Role of non-hepatotropic viruses in acute sporadic viral hepatitis and acute-on-chronic liver failure in adults

Critical care management of acute liver failure

The management of acute liver failure (ALF) in modern hepatology intensive care units (ICU) has improved patient outcomes. Critical care management of hepatic encephalopathy, cerebral edema, fluid and electrolytes; prevention of infections and organ support are central to improved outcomes of ALF. In particular, the pathogenesis of encephalopathy is multifactorial, with ammonia, elevated intra-cranial pressure and systemic inflammation playing a central role. Although ALF remains associated with high mortality, the availability of supportive care, including organ failure support such as plasma exchange, timely mechanical ventilation or continuous renal replacement therapy, either conservatively manages patients with ALF or offers bridging therapy until liver transplantation. Thus, appropriate critical care management has improved the likelihood of patient recovery in ALF. ICU care interventions such as monitoring of cerebral edema, fluid status assessment and interventions for sepsis prevention, nutritional support and management of electrolytes can salvage a substantial proportion of patients. In this review, we discuss the key aspects of critical care management of ALF.

Alzheimer's disease as a viral disease: Revisiting the infectious hypothesis

Alzheimer's disease (AD) represents the most frequent type of dementia in elderly people. Two major forms of the disease exist: sporadic - the causes of which have not yet been fully understood - and familial - inherited within families from generation to generation, with a clear autosomal dominant transmission of mutations in Presenilin 1 (PSEN1), 2 (PSEN2) or Amyloid Precursors Protein (APP) genes. The main hallmark of AD consists of extracellular deposits of amyloid-beta (Aβ) peptide and intracellular deposits of the hyperphosphorylated form of the tau protein. An ever-growing body of research supports the viral infectious hypothesis of sporadic forms of AD. In particular, it has been shown that several herpes viruses (i.e., HHV-1, HHV-2, HHV-3 or varicella zoster virus, HHV-4 or Epstein Barr virus, HHV-5 or cytomegalovirus, HHV-6A and B, HHV-7), flaviviruses (i.e., Zika virus, Dengue fever virus, Japanese encephalitis virus) as well as Human Immunodeficiency Virus (HIV), hepatitis viruses (HAV, HBV, HCV, HDV, HEV), SARS-CoV2, Ljungan virus (LV), Influenza A virus and Borna disease virus, could increase the risk of AD. Here, we summarized and discussed these results. Based on these findings, significant issues for future studies are also put forward.

Oxidative Stress in Liver Pathophysiology and Disease

The liver is an organ that is particularly exposed to reactive oxygen species (ROS), which not only arise during metabolic functions but also during the biotransformation of xenobiotics. The disruption of redox balance causes oxidative stress, which affects liver function, modulates inflammatory pathways and contributes to disease. Thus, oxidative stress is implicated in acute liver injury and in the pathogenesis of prevalent infectious or metabolic chronic liver diseases such as viral hepatitis B or C, alcoholic fatty liver disease, non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH). Moreover, oxidative stress plays a crucial role in liver disease progression to liver fibrosis, cirrhosis and hepatocellular carcinoma (HCC). Herein, we provide an overview on the effects of oxidative stress on liver pathophysiology and the mechanisms by which oxidative stress promotes liver disease.

Viral Hepatitis and Acute-on-Chronic Liver Failure

Acute-on-chronic liver failure (ACLF) is a potentially reversible syndrome that develops in patients with cirrhosis or with underlying chronic liver disease (CLD) and is characterized by acute decompensation, organ failure, and high short-term mortality. Hepatitis A and hepatitis E are major causes of ACLF. Hepatitis B may also cause ACLF through a flare of hepatitis B, acute infection, or reactivation. Besides supportive care, nucleoside/nucleotide analog therapy should also be initiated in this setting. Nonhepatotropic viruses may rarely also cause ACLF with the severe acute respiratory syndrome coronavirus 2 virus recently being identified with poorer outcomes in those with underlying CLD.

Liver failure as the initial presentation in cancer of unknown primary: a case report

BACKGROUND

Liver failure is severe hepatic cellular damage caused by multiple factors that leads to clinical manifestations. Hepatic infiltration by malignancy is rarely reported as a cause of liver failure.

CASE PRESENTATION

A 51-year-old male patient was admitted to the Wuhan Union Hospital complaining of bloating and jaundice. He had been diagnosed with polymyositis ten prior and was taking oral glucocorticoids. Physical examination revealed seroperitoneum and icteric sclera; laboratory tests revealed liver dysfunction, a coagulopathy, and negative results for the common causes of liver failure. Moreover, an ascitic tap and bone marrow aspirate and trephine confirmed a metastatic, poorly differentiated adenocarcinoma. These findings indicate that malignant infiltration is the most likely cause of liver failure. Regrettably, the patient refused complete liver and lymph node biopsies and was discharged on day 31.

CONCLUSION

Clinicians should consider the possibility of malignant infiltration when approaching a case of liver failure with prodromal symptoms or imaging abnormalities, especially in patients with autoimmune diseases, such as polymyositis.

Hepatic Manifestations of Systemic Diseases

In addition to being the primary target of infections such as viral hepatitis, the liver may also be affected by systemic disease. These include bacterial, mycotic, and viral infections, as well as autoimmune and infiltrative diseases. These conditions generally manifest as abnormal liver biochemistries, often with a cholestatic profile, and may present with additional signs/symptoms such as jaundice and fever. A high index of suspicion and familiarity with potential causal entities is necessary to guide appropriate testing, diagnosis, and treatment.

Commentary on COVID-19-induced liver injury in various age and risk groups

Towards the end of 2019, a new type of coronavirus, severe acute respiratory syndrome, emerged in the city of Wuhan in China's Hubei Province. The first occurrence was described as a case of pneumonia. Coronavirus disease 2019 (COVID-19) can progress primarily with symptoms varying from a mild upper respiratory tract infection to severe pneumonia, acute respiratory distress syndrome, and death. Determining the mechanisms of action of this virus, which can affect all systems including gastrointestinal, is vital for predicting the progression of the disease and managing its treatment. It is important to demonstrate the mechanisms of action of COVID-19 in patients without a previously known chronic or systemic disease. Although there is still no specific treatment for the virus, various algorithms have been created. As a result of the applied algorithms, the response to the treatment was satisfactory in some patients, while unexpected side effects occurred in some patients. It helps to clarify whether the unwanted effects that occur are due to the effect of the disease or the side effects of the drugs used in the treatment. There is currently increasing interest in COVID-19 interaction with liver tissue. Therefore, we would like to discuss the details of liver injury/dysfunction in the current literature.

Biliary Intraepithelial Neoplasia With Gallbladder Adenoma and Cirrhosis: A Case Report

Biliary intraepithelial neoplasia (BilIN) is a precursor lesion of cholangiocarcinoma that has been rarely reported. The present study reports a 56-year-old male with low-grade BilIN of the bile ducts and the cystic duct margin. Stent exchange endoscopy demonstrated an irregular, intraductal mass extending along the common bile duct, common hepatic duct, and hepatic duct bifurcation. The peribiliary mass was found to abut the right portal vein, inferior vena cava, and pancreatic head, and replaced the right hepatic artery. In addition, there was evidence of gallbladder adenoma managed with cholecystectomy and a right-lobed liver lesion and cirrhosis, which prompted the discussion of prophylactic liver transplantation. We emphasize the radiological features of BilIN and associated pathological findings through multiple imaging modalities. Consideration of this diagnosis is indicated in western countries and requires timely management based on available guidelines.

Epidemiology of liver failure in Asia-Pacific region

The global burden of deaths caused by liver failure is substantial. The Asia-Pacific region is home to more than half of the global population and accounted for 62.6% of global deaths because of liver diseases in 2015. The aetiology of liver failure varies in different countries at different times. Viruses (Hepatitis A, B and E), drugs (herbs and anti-tuberculous drugs), toxins (alcohol use) and autoimmune flares are mainly responsible of majority of liver failure in individuals with normal liver (acute liver failure; ALF); else these may precipitate liver failure in those with chronic liver disease (acute-on-chronic liver failure; ACLF). Concomitant increases in alcohol misuse and metabolic syndrome in recent years are concerning. Ongoing efforts to address liver failure-related morbidity and mortality require accurate contemporary estimates of epidemiology and outcomes. In light of the ever-changing nature of liver disease epidemiology, accurate estimates for the burden of liver failure across the countries are vital for setting clinical, research and policy priorities. In this review, we aimed to describe the current as well as changing epidemiological trends of common liver failure syndromes, ALF and ACLF in the Asia-Pacific region.

Newer developments in viral hepatitis: Looking beyond hepatotropic viruses

Viral hepatitis in the entirety of its clinical spectrum is vast and most discussion are often restricted to hepatotropic viral infections, including hepatitis virus (A to E). With the advent of more advanced diagnostic techniques, it has now become possible to diagnose patients with non-hepatotropic viral infection in patients with hepatitis. Majority of these viruses belong to the Herpes family, with characteristic feature of latency. With the increase in the rate of liver transplantation globally, especially for the indication of acute hepatitis, it becomes even more relevant to identify non hepatotropic viral infection as the primary hepatic insult. Immunosuppression post-transplant is an established cause of reactivation of a number of viral infections that could then indirectly cause hepatic injury. Antiviral agents may be utilized for treatment of most of these infections, although data supporting their role is derived primarily from case reports. There are no current guidelines to manage patients suspected to have viral hepatitis secondary to non-hepatotropic viral infection, a gap that needs to be addressed. In this review article, the authors analyze the common non hepatotropic viral infections contributing to viral hepatitis, with emphasis on recent advances on diagnosis, management and role of liver transplantation.

Human Herpesviruses Increase the Severity of Hepatitis

Simple Summary

More than 300 million people worldwide suffer from hepatitis B or hepatitis C and more than 1 million people die each year from cirrhosis and liver cancer. In some cases, the nature of hepatitis remains unclear. The purpose of this research was to assess the prevalence of human herpesviruses (cytomegalovirus, Epstein–Barr virus, and herpesvirus type 6) in patients with hepatitis, and to examine their effect on the disease severity. In the clinical materials of 377 patients with acute or chronic hepatitis, DNA of these three herpesviruses was detected in the blood in 13.5% of patients with viral hepatitis B or C and in 10.1% of patients with hepatitis of unspecified etiology. The cirrhosis was diagnosed in patients with herpesviruses 3 times more often than in patients without them. In patients with hepatitis C, the incidence of herpesviruses was higher in the tissue samples of liver biopsies (38.7%) than in the blood. Clinical and virological indicators of hepatitis were considerably higher in the patients with coinfection. Since in patients with hepatitis the presence of herpesviruses is associated with a more severe course of the disease, the detection, and herpesvirus DNA monitoring will help to adjust the course of therapy.

Abstract

Acute and chronic liver diseases are a major global public health problem; nevertheless, the etiology of 12–30% of cases remains obscure. The purpose of this research was to study the incidence of human herpesviruses (HHVs) cytomegalovirus, Epstein–Barr virus (EBV), and HHV-6 in patients with hepatitis and to examine the effect of HHV on the disease severity. We studied the clinical materials of 259 patients with hepatitis treated in Infectious Clinic n.1 (Moscow) and the archived materials of 118 patients with hepatitis C. HHV DNA was detected in the whole blood in 13.5% of patients with hepatitis B or C and in 10.1% of patients with hepatitis of unspecified etiology. EBV demonstrated the highest incidence (58.1%). Cirrhosis was diagnosed in 50% of patients with HHV and in 15.6% of patients without HHV. In patients with hepatitis C, the frequency of HHV was higher in liver biopsy (38.7%) compared to blood. The clinical and virological indicators of hepatitis were considerably higher in patients with coinfection. Conclusion: HHV detected in patients with viral hepatitis has been associated with a significant effect on the severity of the disease, and we suggest monitoring HHV DNA in patients with severe hepatitis and/or poor response to antiviral drugs.

Acute viral hepatitis E complicated with acute pancreatitis in an immunocompetent adult

Acute viral hepatitis has been associated with several extrahepatic complications. Fulminant liver failure secondary to acute viral hepatitis may be complicated by acute pancreatitis. However, in the setting of benign viral hepatitis, in the absence of liver failure, association of pancreatitis is uncommon, that too in an otherwise immunocompetent individual. The exact mechanism of hepatitis-related pancreatitis remains elusive. Proposed mechanisms include immune-mediated injury against infected pancreatic acinar cells, oedema of the ampulla of Vater and release of lysosomal enzymes from the liver. A high index of clinical suspicion is needed in any case of viral hepatitis with severe abdominal pain to recognise acute pancreatitis as a possible complication, which may increase both morbidity and mortality if unrecognised. Herein, we report a case of a young man presenting with acute viral hepatitis due to hepatitis E infection, complicated by acute pancreatitis.

Indian National Association for the Study of the Liver Consensus Statement on Acute Liver Failure (Part 1): Epidemiology, Pathogenesis, Presentation and Prognosis

Acute liver failure (ALF) is an infrequent, unpredictable, potentially fatal complication of acute liver injury (ALI) consequent to varied etiologies. Etiologies of ALF as reported in the literature have regional differences, which affects the clinical presentation and natural course. In this part of the consensus article designed to reflect the clinical practices in India, disease burden, epidemiology, clinical presentation, monitoring, and prognostication have been discussed. In India, viral hepatitis is the most frequent cause of ALF, with drug-induced hepatitis due to antituberculosis drugs being the second most frequent cause. The clinical presentation of ALF is characterized by jaundice, coagulopathy, and encephalopathy. It is important to differentiate ALF from other causes of liver failure, including acute on chronic liver failure, subacute liver failure, as well as certain tropical infections which can mimic this presentation. The disease often has a fulminant clinical course with high short-term mortality. Death is usually attributable to cerebral complications, infections, and resultant multiorgan failure. Timely liver transplantation (LT) can change the outcome, and hence, it is vital to provide intensive care to patients until LT can be arranged. It is equally important to assess prognosis to select patients who are suitable for LT. Several prognostic scores have been proposed, and their comparisons show that indigenously developed dynamic scores have an edge over scores described from the Western world. Management of ALF will be described in part 2 of this document.

Epstein-Barr Virus and Cytomegalovirus Infections of the Liver

Epstein-Barr virus (EBV) and cytomegalovirus (CMV) infections are common and are associated with a variety of liver manifestations. EBV and CMV infections, in immunocompetent hosts, commonly manifest as acute hepatitis, with severity varying from asymptomatic, self-limited icteric hepatitis to acute liver failure. Atypical manifestations, such as cholestasis, chronic hepatitis, precipitation of acute-on-chronic liver failure, and autoimmune hepatitis, are reported with EBV infection, whereas cholestasis, portal vein thrombosis, and Budd-Chiari syndrome are reported with CMV infection. In the setting of liver transplantation, CMV is the most common infectious complication and carries significant morbidity; EBV is the major cause of post-transplant lymphoproliferative disorders.

Cell Culture Systems and Drug Targets for Hepatitis A Virus Infection

Hepatitis A virus (HAV) infection is one of the major causes of acute hepatitis, and this infection occasionally causes acute liver failure. HAV infection is associated with HAV-contaminated food and water as well as sexual transmission among men who have sex with men. Although an HAV vaccine has been developed, outbreaks of hepatitis A and life-threatening severe HAV infections are still observed worldwide. Therefore, an improved HAV vaccine and anti-HAV drugs for severe hepatitis A should be developed. Here, we reviewed cell culture systems for HAV infection, and other issues. This review may help with improving the HAV vaccine and developing anti-HAV drugs.

Intensive Care Management of Acute Liver Failure: Considerations While Awaiting Liver Transplantation

Acute liver failure is a unique clinical phenomenon characterized by abrupt deterioration in liver function and altered mentation. The development of high-grade encephalopathy and multisystem organ dysfunction herald poor prognosis. Etiologic-specific treatments and supportive measures are routinely employed; however, liver transplantation remains the only chance for cure in those who do not spontaneously recover. The utility of artificial and bioartificial assist therapies as supportive care-to allow time for hepatic recovery or as a bridge to liver transplantation-has been examined but studies have been small, with mixed results. Given the severity of derangements, intensive critical care is needed to successfully bridge patients to transplant, and evaluation of candidates occurs rapidly in parallel with serial reassessments of operative fitness. Psychosocial assessment is often suboptimal and relative contraindications to transplant, such as ventilator-dependence may be overlooked. While often employed to guide evaluation, no single prognostic model discriminates those who will spontaneously recover and those who will require transplant. The purpose of this review will be to summarize approaches in critical care, prognostic modeling, and medical evaluation of the acute liver failure transplant candidate.

Modulation of the extrinsic cell death signaling pathway by viral Flip induces acute-death mediated liver failure

During viral infections viruses express molecules that interfere with the host-cell death machinery and thus inhibit cell death responses. For example the viral FLIP (vFLIP) encoded by Kaposi’s sarcoma-associated herpesvirus interacts and inhibits the central cell death effector, Caspase-8. In order to analyze the impact of anti-apoptotic viral proteins, like vFlip, on liver physiology in vivo, mice expressing vFlip constitutively in hepatocytes (vFlip^AlbCre+) were generated. Transgenic expression of vFlip caused severe liver tissue injury accompanied by massive hepatocellular necrosis and inflammation that finally culminated in early postnatal death of mice. On a molecular level, hepatocellular death was mediated by RIPK1-MLKL necroptosis driven by an autocrine TNF production. The loss of hepatocytes was accompanied by impaired bile acid production and disruption of the bile duct structure with impact on the liver-gut axis. Notably, embryonic development and tissue homeostasis were unaffected by vFlip expression. In summary our data uncovered that transgenic expression of vFlip can cause severe liver injury in mice, culminating in multiple organ insufficiency and death. These results demonstrate that viral cell death regulatory molecules exhibit different facets of activities beyond the inhibition of cell death that may merit more sophisticated in vitro and in vivo analysis.

Epstein-Barr virus infection is associated with a higher Child-Pugh score and may predict poor prognoses for patients with liver cirrhosis

BACKGROUND

Studies on Epstein-Barr virus (EBV) have focused mostly on neoplastic disease. Few studies have considered immunocompetent patients who are not severely immunocompromised. Liver cirrhosis is associated with various levels of immune dysfunction. In the current study, we determined EBV infection rates, the influence on liver function, and analyzed the risk factors for death in patients with liver cirrhosis.

METHODS

The medical records of patients diagnosed with liver cirrhosis between 1 January 2014 and 31 December 2016 were reviewed. Patients who were or were not infected with EBV were enrolled in this study. Liver functions were compared. The risk factors for 28-, 90-, and 180-day mortality rates were analyzed by univariate and multivariate logistic regression.

RESULTS

The medical records hospitalized patients diagnosed with liver cirrhosis were reviewed. Of these patients, 97 had assessed EBV deoxyribonucleic acid (DNA) and 36 (37.1%) patients were EBV DNA-positive. The age of the EBV-infected patients was older than patients not infected with EBV. EBV-infected patients had a lower level of albumin, and a lower albumin-to-globulin ratio (P = 0.019 and P = 0.013, respectively). EBV-infected patients had higher Child-Pugh scores (P = 0.033) and higher acute-on-chronic liver failure (ACLF) rate (P = 0.050). The Child-Pugh score and ACLF were the risk factors for the 28-, 90-, and 180-day mortality rates.

CONCLUSIONS

This study revealed that patients with liver cirrhosis had higher EBV infection rates, especially patients > 60 years of age, which likely reflected viral reactivation. And liver injury was aggravated in EBV-infected patients. Thus, EBV infection indirectly influenced the prognosis of EBV-infected patients by increasing the Child-Pugh score and ACLF rate.

Human cytomegalovirus and Epstein-Barr virus infections, risk factors, and their influence on the liver function of patients with acute-on-chronic liver failure

Background

Studies on human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) have focused primarily on the immunosuppressed population. Few studies have considered immunocompetent and not severely immunocompromised patients. We determined the infection rates of HCMV and EBV, their risk factors and their influence on liver function in patients with HBV-related acute-on-chronic liver failure (ACLF).

Methods

Patients infected with ACLF-based hepatitis B virus (HBV) from 1 December 2016 to 31 May 2018 were enrolled in our study and were divided into infected and uninfected groups. The risk factors for HCMV and EBV infection and their influence on liver function were analysed.

Results

A total of 100 hospitalized patients with ACLF due to HBV infection were enrolled in this study. Of these patients, 5% presented HCMV deoxyribonucleic acid (DNA) and 23.0% presented EBV DNA. An HBV DNA count of < 1000 IU/mL increased the occurrence of HCMV infection (P = 0.003). Age, especially older than 60 years, was a risk factor for EBV infection (P = 0.034, P = 0.033). HCMV-infected patients had lower alanine aminotransferase (ALT) levels; albumin levels and Child–Pugh scores in EBV-infected patients were higher than those in uninfected patients.

Conclusions

HCMV and EBV were detected in patients with ACLF caused by HBV infection. Lower replication of HBV (HBV DNA < 1000 IU/mL) may increase the probability of HCMV infection; age, especially older than 60 years of age, was a risk factor for EBV infection. HCMV infection may inhibit HBV proliferation and did not increase liver injury, while co-infection with EBV may influence liver function and may result in a poor prognosis.

Differential Diagnosis of Hepatic Necrosis Encountered at Autopsy

The liver is subject to a variety of extrinsic and intrinsic insults that manifest with both specific and nonspecific patterns of necrosis. In the autopsy setting, these patterns are often encountered as incidental findings or even causes of death. There are several etiologies of hepatic necrosis, including toxins, drug injuries, viral infections, ischemic injuries, and metabolic disease, all of which possess overlapping gross and histologic presentations. Nonetheless, patterned necrosis in the context of clinical and demographic history allows for the forensic pathologist to develop a differential diagnosis, which may then be pruned into a specific or likely cause. The aim of the following review is to elucidate these patterns in the context of the liver diseases from which they arise with the goal developing a differential diagnosis and ultimate determination of etiology. Acad Forensic Pathol. 2018 8(2): 256-295.

Acute Viral Hepatitis: Beyond A, B, and C

From the standpoint of the surgical pathologist "hepatitis" is defined as the set of histologic patterns of lesions found in livers infected by hepatotropic viruses, by non-hepatotrophic viruses leading to liver inflammation in the context of systemic infection, or due to an autoimmune disease, drug, or toxin involving the liver. This article is centered on the histologic patterns of injury in acute viral hepatitis, encompassing the hepatotropic viruses A, B, C, D, and E and the "icteric hemorrhagic fevers" (dengue, hantavirus, yellow fever). A brief mention of viruses causing hepatitis in immunosuppressed patients also is presented.