Genotype 4 HEV infection triggers the initiation and development of acute pancreatitis

Hepatitis A and E Viruses Are Important Agents of Acute Severe Hepatitis in Asia: A Narrative Review

Acute-on-chronic liver failure (ACLF) and acute liver failure (ALF) are severe hepatitis that occur in patients with and without chronic liver diseases and/or cirrhosis, respectively, and both often result in death. Hepatitis A virus (HAV) and hepatitis E virus (HEV) infection can cause these severe conditions. We reviewed the role of HAV and HEV, which infect humans through the fecal-oral route, in ALF and ACLF in Asian countries. This narrative review was the derived from a traditional non-systematic review. Hepatitis A should be recognized as one of the sexually transmitted infections, especially among men who have sex with men. HAV genotype IIIA infection seems to present a more severe clinical manifestation. Acute HEV-1 infection is associated with ALF in pregnant women in India. HEV-4, rather than HEV-3, was found in severe hepatitis in Japan. HEV also plays a role as a cause of acute insult and/or chronic liver disease in immunocompromised patients with ACLF. Further studies are needed for the development of vaccines and antivirals against HAV and HEV infections. Despite the limitations of the recording of cases and the extent of specific vaccinations, multidisciplinary cooperation, involving hepatologists, virologists, experts in public health, etc., may improve the treatment of HAV and HEV infection.

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.

The gamma-glutamyl transpeptidase to platelet ratio: a good noninvasive biomarker for predicting for the occurrence and prognosis of patients with hepatitis E virus-related acute liver failure

Background

The relationship between GPR and hepatitis E has not been reported. This study evaluates the GPR levels in AHE patients and HEV-ALF patients and explores the role of GPR levels in the prognosis of HEV-ALF patients, offering new strategies and methods for the diagnosis and prognosis of HEV-ALF patients.

Methods

Serum samples were collected from 206 AHE patients and 217 HEV-ALF patients admitted to the First Affiliated Hospital of Zhejiang University School of Medicine, Suzhou Yongding Hospital, and Nanjing Medical University Affiliated Suzhou Hospital between January 1, 2017, and November 30, 2024.

Results

The GPR level in the HEV-ALF group was significantly higher than in the AHE group (p < 0.001). OPLS-DA analysis revealed that INR, TBIL, PLT, GPR, TCH, ALT, AFP, TP, ALB, and AST were the major influential factors for the occurrence of HEV-ALF. GPR showed good diagnostic performance with an AUC of 0.701. DCA further supported the utility of GPR across a range of threshold probabilities. Regarding the prediction of 30-day mortality, GPR levels were significantly higher in the non-survival group compared to the survival group (p < 0.001). OPLS-DA analysis highlighted GPR as the most influential factor for predicting 30-day mortality. GPR demonstrated an AUC of 0.703. DCA results also indicated GPR's strong decision-making ability for predicting 30-day mortality in HEV-ALF patients.

Conclusion

GPR is highly expressed in HEV-ALF patients and is closely related to their prognosis.

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.

Cross-species transmission and histopathological variation in specific-pathogen-free minipigs infected with different hepatitis E virus strains

Hepatitis E virus (HEV) is a major cause of viral hepatitis worldwide. Pigs are the natural host of HEV genotype 3 and the main reservoir of HEV. As the host range of HEV genotype 3 expands, the possibility that HEV from various species can be transmitted to humans via pigs is increasing. We investigated the potential cross-species transmission of HEV by infecting minipigs with swine HEV (swHEV), rabbit HEV (rbHEV), and human HEV (huHEV) and examining their histopathological characteristics and distribution in various organs. Fifteen specific-pathogen-free Yucatan minipigs were infected with swHEV, rbHEV, huHEV, or a mock control. In the present study, we analysed faecal shedding, viremia, and serological parameters over a seven-week period. Our results indicated that swHEV exhibited more robust shedding and viremia than non-swHEVs. Only swHEV affected the serological parameters, suggesting strain-specific differences. Histopathological examination revealed distinct patterns in the liver, pancreas, intestine, and lymphoid tissues after infection with each HEV strain. Notably, all three HEVs induced histopathological changes in the pancreas, supporting the association of HEVs with acute pancreatitis. Our results also identified skeletal muscle as a site of HEV antigen presence, suggesting a potential link to myositis. In conclusion, this study provides valuable insights into the infection dynamics of different HEV strains in minipigs, emphasizing the strain-specific variations in virological, serological, and histological parameters. The observed differences in infection kinetics and tissue tropism will contribute to our understanding of HEV pathogenesis and the potential for cross-species transmission.

Three Distinct Reporter Systems of Hepatitis E Virus and Their Utility as Drug Screening Platforms

The hepatitis E virus (HEV) is increasingly acknowledged as the primary cause of acute hepatitis. While most HEV infections are self-limiting, cases of chronic infection and fulminant hepatitis necessitate the administration of anti-HEV medications. However, there is a lack of specific antiviral drugs designed for HEV, and the currently available drug (ribavirin) has been associated with significant adverse effects. The development of innovative antiviral drugs involves targeting distinct steps within the viral life cycle: the early step (attachment and internalization), middle step (translation and RNA replication), and late step (virus particle formation and virion release). We recently established three HEV reporter systems, each covering one or two of these steps. Using these reporter systems, we identified various potential drug candidates that target different steps of the HEV life cycle. Through rigorous in vitro testing using our robust cell culture system with the genotype 3 HEV strain (JE03-1760F/P10), we confirmed the efficacy of these drugs, when used alone or in combination with existing anti-HEV drugs. This underscores their significance in the quest for an effective anti-HEV treatment. In the present review, we discuss the development of the three reporter systems, their applications in drug screening, and their potential to advance our understanding of the incompletely elucidated HEV life cycle.