Liver transplantation in acute liver failure: Dilemmas and challenges

Current progress on the microbial therapies for acute liver failure

Acute liver failure (ALF), associated with a clinical fatality rate exceeding 80%, is characterized by severe liver damage resulting from various factors in the absence of pre-existing liver disease. The role of microbiota in the progression of diverse liver diseases, including ALF, has been increasingly recognized, with the interactions between the microbiota and the host significantly influencing both disease onset and progression. Despite growing interest in the microbiological aspects of ALF, comprehensive reviews remain limited. This review critically examines the mechanisms and efficacy of microbiota-based treatments for ALF, focusing on their role in prevention, treatment, and prognosis over the past decade.

Impact of Renal Replacement Therapy on Outcomes of Living Donor Liver Transplantation for Acute Liver Failure: A Cohort Study

Despite the promising role of renal replacement therapy (RRT) in acute liver failure (ALF), high-risk patients need liver transplantation and remain at risk for death due to cerebral complications. The objective of this study was to report outcomes of living donor liver transplantation (LDLT) for ALF with perioperative RRT. This was a single-center retrospective cohort study. Out of 1167 LDLTs, 24 patients had ALF and met the King's College criteria for transplantation. They were categorized into no-RRT (n = 13) and RRT (n = 11) groups. We looked at 1-year posttransplant survival in these patients. The median serum ammonia level at the time of transplant in the no-RRT and RRT groups was 259.5 mcg/dL (222.7-398) and 70.6 mcg/dL (58.1-92.6) (p = 0.005). In the RRT group, serum ammonia level < 100 mcg/dL was achieved in all patients. Seven (53.8%) patients in the no-RRT group and 11/11 (100%) in the RRT group were extubated and regained full consciousness after LDLT (p = 0.013). The 90-day mortality was 6/13 (46.1%) and 2/11 (18.1%) (p = 0.211). There was no brainstem herniation-related mortality in the RRT group, that is, 5/13 (38.4%) and 0/11 (0%) (p = 0.030). The 1-year posttransplant survival was also significantly higher in the RRT group (p = 0.031). The use of RRT lowers serum ammonia levels and might reduce posttransplant mortality due to brainstem herniation.

Clinical significance and outcomes of adult living donor liver transplantation for acute liver failure: a retrospective cohort study based on 15-year single-center experience

Purpose

This study aimed to describe adult living donor liver transplantation (LDLT) for acute liver failure and evaluate its clinical significance by comparing its surgical and survival outcomes with those of deceased donor liver transplantation (DDLT).

Methods

We retrospectively reviewed the medical records of 267 consecutive patients (161 LDLT recipients and 106 DDLT recipients) aged 18 years or older who underwent liver transplantation between January 2006 and December 2020.

Results

The mean periods from hepatic encephalopathy to liver transplantation were 5.85 days and 8.35 days for LDLT and DDLT, respectively (P = 0.091). Among these patients, 121 (45.3%) had grade III or IV hepatic encephalopathy (living, 34.8% vs. deceased, 61.3%; P < 0.001), and 38 (14.2%) had brain edema (living, 16.1% vs. deceased, 11.3%; P = 0.269) before liver transplantation. There were no significant differences in in-hospital mortality (living, 11.8% vs. deceased, 15.1%; P = 0.435), 10-year overall survival (living, 90.8% vs. deceased, 84.0%; P = 0.096), and graft survival (living, 83.5% vs. deceased, 71.3%; P = 0.051). However, postoperatively, the mean intensive care unit stay was shorter in the LDLT group (5.0 days vs. 9.5 days, P < 0.001). In-hospital mortality was associated with vasopressor use (odds ratio [OR], 3.40; 95% confidence interval [CI], 1.45-7.96; P = 0.005) and brain edema (OR, 2.75; 95% CI, 1.16-6.52; P = 0.022) of recipient at the time of transplantation. However, LDLT (OR, 1.26; 95% CI, 0.59-2.66; P = 0.553) was not independently associated with in-hospital mortality.

Conclusion

LDLT is feasible for acute liver failure when organs from deceased donors are not available.

Acute liver failure: Management update and prognosis

Acute liver failure is a rare but serious syndrome, with an incidence of approximately 2,000 to 3,000 cases per year in North America. Its pathophysiology and clinical course vary, depending on the cause of the primary liver injury, and can lead to high morbidity and mortality or the need for liver transplantation, despite available therapies. This syndrome involves excessive activation of the immune system, with damage in other organs, contributing to its high mortality rate. The most accepted definition includes liver injury with hepatic encephalopathy and coagulopathy within the past 26 weeks in a patient with no previous liver disease. The main causes are paracetamol poisoning, viral hepatitis, and drug-induced liver injury, among others. Identifying the cause is crucial, given that it influences prognosis and treatment. Survival has improved with supportive measures, intensive therapy, complication prevention, and the use of medications, such as N-acetylcysteine. Liver transplantation is a curative option for nonresponders to medical treatment, but adequate evaluation of transplantation timing is vital for improving results. Factors such as patient age, underlying cause, and severity of organ failure influence the post-transplant outcomes and survival.

Molecular Adsorbent Recirculating System in Acute Liver Failure

Acetaminophen (APAP) overdose is the most common cause of acute liver failure (ALF) in the United States. Liver transplantation (LT) is potentially lifesaving for patients with ALF, but its feasibility in clinical practice is limited. Liver assist devices, such as the Molecular Adsorbent Recirculating System (MARS), are used in some centers as a "bridge" to liver transplantation or as a means of liver recovery, but their role in the treatment of ALF is not well-defined. We present the case of a 44-year-old man with APAP-associated ALF who experienced hepatic recovery after treatment with MARS.

Acute liver failure

ABSTRACT

Acute liver failure, commonly caused by acetaminophen overdose, is associated with numerous systemic complications including cerebral edema, hypotension, acute kidney injury, and infection. Management is primarily supportive, with an emphasis on excellent neurocritical care. Although some antidotes and targeted treatments exist, the only definitive treatment remains orthotopic liver transplant.

Treating liver cancer through arginine depletion

Liver cancer, the sixth most common cancer globally and the second-leading cause of cancer-related deaths, presents a critical public health threat. Diagnosis often occurs in advanced stages of the disease, aligning incidence with fatality rates. Given that established treatments, such as stereotactic body radiation therapy and transarterial radioembolization, face accessibility and affordability challenges, the emerging focus on cancer cell metabolism, particularly arginine (Arg) depletion, offers a promising research avenue. Arg-depleting enzymes show efficacy against Arg-auxotrophic cancers, including hepatocellular carcinoma (HCC). Thus, in this review, we explore the limitations of current therapies and highlight the potential of Arg depletion, emphasizing various Arg-hydrolyzing enzymes in clinical development.

Asian Pacific Association for the Study of the Liver clinical practice guidelines on liver transplantation

Liver transplantation is a highly complex and challenging field of clinical practice. Although it was originally developed in western countries, it has been further advanced in Asian countries through the use of living donor liver transplantation. This method of transplantation is the only available option in many countries in the Asia-Pacific region due to the lack of deceased organ donation. As a result of this clinical situation, there is a growing need for guidelines that are specific to the Asia-Pacific region. These guidelines provide comprehensive recommendations for evidence-based management throughout the entire process of liver transplantation, covering both deceased and living donor liver transplantation. In addition, the development of these guidelines has been a collaborative effort between medical professionals from various countries in the region. This has allowed for the inclusion of diverse perspectives and experiences, leading to a more comprehensive and effective set of guidelines.

Changing etiological spectrum of acute liver failure

BACKGROUND AND OBJECTIVES

Acute liver failure (ALF) is an uncommon but potentially dramatic syndrome characterized by massive hepatic necrosis and has a very high mortality rate of 50% to 75% without liver transplantation. This study is aimed at analyzing the etiological spectrum of ALF patients and compare these with ALF mimics such as malaria, dengue fever and other tropical infectious diseases.

METHODS

The study population included patients who presented with ALF and ALF mimics in a tertiary care center over two years. We retrospectively analyzed the patient case files and a comparison was made concerning the baseline demographic details, clinical profile, laboratory values and outcomes.

RESULTS

Sixty-three patients were assessed, with 32 in ALF and 31 in ALF mimics group. The most common cause for ALF was hepatitis A virus (25%), followed by hepatitis B virus (18.7%), drug-induced liver injury (12.7%), autoimmune hepatitis (12.5%), hepatitis E virus (9.3%) and Wilson's disease (6.25%). In the ALF mimics group, malaria (58.06%) was the most common cause, followed by dengue fever (16.1%), leptospirosis (12.9%) and scrub typhus (12.9%). Patients in the ALF mimics group had significantly higher incidence of fever (p = 0.001), hepatosplenomegaly (p = 0.01), anemia (p = 0.02) and shorter jaundice to encephalopathy duration (p = 0.032) as compared to the ALF group, while higher transaminase levels (p = 0.03), bilirubin (p = 0.01), prothrombin time (p = 0.01), serum ammonia (p = 0.02) and mortality (p = 0.02) were observed in ALF patients.

CONCLUSIONS

The most common cause for ALF was hepatitis A virus, followed by hepatitis B virus, while in ALF mimics it was malaria followed by dengue fever, in our study. Patients of ALF mimics can have similar presentation, but a high index of suspicion and awareness is required to identify the common infectious ALF mimics for early diagnosis.

Multi-Task Learning for Post-transplant Cause of Death Analysis: A Case Study on Liver Transplant

Organ transplant is the essential treatment method for some end-stage diseases, such as liver failure. Analyzing the post-transplant cause of death (CoD) after organ transplant provides a powerful tool for clinical decision making, including personalized treatment and organ allocation. However, traditional methods like Model for End-stage Liver Disease (MELD) score and conventional machine learning (ML) methods are limited in CoD analysis due to two major data and model-related challenges. To address this, we propose a novel framework called CoD-MTL leveraging multi-task learning to model the semantic relationships between various CoD prediction tasks jointly. Specifically, we develop a novel tree distillation strategy for multi-task learning, which combines the strength of both the tree model and multi-task learning. Experimental results are presented to show the precise and reliable CoD predictions of our framework. A case study is conducted to demonstrate the clinical importance of our method in the liver transplant.

MFGE-8 identified in fetal mesenchymal-stromal-cell-derived exosomes ameliorates acute hepatic failure pathology

Liver transplantation is the gold-standard therapy for acute hepatic failure (AHF) with limitations related to organ shortage and life-long immunosuppressive therapy. Cell therapy emerges as a promising alternative to transplantation. We have previously shown that IL-10 and Annexin-A1 released by amniotic fluid human mesenchymal stromal cells (AF-MSCs) and their hepatocyte progenitor-like (HPL) or hepatocyte-like (HPL) cells induce liver repair and downregulate systemic inflammation in a CCl4-AHF mouse model. Herein, we demonstrate that exosomes (EXO) derived from these cells improve liver phenotype in CCl4-induced mice and promote oval cell proliferation. LC-MS/MS proteomic analysis identified MEFG-8 in EXO cargo that facilitates rescue of AHF by suppressing PI3K signaling. Administration of recombinant MFGE-8 protein also reduced liver damage in CCl4-induced mice. Clinically, MEFG-8 expression was decreased in liver biopsies from AHF patients. Collectively, our study provides proof-of-concept for an innovative, cell-free, less immunogenic, and non-toxic alternative strategy for AHF.

Refining Auxiliary Orthotopic Liver Transplantation (AOLT) Improves Outcomes in Adult Patients With Acute Liver Failure

OBJECTIVE

To investigate whether and how experience accumulation and technical refinements simultaneously implemented in auxiliary orthotopic liver transplantation (AOLT) may impact on outcomes.

BACKGROUND

AOLT for acute liver failure (ALF) provides the unique chance of complete immunosuppression withdrawal after adequate native liver remnant regeneration but is a technically demanding procedure. Our department is a reference center for ALF and an early adopter of AOLT.

METHODS

This is a single-center retrospective before/after study of a prospectively maintained cohort of 48 patients with ALF who underwent AOLT between 1993 and 2019. In 2012, technical refinements were implemented to improve outcomes: (i) favoring the volume of the graft rather than that of the native liver, (ii) direct anastomosis of graft hepatic artery with recipient right hepatic artery instead of the use of large size vessels, (iii) end-to-side hepaticocholedocostomy instead of bilioenteric anastomosis. Early experience (1993-2011) group (n=26) and recent experience (2012-2019) group (n=22) were compared. Primary endpoint was 90-day severe morbidity rate (Clavien-Dindo≥IIIa) and secondary endpoints were overall patient survival and complete immunosuppression withdrawal rates.

RESULTS

Compared with the earlier experience group, the recent experience group was associated with a lower severe complication rate (27% vs 65%, P <0.001), as well as less biliary (18% vs 54%, P =0.017) and arterial (0% vs 15%, P =0.115) complications. The 1-, 3-, and 5-year patient survival was significantly improved (91%, 91%, 91% vs 76%, 61%, 60%, P =0.045). The rate of complete immunosuppression withdrawal increased to 94% vs 70%, ( P =0.091) with no need of long-term graft explant.

CONCLUSION

These technical refinements favoring the liver graft and reducing morbidity may promote AOLT implementation among LT centers.

Acute Liver Failure Caused by Secondary Hemophagocytic Lymphohistiocytosis After COVID-19 Vaccination - Case Report and Literature Review

Hemophagocytic lymphohistiocytosis (HLH) is a congenital or acquired hyperinflammatory syndrome, in some cases accompanied by acute liver failure. We present a case report of acute liver failure associated with HLH after COVID-19 vaccination and bring a literature review of the connection between HLH and COVID-19 vaccination. HLH has significant mortality rate, and liver transplantation is not a therapeutic option. Therefore, early recognition and timely conservative treatment are corner stones in reducing HLH-related morbidity and mortality.

Prognostic Scores in Acute Liver Failure Due to Viral Hepatitis

Viral infections are among the major causes of acute liver failure (ALF) worldwide. While the role of agents such as hepatitis A, B, C, D and E viruses in precipitating ALF are well known, improvements in serological assays have led to the detection of viral agents such as Epstein Barr virus, cytomegalovirus etc. as atypical causes of ALF. Despite the plethora of literature available on viral hepatitis and ALF, there is very limited large-scale epidemiologic data on the prevalence, risk factors of progression and outcomes in ALF of viral causes. This is important as viral infections remain the leading cause of ALF in the East and in developing countries, while the impact of viral ALF in the West has largely been ameliorated by effective vaccination and sanitization programs. This review focuses specifically on the available prognostic scores that aid in the management of ALF of viral etiologies while also briefly reviewing the current literature on newer viral agents known to cause ALF, risk factors of progression, outcomes and how management algorithms can be developed by incorporation of prognostic scoring systems for referral and transplant listing.

Preclinical Experience of the Mayo Spheroid Reservoir Bioartificial Liver (SRBAL) in Management of Acute Liver Failure

The Spheroid Reservoir Bioartificial Liver (SRBAL) is an innovative treatment option for acute liver failure (ALF). This extracorporeal support device, which provides detoxification and other liver functions using high-density culture of porcine hepatocyte spheroids, has been reported in three randomized large animal studies. A meta-analysis of these three preclinical studies was performed to establish efficacy of SRBAL treatment in terms of survival benefit and neuroprotective effect. The studies included two hepatotoxic drug models of ALF (D-galactosamine, α-amanitin/lipopolysaccharide) or a liver resection model (85% hepatectomy) in pigs or monkeys. The SRBAL treatment was started in three different settings starting at 12 h, 24 h or 48 h after induction of ALF; comparisons were made with two similar control groups in each model. SRBAL therapy was associated with significant survival and neuroprotective benefits in all three animal models of ALF. The benefits of therapy were dose dependent with the most effective configuration of SRBAL being continuous treatment of 24 h duration and dose of 200 g of porcine hepatic spheroids. Future clinical testing of SRBAL in patients with ALF appears warranted.

The role of platelet mediated thromboinflammation in acute liver injury

Acute liver injuries have wide and varied etiologies and they occur both in patients with and without pre-existent chronic liver disease. Whilst the pathophysiological mechanisms remain distinct, both acute and acute-on-chronic liver injury is typified by deranged serum transaminase levels and if severe or persistent can result in liver failure manifest by a combination of jaundice, coagulopathy and encephalopathy. It is well established that platelets exhibit diverse functions as immune cells and are active participants in inflammation through processes including immunothrombosis or thromboinflammation. Growing evidence suggests platelets play a dualistic role in liver inflammation, shaping the immune response through direct interactions and release of soluble mediators modulating function of liver sinusoidal endothelial cells, stromal cells as well as migrating and tissue-resident leucocytes. Elucidating the pathways involved in initiation, propagation and resolution of the immune response are of interest to identify therapeutic targets. In this review the provocative role of platelets is outlined, highlighting beneficial and detrimental effects in a spatial, temporal and disease-specific manner.

The Role of NLRP3 Inflammasome Activation Pathway of Hepatic Macrophages in Liver Ischemia-Reperfusion Injury

Ischemia-reperfusion injury (IRI) is considered an inherent component involved in liver transplantation, which induce early organ dysfunction and failure. And the accumulating evidences indicate that the activation of host innate immune system, especially hepatic macrophages, play a pivotal role in the progression of LIRI. Inflammasomes is a kind of intracellular multimolecular complexes that actively participate in the innate immune responses and proinflammatory signaling pathways. Among them, NLRP3 inflammasome is the best characterized and correspond to regulate caspase-1 activation and the secretion of proinflammatory cytokines in response to various pathogen-derived as well as danger-associated signals. Additionally, NLRP3 is highly expressed in hepatic macrophages, and the assembly of NLRP3 inflammasome could lead to LIRI, which makes it a promising therapeutic target. However, detailed mechanisms about NLRP3 inflammasome involving in the hepatic macrophages-related LIRI is rarely summarized. Here, we review the potential role of the NLRP3 inflammasome pathway of hepatic macrophages in LIRI, with highlights on currently available therapeutic options.