How to manage: acute liver failure

The challenges and potential of microRNA-based therapy for patients with liver failure syndromes and hepatocellular carcinoma

INTRODUCTION

Morbidity and mortality from liver disease continues to rise worldwide. There are currently limited curative treatments for patients with liver failure syndromes, encompassing acute liver failure and decompensated cirrhosis states, outside of transplantation. Whilst there have been improvements in therapeutic options for patients with hepatocellular carcinoma (HCC), there remain challenges necessitating novel therapeutic agents. microRNA have long been seen as potential therapeutic targets but there has been limited clinical translation.

AREAS COVERED

We will discuss the limitations of conventional non-transplant management of patients with liver failure syndromes and HCC. We will provide an overview of microRNA and the challenges in developing and delivering microRNA-based therapeutic agents. We will finally provide an overview of microRNA-based therapeutic agents which have progressed to clinical trials.

EXPERT OPINION

microRNA have great potential to be developed into therapeutic agents due to their association with critical biological processes which govern health and disease. Utilizing microRNA sponges to target multiple microRNA associated with specific biological processes may improve their therapeutic efficacy. However, there needs to be significant improvements in delivery systems to ensure the safe delivery of microRNA to target sites and minimize systemic distribution. This currently significantly impacts the clinical translation of microRNA-based therapeutic agents.

The challenges and potential in developing microRNA associated with regeneration as biomarkers to improve prognostication for liver failure syndromes and hepatocellular carcinoma

INTRODUCTION

Determining the need for liver transplantation remains critical in the management of hepatocellular carcinoma (HCC) and liver failure syndromes (including acute liver failure and decompensated cirrhosis states). Conventional prognostic models utilize biomarkers of liver and non-liver failure and have limitations in their application. Novel biomarkers which predict regeneration may fulfil this niche. microRNA are implicated in health and disease and are present in abundance in the circulation. Despite this, they have not translated into mainstream clinical biomarkers.

AREAS COVERED

We will discuss current challenges in the prognostication of patients with liver failure syndromes as well as for patients with HCC. We will discuss biomarkers implicated with liver regeneration. We then provide an overview of the challenges in developing microRNA into clinically tractable biomarkers. Finally, we will provide a scoping review of microRNA which may have potential as prognostic biomarkers in liver failure syndromes and HCC.

EXPERT OPINION

Novel biomarkers are needed to improve prognostic models in liver failure syndromes and HCC. Biomarkers associated with liver regeneration are currently lacking and may fulfil this niche. microRNA have the potential to be developed into clinically tractable biomarkers but a consensus on standardizing methodology and reporting is required prior to large-scale studies.

Acute liver failure in low-income and middle-income countries

Acute liver failure is a rare condition involving the rapid development, progression, and worsening of liver dysfunction, characterised by coagulopathy and encephalopathy, and has a high mortality unless liver transplantation is performed. Population-based studies are scarce, and most published data are from high-income countries, where the main cause of acute liver failure is paracetamol overdose. This Review provides an overview of the scanty literature on acute liver failure in low-income and middle-income countries, where patients are often admitted to primary care hospitals and viral hepatitis (especially hepatitis E), tropical infections (eg, dengue), traditional medicines, and drugs (especially anti-tuberculosis drugs) have an important role. We discuss incidence, cause, occurrence in children and pregnant women, prognostic factors and scores, treatment, and mortality. To conclude, we advocate for international collaboration, the establishment of central registries for the condition, and better diagnostics.

Novel treatment of acute and acute-on-chronic liver failure: Interleukin-22

Acute liver failure (ALF) is a life-threatening medical condition, characterized by rapidly progressive hepatic dysfunction, coagulopathy and hepatic encephalopathy in patients without chronic liver disease, while acute-on-chronic liver failure (ACLF) occurs in patients with existing chronic liver disease. ALF and ACLF are often associated with multiple organ failure and a high short-term mortality. In this review, we briefly discuss the causes and pathogenesis of ALF and ACLF, the current options available for the treatment of both deadly maladies and interleukin-22 (IL-22), a novel promising drug that may have great therapeutic potential for ALF and ACLF treatment. IL-22 is a cytokine produced by immune cells but mainly targets epithelial cells including hepatocytes. IL-22 has been shown to protect against organ damage and reduce bacterial infection in many preclinical models and several clinical trials including alcohol-associated hepatitis. The potential application of IL-22 for the treatment of ALF and ACLF is also elaborated.

Critical care hepatology: definitions, incidence, prognosis and role of liver failure in critically ill patients

Organ dysfunction or overt failure is a commonplace event in the critically ill affecting up to 70% of patients during their stay in the ICU. The outcome depends on the resolution of impaired organ function, while a domino-like deterioration of organs other than the primarily affected ones paves the way for increased mortality. “Acute Liver Failure” was defined in the 1970s as a rare and potentially reversible severe liver injury in the absence of prior liver disease with hepatic encephalopathy occurring within 8 weeks. Dysfunction of the liver in general reflects a critical event in “Multiple Organ Dysfunction Syndrome” due to immunologic, regulatory and metabolic functions of liver parenchymal and non-parenchymal cells. Dysregulation of the inflammatory response, persistent microcirculatory (hypoxic) impairment or drug-induced liver injury are leading problems that result in “secondary liver failure,” i.e., acquired liver injury without underlying liver disease or deterioration of preexisting (chronic) liver disease (“Acute-on-Chronic Liver Failure”). Conventional laboratory markers, such as transaminases or bilirubin, are limited to provide insight into the complex facets of metabolic and immunologic liver dysfunction. Furthermore, inhomogeneous definitions of these entities lead to widely ranging estimates of incidence. In the present work, we review the different definitions to improve the understanding of liver dysfunction as a perpetrator (and therapeutic target) of multiple organ dysfunction syndrome in critical care.

Graphic Abstract

A rare cause of acute liver failure due to haemophagocytic lymphohistiocytosis secondary to diffuse large B-cell lymphoma

Acute liver failure is a life-threatening condition commonly caused by drug-induced hepatotoxicity or viral hepatitides. However, there are a number of rarer causes such as haemophagocytic lymphohistiocytosis. Haemophagocytic lymphohistiocytosis is a syndrome of uncontrolled immune cell activation, triggered by infection or malignancy, which carries a high mortality. Whilst mild to moderate liver injury is commonly seen with haemophagocytic lymphohistiocytosis, acute liver failure has rarely been reported in adults. We present a case of a 74-year-old man with acute liver failure secondary to haemophagocytic lymphohistiocytosis triggered by undiagnosed large B-cell lymphoma. Initially treated for biliary sepsis, there was a delay in the diagnosis of haemophagocytic lymphohistiocytosis and despite initiating chemotherapy, he died soon after. This case highlights the importance of considering haemophagocytic lymphohistiocytosis as a rare cause of acute liver failure, as given the life-threatening potential of haemophagocytic lymphohistiocytosis, a prompt diagnosis may allow early initiation of chemotherapy for any chance of survival.

Acute liver failure masquerading an occult malignancy

Acute liver failure (ALF) is a rare initial presentation of metastatic liver disease and is associated with high fatality. Our case report describes acute hepatic decompensation from an occult pancreatic malignancy. A 64-year-old man presented with abdominal distension for 2 weeks associated with decreased appetite and a weight loss of 13.6 kg, over the past 8 months. Significant admission labs were serum creatinine: 6.15 mg/dL, serum bilirubin: 27 mg/dL, aspartate aminotransferase (AST): 316 u/L, alanine aminotransferase (ALT): 198 u/L and serum alkaline phosphatase: 2121 u/L. He was admitted to the medical intensive care unit and was started on dialysis for acute renal failure. MRI of the abdomen showed multiple masses in the liver concerning for metastatic disease, cystic lesions in the pancreatic body and ascites. He underwent paracentesis and ascitic fluid analysis was positive for adenocarcinoma. CA 19-9 was 17 828 u/mL. The patient's condition gradually deteriorated, and he died of cardiac arrest.