Chronic Hepatitis E is associated with cholangitis

Cholestasis in hepatitis E virus infection

Hepatitis E virus (HEV) infection causes acute hepatitis, chronic hepatitis, particularly in compromised hosts, and various extrahepatic manifestations. HEV infection is reportedly associated with biliary-pancreatic diseases, such as gallstones, cholangitis, choledocholithiasis, and acute pancreatitis. Severe jaundice and prolonged cholestasis are also atypical manifestations of HEV infection. The mechanism and genes involved in cholestasis, namely sinusoidal uptake of blood, bile salt synthesis and secretion from hepatocytes to the canaliculus, have been elucidated. HEV infection triggers severe jaundice and prolonged cholestasis in patients with genetic variants in adenosine triphosphatase phospholipid transporting 8B1, adenosine triphosphate-binding cassette (ABC) protein B4, ABCB11, Myosin VB, and/or farnesoid X receptor (FXR/NR1H4). Although prolonged cholestasis associated with these gene mutations does not seem to be specific to HEV infection, these mutations may be risk factors related to the severity of HEV infection. The use of the pregnane X receptor agonist rifampicin and the peroxisome proliferator-activated receptor activator bezafibrate may be useful for the treatment of cholestasis. These studies provide new insights into understanding the mechanisms of severe jaundice and prolonged cholestasis caused by HEV infection.

AMPK activation by hepatitis E virus infection inhibits viral replication through attenuation of autophagosomes and promotion of innate immunity

Hepatitis E virus (HEV) infection is generally asymptomatic or leads to acute and self-limiting hepatitis. The mechanisms orchestrating such an infection course remain to be elucidated. AMP-activated protein kinase (AMPK) is a pivotal cellular sensor for maintaining metabolic homeostasis. Here, we show that AMPK is activated in response to HEV infection and is associated with mitochondrial damage and ATP deficiency. AMPK activation, in turn, inhibits HEV replication. Mechanistic studies reveal that AMPK activation triggers the expression of interferon (IFN)-stimulated genes that possess antiviral properties. In parallel, AMPK inhibits autophagosome accumulation to exert antiviral effects. Interestingly, AMPK activation also suppresses the inflammatory response triggered by HEV infection. Consistently, AMPK activation simultaneously exerts anti-inflammatory and antiviral effects in a coculture system of HEV-infected liver cells with macrophages. These findings pave the way for the development of AMPK-targeted therapeutics to treat hepatitis E.

Recent advances in hepatitis E virus research and the Japanese clinical practice guidelines for hepatitis E virus infection

Acute hepatitis E was considered rare until reports emerged affirming the existence of hepatitis E virus (HEV) genotypes 3 and 4 infections in Japan in the early 2000s. Extensive studies by Japanese researchers have highlighted the pivotal role of pigs and wild animals, such as wild boars and deer, as reservoirs for HEV, linking them to zoonotic infections in Japan. Currently, when hepatitis occurs subsequent to the consumption of undercooked or grilled pork, wild boar meat, or offal (including pig liver and intestines), HEV infection should be considered. Following the approval of anti-HEV immunoglobulin A antibody as a diagnostic tool for hepatitis E by Japan's Health Insurance System in 2011, the annual number of diagnosed cases of HEV infection has surged. Notably, the occurrence of post-transfusion hepatitis E promoted nationwide screening of blood products for HEV using nucleic acid amplification tests since 2020. Furthermore, chronic hepatitis E has been observed in immunosuppressed individuals. Considering the significance of hepatitis E, heightened preventive measures are essential. The Japan Agency for Medical Research and Development Hepatitis A and E viruses (HAV and HEV) Study Group, which includes special virologists and hepatologists, held a virtual meeting on February 17, 2024. Discussions encompassed pathogenesis, transmission routes, diagnosis, complications, severity factors, and ongoing and prospective vaccination or treatments for hepatitis E. Rigorous assessment of referenced studies culminated in the formulation of recommendations, which are detailed within this review. This comprehensive review presents recent advancements in HEV research and Japanese clinical practice guidelines for HEV infection.

Favourable outcome of acute hepatitis E infection in patients with ANCA-associated vasculitis

BACKGROUND

Hepatitis E virus (HEV) infection is a frequent cause of acute viral hepatitis. Immunocompromised patients are at increased risk for viral infection and chronic courses of hepatitis. Whether patients with autoimmune diseases are at risk of developing clinically relevant hepatitis or even chronic liver disease after HEV infection is discussed controversially. ANCA-associated vasculitis is a rare autoimmune disease with potentially life-threatening organ involvement, thus requiring intensive immunosuppression with glucocorticoids, cyclophosphamide, or rituximab. As there are no reports available on the infection with HEV in patients with ANCA-associated vasculitis, clinical decision making in such cases is based on experiences from other disease entities. Therefore, in this study we analyzed the course of liver disease and the therapeutic management of autoimmune vasculitis in a retrospective cohort of five patients with ANCA-associated vasculitis and acute hepatitis E.

RESULTS

Four patients were on immunosuppressive maintenance therapy and one patient was on remission induction therapy with cyclophosphamide and high dose glucocorticoids. All patients had at least one potentially hepatotoxic co-medication at the time of hepatitis. Hepatitis-associated clinical symptoms were recorded in four of five patients. The course of hepatitis was characterized by strongly elevated transaminases, a temporary liver failure was observed in one case. The management of hepatitis E included cessation of the immunosuppressants in all patients, whereas oral glucocorticoids were not discontinued. Under this regime, all patients cleared the virus without additional anti-viral treatment. Liver enzymes normalized one month after they peaked. In the follow-up period of at least 1.5 years (range 1.5-12 years), no chronic liver disease was observed, although one patient died of cholangiocarcinoma with liver metastases some years after HEV infection. Vasculitis was not active in our patient cohort at the time of HEV infection. However, inflammatory flares occured in three of five patients after discontinuation of the immunosuppressive therapy. Immunosuppressants were paused for a median time of 4 weeks and after their resumption vasculitic disease activity was controlled in all patients.

CONCLUSIONS

Acute HEV infection in patients with ANCA-associated vasculitis shows a favorable outcome of liver disease but bears the risk of inflammatory flares due to cessation of immunosuppression.

Chronic hepatitis E in an elderly immunocompetent patient who achieved a sustained virologic response with ribavirin treatment

A woman in her late 70 s was diagnosed with liver injury at a health examination. Despite treatment with ursodeoxycholic acid at a nearby hospital, her transaminase levels elevated in two peaks. She was transferred to our hospital 77 days after the health examination. She weighed 42 kg and had a low body mass index of 19.8 kg/m². Viral markers, including immunoglobulin A (IgA) against hepatitis E virus (anti-HEV IgA), were negative. Drug-induced liver injury was negligible. We suspected autoimmune hepatitis because of the patient's female gender and positive antinuclear antibody. However, prednisolone and azathioprine failed to completely improve her hepatitis. On day 643, anti-HEV IgA was re-evaluated and found to be positive. She was diagnosed with autochthonous chronic hepatitis E because the virus strains in the preserved serum on day 77 and the serum on day 643 had identical nucleotide sequences (genotype 3a). Following prednisolone and azathioprine discontinuation, ribavirin (RBV) was administered for 3 months. HEV RNA disappeared and remained negative for more than 6 months after the cessation of RBV. The HEV RNA titer of 6.2 log₁₀ copies/mL on day 77 was unusually high 2.5 months after the onset, suggesting that hepatitis E had already been chronic before immunosuppressive treatment for possible autoimmune hepatitis. After getting married at 23 years old, she had been a housewife and had no comorbidities that might deteriorate her immunity. Chronicity should be kept in mind when encountering HEV infection in elderly and underweight patients.

Chronic hepatitis E: Advancing research and patient care

The hepatitis E virus (HEV) was initially thought to exclusively cause acute hepatitis. However, the first diagnosis of chronic hepatitis E in transplant recipients in 2008 profoundly changed our understanding of this pathogen. We have now begun to understand that specific HEV genotypes can cause chronic infection in certain immunocompromised populations. Over the past decade, dedicated clinical and experimental research has substantiated knowledge on the epidemiology, transmission routes, pathophysiological mechanisms, diagnosis, clinical features and treatment of chronic HEV infection. Nevertheless, many gaps and major challenges remain, particularly regarding the translation of knowledge into disease prevention and improvement of clinical outcomes. This article aims to highlight the latest developments in the understanding and management of chronic hepatitis E. More importantly, we attempt to identify major knowledge gaps and discuss strategies for further advancing both research and patient care.

Recapitulating hepatitis E virus-host interactions and facilitating antiviral drug discovery in human liver-derived organoids

Hepatotropic viruses naturally have narrow host and tissue tropisms, challenging the development of robust experimental models. The advent of organoid technology provides a unique opportunity for moving the field forward. Here, we demonstrate that three-dimensional cultured organoids from fetal and adult human liver with cholangiocyte or hepatocyte phenotype support hepatitis E virus (HEV) replication. Inoculation with infectious HEV particles demonstrates that human liver–derived organoids support the full life cycle of HEV infection. By directing organoids toward polarized monolayers in a transwell system, we observed predominantly apical secretion of HEV particles. Genome-wide transcriptomic and tRNAome analyses revealed robust host responses triggered by viral replication. Drug screening in organoids identified brequinar and homoharringtonine as potent HEV inhibitors, which are also effective against the ribavirin resistance variant harboring G1634R mutation. Thus, successful recapitulation of HEV infection in liver-derived organoids shall facilitate the study of virus-host interactions and development of antiviral therapies.

Pharmacological perspectives and molecular mechanisms of coumarin derivatives against virus disease

Infections caused by viruses are one of the foremost causes of morbidity and mortality in the world. Although a number of antiviral drugs are currently used for treatment of various kinds of viral infection diseases, there is still no available therapeutic agent for most of the viruses in clinical practice. Coumarin is a chemical compound which is found naturally in a variety of plants, it can also be synthetically produced possessing diverse biological effects. More recently, reports have highlighted the potential role of coumarin derivatives as antiviral agents. This review outlines the advances in coumarin-based compounds against various viruses including human immunodeficiency virus, hepatitis virus, herpes simplex virus, Chikungunya virus and Enterovirus 71, as well as the structure activity relationship and the possible mechanism of action of the most potent coumarin derivatives.

Autoimmune liver disease-associated serologic profiling in Chinese patients with acute hepatitis E virus infection

The association between hepatitis E virus (HEV) and autoimmune liver diseases has been well-researched; however, the focus has been on autoimmune hepatitis (AIH) and not primary biliary cholangitis (PBC). Therefore, we aimed to investigate the prevalence and evolution of AIH- and PBC-related autoantibodies in Chinese patients with HEV infection. In this retrospective study, 164 patients with acute HEV were included, specifically those whose liver autoantibody results were available and who had no pre-existing liver disease at the time of HEV diagnosis. Positive liver autoimmune serology was present in 69 (42.1%) patients and 21 (12.8%) had at least two autoantibodies at diagnosis. Greater age and alkaline phosphatase levels were independent risk factors for autoantibody positivity. Follow-up serologic tests, which were available for 27 of the 69 autoantibody-positive patients, showed that although antinuclear antibodies disappeared in 11/20 (55.0%) and antimitochondrial antibodies disappeared in 4/5 (80%) patients, 16 still remained positive for autoantibodies and two of them even developed new PBC-related antibodies, as described below. One patient developed a rim-like ANA pattern, accompanied by an enhancement of anti-gp210 positivity; and the other was diagnosed as PBC, based on chronic elevation of cholestatic enzymes and presentation with de novo AMA-M2, 18 months after HEV clearance. In conclusion, AIH- and PBC-related autoantibodies are frequently present during acute HEV infection, indicating that HEV should be excluded before diagnosing AIH and/or PBC. Importantly, some cases maintained or developed autoantibodies after viral clearance, and one patient subsequently developed PBC, highlighting that these individuals warrant long-term follow-up.

Laboratory-based Surveillance and Clinical Profile of Sporadic HEV Infection in Shanghai, China

The study aimed to describe the epidemiological, virological and clinical features of sporadic HEV infection in eastern China. A total of 6112 patient sera were tested for anti-HEV IgG or anti-HEV IgM during one consecutive year (between August 2018 and July 2019). HEV RNA presence was evaluated by RT-PCR and HEV sequences were phylogenetically analyzed. Clinical features of confirmed HEV-infected patients were delineated. The sero-positivity rate of anti-HEV IgG maintained stable around 40%, while an obvious winter spike of anti-HEV IgM prevalence was observed. A total of 111 patients were confirmed of HEV viremia by molecular diagnosis. Subtype 4d was predominant. Phylogenetic analyses suggest that certain strains circulate across species and around the country. Subjects with confirmed current HEV infection had a high median age (58 years) and males were predominant (62.2%). Most patients presented with jaundice (75.7%) and anorexia (68.0%). Significantly elevated levels of liver enzymes and bilirubin were observed. Remarkably, the baseline bilirubin level was positively correlated with illness severity. Pre-existing HBV carriage may deteriorate illness. The clinical burden caused by locally acquired HEV infection is increasing. Surveillance should be enforced especially during the transition period from winter to spring. Patients with higher level of bilirubin at disease onset had slower recovery from HEV infection.

The histologic presentation of hepatitis E reflects patients' immune status and pre-existing liver condition

Infection with the hepatitis E virus (HEV) is one of the main causes of acute hepatitis worldwide. Given that, the histopathology of hepatitis E is relatively poorly characterized, and it is unclear what exactly determines its remarkable variability. The aim of our study was a systematic analysis of hepatitis E histology, especially with regard to the clinical setting. Fifty-two liver samples (48 biopsies, 1 liver explant, 3 autopsy livers) from 41 patients with molecularly proven hepatitis E (28 HEV genotype (gt) 3, three gt 1, one gt 4 and 9 undetermined gt) were systematically evaluated for 33 histopathologic features. Following one approach, the biopsies were assigned to one of five generic histologic patterns. In another approach, they were subjected to hierarchical clustering. We found that 23/41 (56%) patients were immunocompromised, whereas 18 (44%) had no known immunosuppression. Five patients (12%) had pre-existing liver disease (LD). The histopathologic spectrum ranged from almost normal to acute, chronic, and steato-hepatitis to subtotal necrosis, and was thus distributed across all five generic patterns. Hierarchical clustering, however, identified three histopathologic clusters (C1-C3), which segregated along the immune status and pre-existing LD: C1 comprised mostly patients with pre-existing LD; histology mainly reflected the respective LD without pointing to the additional hepatitis E. C2 comprised mostly immunocompetent patients; histology mainly displayed florid hepatitis. C3 comprised mostly immunocompromised patients; histology mainly displayed smoldering hepatitis. Accordingly, C1-C3 differed markedly with respect to their clinical and histopathologic differential diagnoses. Hierarchical clustering suggests three groups with distinct histopathologies, indicating biologically different manifestations of hepatitis E. The association of histopathologic changes with the patient's immune status and pre-existing LD plausibly explains the diversity of hepatitis E histopathology, and suggests that these factors are the crucial underlying determinants. We expect our results to improve patient management by guiding the clinico-pathologic diagnosis of hepatitis E.

Clinicopathologic features and pathologic diagnosis of hepatitis E

Infection with the hepatitis E virus (HEV) is one of the most common causes, if not the most common, of acute hepatitis worldwide. In the last decade, we have learned that, in addition to the endemically and epidemically occurring form of hepatitis E, which is predominantly transmitted by contaminated drinking water and constitutes a significant health problem in resource-poor countries, there is a globally existing form of hepatitis E, which is a zoonosis and as such is primarily transmitted by the consumption of contaminated meat products. Although in most cases hepatitis E is subclinical or mild and self-limiting, pregnant women and patients with liver cirrhosis may have severe, occasionally even fatal disease, and immunocompromised individuals may develop chronic hepatitis E. Considering the substantial global health burden caused by HEV infection, it is surprising how limited our knowledge of hepatitis E pathology still is. In this article, we describe localization studies on HEV infection and discuss their implications for everyday diagnostics. Furthermore, we outline and discuss the spectrum of histologic changes, which can be found in HEV infection in various clinical contexts.