Two-tier regenerative response in liver failure in humans

Liver histology and hepatic progenitor cell activity in pediatric acute liver failure: Implications for clinical outcome

BACKGROUND

Hepatic progenitor cell (HPC) activity and regenerative process that follows pediatric acute liver failure (PALF) is still not well understood. This clinicopathological study was thus conducted with an aim to study the correlation of liver histology and HPC activity with outcomes in PALF.

METHODS

All PALF patients with available hepatic histological specimens were included and specimens were analyzed for hepatocyte loss, HPC activity [using cytokeratin (CK) 7, CK19, sex-determining region Y-related high mobility group box(SOX)9 and epithelial cell adhesion molecule (EpCAM)], hepatocyte proliferation (using Ki67), and hepatocyte senescence (using p53 and p21).

RESULTS

Ninety-four children were included: 22 (23.4%) survived with native liver (SNL) (i.e., the good outcome group) while rest (i.e., the poor outcome group) either died [33%, 35.1%] or received liver transplant (LT) [39%, 41.5%]. When compared to subjects with poor outcomes, those in the SNL group exhibited significantly less severe hepatocyte loss, fewer HPC/hpf, more proliferating hepatocytes, and less senescent hepatocytes (p < .05). Increasing severity of hepatocyte loss (adjusted OR: 9.95, 95% CI: 4.22-23.45, p < .001) was identified as an independent predictor of poor outcome. Eighty percent children with >50% native hepatocyte loss had poor outcome within 10 days of hospitalization.

CONCLUSION

In PALF, more severe hepatocyte loss, higher number of HPC activation, lesser number of proliferating hepatocytes, and greater number of senescent hepatocytes are associated with a poor outcome. Loss of >50% hepatocytes is an independent predictor of poor outcome in PALF.

Liver histology and hepatic progenitor cell activity in pediatric acute liver failure: Implications for clinical outcome

Background

Hepatic progenitor cell (HPC) activity and regenerative process that follows pediatric acute liver failure (PALF) is still not well understood. This clinicopathological study was thus conducted with an aim to study the correlation of liver histology and HPC activity with outcomes in PALF.

Methods

All PALF patients with available hepatic histological specimens were included and specimens were analyzed for hepatocyte loss, HPC activity [using cytokeratin (CK) 7, CK19, sex‐determining region Y‐related high mobility group box(SOX)9 and epithelial cell adhesion molecule (EpCAM)], hepatocyte proliferation (using Ki67), and hepatocyte senescence (using p53 and p21).

Results

Ninety‐four children were included: 22 (23.4%) survived with native liver (SNL) (i.e., the good outcome group) while rest (i.e., the poor outcome group) either died [33%, 35.1%] or received liver transplant (LT) [39%, 41.5%]. When compared to subjects with poor outcomes, those in the SNL group exhibited significantly less severe hepatocyte loss, fewer HPC/hpf, more proliferating hepatocytes, and less senescent hepatocytes (p < .05). Increasing severity of hepatocyte loss (adjusted OR: 9.95, 95% CI: 4.22–23.45, p < .001) was identified as an independent predictor of poor outcome. Eighty percent children with >50% native hepatocyte loss had poor outcome within 10 days of hospitalization.

Conclusion

In PALF, more severe hepatocyte loss, higher number of HPC activation, lesser number of proliferating hepatocytes, and greater number of senescent hepatocytes are associated with a poor outcome. Loss of >50% hepatocytes is an independent predictor of poor outcome in PALF.

Exploration and verification of COVID-19-related hub genes in liver physiological and pathological regeneration

Objectives An acute injury is often accompanied by tissue regeneration. In this process, epithelial cells show a tendency of cell proliferation under the induction of injury stress, inflammatory factors, and other factors, accompanied by a temporary decline of cellular function. Regulating this regenerative process and avoiding chronic injury is a concern of regenerative medicine. The severe coronavirus disease 2019 (COVID-19) has posed a significant threat to people's health caused by the coronavirus. Acute liver failure (ALF) is a clinical syndrome resulting from rapid liver dysfunction with a fatal outcome. We hope to analyze the two diseases together to find a way for acute failure treatment. Methods COVID-19 dataset (GSE180226) and ALF dataset (GSE38941) were downloaded from the Gene Expression Omnibus (GEO) database, and the "Deseq2" package and "limma" package were used to identify differentially expressed genes (DEGs). Common DEGs were used for hub genes exploration, Protein-Protein Interaction (PPI) network construction, Gene Ontology (GO) functional enrichment, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment. The real-time reverse transcriptase-polymerase chain reaction (RT-qPCR) was used to verify the role of hub genes in liver regeneration during in vitro expansion of liver cells and a CCl4-induced ALF mice model. Results: The common gene analysis of the COVID-19 and ALF databases revealed 15 hub genes from 418 common DEGs. These hub genes, including CDC20, were related to cell proliferation and mitosis regulation, reflecting the consistent tissue regeneration change after the injury. Furthermore, hub genes were verified in vitro expansion of liver cells and in vivo ALF model. On this basis, the potential therapeutic small molecule of ALF was found by targeting the hub gene CDC20. Conclusion We have identified hub genes for epithelial cell regeneration under acute injury conditions and explored a new small molecule Apcin for liver function maintenance and ALF treatment. These findings may provide new approaches and ideas for treating COVID-19 patients with ALF.

Non-alcoholic fatty liver disease (NAFLD) in lean individuals - Single centre large cohort clinicopathologic and immunophenotypic study

BACKGROUND

Non-alcoholic fatty liver disease is one of the most common causes of chronic liver diseases and occurs even in lean individuals having normal or low body mass index (BMI). Crucial issue is understanding the clinical, pathobiologic and metabolic characteristics in comparison to obese patients. Very few studies have compared clinicopathological characteristics between lean and obese. Published literature is generally in a small cohort of patients, rarely included over-weight as separate category, and most often had non-standardized use of BMI criteria with discordant conclusions. There is very sparse published literature on liver biopsy-confirmed cohort and that to from Asia; also, none had explored the role of mediators such as stellate cells, progenitor cells and macrophages.

AIMS

To evaluate the prevalence of NAFLD in lean patients in a large cohort of histology-confirmed NAFLD, and explore clinico-pathological spectrum of lean NAFLD in comparison to over-weight and obese. Also, to investigate role of hepatic stellate cells, macrophage polarization and their relation to hepatic progenitor cells, in particular the relation to fibrosis and to different BMI categories.

METHODS

Prospective analysis of eleven-year retrospective cross-sectional data of all consecutive patients of NAFLD diagnosed in the period between the year 2011 and 2021. All histologically confirmed cases of NAFLD fulfilling inclusion and exclusion criteria were stratified to three groups according to BMI based on Asian criteria. Demographic, lab, metabolic, and histological comparisons between lean and overweight-obese patients were performed. Histological grading and staging of NAFLD components were performed by NAS-CRN score. Immunohistochemical and image analysis-based assessment and quantification of stellate cells, progenitor cells, and macrophage polarization was performed. Appropriate statistical methods were applied, and study was approved by the Institutional ethics committee.

RESULTS

Lean patients with biopsy-proven diagnosis constituted 21 % (n = 267) of total NAFLD (n = 1273). Other groups were-over-weight patients (232;18.2 %), and the highest were obese patients (774; 60.8 %). 13.9 % of the lean patients with NAFLD were under-weight with BMI<18.5 kg/m2. Lean patients had significantly lower BMI and waist circumference along with lesser fasting glucose levels in comparison to the other groups. Rest of the metabolic parameters were nearly similar. Lean patients showed higher serum ALT levels, and histological characteristics such as ballooning of hepatocytes and steatosis were also more marked in comparison to other groups. Lobular inflammation and advanced fibrosis were significantly less common in lean patients with NASH related cirrhosis found in only 20.9 % of them. Immunophenotypic studies revealed the inter-relationship of HPCs, HSCs, and macrophages was influenced by the stage of fibrosis and not by the BMI.

CONCLUSIONS

Prevalence of NAFLD in lean individuals in a histological-confirmed patient cohort was 21 %. (n = 267/1273). Major strengths of this study are large cohort of lean individuals from a single center, inclusion of only histology-confirmed cases, Asia specific BMI criteria usage, comparative clinical, metabolic, immune-morphologic and image analysis-based characterization, inclusion of over-weight in addition to obese patients, and investigating cross-talk of principal patho-physiologic markers.

Establishment of a murine model of acute-on-chronic liver failure with multi-organ dysfunction

BACKGROUND AND AIMS

Acute-on-chronic liver failure (ACLF) is a distinct clinical entity with high probability of organ failure and mortality. Since patients generally present late, experimental models are needed to understand the pathophysiology and natural course of the disease.

METHODOLOGY

To reproduce the syndrome of ACLF, chronic liver disease was induced in C57BL6 mice (6-8 weeks; approximately 20-24 g weight) by intraperitoneal administration of carbon tetrachloride (CCl₄) for 10 weeks followed by an acute injury with acetaminophen (APAP) and lipopolysaccharide (LPS). Blood, ascitic fluid, and organs were collected to study cell death, regeneration, and fibrosis.

RESULTS

At 24 h post-APAP/LPS infusion, the liver tissue showed increased hepatocyte ballooning and endothelial cell TUNEL positivity. This was followed by progressive hepatocyte necrosis from perivascular region at day 7 to lobular region by day 11. ACLF (day 7 and day 11) animals showed increase in bilirubin (p < 0.05), prothrombin time (p < 0.0001), blood ammonia (p < 0.001), and portal pressure post-acute hepatocellular injury similar to human ACLF. Ascites was noticed by day 11 with median serum-ascites albumin gradient of 1.2 (1.1-1.3) g/dL. In comparison to cirrhosis, ACLF group (day 7 and day 11) showed significant decrease in Sirius red (p ≤ 0.0001), collagen1 (p < 0.0001), and a-SMA proportionate area (p < 0.0001) with loss of hepatocytes regeneration (p < 0.005). At day 11, ACLF animals also showed significant increase in serum creatinine (p < 0.05) and acute tubular necrosis suggestive of organ failure, compared to cirrhotic animals.

CONCLUSION

The CCL4/APAP/LPS (CALPS) model of ACLF mimics the clinical, biochemical, and histological features of ACLF with demonstrable progressive hepatocellular necrosis, liver failure, impaired regeneration, development of portal hypertension, and organ dysfunction in an animal with chronic liver disease.

Development of Ectopic Livers by Hepatocyte Transplantation Into Swine Lymph Nodes

Orthotopic liver transplantation continues to be the only effective therapy for patients with end-stage liver disease. Unfortunately, many of these patients are not considered transplant candidates, lacking effective therapeutic options that would address both the irreversible progression of their hepatic failure and the control of their portal hypertension. In this prospective study, a swine model was exploited to induce subacute liver failure. Autologous hepatocytes, isolated from the left hepatic lobe, were transplanted into the mesenteric lymph nodes (LNs) by direct cell injection. At 30-60 days after transplantation, hepatocyte engraftment in LNs was successfully identified in all transplanted animals with the degree of ectopic liver mass detected being proportional to the induced native liver injury. These ectopic livers developed within the LNs showed remarkable histologic features of swine hepatic lobules, including the formation of sinusoids and bile ducts. On the basis of our previous tyrosinemic mouse model and the present pig models of induced subacute liver failure, the generation of auxiliary liver tissue using the LNs as hepatocyte engraftment sites represents a potential therapeutic approach to supplement declining hepatic function in the treatment of liver disease.

Still 'dwelling in the possibility' - critical update on stem cell therapy for acute on chronic liver failure

Stem cells therapy could improve survival in patients with liver failure. Studies on stem cell therapy and related growth factors in decompensated cirrhosis has been on the forefront but has shown heterogenous results. Recent high-quality studies have shown a lack of efficacy and safety. Patients with acute-on-chronic liver failure (ACLF) are a unique group with high mortality in the short-term associated with rapid onset extrahepatic organ failures. In these patients, there is an urgent need to identify treatments that can improve liver cell function and mass, prevent sepsis/organ failure, ameliorate systemic inflammation, and increase transplant-free survival. Stem cells are a novel treatment in ACLF but with unclear efficacy and safety. In this narrative review, we discuss the basics of liver regeneration in patients with ACLF and update current clinical status of stem cell use in patients with ACLF for improving our understanding of future directions.

Distinct EpCAM-Positive Stem Cell Niches Are Engaged in Chronic and Neoplastic Liver Diseases

In normal human livers, EpCAM^pos cells are mostly restricted in two distinct niches, which are (i) the bile ductules and (ii) the mucous glands present inside the wall of large intrahepatic bile ducts (the so-called peribiliary glands). These EpCAM^pos cell niches have been proven to harbor stem/progenitor cells with great importance in liver and biliary tree regeneration and in the pathophysiology of human diseases. The EpCAM^pos progenitor cells within bile ductules are engaged in driving regenerative processes in chronic diseases affecting hepatocytes or interlobular bile ducts. The EpCAM^pos population within peribiliary glands is activated when regenerative needs are finalized to repair large intra- or extra-hepatic bile ducts affected by chronic pathologies, including primary sclerosing cholangitis and ischemia-induced cholangiopathies after orthotopic liver transplantation. Finally, the presence of distinct EpCAM^pos cell populations may explain the histological and molecular heterogeneity characterizing cholangiocarcinoma, based on the concept of multiple candidate cells of origin. This review aimed to describe the precise anatomical distribution of EpCAM^pos populations within the liver and the biliary tree and to discuss their contribution in the pathophysiology of human liver diseases, as well as their potential role in regenerative medicine of the liver.

Cellular and functional loss of liver endothelial cells correlates with poor hepatocyte regeneration in acute-on-chronic liver failure

BACKGROUND AND AIM

Acute hepatic insult triggers regeneration. If acute-on-chronic liver failure (ACLF) patients have a poorer regenerative response than acute liver failure (ALF) patients, and if so, the mechanisms underlying this, are not well understood.

METHODS

We investigated the status of hepatocyte proliferation, hepatic progenitor cell (HPC) mediated regeneration, non-parenchymal cells (through immunohistochemistery), cytokines and growth factors (cytokine bead array) in liver and peripheral blood of ACLF (n = 29) and ALF (n = 17) patients. Liver endothelial cells, mesenchymal cells and Kupffer cells were isolated from explant livers and analysis of regenerative factors was done by qRT-PCR.

RESULTS

Unlike ALF, the ACLF livers showed decreased hepatocyte proliferation (p < 0.001) and profound ductular-reaction with increased CK19 + hepatocytes (p < 0.0001). However, only decrease in Ki67+ hepatocytes was associated with 28 day mortality in ACLF (p < 0.001; HR = 0.78; 95% CI 0.69-0.88). In both groups, increase in plasma hepatocyte growth factor (HGF) (OR = 21.87 p = 0.002;), macrophage colony stimulating factor (MCSF) (OR = 21.73; p = 0.002) and stromal derived factor (SDF1)(OR = 10.2; p = 0.001) were associated with hepatocyte proliferation and decreased (> fivefolds) levels were associated with poor hepatocyte regeneration in ACLF patients. ACLF livers showed decrease in endothelial cells (p < 0.01) and expression of regenerative angiocrine factors C-X-C chemokine receptor type 7 (CXCR7), Inhibitor of DNA Binding 1(IDI) and HGF compared to ALF. In co-culture, while ALF liver mesenchymal stromal cells (LMSCs) induced the expression of CXCR7, IDI and HGF in human umbilical cord endothelial cells (HUVECs), the ACLF LMSCs were defective and showed decreased production of SDF-1, HGF and MCSF compared to ALF.

CONCLUSIONS

Decrease in hepatic endothelial cells and their regenerative angiocrine functions indicated by defective CXCR7-ID1 dependent HGF expression underlie the poor hepatocyte proliferation in ACLF compared to ALF patients. A robust hepatocyte self-replication is lacking in the livers of ACLF patients and is associated with poor survival.

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.

Contribution of Resident Stem Cells to Liver and Biliary Tree Regeneration in Human Diseases

Two distinct stem/progenitor cell populations of biliary origin have been identified in the adult liver and biliary tree. Hepatic Stem/progenitor Cells (HpSCs) are bipotent progenitor cells located within the canals of Hering and can be differentiated into mature hepatocytes and cholangiocytes; Biliary Tree Stem/progenitor Cells (BTSCs) are multipotent stem cells located within the peribiliary glands of large intrahepatic and extrahepatic bile ducts and able to differentiate into hepatic and pancreatic lineages. HpSCs and BTSCs are endowed in a specialized niche constituted by supporting cells and extracellular matrix compounds. The actual contribution of these stem cell niches to liver and biliary tree homeostatic regeneration is marginal; this is due to the high replicative capabilities and plasticity of mature parenchymal cells (i.e., hepatocytes and cholangiocytes). However, the study of human liver and biliary diseases disclosed how these stem cell niches are involved in the regenerative response after extensive and/or chronic injuries, with the activation of specific signaling pathways. The present review summarizes the contribution of stem/progenitor cell niches in human liver diseases, underlining mechanisms of activation and clinical implications, including fibrogenesis and disease progression.

Decellularized Liver Matrix-Modified Cryogel Scaffolds as Potential Hepatocyte Carriers in Bioartificial Liver Support Systems and Implantable Liver Constructs

Recent progress in the use of decellularized organ scaffolds as regenerative matrices for tissue engineering holds great promise in addressing the issue of donor organ shortage. Decellularization preserves the mechanical integrity, composition, and microvasculature critical for zonation of hepatocytes in the liver. Earlier studies have reported the possibility of repopulating decellularized matrices with hepatic cell lines or stem cells to improve liver regeneration. In this work, we study the versatility of the decellularized liver matrix as a substrate coating of three-dimensional cryogel scaffolds. The coated cryogels were analyzed for their ability to maintain hepatic cell growth and functionality in vitro, which was found to be significantly better than the uncoated cryogel scaffolds. The decellularized liver matrix-coated cryogel scaffolds were evaluated for their potential application as a cell-loaded bioreactor for bioartificial liver support and as an implantable liver construct. Extracorporeal connection of the coated cryogel bioreactor to a liver failure model showed improvement in liver function parameters. Additionally, offline clinical evaluation of the bioreactor using patient-derived liver failure plasma showed its efficacy in improving liver failure conditions by approximately 30-60%. Furthermore, implantation of the decellularized matrix-coated cryogel showed complete integration with the native tissue as confirmed by hematoxylin and eosin staining of tissue sections. HepG2 cells and primary human hepatocytes seeded in the coated cryogel scaffolds implanted in the liver failure model maintained functionality in terms of albumin synthesis and cytochrome P450 activity post 2 weeks of implantation. In addition, a 20-60% improvement in liver function parameters was observed post implantation. These results, put together, suggest a possibility of using the decellularized matrix-coated cryogel scaffolds for liver tissue engineering applications.

Stem/Progenitor Cell Niches Involved in Hepatic and Biliary Regeneration

Niches containing stem/progenitor cells are present in different anatomical locations along the human biliary tree and within liver acini. The most primitive stem/progenitors, biliary tree stem/progenitor cells (BTSCs), reside within peribiliary glands located throughout large extrahepatic and intrahepatic bile ducts. BTSCs are multipotent and can differentiate towards hepatic and pancreatic cell fates. These niches' matrix chemistry and other characteristics are undefined. Canals of Hering (bile ductules) are found periportally and contain hepatic stem/progenitor cells (HpSCs), participating in the renewal of small intrahepatic bile ducts and being precursors to hepatocytes and cholangiocytes. The niches also contain precursors to hepatic stellate cells and endothelia, macrophages, and have a matrix chemistry rich in hyaluronans, minimally sulfated proteoglycans, fetal collagens, and laminin. The microenvironment furnishes key signals driving HpSC activation and differentiation. Newly discovered third niches are pericentral within hepatic acini, contain Axin2+ unipotent hepatocytic progenitors linked on their lateral borders to endothelia forming the central vein, and contribute to normal turnover of mature hepatocytes. Their relationship to the other stem/progenitors is undefined. Stem/progenitor niches have important implications in regenerative medicine for the liver and biliary tree and in pathogenic processes leading to diseases of these tissues.

Molecular and Cellular Functions Distinguish Superior Therapeutic Efficiency of Bone Marrow CD45 Cells Over Mesenchymal Stem Cells in Liver Cirrhosis

Liver fibrosis is strongly associated with chronic inflammation. As an alternative to conventional treatments for fibrosis, mesenchymal stem cells (MSCs) therapy is found to be attractive due to its immunomodulatory functions. However, low survival rate and profibrogenic properties of MSCs remain the major concerns, leading to skepticism in many investigators. Here, we have asked the question whether bone marrow (BM)-derived CD45 cells is the better candidate than MSCs to treat fibrosis, if so, what are the molecular mechanisms that make such distinction. Using CCl4 -induced liver fibrosis mouse model of a Metavir fibrosis score 3, we showed that BM-CD45 cells have better antifibrotic effect than adipose-derived (AD)-MSCs. In fact, our study revealed that antifibrotic potential of CD45 cells are compromised by the presence of MSCs. This difference was apparently due to significantly high level expressions of matrix metalloproteinases-9 and 13, and the suppression of hepatic stellate cells' (HpSCs) activation in the CD45 cells transplantation group. Mechanism dissection studied in vitro supported the above opposing results and revealed that CD45 cell-secreted FasL induced apoptotic death of activated HpSCs. Further analyses suggest that MSC-secreted transforming growth factor β and insulin-like growth factor-1 promoted myofibroblastic differentiation of HpSCs and their proliferation. Additionally, the transplantation of CD45 cells led to functional improvement of the liver through repair and regeneration. Thus, BM-derived CD45 cells appear as a superior candidate for the treatment of liver fibrosis due to structural and functional improvement of CCl4 -induced fibrotic liver, which were much lower in case of AD-MSC therapy.

Acute-on-chronic liver failure: consensus recommendations of the Asian Pacific Association for the Study of the Liver (APASL) 2014

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. Due to the rapid advancements in the knowledge and available information, a consortium of members from countries across Asia Pacific, "APASL ACLF Research Consortium (AARC)," was formed in 2012. A large cohort of retrospective and prospective data of ACLF patients was collated and followed up in this data base. The current ACLF definition was reassessed based on the new AARC data base. These initiatives were concluded on a 2-day meeting in February 2014 at New Delhi and led to the development of the final AARC consensus. Only those statements which were based on the evidence and were unanimously recommended were accepted. These statements were circulated again to all the experts and subsequently presented at the annual conference of the APASL at Brisbane, on March 14, 2014. The suggestions from the delegates were analyzed by the expert panel, and the modifications in the consensus were made. The final consensus and guidelines document was prepared. After detailed deliberations and data analysis, the original proposed definition was found to withstand the test of time and identify a homogenous group of patients presenting with liver failure. Based on the AARC data, liver failure grading, and its impact on the "Golden therapeutic Window," extra-hepatic organ failure and development of sepsis were analyzed. 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 are presented here.