Chronic Hepatitis E Infection in a Persistently Immunosuppressed Patient Unable to Be Eliminated after Ribavirin Therapy

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.

A case of hepatitis E that developed during chemotherapy for malignant lymphoma and responded to ribavirin

BACKGROUND

The main differences in cases of sudden elevation of hepatic enzyme levels during immunochemotherapy are the reactivation of the hepatitis B virus or drug-induced liver injury. Here, we report a case of acute liver injury caused by the hepatitis E virus (HEV) during chemotherapy for malignant lymphoma, wherein the patient was successfully treated for the hepatitis and resumed chemotherapy to completion.

CASE

A 57-year-old woman visited her local doctor because she felt lightweight and tired. The patient underwent lower gastrointestinal endoscopy and was diagnosed with a malignant lymphoma of the small intestine (diffuse large B-cell lymphoma). The patient had a history of oral consumption of undercooked pork liver to improve anemia and was diagnosed with acute hepatitis E.

CONCLUSION

This report highlights the successful treatment of HEV infection in a patient undergoing immunosuppressive therapy for malignant lymphomas. A novel aspect of this study is the safe and effective use of ribavirin, an antiviral medication, along with continued chemotherapy, which resulted in sustained virological response (SVR) and the completion of the planned chemotherapy regimen. This report also provides new insights into the management of HEV infections in immunosuppressed patients undergoing chemotherapy and emphasizes the importance of considering HEV as a potential cause of acute liver injury in such cases. The successful use of ribavirin along with continued chemotherapy offers a promising treatment strategy for clinicians to consider in similar scenarios.

The Diagnosis, Pathophysiology, and Treatment of Chronic Hepatitis E Virus Infection-A Condition Affecting Immunocompromised Patients

Hepatitis E is a zoonosis caused by hepatitis E virus (HEV), which was first discovered 40 years ago. Twenty million HEV infections worldwide are estimated each year. Most hepatitis E cases are self-limiting acute hepatitis, but the virus has been recognized to cause chronic hepatitis. Following the first case report of chronic hepatitis E (CHE) in a transplant recipient, CHE has recently been identified as associated with chronic liver damage induced by HEV genotypes 3, 4, and 7-usually in immunocompromised patients such as transplant recipients. In addition, patients infected with HIV and those receiving chemotherapy for malignancy, along with patients with rheumatic disease and COVID-19, have recently been reported as having CHE. CHE can be easily misdiagnosed by usual diagnostic methods of antibody response, such as anti-HEV IgM or IgA, because of the low antibody response in the immunosuppressive condition. HEV RNA should be evaluated in these patients, and appropriate treatments-such as ribavirin-should be given to prevent progression to liver cirrhosis or liver failure. While still rare, cases of CHE in immunocompetent patients have been reported, and care must be taken not to overlook these instances. Herein, we conduct an overview of hepatitis E, including recent research developments and management of CHE, in order to improve our understanding of such cases. The early diagnosis and treatment of CHE should be performed to decrease instances of hepatitis-virus-related deaths around the world.

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.

Genetic diversity of hepatitis E virus (HEV) in imported and domestic camels in Saudi Arabia

Camels gained attention since the discovery of MERS-CoV as intermediary hosts for potentially epidemic zoonotic viruses. DcHEV is a novel zoonotic pathogen associated with camel contact. This study aimed to genetically characterize DcHEV in domestic and imported camels in Saudi Arabia. DcHEV was detected by RT-PCR in serum samples, PCR-positive samples were subjected to sequencing and phylogenetic analyses. DcHEV was detected in 1.77% of samples with higher positivity in domestic DCs. All positive imported dromedaries were from Sudan with age declining prevalence. Domestic DcHEV sequences clustered with sequences from Kenya, Somalia, and UAE while imported sequences clustered with one DcHEV isolate from UAE and both sequences clustered away from isolates reported from Pakistan. Full-genome sequences showed 24 amino acid difference with reference sequences. Our results confirm the detection of DcHEV in domestic and imported DCs. Further investigations are needed in human and camel populations to identify DcHEV potential zoonosis threat.

Hepatitis E Virus Infection-Immune Responses to an Underestimated Global Threat

Infection with the hepatitis E virus (HEV) is one of the main ubiquitous causes for developing an acute hepatitis. Moreover, chronification plays a predominant role in immunocompromised patients such as transplant recipients with more frequent severe courses. Unfortunately, besides reduction of immunosuppression and off-label use of ribavirin or pegylated interferon alfa, there is currently no specific anti-viral treatment to prevent disease progression. So far, research on involved immune mechanisms induced by HEV is limited. It is very difficult to collect clinical samples especially from the early phase of infection since this is often asymptomatic. Nevertheless, it is certain that the outcome of HEV-infected patients correlates with the strength of the proceeding immune response. Several lymphoid cells have been identified in contributing either to disease progression or achieving sustained virologic response. In particular, a sufficient immune control by both CD4⁺ and CD8⁺ T cells is necessary to prevent chronic viral replication. Especially the mechanisms underlying fulminant courses are poorly understood. However, liver biopsies indicate the involvement of cytotoxic T cells in liver damage. In this review, we aimed to highlight different parts of the lymphoid immune response against HEV and point out questions that remain unanswered regarding this underestimated global threat.

Hepatitis E in Sub Saharan Africa - A significant emerging disease

Hepatitis E is an emerging endemic disease found across the African continent, but there are clear differences in epidemiology between North Africa and countries south of the Sahara. In this systematic review, Google scholar and PubMed databases were searched for peer-reviewed articles on HEV epidemiology. Publications meeting our inclusion criteria were critically reviewed to extract consistent findings and identify knowledge gaps. Hepatitis E has been reported in 25 of the 49 countries in Sub Saharan Africa.

Mortality rates of 1–2% in the general population and ~ 20% in pregnant women. Outbreaks were closely linked to refugees and Internally Displaced Persons in camps which accounted for 50% of reported outbreaks. There was very little research and concrete evidence for sources of contamination and transmission routes. There are indications of zoonotic transmission of Hepatitis E Virus infection but further research in these fields is required.

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No data from 50% of African countries

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Outbreaks closely linked to refugee and IDP camps

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Little data on sources of HEV contamination

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Indications but little evidence of zoonotic transmission

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Low awareness amongst health professionals and general public

Seroprevalence of Dromedary Camel HEV in Domestic and Imported Camels from Saudi Arabia

Hepatitis E Virus (HEV) imposes a major health concern in areas with very poor sanitation in Africa and Asia. The pathogen is transmitted mainly through ingesting contaminated water or food, coming into contact with affected people, and blood transfusions. Very few reports including old reports are available on the prevalence of HEV in Saudi Arabia in humans and no reports exist on HEV prevalence in camels. Dromedary camel trade and farming are increasing in Saudi Arabia with importation occurring unidirectionally from Africa to Saudi Arabia. DcHEV transmission to humans has been reported in one case from the United Arab Emeritus (UAE). This instigated us to perform this investigation of the seroprevalence of HEV in imported and domestic camels in Saudi Arabia. Serum samples were collected from imported and domestic camels. DcHEV-Abs were detected in collected sera using ELISA. The prevalence of DcHEV in the collected samples was 23.1% with slightly lower prevalence in imported camels than domestic camels (22.4% vs. 25.4%, p value = 0.3). Gender was significantly associated with the prevalence of HEV in the collected camels (p value = 0.015) where males (31.6%) were more infected than females (13.4%). This study is the first study to investigate the prevalence of HEV in dromedary camels from Saudi Arabia. The high seroprevalence of DcHEV in dromedaries might indicate their role as a zoonotic reservoir for viral infection to humans. Future HEV seroprevalence studies in humans are needed to investigate the role of DcHEV in the Saudi human population.

Time course alterations of virus sequences and immunoglobulin titers in a chronic hepatitis E patient

AIM

Hepatitis E virus (HEV) can cause chronic infection in immunocompromised hosts. However, the dynamics of HEV during persistent infection is not well understood. To elucidate time course alterations in virus sequences and anti-HEV antibodies during persistent infection, we analyzed the HEV sequences and titers of anti-HEV antibodies from a chronic hepatitis E patient.

METHODS

Serum samples were obtained from a chronic hepatitis E patient under corticosteroid therapy for neurological disease. The titers of anti-HEV antibodies (immunoglobulin A, immunoglobulin M, and immunoglobulin G) in serum samples were detected by enzyme immunoassay. The full or near-full nucleotide sequences of HEV isolated from consecutive serum samples were identified and compared. Phylogenetic analysis was also performed.

RESULTS

Alterations of anti-HEV antibodies from a chronic hepatitis E patient were different from those previously reported in acute hepatitis E patients. The virus sequence was unchanged in the period without treatment, but nucleotide mutations were observed after ribavirin treatment was started. In addition, the sequence of this strain had extremely high identity to that isolated from swine liver in Japan.

CONCLUSIONS

Virus mutations in HEV emerged after ribavirin treatment was started. Sequence analysis may useful for deciding the treatment strategy for chronic hepatitis E patients who did not eliminate the virus with 3 months of RBV treatment and inferring the origin of the infection. This report provides insights into the chronicity of hepatitis E, and the impact of persistent infection and ribavirin treatment on the emergence of virus mutations.

Chronic Hepatitis E is associated with cholangitis

BACKGROUND AND AIMS

Sporadic hepatitis E is an emerging indigenous disease in Europe induced by genotype 3 of the virus. While the disease takes an acute self-limited course in immunocompetent individuals, under immunocompromised conditions chronic hepatitis E might develop. The histology of chronic hepatitis E has not been described in detail systematically.

METHODS

Liver biopsies from 19 immunosuppressed patients with chronic hepatitis E were collected: 17 were organ transplant recipients, one had a CD4-deficiency and one had received steroid therapy because of ulcerative colitis. Biopsies were processed with standard stains. Evaluation of histologic activity and fibrosis was performed according to Ishak. Additionally, immunohistochemistry with antibodies directed against open reading frame 2 and 3 of the virus was performed and liver biopsies were tested for hepatitis E virus RNA.

RESULTS

Biochemical data showed an increase in alanine transaminase, aspartate transaminase, gamma-glutamyl transferase and total bilirubin. Histopathology displayed typical features of chronic hepatitis with mild to moderate activity. The number of polymorphonuclear leucocytes was considerably increased and all patients had a florid cholangitis that presented as a destructive form in five of them. Hepatocytes and bile duct epithelia stained positive for hepatitis E virus by immunohistochemistry.

CONCLUSIONS

Chronic hepatitis E in immunocompromised individuals runs a similar course as hepatitis B and C and shows similar histopathology. However, the presence of destructive cholangitis in some cases accompanied by an increased number of polymorphonuclear leucocytes is markedly different. Immunohistochemically the virus is present in bile duct epithelia, seemingly the cause for cholangitis.

The spontaneous clearance of hepatitis E virus (HEV) and emergence of HEV antibodies in a transfusion-transmitted chronic hepatitis E case after completion of chemotherapy for acute myeloid leukemia

A 64-year-old woman was infected with hepatitis E virus (HEV) during chemotherapy for leukemia. By retrospective analyses of stored serum from the blood products and the patient, the source of the infection was determined to be platelet concentration (PC) transfused during chemotherapy. The partial nucleotide sequence of the HEV strain isolated from the donated PC and that from the patient's sera was identical and was subgenotype 3b. Clinical indicators such as alanine aminotransferase, HEV RNA titer, and anti-HEV antibodies in the serum were investigated from the beginning of the infection until 1 year after the termination of HEV infection. HEV RNA had propagated over 6 months and then cleared spontaneously after the completion of chemotherapy. Anti-HEV antibodies appeared in the serum just before the clearance of HEV RNA. Interestingly, HEV RNA was detected in the patient's urine, spinal fluid, and saliva. The HEV RNA titers in those samples were much lower than in the serum and feces. No renal, neurological, or salivary gland disorders appeared during the follow-up. We observed virological and biochemical progress and cure of transfusion-transmitted chronic hepatitis E in the patient despite an immunosuppressive status during and after chemotherapy against hematological malignancy.

Recent Advances Towards the Development of a Potent Antiviral Against the Hepatitis E Virus

Hepatitis E virus (HEV) is one of the leading causes of acute viral hepatitis. It also causes acute liver failure and acute-on-chronic liver failure in many patients, such as those suffering from other infections/liver injuries or organ transplant/chemotherapy recipients. Despite widespread sporadic and epidemic incidents, there is no specific treatment against HEV, justifying an urgent need for developing a potent antiviral against it. This review summarizes the known antiviral candidates and provides an overview of the potential targets for the development of specific antivirals against HEV.

Vaccine Development against Zoonotic Hepatitis E Virus: Open Questions and Remaining Challenges

Hepatitis E virus (HEV) is a fecal-orally transmitted foodborne viral pathogen that causes acute hepatitis in humans and is responsible for hepatitis E outbreaks worldwide. Since the discovery of HEV as a zoonotic agent, this virus has been isolated from a variety of hosts with an ever-expanding host range. Recently, a subunit HEV vaccine developed for the prevention of human disease was approved in China, but is not yet available to the rest of the world. Meanwhile, notable progress and knowledge has been made and revealed in recent years to better understand HEV biology and infection, including discoveries of quasi-enveloped HEV virions and of a new function of the HEV-ORF3 product. However, the impact of these new findings on the development of a protective vaccine against zoonotic HEV infection requires further discussion. In this review, hallmark characteristics of HEV zoonosis, the history of HEV vaccine development, and recent discoveries in HEV virology are described. Moreover, special attention is focused on quasi-enveloped HEV virions and the potential role of the HEV-ORF3 product as antibody-neutralization target on the surface of quasi-enveloped HEV virions to provide new insights for the future development of improved vaccines against zoonotic HEV infection.

Transfusion-Transmitted Hepatitis E: NAT Screening of Blood Donations and Infectious Dose

The risk and importance of transfusion-transmitted hepatitis E virus (TT-HEV) infections by contaminated blood products is currently a controversial discussed topic in transfusion medicine. The infectious dose, in particular, remains an unknown quantity. In the present study, we illuminate and review this aspect seen from the viewpoint of a blood donation service with more than 2 years of experience in routine HEV blood donor screening. We systematically review the actual status of presently known cases of TT-HEV infections and available routine NAT-screening assays. The review of the literature revealed a significant variation regarding the infectious dose causing hepatitis E. We also present the outcome of six cases confronted with HEV-contaminated blood products, identified by routine HEV RNA screening of minipools using the highly sensitive RealStar HEV RT-PCR Kit (95% LOD: 4.7 IU/mL). Finally, the distribution of viral RNA in different blood components [plasma, red blood cell concentrate (RBC), platelet concentrates (PC)] was quantified using the first WHO international standard for HEV RNA for NAT-based assays. None of the six patients receiving an HEV-contaminated blood product from five different donors (donor 1: RBC, donor 2–5: APC) developed an acute hepatitis E infection, most likely due to low viral load in donor plasma (<100 IU/mL). Of note, the distribution of viral RNA in blood components depends on the plasma content of the component; nonetheless, HEV RNA could be detected in RBCs even when low viral plasma loads of 100–1,000 IU/mL are present. Comprehensive retrospective studies of TT-HEV infection offered further insights into the infectivity of HEV RNA-positive blood products. Minipool HEV NAT screening (96 samples) of blood donations should be adequate as a routine screening assay to identify high viremic donors and will cover at least a large part of viremic phases.

Hepatitis E: Update on Prevention and Control

Hepatitis E virus (HEV) is a common etiology of acute viral hepatitis worldwide. Recombinant HEV vaccines have been developed, but only one is commercially available and licensed in China since 2011. Epidemiological studies have identified genotype 3 as the major cause of chronic infection in immunocompromised individuals. Ribavirin has been shown to be effective as a monotherapy to induce HEV clearance in chronic patients who have undergone solid organ transplant (SOT) under immunosuppressive therapy. Efforts and improvements in prevention and control have been made to reduce the instances of acute and chronic hepatitis E in endemic and nonendemic countries. However, this review shows that further studies are required to demonstrate the importance of preventive vaccination and treatment worldwide, with emphasis on hepatitis E infection in the public health system.

Unique clinical courses of transfusion-transmitted hepatitis E in patients with immunosuppression

BACKGROUND

The high prevalence of specific immunoglobulin G for hepatitis E virus (HEV) in Japanese people raises the possibility of a high incidence of HEV-viremic blood donors and therefore frequent transfusion-transmitted HEV (TT-HEV).

STUDY DESIGN AND METHODS

TT-HEV cases established in Japan through hemovigilance and those published in the literature were collected. Infectivity of HEV-contaminated blood components and disease severity in relation to immunosuppression were investigated.

RESULTS

Twenty established TT-HEV cases were recorded over the past 17 years. A lookback study verified that five of 10 patients transfused with known HEV-contaminated blood components acquired HEV infection. The minimal infectious dose of HEV through transfusion was 3.6 × 10⁴ IU. Nine of the 19 TT-HEV cases analyzed had hematologic diseases. Only two cases showed the maximal alanine aminotransferase level of more than 1000 U/L. Two patients with hematologic malignancy and two liver transplant recipients had chronic liver injury of moderate severity.

CONCLUSION

The infectivity of HEV-contaminated components was 50%. Immunosuppression likely causes the moderate illness of TT-HEV, but it may lead to the establishment of chronic sequelae. Transfusion recipients, a population that is variably immunosuppressed, are more vulnerable to chronic liver injury as a result of TT-HEV than the general population is as a result of food-borne infection.