First Case Genotype 4 Hepatitis E Infection After a Liver Transplant

Post-infantile Giant Cell Hepatitis: A Literature Review and Meta-analysis

Post-infantile giant cell hepatitis (PIGCH) is a rare disease entity in adults with a multifactorial etiology and widely variable clinical courses and outcomes. The factors associated with the worse outcomes of this disease entity are still unclear. We identified 68 PIGCH patients by searching PubMed and performed meta-analysis. Among the 68 patients, 32% of the cases were associated with autoimmune disorders, followed by 21% associated with viral infections, 10% with medication, and 7% with malignancy. Twenty-four percent of the patients had more than one etiological factor, and 6% had other uncommon etiologies or an etiology that could not be identified. At the time of this report, 17 patients had died of the disease (poor outcome), and 51 patients remained alive with the disease (good outcome). Compared to the patients with a good outcome, the patients with a poor outcome were characterized by older age, lower levels of platelets and albumin, higher level of total bilirubin, and a diffuse distribution pattern of giant cells in the liver. There were no differences in gender distribution, aminotransferase, alkaline phosphatase, gamma-glutamyl transferase, etiological distribution, or other histological features, including interface hepatitis, necrosis, lobular inflammation, portal inflammation, cholestasis, or fibrosis. Further studies would be needed to better understand the disease mechanisms and unmask any additional etiological factors and targeted therapies.

Epidemiology and treatment of hepatitis E in the liver transplantation setting: A literature review

Hepatitis E virus (HEV) is a common cause of acute hepatitis in developing countries, but it can also take a chronic course especially in immunocompromised patients. Its epidemiology after liver transplantation (LT) is hard to assess and treatment options are still explored. Between 2009 and 2020, literature reporting HEV prevalence and treatment in LT recipients was searched and a synthesis was attempted. Sixteen studies reported HEV prevalence in consecutive LT patients: HEV RNA positivity ranged between 0%-1.4% and 0%-7.7% for Western and Eastern cohorts, respectively. In studies published between 2009-2014 and 2015-2020, HEV RNA positivity ranged between 0.35%-1.3% (all European) and 0%-7.7% (European: 0%-1.4%), respectively. Five studies evaluated HEV prevalence in LT recipients with abnormal liver enzymes: HEV RNA positivity was 2.9% in studies published between 2009 and 2014 and from 3.5% to 20% in studies published between 2015 and 2020. Twenty-seven studies reported HEV treatment in LT recipients: sustained virologic response was achieved in 15% by immunosuppression reduction alone and in 83% of cases by ribavirin regiments. Chronic HEV infection is affecting LT recipients, mostly those with abnormal liver enzymes and in Eastern countries. HEV diagnoses should be based on PCR techniques. Successful treatment can be achieved with ribavirin in most cases.

Broadly Reactive Real-Time RT-PCR Assay for the Detection of Hepatitis E Virus and Simultaneous Genotyping by Single Nucleotide Polymorphism Analysis

Hepatitis E virus (HEV) infection is a global public health concern. Although HEV infection is usually asymptomatic and self-limiting, extrahepatic manifestations and chronic infections in immunocompromised patients have been described. HEV strains infecting humans have been classified into four main genotypes. In this study we have developed and validated a novel sensitive real-time RT-PCR assay for the detection of all four HEV genotypes. Simultaneous discrimination of genotypes 1, 2, and 4 from genotype 3 by single nucleotide polymorphism (SNP) analysis was possible. In all, 201 serum samples from cases and carriers previously tested for HEV by nested RT-PCR were analyzed. Twenty-seven HEV-positive samples could not be typed by the nested RT-PCR and nucleotide sequencing, but were newly typed by SNP analysis. As polymorphisms were present at the primer or probe binding site, we adopted a degenerate primer and mixed probes. When a mixed probe was added, the fluorescence intensity increased, facilitating genotype determination.

IMPORTANCE The distribution of HEV-3 and HEV-4 has been changing. HEV-4, which had been predominantly found in Asia, is now being detected in other parts of the world, and there are now reports of chronic infections. Additionally, neurological disorders have frequently been reported in patients with acute or chronic HEV infections. HEV-4 has also been shown to lead to a higher severity in terms of acute hepatitis than does HEV-3. Early typing can provide useful information regarding the route of infection and for tailoring treatment to the expected course of the disease. The present method afforded a good detection rate even when polymorphisms were present within the target region for viral gene detection. We believe that this method can be applied to the analysis of mutation-prone viral genes in the future.

BALB/c Mouse Is a Potential Animal Model System for Studying Acute and Chronic Genotype 4 Hepatitis E Virus Infection

Hepatitis E virus (HEV) is the main pathogen of hepatitis worldwide. However, its infection biology and pathogenesis remain largely unknown. Suitable small-animal models are required to advance the study of HEV infection. Although an efficient model of genotype 1 (gt1) and gt3 HEV infection has been established in human liver chimeric mice, the infectivity of gt4 HEV infection in mice has not been comprehensively characterized. In this study, immunocompromised BALB/c nude, immunocompetent BALB/c, and C57BL/6 mice were inoculated with either gt3 or gt4 HEV (19 HEV strains, including human, swine, macaque-adapted, and cow HEV strains). Infectivity was identified by viral RNA and antigen detection, inflammation, and histopathological analysis. Then, HEV-infected BALB/c mice were treated with antiviral drugs. Acute HEV infection was established in BALB/c mice inoculated with eight gt4 HEV strains. However, gt3 HEV strains failed to achieve active HEV infection. HEV infection was established in BALB/c nude and regular mice inoculated with gt4 HEV but not in C57BL/6 mice. Gt4 HEV infection resulted in rapid viremia and high titers in feces, sera, and replication sites. HEV infection in mice showed no gender preference. Furthermore, chronic gt4 HEV infection was well imitated in BALB/c mice for 32 weeks and caused liver fibrosis.

CONCLUSION

BALB/c mice have a great potential for reproducing the process of gt4 HEV infection. The successful establishment of a gt4 HEV small-animal model provides an opportunity to further understand HEV infection biology and zoonotic transmission and develop anti-HEV vaccine.

Cross-sectional Seroprevalence and Genotype of Hepatitis E Virus in Humans and Swine in a High-density Pig-farming Area in Central China

Hepatitis E virus (HEV) infection is a common public health problem in developing countries. However, the current prevalence of HEV and the relationship of HEV genotype between swine and human within high-density pig-farming areas in central China are still inadequately understood. Here, cross-sectional serological and genotypic surveys of HEV among the 1232 general population, 273 workers occupationally exposed to swine, and 276 pigs in a high-density pig-breeding area, were undertaken by ELISA and nested RT-PCR methods. Anti-HEV IgG was detected in 26.22% of general population and 48.35% of occupational workers. The prevalence of swine serum HEV-Ag was 6.52%. The prevalence of anti-HEV IgG was significantly higher among the workers occupationally exposed to swine than among the general population. An increased HEV seropositivity risk among the general population was associated with either being a peasant or male and was very strongly associated with the increase of age. Among the occupationally exposed group, the prevalence of anti-HEV IgG antibodies increased with age and working years. Among the 30 HEV-IgM-positive people, the infection rates of clerks in the public, peasants, pork retailers, and pig farmers were higher than those of others. A phylogenetic analysis revealed that all the isolates belonged to subgenotype 4_d, and four people and four pigs shared 97.04%-100% sequence homology. This study revealed a high HEV seroprevalence among the general population and workers occupationally exposed to swine in the Anlu City, and supports the notion that swine are a source of human HEV infection.

Risk factors for ribavirin treatment failure in Asian organ transplant recipients with chronic hepatitis E infection

BACKGROUND

Hepatitis E virus (HEV) infection is a cause of chronic hepatitis in immunosuppressed patients. Sustained virologic response rates to a 12-wk course of ribavirin therapy were reported to be > 70% in the West. This study describes the outcome of HEV treatment in a transplant center in Singapore.

AIM

To study the outcome of ribavirin treatment in a series of chronic HEV patients, and the cause of treatment failure.

METHODS

We studied all of the transplant recipients who were diagnosed with HEV infection between 2012 to 2015. The outcome of therapy and virologic relapse are monitored for three years after the end of therapy.

RESULTS

Ten transplant recipients (4 liver, 5 kidney, and 1 bone marrow transplantation) with positive HEV RNA were studied. Nine patients received at least 12 wk of ribavirin therapy, and the remaining patient resolved after reducing immunosuppression therapy. Two subjects had prolonged viremia that lasted more than one year, despite continuous ribavirin therapy. Four ribavirin-treated patients (44.4%) had HEV RNA relapse after achieving a virologic response by the end of treatment. The overall failure rate is 66.7%. Being a kidney transplant recipient is the strongest risk factor for not achieving an initial sustained virologic response (0/5 treated, Chi-Square test, P < 0.05). The most common side effect of ribavirin is anemia (100%) (haemoglobin reduction of 3-6.2 g/dL). Seven patients required either a blood transfusion or erythropoietin therapy.

CONCLUSION

The sustained virologic response rate of 12-wk ribavirin therapy for HEV infection in this Asian series was lower than expected. Kidney transplant recipients had a higher rate of treatment failure due to higher immunosuppression requirements and adverse effects.

Genetic Variability and Evolution of Hepatitis E Virus

Hepatitis E virus (HEV) is a single-stranded positive-sense RNA virus. HEV can cause both acute and chronic hepatitis, with the latter usually occurring in immunocompromised patients. Modes of transmission range from the classic fecal-oral route or zoonotic route, to relatively recently recognized but increasingly common routes, such as via the transfusion of blood products or organ transplantation. Extrahepatic manifestations, such as neurological, kidney and hematological abnormalities, have been documented in some limited cases, typically in patients with immune suppression. HEV has demonstrated extensive genomic diversity and a variety of HEV strains have been identified worldwide from human populations as well as growing numbers of animal species. The genetic variability and constant evolution of HEV contribute to its physiopathogenesis and adaptation to new hosts. This review describes the recent classification of the Hepeviridae family, global genotype distribution, clinical significance of HEV genotype and genomic variability and evolution of HEV.

Donor-Derived Genotype 4 Hepatitis E Virus Infection, Hong Kong, China, 2018

Hepatitis E virus (HEV) genotype 4 (HEV-4) is an emerging cause of acute hepatitis in China. Less is known about the clinical characteristics and natural history of HEV-4 than HEV genotype 3 infections in immunocompromised patients. We report transmission of HEV-4 from a deceased organ donor to 5 transplant recipients. The donor had been viremic but HEV IgM and IgG seronegative, and liver function test results were within reference ranges. After a mean of 52 days after transplantation, hepatitis developed in all 5 recipients; in the liver graft recipient, disease was severe and with progressive portal hypertension. Despite reduced immunosuppression, all HEV-4 infections progressed to persistent hepatitis. Four patients received ribavirin and showed evidence of response after 2 months. This study highlights the role of organ donation in HEV transmission, provides additional data on the natural history of HEV-4 infection, and points out differences between genotype 3 and 4 infections in immunocompromised patients.

Hepatitis E virus: reasons for emergence in humans

Hepatitis E virus (HEV) infects both humans and other animal species. Recently, we have seen a steady increase in autochthonous cases of human HEV infection in certain areas especially in Europe, and large outbreaks in several African countries among the displaced population. This mini-review critically analyzes potential host, environmental, and viral factors that may be associated with the emergence of hepatitis E in humans. The existence of numerous HEV reservoir animals such as pig, deer and rabbit results in human exposure to infected animals via direct contact or through animal meat consumption. Contamination of drinking, irrigation and coastal water by animal and human wastes lead to emergence of endemic cases in industrialized countries and outbreaks in displaced communities especially in war-torn countries.

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

Recent case reports have shown that hepatitis E virus (HEV) infection can cause chronic hepatitis in immunosuppressed or immunocompromised patients. A 37-year-old woman suffered from prolonged elevation of aminotransferases after chemotherapy for Burkitt's lymphoma and was diagnosed with chronic hepatitis E due to a transfusion during chemotherapy. After an 8-month administration of ribavirin, complete HEV clearance was not achieved, likely due to prolonged hypogammaglobulinemia. This case indicates that HEV infection should be ruled out during liver dysfunction in immunosuppressed or immunocompromised patients and suggests that an alternative therapeutic strategy for such patients will be needed.