ca²⁺ ratio higher than he safety margin. There were no statistically significant changes in pH and lactate level irrespective of anticoagulation; bicarbonate dropped significantly only in the heparin group (P = 0.03). The frequency of bleeding complications and the need for transfusions did not differ significantly between groups. Regional anticoagulation with citrate can be an effective and safe method of anticoagulation during MARS therapy, but requires attentive monitoring and further studies in liver failure patients.