Hepatitis E blood donor screening - More than a mere drop in the ocean?

Hepatitis E virus infection in hematopoietic stem cell transplant recipients: a systematic review and meta-analysis

Although most patients with hepatitis E virus (HEV) infection are asymptomatic or have mild symptoms, its infection is generally underdiagnosed and overlooked. In immunocompromised patients, HEV infection can lead to acute liver failure and death. However, the clinical evidence of HEV infection in hematopoietic stem cell transplant (HSCT) recipients is scarce; thus, we conducted this systematic review and meta-analysis to assess the prevalence of HEV infection in this population. We searched MEDLINE, EMBASE, and the Cochrane Library databases from inception through October 2020 to identify studies that reported the prevalence of HEV infection among HSCT recipients. HEV infections were confirmed by HEV-IgG/IgM or HEV-RNA assay. A total of 1977 patients from nine studies with a follow-up time up to 40 months were included in the final analysis. The pooled prevalence of positive HEV-RNA was 3.0% (95% CI 2.3% to 4.0%). The pooled prevalence of positive HEV-IgG was 10.3% (95% CI 4.5% to 21.8%). The pooled prevalence of de novo HEV infection was 2.9% (95% CI 1.8% to 4.5%). Age and male gender were not associated with HEV-RNA or HEV-IgG positivity in the meta-regression analysis. In conclusion, the prevalence of HEV-IgG in HSCT recipients was about 10%, while the prevalence of HEV-RNA was only 3%. However, further studies that focus on the clinical outcomes in this population are warranted.

An RNA Interference/Adeno-Associated Virus Vector-Based Combinatorial Gene Therapy Approach Against Hepatitis E Virus

Hepatitis E virus (HEV) is a major public health problem with limited therapeutic options. Here, we engineered adeno-associated viral vectors of serotype 6 (AAV6) to express short hairpin RNAs (shRNAs) against HEV transcripts with the prospect of down-regulating HEV replication in vivo. We designed 20 different shRNAs, targeting the genome of the HEV genotype 3 (GT3) Kernow-C1 p6 strain, for delivery upon AAV6 transduction. Using an original selectable HEV GT3 reporter replicon, we identified three shRNAs that efficiently down-regulated HEV replication. We further confirmed their inhibitory potency with full-length HEV infection. Seventy-two hours following transduction, HEV replication in both systems decreased by up to 95%. The three most potent inhibitory shRNAs identified were directed against the methyltransferase domain, the junction region between the open reading frames (ORFs), and the 3´ end of ORF2. Targeting all three regions by multiplexing the shRNAs further enhanced their inhibitory potency over a prolonged period of up to 21 days following transduction. Conclusion: Combining RNA interference and AAV vector-based gene therapy has great potential for suppressing HEV replication. Our strategy to target the viral RNA with multiplexed shRNAs should help to counteract viral escape through mutations. Considering the widely documented safety of AAV vector-based gene therapies, our approach is, in principle, amenable to clinical translation.

Hepatitis E virus re-infection accelerates hepatocellular carcinoma development and relapse in a patient with liver cirrhosis: A case report and review of literature

BACKGROUND

Hepatitis E virus (HEV) superinfection is a suspected promoting factor for hepatocellular carcinoma (HCC) in patients with chronic hepatitis and cirrhosis. However, to date, very few cases of HEV-related HCC have been reported. Nevertheless, the role of HEV re-infection in cirrhotic liver without other chronic hepatitis infections has rarely been explored.

CASE SUMMARY

A 53-year-old male farmer was diagnosed with liver cirrhosis and splenomegaly in August 2016, accompanied with negative HEV-IgM and positive HEV-IgG. No evidence of hepatitis B virus or hepatitis C virus infection was found. Since then the patient was evaluated for liver function and viral parameters every 3 mo. In June 2017, the patient presented severe fatigue with whole body itching and was diagnosed with HCC. Afterwards this patient experienced quick HCC development, progression, relapse, and metastasis in the following 8 mo, and presented persistent dual positivity of HEV-IgM and HEV-IgG. This patient had a long history of smoking and alcohol consumption.

CONCLUSION

This unique case invokes the importance of HEV surveillance and treatment among cirrhotic patients, HCC cases, and blood donors.

Recent data on hepatitis E

PURPOSE OF REVIEW

Hepatitis E virus (HEV) has gained increased global recognition in recent years, particularly in developed countries. We summarized here a selection of the literature published since the 1st of June, 2017.

RECENT FINDINGS

Longitudinal studies are increasingly conducted in Europe, to determine trends in HEV prevalence. The spectrum of mammals infected with HEV and potentially capable to transmit it to humans has widened. New virological data on HEV repCon and pathogenicity have been reported and clinical features of HEV infections have been precised or newly described. Finally, there are some new data on the therapeutic management of HEV infections in various clinical settings.

SUMMARY

HEV emergence in developed countries appears to be based on improved diagnosis tools and increased awareness of clinicians that HEV transmission is essentially autochthonous and is a possible cause of life-threatening acute hepatitis, chronic hepatitis, cirrhosis, and extra-hepatic symptoms. In addition, the distribution of HEV strains evolves. Ribavirin remains to date the only specific treatment recommended for HEV infection, being efficient in the majority but not in all cases.

The Clinical Perspective on Hepatitis E

Every year, there are an estimated 20 million hepatitis E virus (HEV) infections worldwide, leading to an estimated 3.3 million symptomatic cases of hepatitis E. HEV is largely circulating in the west and is associated with several hepatic and extrahepatic diseases. HEV Genotype 1 and 2 infections are waterborne and causative for epidemics in the tropics, while genotype 3 and 4 infections are zoonotic diseases and are mainly transmitted by ingestion of undercooked pork in industrialized nations. The clinical course of these infections differs: genotype 1 and 2 infection can cause acute illness and can lead to acute liver failure (ALF) or acute on chronic liver failure (ACLF) with a high mortality rate of 20% in pregnant women. In contrast, the majority of HEV GT-3 and -4 infections have a clinically asymptomatic course and only rarely lead to acute on chronic liver failure in elderly or patients with underlying liver disease. Immunosuppressed individuals infected with genotype 3 or 4 may develop chronic hepatitis E, which then can lead to life-threatening cirrhosis. Furthermore, several extra-hepatic manifestations affecting various organs have been associated with ongoing or previous HEV infections but the causal link for many of them still needs to be proven. There is no approved specific therapy for the treatment of acute or chronic HEV GT-3 or -4 infections but off-label use of ribavirin has been demonstrated to be safe and effective in the majority of patients. However, in approximately 15% of chronically HEV infected patients, cure is not possible.