Immune-Escape Hepatitis B Virus Mutations Associated with Viral Reactivation upon Immunosuppression

Risk of hepatitis B virus reactivation in cancer patients undergoing treatment with tyrosine kinase-inhibitors

This editorial commented on an article in the World Journal of Gastroenterology titled "Risks of Reactivation of Hepatitis B Virus in Oncological Patients Using Tyrosine Kinase-Inhibitors: Case Report and Literature Analysis" by Colapietro et al. In this editorial, we focused on providing a more comprehensive exploration of hepatitis B virus reactivation (HBVr) associated with the usage of tyrosine kinase inhibitors (TKIs). It includes insights into the mechanisms underlying HBV reactivation, the temporal relationship between TKIs and HBV reactivation, and preventive measures. The aim is to understand the need for nucleos(t)ide analogs (NAT) and serial blood tests for early recognition of reactivation and acute liver injury, along with management strategies. TKIs are considered to be an intermediate (1%-10%) of HBVr. Current guidelines stipulate that patients receiving therapy with high or moderate risks of reactivation or recent cancer diagnosis must have at least tested hepatitis B surface antigen, anti-hepatitis B core antigen (HBc), and anti-hepatitis B surface antibody. Anti-HBc screening in highly endemic areas means people with negative tests should be vaccinated against HBV. Nucleoside or nucleotide analogs (NAs) like entecavir (ETV), tenofovir disoproxil fumarate (TDF), and tenofovir alafenamide (TAF) form the basis of HBV reactivation prophylaxis and treatment during immunosuppression. Conversely, lamivudine, telbivudine, and adefovir are generally discouraged due to their reduced antiviral efficacy and higher risk of fostering drug-resistant viral strains. However, these less effective NAs may still be utilized in cases where ETV, TDF, and TAF are not feasible treatment options.

Spontaneous reactivation of hepatitis B virus with multiple novel mutations in an elderly patient with resolved hepatitis B virus infection

Spontaneous reactivation of the Hepatitis B virus (HBV) is rare in individuals with previously resolved infections. This report presents the case of a 71 year-old Japanese woman who experienced HBV reactivation without any prior immunosuppressive therapy or chemotherapy. Before the onset of liver injury, the patient was negative for hepatitis B surface antigen (HBsAg) but positive for hepatitis B surface antibody. She subsequently developed liver injury, with the reappearance of HBsAg and HBV DNA. The patient was successfully treated with tenofovir alafenamide, and prednisolone. Full-genome sequencing of HBV revealed subgenotype B1 without hepatitis B e-negative mutations in the precore and core promoter regions and 12 amino acid alterations in the pre-S1/S, P, and X genes. Notably, the S gene mutations D144A and K160N, which alter the antigenicity of HBsAg and potentially contribute to its reactivation, were identified. This case emphasizes the importance of vigilance for spontaneous reactivation of resolved HBV, highlighting the need for comprehensive genomic analysis to understand the associated virological intricacies.

Immune-Escape Mutations Are Prevalent among Patients with a Coexistence of HBsAg and Anti-HBs in a Tertiary Liver Center in the United States

The concurrent seropositivity of HBsAg and anti-HBs has been described among patients with chronic hepatitis B (CHB), but its prevalence is variable. HBV S-gene mutations can affect the antigenicity of HBsAg. Patients with mutations in the 'α' determinant region of the S gene can develop severe HBV reactivation under immunosuppression. In this study at a tertiary liver center in the United States, we evaluated the frequency and virological characteristics of the HBsAg mutations among CHB patients with the presence of both HBsAg and anti-HBs. In this cohort, 45 (2.1%) of 2178 patients were identified to have a coexistence of HBsAg and anti-HBs, and 24 had available sera for the genome analysis of the Pre-S1, Pre-S2, and S regions. The frequency of mutations in the S gene was significantly higher among those older than 50 years (mean 8.5 vs. 5.4 mutations per subject, p = 0.03). Twelve patients (50%) had mutations in the 'α' determinant region of the S gene. Mutations at amino acid position 126 were most common in eight subjects. Three had a mutation at position 133. Only one patient had a mutation at position 145-the classic vaccine-escape mutation. Despite the universal HBV vaccination program, the vaccine-escape mutant is rare in our cohort of predominantly Asian patients.

Characterization of mutations in hepatitis B virus DNA isolated from Japanese HBsAg-positive blood donors in 2021 and 2022

Missense mutations in certain small envelope proteins diminish the efficacy of antibodies. Consequently, tracking the incidence and types of vaccine-escape mutations (VEMs) was crucial both before and after the introduction of universal hepatitis B vaccination in Japan in 2016. In this study, we isolated hepatitis B virus (HBV) DNA from 58 of 169 hepatitis B surface antigen (HBsAg)-positive blood samples from Japanese blood donors and determined the nucleotide sequence encoding the small envelope protein. DNA from six (10%) of the samples had VEMs, but no missense mutations, such as G145R, were detected. Complete HBV genome sequences were obtained from 29 of the 58 samples; the viral genotype was A1 in one (3%), A2 in three (10%), B1 in nine (31%), B2 in five (17%), B4 in one (3%), and C2 in 10 (34%) samples. Tenofovir-resistance mutations were detected in two (7%) samples. In addition, several core promoter mutations, such as 1762A>T and 1764G>A, and a precore nonsense mutation, 1986G>A, which are risk factors for HBV-related chronic liver disease, were detected. These findings provide a baseline for future research and highlight the importance of ongoing monitoring of VEMs and drug resistance mutations in HBV DNA from HBsAg-positive blood donors without HBV antibodies.

Comprehensive analysis of antigenic variations and genomic properties of hepatitis B virus in clinical samples in the mid-north east region of Bangladesh

This investigation delineates an exhaustive analysis of the clinical, immunological, and genomic landscapes of hepatitis B virus (HBV) infection across a cohort of 22 verified patients. The demographic analysis unveiled a pronounced male bias (77.27%), with patient ages spanning 20 to 85 years and durations of illness ranging from 10 days to 4 years. Predominant clinical manifestations included fever, fatigue, anorexia, abdominal discomfort, and arthralgia, alongside observed co-morbidities such as chronic renal disorders and hepatocellular carcinoma. Antigenic profiling of the HBV envelope proteins elucidated significant heterogeneity among the infected subjects, particularly highlighted by discordances in the detection capabilities of small and large HBsAg assays, suggesting antigenic diversity. Quantitative assessment of viral loads unveiled a broad spectrum, accompanied by atypical HBeAg reactivity patterns, challenging the reliability of existing serological markers. Correlative studies between viral burden and antigenicity of the envelope proteins unearthed phenomena indicative of diagnostic evasion. Notably, samples demonstrating robust viral replication were paradoxically undetectable by the large HBsAg ELISA kit, advocating for more sophisticated diagnostic methodologies. Genotypic examination of three HBV isolates classified them as genotype D (D2), with phylogenetic alignment to strains from various global origins. Mutational profiling identified pivotal mutations within the basic core promoter and preS2/S1 regions, associated with an augmented risk of hepatocellular carcinoma. Further, mutations discerned in the small HBsAg and RT/overlap regions were recognized as contributors to vaccine and/or diagnostic escape mechanisms. In summation, this scholarly discourse elucidates the intricate interplay of clinical presentations, antigenic diversity, and genomic attributes in HBV infection, accentuating the imperative for ongoing investigative endeavors to refine diagnostic and therapeutic modalities.

Occult Hepatitis B Infection among Blood Donors in Northwestern Greece

Background: Occult hepatitis B virus infection (OBI) is characterized by the presence of HBV DNA in individuals who test negative for hepatitis B surface antigen (HBsAg). It poses diagnostic challenges and contributes to chronic liver diseases. Understanding its epidemiology, pathogenesis and clinical outcomes remains essential. This study aimed to assess the prevalence and characteristics of OBI in Northwestern Greece. Methods:Serum samples were prospectively collected from 702 blood donors at the University Hospital of Ioannina, Greece, between February 2018 and September 2022. The investigation focused on the presence of hepatitis B virus (HBV) markers, utilizing the Abbott Architect HBsAg and HBcAb HB Qualitative II kit for the detection of HBsAg and anti-HBc, respectively. Further analysis was conducted on serum samples from individuals who tested negative for HBsAg but positive for anti-HBc, employing polymerase chain reaction (PCR) to detect HBV-DNA. In instances of OBI, sequencing and mutation analysis of the HBV pre-S/S gene were carried out for comprehensive characterization. Results:Screening revealed 56 cases (7.9%) with active HBV infection (HBsAg positive) and identified 144 cases (20.5%) indicative of past HBV infection (HBsAg negative, anti-HBc positive). Additionally, a prevalence of 5.4% (38/702) of OBI was detected. Among these, 36 cases exhibited a low HBV DNA load of less than 225 IU/mL. Notably, one OBI patient was co-infected with HIV. Furthermore, two cases of OBI with high HBV-DNA levels exceeding 200,000 IU/ml were detected. Sequencing analysis unveiled S- and pre-S mutations in four cases of OBI, including both instances with elevated HBV-DNA levels. Conclusion:In a region with a high proportion of immigrants from countries where HBV is endemic, a high prevalence of HBV infection and occult HBV infection (OBI) has been detected. Furthermore, mutations in the S gene were found to be associated with cases of OBI with high levels of HBV-DNA. However, additional research is needed to validate the results and understand the clinical relevance of specific OBI mutations for disease progression and treatment efficacy.

Lipid Metabolism Modulation during SARS-CoV-2 Infection: A Spotlight on Extracellular Vesicles and Therapeutic Prospects

Extracellular vesicles (EVs) have a significant impact on the pathophysiological processes associated with various diseases such as tumors, inflammation, and infection. They exhibit molecular, biochemical, and entry control characteristics similar to viral infections. Viruses, on the other hand, depend on host metabolic machineries to fulfill their biosynthetic requirements. Due to potential advantages such as biocompatibility, biodegradation, and efficient immune activation, EVs have emerged as potential therapeutic targets against the SARS-CoV-2 infection. Studies on COVID-19 patients have shown that they frequently have dysregulated lipid profiles, which are associated with an increased risk of severe repercussions. Lipid droplets (LDs) serve as organelles with significant roles in lipid metabolism and energy homeostasis as well as having a wide range of functions in infections. The down-modulation of lipids, such as sphingolipid ceramide and eicosanoids, or of the transcriptional factors involved in lipogenesis seem to inhibit the viral multiplication, suggesting their involvement in the virus replication and pathogenesis as well as highlighting their potential as targets for drug development. Hence, this review focuses on the role of modulation of lipid metabolism and EVs in the mechanism of immune system evasion during SARS-CoV-2 infection and explores the therapeutic potential of EVs as well as application for delivering therapeutic substances to mitigate viral infections.

Hepatitis B Surface Antigen Isoforms: Their Clinical Implications, Utilisation in Diagnosis, Prevention and New Antiviral Strategies

The hepatitis B surface antigen (HBsAg) is a multifunctional glycoprotein composed of large (LHB), middle (MHB), and small (SHB) subunits. HBsAg isoforms have numerous biological functions during HBV infection-from initial and specific viral attachment to the hepatocytes to initiating chronic infection with their immunomodulatory properties. The genetic variability of HBsAg isoforms may play a role in several HBV-related liver phases and clinical manifestations, from occult hepatitis and viral reactivation upon immunosuppression to fulminant hepatitis and hepatocellular carcinoma (HCC). Their immunogenic properties make them a major target for developing HBV vaccines, and in recent years they have been recognised as valuable targets for new therapeutic approaches. Initial research has already shown promising results in utilising HBsAg isoforms instead of quantitative HBsAg for correctly evaluating chronic infection phases and predicting functional cures. The ratio between surface components was shown to indicate specific outcomes of HBV and HDV infections. Thus, besides traditional HBsAg detection and quantitation, HBsAg isoform quantitation can become a useful non-invasive biomarker for assessing chronically infected patients. This review summarises the current knowledge of HBsAg isoforms, their potential usefulness and aspects deserving further research.

Prevalence of occult hepatitis B virus infection and characterisation of hepatitis B surface antigen mutants among adults in western Croatia

INTRODUCTION AND OBJECTIVES

Occult hepatitis B virus (HBV) infection (OBI) is characterised by low levels of hepatitis B virus (HBV) DNA in the blood/liver of patients with negative hepatitis B surface antigen (HBsAg). This study aimed to determine the OBI prevalence and virological characteristics (viral genotypes and HBsAg mutants) in patients with an "anti-HBc only" serological profile.

MATERIALS AND METHODS

A total of 24 900 serum samples were routinely screened for hepatitis B markers over a five-year period. All anti-HBc-positive/HBsAg-negative/anti-HBs-negative sera were selected and analysed for the presence of HBV DNA. Mutational analyses of the HBs gene and polymerase gene sequences were performed.

RESULTS

1749 (7.02%) sera were anti-HBc positive, and 113 (0.45%) sera had an "anti-HBc only" serological profile (HBsAg/anti-HBs negative). HBV DNA was detected in 12/113 (10.61%) "anti-HBc only" positive sera, representing 0.048% of all routinely tested samples. Due to extremely low viremia, HBV genome was successfully sequenced in only two sera where subgenotype D3 was confirmed. Mutational analyses of the S gene revealed multiple missense mutations. In addition to the M133I, Y134F, and G145R mutations, already associated with diagnostic escape, we also found nine novel OBI-related S-gene mutations - S136Y, F158L, K160N, E164G, S167L, A168V, L175S, S210I and F212C.

CONCLUSIONS

We detected multiple known and novel S gene mutations in 2/12 (16.6%) OBI cases, nevertheless, further studies are required to determine their role in the pathogenesis of OBI. Understanding the frequencies of clinically relevant HBV mutations may contribute to improvement of diagnostic protocols.

Patterns of hepatitis b virus immune escape and pol/rt mutations across clinical cohorts of patients with genotypes a, e and occult hepatitis b infection in Nigeria: A multi-centre study

Hepatitis B virus (HBV) immune escape and Pol/RT mutations account for HBV immunoprophylactic, therapeutic, and diagnostic failure globally. Little is known about circulating HBV immune escape and Pol/RT mutants in Nigeria. This study focused on narrowing the knowledge gap of the pattern and prevalence of the HBV mutants across clinical cohorts of infected patients in southwestern Nigeria. Ninety-five enrollees were purposively recruited across clinical cohorts of HBV-infected patients with HBsAg or anti-HBc positive serological outcome and occult HBV infection. Total DNA was extracted from patients' sera. HBV S and Pol gene-specific nested PCR amplification was carried out. The amplicons were further sequenced for serotypic, genotypic, phylogenetic, and mutational analysis. HBV S and Pol genes were amplified in 60 (63.2%) and 19 (20%) of HBV isolates, respectively. All the sixty HBV S gene and 14 of 19 Pol gene sequences were exploitable. The ayw4 serotype was predominant (95%) while ayw1 serotype was identified in 5% of isolates. Genotype E predominates in 95% of sequences, while genotype A, sub-genotype A3 was observed in 5%. Prevalence of HBV IEMs in the "a" determinant region was 29%. Commonest HBV IEM was S113T followed by G145A and D144E. The Pol/RT mutations rtV214A and rtI163V among others were identified in this study. This study provided data on the occurrence of existing and new HBV IEMs and Pol gene mutations in Nigeria.

High Frequency of Antiviral Resistance Mutations in HBV Genotypes A2 and H: Multidrug Resistance Strains in Mexico

Background and Aims

Lamivudine (3TC), telbivudine (LdT), entecavir (ETV), adefovir (ADF), and tenofovir (TFV) are drugs used to treat hepatitis B virus (HBV) infection, but specific mutations allow some viruses to become resistant to antiviral drugs or to acquire immune escape capacities. These mutations have not been thoroughly investigated in Mexico. This study aimed to estimate the prevalence of HBV antiviral resistance and escape mutations.

Methods

This cross-sectional study analyzed 158 samples. HBV DNA was extracted, amplified, and sequenced in serum samples using the spin column method, PCR assay, and Sanger's sequencing, respectively. HBV genotypes were determined, and HBV mutations were tested using the Geno2pheno tool.

Results

Overall, 68.4% (108/158) of HBV patients were infected with genotype H, followed by G (11.4%, 18/158), A2 (10.8%, 17/158), F1b (6.9.0%, 11/158), D (1.9%, 3/158), and E (0.6%, 1/158), and 5.1% (8/158) had evidence of recombination. The prevalence of resistance mutations was 8.2% (13/158) and the most common combined mutation was rt180M+rt204V. Notably, we found the combinations rt180M+rt204V+rt173L (n=2) and rt180M+rt204V+rt202G (n=1) that confer multidrug resistance to 3TC, LdT, and ETV. Resistance mutations were found in genotypes A2 (11.8%, 2/17), and H (10.2%, 11/108), and escape mutations were detected in HBV genotypes A2 (11.8%, 2/17), H (10.2%, 11/108), F1b (9.1%, 1/11) and G (5.6%, 1/18).

Conclusions

The highest prevalence of antiviral resistance mutations or escape mutations was detected in HBV genotypes A2 and H. The earliest cases of HBV multidrug resistance were detected in Mexico.

Possible Association between Genetic Diversity of Hepatitis B Virus and Its Effect on the Detection Rate of Hepatitis B Virus DNA in the Placenta and Fetus

Background: The prevalence of HBV infection and HBV genotypes varies from country to country, and the role of HBV genotypes in the presence of HBV in the placenta and fetus has never been explored. This study was conducted to (1) identify HBV genotypes, and their frequencies, that infected Northern Thai pregnant women; (2) evaluate the association between HBV genotypes and the detection rate of HBV DNA in the placenta and fetus; (3) evaluate the association between specific mutations of the HBV genome and HBV DNA detection in placental tissue; and (4) identify the mutation of the HBV genome that might occur between maternal blood, placenta, and cord blood. Methods: Stored samples of the maternal blood, placental tissue, and cord blood that were collected from 145 HBsAg-positive pregnant Thai women were analyzed to identify HBV DNA. Results: Approximately 25% of infected mothers had fetal HBV DNA detection, including cases with concomitant HBV DNA detection in the placenta (77.3%). A total of 11.7% of cases with placental detection had no HBV DNA detection in the maternal blood, indicating that the placenta could be a site of HBV accumulation. Of the 31 HBV-positive blood samples detected by nested PCR, the detected strains were subgenotype C1 (77.4%), subgenotype B9 (9.7%), and subgenotype C2, B2, B4, and recombinant B4/C2 (3.2% for each). Genotype B had a trend in increased risk of placental HBV DNA detection compared to genotype C, with a relative risk of 1.40 (95% CI: 1.07-1.84). No specific point mutation had a significant effect on HBV DNA detection in placental tissue. Mutation of C454T tended to enhance HBV DNA detection in placental tissue, whereas T400A tended to have a lower detection rate. No mutation was detected in different sample types collected from the same cases. Conclusions: HBV DNA detection in the fetus was identified in approximately 25% of HBV-positive mothers, associated with the presence of HBV in the placenta in most cases. The placenta could possibly be a site of HBV accumulation. Subgenotype C1 was the most common subgenotype, followed by subgenotype B9. HBV genotype B possibly had a higher trend in intrauterine detection than HBV genotype C. Mutation is unlikely to occur during intrauterine exposure.

Unusual serological profile in hepatitis B virus (HBV) infection associated with a probable clinical case of acute exacerbation of pre-existing chronic HBV infection

BACKGROUND

Acute or chronic HBV infection in an individual can be laboratory characterized according to the serological profile of the viral markers in the bloodstream, and the dynamics monitoring of these markers is necessary to assess the disorder course and the infection outcome. However, under certain circumstances unusual or atypical serological profiles may be observed in both acute and chronic HBV infection. They are considered as such because they do not properly characterize the form or infection clinical phase or because they seem inconsistent, considering the viral markers dynamics in both clinical contexts. This manuscript comprises the analysis of an unusual serological profile in HBV infection.

METHODS AND RESULTS

This clinical-laboratory study, had as reference a patient who presented clinical profile suggestive of acute HBV infection after recent exposure, whose laboratory data were initially compatible with this clinical presentation. However, the serological profile analysis and its monitoring demonstrated unusual pattern of viral markers expression, which has been observed in several clinical contexts, and is often associated a number of agent- or host-related factors.

CONCLUSION

The serological profile analyzed here, associated with the biochemical markers serum levels found, is indicative of active chronic infection, consequence of viral reactivation. This finding suggests that in the event of unusual serological profiles in HBV infection, if the influence of agent- or host-related factors is not properly considered and neither the viral markers dynamics properly analyzed, there may be mistake in the infection clinical diagnosis, especially when the patient's clinical and epidemiological history is unknown.

[Frequency of drug resistance and immune escape mutations in the hepatitis B virus genome detected in pregnant women in the Republic of Guinea]

The aim of the work is to assess the prevalence of hepatitis B virus drug resistance mutations and immune escape mutations in pregnant women in the Republic of Guinea.

MATERIALS AND METHODS

Blood plasma samples obtained from 480 pregnant women from different regions of the Republic of Guinea with laboratory-confirmed viral hepatitis B were studied. Nucleotide sequences for genotype identification and mutation detection were obtained using nested-PCR followed by Sanger sequencing, based on overlapping pairs of primers spanning the complete genome of the virus.

RESULTS AND DISCUSSION

In the examined group, the viral genotype E was the most prevalent (92.92%) compared with subgenotypes A1 (1.67%), A3 (1.46%), D1 (0.63%), D2 (1.04%) and D3 (2.29%). Among the examined HBV-infected pregnant women, 188 (39.17%) had undetectable HBsAg. Drug resistance mutations were detected in 33 individuals, which amounted to 6.88%. The following mutations were found: S78T (27.27%), L80I (24.24%), S202I (15.15%), M204I/V (42.42%). The presence of polymorphic variants not described as drug resistant has also been shown in positions associated with the development of drug resistance to tenofovir, lamivudine, telbivudine and entecavir (L80F, S202I, M204R). When analyzing the MHR and the region of a determinant, mutations were detected in 318 (66.25%) of pregnant women. In 172 of them, which amounted to 54.09%, multiple mutations were found. The amino acid substitutions in 13 positions associated with HBsAg-negative hepatitis B and/or potentially affecting HBsAg antigenicity were identified.

CONCLUSION

The high prevalence of immune escape and drug resistance mutations potentially associated with false-negative result of HBsAg screening, prophylaxis failure, and virological failure of therapy that has been identified among treatment naive pregnant women imposes a serious problem.

Molecular and Genetic Characterization of Hepatitis B Virus (HBV) among Saudi Chronically HBV-Infected Individuals

The study aimed to characterize the genotype and subgenotypes of HBV circulating in Saudi Arabia, the presence of clinically relevant mutations possibly associated with resistance to antivirals or immune escape phenomena, and the possible impact of mutations in the structural characteristics of HBV polymerase. Plasma samples from 12 Saudi Arabian HBV-infected patients were analyzed using an in-house PCR method and direct sequencing. Saudi patients were infected with mainly subgenotype D1. A number of mutations in the RT gene (correlated to antiviral resistance) and within and outside the major hydrophilic region of the S gene (claimed to influence immunogenicity and be related to immune escape) were observed in almost all patients. Furthermore, the presence of mutations in the S region caused a change in the tertiary structure of the protein compared with the consensus region. Clinical manifestations of HBV infection may change dramatically as a result of viral and host factors: the study of mutations and protein-associated cofactors might define possible aspects relevant for the natural and therapeutic history of HBV infection.

Hepatitis Virus and Hepatocellular Carcinoma: Recent Advances

Hepatocellular carcinoma (HCC) remains a global health challenge, causing 600,000 deaths each year. Infectious factors, including hepatitis B virus (HBV), hepatitis C virus (HCV) and hepatitis D virus (HDV), have long been considered the major risk factors for the development and progression of HCC. These pathogens induce hepatocyte transformation through a variety of mechanisms, including insertional mutations caused by viral gene integration, epigenetic changes, and the induction of long-term immune dysfunction. The discovery of these mechanisms, while advancing our understanding of the disease, also provides targets for new diagnostic and therapeutic approaches. In addition, the discovery and research of chronic HEV infection over the past decade indicate that this common hepatitis virus also seems to have the potential to induce HCC. In this review, we provide an overview of recent studies on the link between hepatitis virus and HCC, as well as new diagnostic and therapeutic approaches to HCC based on these findings. Finally, we also discuss the potential relationship between HEV and HCC. In conclusion, these associations will further optimize the diagnosis and treatment of infection-associated HCC and call for better management policies.

Low Risk of Occult Hepatitis B Infection among Vietnamese Blood Donors

Occult hepatitis B infection (OBI) is characterized by the presence of low levels of hepatitis B virus (HBV) DNA and undetectable HBsAg in the blood. The prevalence of OBI in blood donors in Asia ranges from 0.013% (China) to 10.9% (Laos), with no data available from Vietnam so far. We aimed to investigate the prevalence of OBI among Vietnamese blood donors. A total of 623 (114 women and 509 men) HBsAg-negative blood donors were screened for anti-HBc and anti-HBs by ELISA assays. In addition, DNA from sera was isolated and nested PCR was performed for the HBV surface gene (S); a fragment of the S gene was then sequenced in positive samples. The results revealed that 39% (n = 242) of blood donors were positive for anti-HBc, and 70% (n = 434) were positive for anti-HBs, with 36% (n = 223) being positive for both anti-HBc and anti-HBs. In addition, 3% of blood donors (n = 19) were positive for anti-HBc only, and 34% (n = 211) had only anti-HBs as serological marker. A total of 27% (n = 170) were seronegative for any marker. Two of the blood donors (0.3%) were OBI-positive and sequencing revealed that HBV sequences belonged to HBV genotype B, which is the predominant genotype in Vietnam.

Molecular Characterization of Hepatitis B Virus Infection in a Patient with Cutaneous Lupus Erythematosus

Hepatitis B virus (HBV) infection is a serious global health problem. Patients with autoimmune diseases, such as Lupus Erythematosus, are exposed to a higher risk of acquiring infections. In this study, a molecular characterization, genomic investigation of the Hepatitis B virus, polymerase (P) and surface (S) genes, from a patient affected by Cutaneous Lupus Erythematosus (CLE), was presented. Viral DNA was extracted from 200 μL of serum, and the HBV-DNA was amplified by real-time polymerase chain reaction (PCR) with the Platinum Taq DNA Polymerase. The PCR products were purified and sequencing reactions were performed. A phylogenetic analysis was performed through maximum likelihood and Bayesian approaches. The HBV CLE isolate was classified as sub-genotype D3 and related to other Italian HBV D3 genomes, and some from foreign countries. No drug resistant mutations were identified. One mutation (a.a. 168 M) was located in the last part of the major hydrophilic region (MHR) of the surface antigen (HBsAg). Moreover, three sites (351G, 526Y, 578C) in the polymerase were exclusively present in the CLE patient. The mutations identified exclusively in the HBsAg of our CLE patient may have been selected because of the Lupus autoantibodies, which are characteristic in the Lupus autoimmune disease, using a possible molecular mimicry mechanism.

PPD in HBsAg vaccine formulation suppressed IFN-γ and IL-4 cytokine responses and induced long-lived humoral immune responses: Results from 220-day monitoring of specific IgG responses

OBJECTIVES

Here, immune responses and long-lived IgG responses of HBsAg-Alum, HBsAg-MF59, as well as HBsAg-MF59 were compared when formulated with PPD.

MATERIALS AND METHODS

BALB/c mice were vaccinated subcutaneously three times with a two-week -interval. Then, specific IgG, long-lived IgG responses up to 220 days, and IgG1/IgG2a isotypes, and IFN-γ and IL-4 on spleen cell culture supernatant were assessed using ELISA.

RESULTS

IFN-γ cytokine response between MF59- and Alum-adjuvanted vaccines did not show a significant difference. HBsAg-Alum revealed an increase in IL-4 cytokine versus HBsAg-MF59 at borderline (P=0.0553). In addition, HBsAg-MF59+PPD 10 µg showed a significant decrease in IL-4 and IFN-γ cytokines versus HBsAg-MF59. Furthermore, HBsAg-MF59+PPD10 µg showed a significant increase in the IL-2/IL-4 ratio versus HBsAg-MF59 (P=0.0339). Specific IgG antibody showed a significant increase in HBsAg-MF59, as compared with HBsAg-Alum. Furthermore, HBsAg-MF59 plus PPD showed a significant increase in IgG responses versus HBsAg-MF59 and HBsAg-Alum groups. Long-lived IgG responses showed a significant increase in HBsAgMF59 versus HBsAg-Alum group and PPD in the HBsAg-MF59 vaccine formulation, resulting in a significant increase in IgG responses versus HBsAg-MF59 group. In addition, HBsAg-MF59 plus PPD suppressed IgG1 response versus HBsAg-Alum. However, HBsAg-MF59 showed a significant increase in IgG2α versus the HBsAg-Alum group (P=0.0190). Immunization with HBsAg-MF59+PPD (10 µg) showed a significant increase versus the HBsAg-MF59 group (P=0.0040). IgG2a/IgG1 ratio in HBsAg-MF59+PPD1µg and HBsAg-MF59+PPD10 µg groups showed a significant increase versus HBsAg-MF59 groups (P<0.0345).

CONCLUSION

PPD leads to a more potent long-lived IgG responses in the HBsAg vaccine, highlighting its potential as a component of a complex adjuvant.

Whole genome analysis of hepatitis B virus before and during long-term therapy in chronic infected patients: Molecular characterization, impact on treatment and liver disease progression

Hepatitis B virus (HBV) infection remains a serious public health concern worldwide despite the availability of an efficient vaccine and the major improvements in antiviral treatments. The aim of the present study is to analyze the mutational profile of the HBV whole genome in ETV non-responder chronic HBV patients, in order to investigate antiviral drug resistance, immune escape, and liver disease progression to Liver Cirrhosis (LC) or Hepatocellular Carcinoma (HCC). Blood samples were collected from five chronic hepatitis B patients. For each patient, two plasma samples were collected, before and during the treatment. Whole genome sequencing was performed using Sanger technology. Phylogenetic analysis comparing the studied sequences with reference ones was used for genotyping. The mutational profile was analyzed by comparison with the reference sequence M32138. Genotyping showed that the studied strains belong to subgenotypes D1, D7, and D8. The mutational analysis showed high genetic variability. In the RT region of the polymerase gene, 28 amino acid (aa) mutations were detected. The most significant mutations were the pattern rtL180M + rtS202G + rtM204V, which confer treatment resistance. In the S gene, 35 mutations were detected namely sP120T, sT126S, sG130R, sY134F, sS193L, sI195M, and sL216stop were previously described to lead to vaccine, immunotherapy, and/or diagnosis escape. In the C gene, 34 mutations were found. In particular, cG1764A, cC1766G/T, cT1768A, and cC1773T in the BCP; cG1896A and cG1899A in the precore region and cT12S, cE64D, cA80T, and cP130Q in the core region were associated with disease progression to LC and/or HCC. Other mutations were associated with viral replication increase including cT1753V, cG1764A/T, cC1766G/T, cT1768A, and cC1788G in the BCP as well as cG1896A and cG1899A in the precore region. In the X gene, 30 aa substitutions were detected, of which substitutions xT36D, xP46S, xA47T, xI88F, xA102V, xI127T, xK130M, xV131I, and xF132Y were previously described to lead to LC and/or HCC disease progression. In conclusion, our results show high genetic variability in the long-term treatment of chronic HBV patients causing several effects. This could contribute to guiding national efforts to optimize relevant HBV treatment management in order to achieve the global hepatitis elimination goal by 2030.

Establishing an In Vitro System to Assess How Specific Antibodies Drive the Evolution of Foot-and-Mouth Disease Virus

Viruses can evolve to respond to immune pressures conferred by specific antibodies generated after vaccination and/or infection. In this study, an in vitro system was developed to investigate the impact of serum-neutralising antibodies upon the evolution of a foot-and-mouth disease virus (FMDV) isolate. The presence of sub-neutralising dilutions of specific antisera delayed the onset of virus-induced cytopathic effect (CPE) by up to 44 h compared to the untreated control cultures. Continued virus passage with sub-neutralising dilutions of these sera resulted in a decrease in time to complete CPE, suggesting that FMDV in these cultures adapted to escape immune pressure. These phenotypic changes were associated with three separate consensus-level non-synonymous mutations that accrued in the viral RNA-encoding amino acids at positions VP2⁶⁶, VP2⁸⁰ and VP1¹⁵⁵, corresponding to known epitope sites. High-throughput sequencing also identified further nucleotide substitutions within the regions encoding the leader (L^pro), VP4, VP2 and VP3 proteins. While association of the later mutations with the adaptation to immune pressure must be further verified, these results highlight the multiple routes by which FMDV populations can escape neutralising antibodies and support the application of a simple in vitro approach to assess the impact of the humoral immune system on the evolution of FMDV and potentially other viruses.

From HIV to COVID-19, Molecular mechanisms of pathogens' trade-off and persistence in the community, potential targets for new drug development

BACKGROUND

On the staggering emergence of the Omicron variant, numerous questions arose about the evolution of virulence and transmissibility in microbes.

MAIN BODY OF THE ABSTRACT

The trade-off hypothesis has long speculated the exchange of virulence for the sake of superior transmissibility in a wide array of pathogens. While this certainly applies to the case of the Omicron variant, along with influenza virus, various reports have been allocated for an array of pathogens such as human immunodeficiency virus (HIV), malaria, hepatitis B virus (HBV) and tuberculosis (TB). The latter abide to another form of trade-off, the invasion-persistence trade-off. In this study, we aim to explore the molecular mechanisms and mutations of different obligate intracellular pathogens that attenuated their more morbid characters, virulence in acute infections and invasion in chronic infections.

SHORT CONCLUSION

Recognizing the mutations that attenuate the most morbid characters of pathogens such as virulence or persistence can help in tailoring new therapies for such pathogens. Targeting macrophage tropism of HIV by carbohydrate-binding agents, or targeting the TMPRSS2 receptors to prevent pulmonary infiltrates of COVID-19 is an example of how important is to recognize such genetic mechanisms.

Association of Pre-S/S and Polymerase Mutations with Acute and Chronic Hepatitis B Virus Infections in Patients from Rio de Janeiro, Brazil

Several hepatitis B virus (HBV)-related factors, including the viral load, genotype, and genomic mutations, have been linked to the development of liver diseases. Therefore, in this study we aimed to investigate the influence of HBV genetic variability during acute and chronic infection phases. A real-time nested PCR was used to detect HBV DNA in all samples (acute, n = 22; chronic, n = 49). All samples were sequenced for phylogenetic and mutation analyses. Genotype A, sub-genotype A1, was the most common genotype in the study population. A total of 190 mutations were found in the pre-S/S gene area and the acute profile revealed a greater number of nucleotide mutations (p < 0.05). However, both profiles contained nucleotide mutations linked to immune escape and an increased risk of hepatocellular carcinomas (acute, A7T; chronic, A7Q). Furthermore, 17 amino acid substitutions were identified in the viral polymerase region, including the drug resistance mutations lamivudine and entecavir (rtL180M), with statistically significant differences between the mutant and wild type strains. Owing to the natural occurrence of these mutations, it is important to screen for resistance mutations before beginning therapy.

Occult hepatitis B — the result of the host immune response interaction with different genomic expressions of the virus

With over 40 years of history, occult hepatitis B infection (OBI) continues to remain an important and challenging public health problem. Defined as the presence of replication-competent hepatitis B virus (HBV) DNA (i.e., episomal HBV covalently closed circular DNA) in the liver and/or HBV DNA in the blood of people who test negative for hepatitis B surface antigen (HBsAg) in currently available assays, OBI is currently diagnosed using polymerase chain reaction (PCR) and real-time PCR assays. However, all efforts should be made to exclude a false negative HBsAg in order to completely follow the definition of OBI. In recent years, significant advances have been made in understanding the HBV lifecycle and the molecular mechanisms that lead to the persistence of the virus in the occult form. These factors are mainly related to the host immune system and, to a smaller proportion, to the virus. Both innate and adaptive immune responses are important in HBV infection management, and epigenetic changes driven by host mechanisms (acetylation, methylation, and microRNA implication) are added to such actions. Although greater genetic variability in the S gene of HBV isolated from OBIs was found compared with overt infection, the mechanisms of OBI are not mainly viral mutations.

Effect of an Electronic Alert System on Hepatitis B Virus Reactivation in Patients Receiving Immunosuppressive Drug Therapy

Hepatitis B virus (HBV) reactivation (HBVr) can occur in patients receiving immunosuppressive drug therapies, causing significant morbidity and mortality. Although the guidelines for HBVr have been proposed by several academic societies, some providers do not follow them, resulting in HBVr and death. As HBV-DNA levels increase before liver enzyme levels do, we previously constructed an electronic alert system that recommends the measurement of HBV-DNA. Here, we investigated whether this alert system improves the HBV-DNA measurement rate and elicits responses according to guidelines. A total of 5329 patients were divided into two groups, before and after the introduction of the alert system, and the HBV-DNA measurement rates in both groups were compared. Because of the introduction of the alert system, the HBV-DNA measurement rate among HBsAg-negative patients with anti-HBs and/or anti-HBc before immunosuppressive drug therapy improved significantly. The HBV-DNA monitoring rate within 3 months also improved significantly (p = 0.0034) in HBV-remission phase patients. HBVr was detected immediately, and the affected patients were treated with nucleotide analogs before severe hepatitis onset. The introduction of the alert system for HBVr improved the HBV-DNA measurement rates in patients receiving immunosuppressive drug therapy, leading to the rapid treatment of patients with HBVr.

Risk scores to predict HCC and the benefits of antiviral therapy for CHB patients in gray zone of treatment guidelines

BACKGROUNDS

ALT ≥ 80 U/L and HBV DNA ≥ 2000 IU/ml are treatment criteria of APASL guidelines for chronic hepatitis B (CHB) patients. The need of antiviral therapy for patients in gray zone (ALT < 80 U/L or HBV DNA < 2000 IU/ml) is controversial. This study aimed to develop a scoring system to predict hepatocellular carcinoma (HCC) and evaluate the benefit of antiviral therapy in these patients.

METHODS

Seven hundred and forty-nine patients were analyzed. Significant variables were weighted to develop a scoring system for HCC prediction. The area under receiver operating curves (AUROC) were estimated and validated by REVEAL-HBV cohort (n = 3527).

RESULTS

Older age (p < 0.001), male sex (p = 0.036), family history of HCC (p = 0.002) and HBV DNA ≥ 2000 IU/ml (p = 0.045) were independently associated with HCC. A 14-point risk score system predicts 3 and 5-years HCC risk to be 0.866 and 0.868 of AUROC, respectively in the derivation cohort; 0.821 and 0.820, in the REVEAL-HBV cohort. The cumulative HCC incidence was higher in the high risk (score ≥ 8) group both in derivation and validation cohorts (p < 0.001). Patients with antiviral therapy had lower HCC incidence compared to those without (p = 0.016). Of note, antiviral therapy significantly decreased HCC in the high risk group (p = 0.005), but not in the low risk group (p = 0.705).

CONCLUSIONS

A risk scoring system is established and validated. Of CHB patients in gray zone of APASL guidelines, those with risk scores ≥ 8 had higher risk of HCC, but the risk could be significantly reduced by antiviral therapy.

Hepatitis B virus reactivation: overview and management

Hepatitis B virus (HBV) can hide in the liver in the form of covalently closed circular DNA. When the body’s immunity changes, HBV reactivation (HBV-R) can occur. The risk of HBV-R is determined by the complex interaction among virological factors, medication factors and host factors. However, many patients do not know that they are infected with HBV, and doctors often do not invest enough time to systematically evaluate the patient’s HBV-R risk factors before immunosuppressive treatment. Therefore, HBV clinical screening should be vigorously promoted to achieve early detection and early prevention for patients with high risk of HBV-R. The mechanism, clinical features, risk factors, HBV-R under different disease etiologies, prevention and treatment of HBV-R were summarized to improve the in-depth understanding and awareness.

Hepatitis B Virus Reactivation upon Immunosuppression: Is There a Role for Hepatitis B Core-Related Antigen in Patients with Immune-Escape Mutants? A Case Report

The reactivation of hepatitis B virus (HBVr) in patients undergoing pharmacological immunosuppression is a potentially fatal clinical event that may occur in patients with overt or occult HBV infection. The risk of HBVr is mainly determined by the type of immunosuppressive therapy and the HBV serologic profile, with a higher risk in patients positive for the hepatitis B surface antigen (HBsAg), and a lower risk in HBsAg-negative/antibodies to core antigen-positive subjects. Notably, a considerable proportion of patients experiencing HBVr showed a high degree of variability of the HBV S gene, possibly leading to immune escape mutants. These mutations, usually in the “a-determinant” of the HBsAg, can cause diagnostic problems and consequently hamper the appropriate management strategy of patients at risk of HBVr. Here, we describe a case of HBVr in a patient with a diagnosis of chronic myeloid leukemia and a previous history of kidney transplant, providing evidence of the potential usefulness of hepatitis B core-related antigen measurement in patients with HBV immune-escape mutants at risk of viral reactivation.

Peripheral Immune Cells Exhaustion and Functional Impairment in Patients With Chronic Hepatitis B

After infection of hepatitis B virus (HBV), the virus induces a variety of immune disorders in the host, leading to immune escape and, finally, the chronicity of the disease. This study investigated immune cell defects and functional impairment in patients with chronic hepatitis B (CHB). We analyzed the percentage, function, and phenotypes of various immune cell subpopulations in the peripheral blood along with the concentrations of cytokines in the plasma. We compared the results between patients with CHB and healthy individuals. It was found that in patients with CHB, the cell function was impaired and, there was increased expression of inhibitory receptors, such as NKG2A and PD-1 in both NK and T cells. The impairment of function was mainly in cytokine secretion, and the cytotoxicity was not significantly diminished. We also found that the proportion of dendritic cells (DC) decreased and regulatory B cells (Breg) increased in CHB. In addition, the Breg cells were negatively correlated with T cell cytokine and positively correlated with ALT and HBV viral load. Taken together, various disorders and functional impairments were found in the immune cells of peripheral blood in CHB patients, especially NK and T cells. These cells showed exhaustion and the increase of regulatory B cells may be one of the reasons for this phenomenon.

Virus reactivation in a non-cirrhotic HBV patient requiring liver transplantation after cessation of nucleoside analogue therapy

Nucleos(t)ide analogues (NAs) are a mainstay of therapy for chronic hepatitis B (CHB) infections and have a profound effect on hepatitis B virus (HBV) suppression. We report a rare case of HBV reactivation in a CHB patient without cirrhosis following cessation of NA therapy that resulted in acute liver failure requiring liver transplantation. Investigation of the viral genetics and host immune responses suggest that viral mutations known to promote virus replication are associated with reactivation, whereas adaptive immunity to HBV remained defective in this patient. Viral sequencing may be useful for identifying mutations that are unfavorable for therapy withdrawal.

Persistence of Hepatitis B Virus Infection: A Multi-Faceted Player for Hepatocarcinogenesis

Hepatitis B virus (HBV) infection has a multi-dimensional effect on the host, which not only alters the dynamics of immune response but also persists in the hepatocytes to predispose oncogenic factors. The virus exists in multiple forms of which the nuclear localized covalently closed circular DNA (cccDNA) is the most stable and the primary reason for viral persistence even after clearance of surface antigen and viral DNA. The second reason is the existence of pregenomic RNA (pgRNA) containing virion particles. On the other hand, the integration of the viral genome in the host chromosome also leads to persistent production of viral proteins along with the chromosomal instabilities. The interferon treatment or administration of nucleot(s)ide analogs leads to reduction in the viral DNA load, but the pgRNA and surface antigen clearance are a slow process and complete loss of serological HBsAg is rare. The prolonged exposure of immune cells to the viral antigens, particularly HBs antigen, in the blood circulation results in T-cell exhaustion, which disrupts immune clearance of the virus and virus-infected cells. In addition, it predisposes immune-tolerant microenvironment, which facilitates the tumor progression. Thus cccDNA, pgRNA, and HBsAg along with the viral DNA could be the therapeutic targets in the early disease stages that may improve the quality of life of chronic hepatitis B patients by impeding the progression of the disease toward hepatocellular carcinoma.

Clinical Implications of HBV PreS/S Mutations and the Effects of PreS2 Deletion on Mitochondria, Liver Fibrosis, and Cancer Development

BACKGROUND AND AIMS

PreS mutants of HBV have been reported to be associated with HCC. We conducted a longitudinal study of the role of HBV preS mutations in the development of HCC, particularly in patients with chronic hepatitis B (CHB) having low HBV DNA or alanine aminotransferase (ALT) levels, and investigated the effects of secretion-defective preS2 deletion mutant (preS2ΔMT) on hepatocyte damage in vitro and liver fibrosis in vivo.

APPROACH AND RESULTS

Association of preS mutations with HCC in 343 patients with CHB was evaluated by a retrospective case-control follow-up study. Effects of preS2ΔMT on HBsAg retention, endoplasmic reticulum (ER) stress, calcium accumulation, mitochondrial dysfunction, and liver fibrosis were examined. Multivariate analysis revealed a significant association of preS mutations with HCC (HR, 3.210; 95% CI, 1.072-9.613; P = 0.037) including cases with low HBV DNA or ALT levels (HR, 2.790; 95% CI, 1.133-6.873; P = 0.026). Antiviral therapy reduced HCC risk, including cases with preS mutations. PreS2ΔMT expression promoted HBsAg retention in the ER and unfolded protein response (UPR). Transmission electron microscopic examination, MitoTracker staining, real-time ATP assay, and calcium staining of preS2ΔMT-expressing cells revealed aberrant ER and mitochondrial ultrastructure, reduction of mitochondrial membrane potential and ATP production, and calcium overload. Serum HBV secretion levels were ~100-fold lower in preS2ΔMT-infected humanized Fah-/-/ Rag2-/-/Il2rg-/- triple knockout mice than in wild-type HBV-infected mice. PreS2ΔMT-infected mice displayed up-regulation of UPR and caspase-3 and enhanced liver fibrosis.

CONCLUSIONS

PreS mutations were significantly associated with HCC development in patients with CHB, including those with low HBV DNA or ALT levels. Antiviral therapy reduced HCC occurrence in patients with CHB, including those with preS mutations. Intracellular accumulation of mutated HBsAg induced or promoted ER stress, calcium overload, mitochondrial dysfunction, impaired energy metabolism, liver fibrosis, and HCC.

Low Genetic Diversity of Hepatitis B Virus Surface Gene amongst Australian Blood Donors

Variants in the small surface gene of hepatitis B virus (HBV), which codes for viral surface antigen (HBsAg), can affect the efficacy of HBsAg screening assays and can be associated with occult HBV infection (OBI). This study aimed to characterise the molecular diversity of the HBV small surface gene from HBV-reactive Australian blood donors. HBV isolates from 16 HBsAg-positive Australian blood donors' plasma were sequenced and genotyped by phylogenies of viral coding genes and/or whole genomes. An analysis of the genetic diversity of eight HBV small surface genes from our 16 samples was conducted and compared with HBV sequences from NCBI of 164 international (non-Australian) blood donors. Genotypes A-D were identified in our samples. The region of HBV small surface gene that contained the sequence encoding the 'a' determinant had a greater genetic diversity than the remaining part of the gene. No escape mutants or OBI-related variants were observed in our samples. Variant call analysis revealed two samples with a nucleotide deletion leading to truncation of polymerase and/or large/middle surface amino acid sequences. Overall, we found that HBV small surface gene sequences from Australian donors demonstrated a lower level of genetic diversity than those from non-Australian donor population included in the study.

Detection of Q129H Immune Escape Mutation in Apparently Healthy Hepatitis B Virus Carriers in Southwestern Nigeria

As the global effort to eradicate hepatitis B continues, immune escape mutations (IEMs) and drug resistance mutations (DRMs) affecting its diagnosis, treatment, and prevention are compromising this goal. However, knowledge about the prevalence and circulation of these mutations in Nigeria is scarce. Serum samples (n = 199) from apparently healthy prospective blood donors, pregnant women, and individuals presenting with fever in southwestern Nigeria were analyzed for the presence of IEMs and DRMs by means of nested PCR in the HBV S (HBs) and HBV polymerase (Pol) genes, followed by phylogenetic and mutational analyses. In total, 25.1% (n = 50/199) of samples were positive for HBV, as measured by PCR. In 41 samples (20.6%), both fragments could be amplified, whereas the HBs gene and the Pol gene fragment alone were detected in 0.5% (n = 1/199) and 4% (n = 8/199) of samples, respectively. Sequences were successfully obtained for all 42 HBs gene fragments but for only 31/49 Pol gene fragments (totaling 73 sequences from 44 individuals). All sequences were identified as HBV genotype E. IEMs were present in 18.2% (n = 8/44) of the sequences of HBV-positive individuals with available sequences. IEM Q129H was detected in eight out of the 44 (18.2%) HBV isolates sequenced in this study; however, no DRMs were observed. This study confirms the circulation of HBV IEMs and reports the presence of Q129H IEM for the first time in Nigeria. Intensified research on the dynamics of IEM is necessary in order to enhance the elimination of HBV.

Characterization of Antigen Escape Mutations in Chronic HBV-Infected Patients in Upper Egypt

Background

Mutations within the “a” determinant region (position 124–147) that is present in the major hydrophilic region (MHR, position 99–160) of the hepatitis B surface antigen (HBsAg) are associated with vaccine-escape, lack of diagnosis, and failure to hepatitis B immunoglobulin (HBIG) therapy. Data regarding the amino acid changes of “a” determinant region of HBsAg are limited in Egypt. The prevalence and mutations in this region among chronic HBV (CHB)-infected patients in Upper Egypt are not known.

Material and Methods

Blood samples were collected from HBsAg-positive CHB-infected patients (n=123) admitted to Assiut University Hospitals. Serum samples were screened for HBsAg, HBeAg, anti-HBs and anti-HBe antibodies using commercially available ELISA kits. Viral load was determined by qPCR. In addition, mutational analysis was carried out targeting the HBV surface gene to determine the HBV genotype and vaccine escape mutations.

Results

Sequencing analysis of HBV DNA revealed that genotype D is the major circulating type (81.3%), followed by genotype E (18.7%). Analysis of the HBV genome revealed that 103/123 (83.7%) patients showed wild-type sequences and 20/123 (16.3%) showed mutations in the HBsAg gene. Mutation in seventeen patients (17/20, 85%) showed only one mutation, and three patients showed two mutations (3/20, 15%) in the “a” determinant region. The observed mutations were T115S (3/20, 15%), P120T/S (3/20, 15%), T126S (1/20, 5%), Q129R (2/20, 10%), M133T (2/20, 10%), S143L (5/20, 25%), D144E/A (3/20, 15%), and G145R/A (4/20, 20%). Mutations in the “a” determinant region were detected in genotype D isolates only.

Conclusion

We described for the first time the prevalence and characterization of vaccine escape mutants in CHB patients in Upper Egypt. Mutational analysis of the “a” determinant region revealed the presence of a wide spectrum of mutants in the circulating HBV isolates that could be a potential threat to HBV diagnosis, therapy success, and HBV vaccination program in Upper Egypt.

Extracellular vesicles carry SARS-CoV-2 spike protein and serve as decoys for neutralizing antibodies

In late 2019, a novel coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan, China. SARS-CoV-2 and the disease it causes, coronavirus disease 2019 (COVID-19), spread rapidly and became a global pandemic in early 2020. SARS-CoV-2 spike protein is responsible for viral entry and binds to angiotensin converting enzyme 2 (ACE2) on host cells, making it a major target of the immune system - particularly neutralizing antibodies (nAbs) that are induced by infection or vaccines. Extracellular vesicles (EVs) are small membraned particles constitutively released by cells, including virally-infected cells. EVs and viruses enclosed within lipid membranes share some characteristics: they are small, sub-micron particles and they overlap in cellular biogenesis and egress routes. Given their shared characteristics, we hypothesized that EVs released from spike-expressing cells could carry spike and serve as decoys for anti-spike nAbs, promoting viral infection. Here, using mass spectrometry and nanoscale flow cytometry (NFC) approaches, we demonstrate that SARS-CoV-2 spike protein can be incorporated into EVs. Furthermore, we show that spike-carrying EVs act as decoy targets for convalescent patient serum-derived nAbs, reducing their effectiveness in blocking viral entry. These findings have important implications for the pathogenesis of SARS-CoV-2 infection in vivo and highlight the complex interplay between viruses, extracellular vesicles, and the immune system that occurs during viral infections.

Risk factors for losing hepatitis B virus surface antibody in patients with HBV surface antigen negative/surface antibody positive serostatus receiving biologic disease-modifying anti-rheumatic drugs: a nested case-control study

BACKGROUND

Hepatitis B virus (HBV) reactivation consequent to immunosuppressive therapy is an increasingly prevalent problem with serious clinical implications. Treatment with biologic agents conduces to the loss of protective antibody to HBV surface antigen (anti-HBs), which significantly increases the risk of HBV reactivation. Hence, we investigated the risk factors for losing anti-HBs in patients with rheumatic diseases and HBV surface antigen negative/anti-HBs positive (HBsAg-/anti-HBs+) serostatus during treatment with biologic disease-modifying anti-rheumatic drugs (DMARDs).

METHODS

Using a nested case-control design, we prospectively enrolled patients with rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis/psoriasis, or juvenile idiopathic arthritis, who were treated with biologic DMARDs at Changhua Christian Hospital, Taiwan, from January 2013 to June 2019 and had HBsAg-/anti-HBs+ serostatus; the analytic sample excluded all patients with HBsAg+ or anti-HBs- serostatus. Anti-HBs titers were monitored 6-monthly and cases were defined as anti-HBs < 10 mIU/ml during follow-up. Cases were matched one-to-all with controls with anti-HBs ≥ 10 mIU/ml on the same ascertainment date and equivalent durations of biologic DMARDs treatment (control patients could be resampled and could also become cases during follow-up). Between-group characteristics were compared and risk factors for anti-HBs loss were investigated by conditional logistic regression analyses.

RESULTS

Among 294 eligible patients, 23 cases were matched with 311 controls. The incidence of anti-HBs loss was ~ 2.7%/person-year during biologic DMARDs treatment. Besides lower baseline anti-HBs titer (risk ratio 0.93, 95% CI 0.89-0.97), cases were significantly more likely than controls to have diabetes mellitus (risk ratio 4.76, 95% CI 1.48-15.30) and chronic kidney disease (risk ratio 14.00, 95% CI 2.22-88.23) in univariate analysis. Risk factors remaining significantly associated with anti-HBs loss in multivariate analysis were lower baseline anti-HBs titer (adjusted risk ratio 0.93, 95% CI 0.88-0.97) and chronic kidney disease (adjusted risk ratio 45.68, 95% CI 2.39-871.5).

CONCLUSIONS

Besides lower baseline anti-HBs titer, chronic kidney disease also strongly predicts future anti-HBs negativity in patients with HBsAg-/anti-HBs+ serostatus who receive biologic DMARDs to treat rheumatic diseases. Patients with low anti-HBs titer (≤ 100 mIU/ml) and/or chronic kidney disease should be monitored during biologic DMARDs therapy, to enable timely prophylaxis to preempt potential HBV reactivation.

Occult Hepatitis B Reactivation after Liver Transplant: The Role of a Novel Mutation in the Surface Antigen

Occult hepatitis B infection is characterized by loss of hepatitis B surface antigen (HBsAg) and persistence of low levels of hepatitis B virus (HBV) replication that may or may not be detectable in plasma/serum. We present a case of HBV reactivation in a male patient who underwent orthotopic liver transplant for hepatocellular carcinoma secondary to active hepatitis C (HCV) infection. Pre-transplant, he was HBsAg-negative and hepatitis B core antibody-positive, with an undetectable HBV viral load that was incidentally found to be positive at a very low HBV viral load on the day of transplant. Post-transplant, his HBsAg remained undetectable, with an undetectable HBV viral load, until eradication of his HCV infection with direct acting antiviral agents. After eradication of HCV, there was reactivation of HBV, with a high viral load and emergence of serum HBsAg. A deep sequencing genetic analysis of his HBV both pre- and post-transplant revealed the presence of a mutation in the "a" determinant of the HBV surface antigen. The role of HBV genotype 'a' determinant mutation in HBV reactivation post-transplant is unknown and needs further examination. Our experience suggests a possible role for antiviral prophylaxis in these patients or monitoring of HBV viral loads post-transplant.

Predominance of HBV Genotype B and HDV Genotype 1 in Vietnamese Patients with Chronic Hepatitis

Hepatitis delta virus (HDV) coinfection will additionally aggravate the hepatitis B virus (HBV) burden in the coming decades, with an increase in HBV-related liver diseases. Between 2018 and 2019, a total of 205 HBV patients clinically characterized as chronic hepatitis B (CHB; n = 115), liver cirrhosis (LC; n = 21), and hepatocellular carcinoma (HCC; n = 69) were recruited. HBV surface antigen (HBsAg), antibodies against surface antigens (anti-HBs), and core antigens (anti-HBc) were determined by ELISA. The presence of hepatitis B viral DNA and hepatitis delta RNA was determined. Distinct HBV and HDV genotypes were phylogenetically reconstructed and vaccine escape mutations in the “a” determinant region of HBV were elucidated. All HBV patients were HbsAg positive, with 99% (n = 204) and 7% (n = 15) of them being positive for anti-HBc and anti-HBs, respectively. Anti-HBs positivity was higher among HCC (15%; n = 9) compared to CHB patients. The HBV-B genotype was predominant (65%; n = 134), followed by HBV-C (31%; n = 64), HBV-D, and HBV-G (3%; n = 7). HCC was observed frequently among young individuals with HBV-C genotypes. A low frequency (2%; n = 4) of vaccine escape mutations was observed. HBV-HDV coinfection was observed in 16% (n = 33) of patients with the predominant occurrence of the HDV-1 genotype. A significant association of genotypes with alanine aminotransferase (ALT) and aspartate aminotransferase (AST) enzyme levels was observed in HBV monoinfections. The prevalence of the HDV-1 genotype is high in Vietnam. No correlation was observed between HDV-HBV coinfections and disease progression when compared to HBV monoinfections.

Management of Hepatitis B Virus in Allogeneic Hematopoietic Stem Cell Transplantation

The high morbidity of HBV reactivation following allogeneic hematopoietic stem cell transplantation (allo-HSCT) is partially due to the intense immunologic potency of complex therapeutic regimens, the use of antithymocyte globulin and calcineurin inhibitors to prevent graft versus-host disease (GVHD), prolonged immune reconstitution, and hematological malignancies infected with hepatitis B virus (HBV). Immunosuppression results in the reactivation of HBV replication from covalently closed circular DNA (cccDNA) residing in hepatocytes. However, the role of viral mutations during HBV reactivation needs to be validated. All individuals scheduled to receive allo-HSCT or wish to donate stem cells should be screened for hepatitis B surface antigen (HBsAg), antibodies to hepatitis B core (anti-HBc), and HBV-DNA. HBsAg-positive recipients of allo-HSCT have a high risk of HBV reactivation; thus, they should receive prophylactic antiviral therapy. The high barrier to resistance nucleos(t)-ide analogs (NAs) seems to be superior to the low barrier agents. Resolved-HBV recipients have a lower risk of HBV reactivation than HBsAg-positive recipients. Although prophylactic antiviral therapy remains controversial, regular monitoring of alanine transaminase (ALT) and HBV-DNA combined with preemptive antiviral treatment may be an optimized strategy. However, optimal antiviral therapy duration and time intervals for monitoring remain to be established. Accepting stem cells from HBsAg-positive donors is associated with a risk of developing HBV-related hepatitis. The overall intervention strategy, including donors and recipients, may decrease the risk of HBV-related hepatitis following HSCT from HBsAg positive stem cells. In this review, we summarize the issues of HBV in allo-HSCT, including HBV reactivation mechanism, HBsAg-positive recipients, HBV-resolved infection recipients, and donor-related factors, and discuss their significance.

Case of hepatitis B virus reactivation after ibrutinib therapy in which the patient remained negative for hepatitis B surface antigens throughout the clinical course

A 71-year-old man was diagnosed with B-cell chronic lymphocytic leukemia. He was negative for hepatitis B surface antigen (HBsAg), positive for antibodies against the hepatitis B surface and core, and negative for hepatitis B virus (HBV)-DNA before starting chemotherapy. A total of 13 months after the initiation of ibrutinib (a Bruton's tyrosine kinase inhibitor), the patient's alanine aminotransferase levels suddenly increased to 427 U/L. As the level of serum HBV-DNA increased to 5.2 logIU/mL, a diagnosis of HBV reactivation was made, whereas the patient remained negative for HBsAg. The patient's serum alanine aminotransferase levels normalized after the initiation of entecavir at a dose of 1 mg/day. However, it took >1 year to achieve an undetectable level of HBV-DNA, even with an add-on therapy of tenofovir disoproxil fumarate. Interestingly, the patient remained negative for HBsAg throughout the clinical course owing to triple HBsAg escape mutations: Q101K, M133L, and G145A.

Comprehensive Analysis of Clinically Significant Hepatitis B Virus Mutations in Relation to Genotype, Subgenotype and Geographic Region

Hepatitis B virus (HBV) is a highly variable DNA virus due to its unique life cycle, which involves an error-prone reverse transcriptase. The high substitution rate drives the evolution of HBV by generating genetic variants upon which selection operates. HBV mutants with clinical implications have been documented worldwide, indicating the potential for spreading and developing their own epidemiology. However, the prevalence of such mutants among the different HBV genotypes and subgenotypes has not been systematically analyzed. In the current study, we performed large-scale analysis of 6,479 full-length HBV genome sequences from genotypes A-H, with the aim of gaining comprehensive insights into the relationships of relevant mutations associated with immune escape, antiviral resistance and hepatocellular carcinoma (HCC) development with HBV (sub)genotypes and geographic regions. Immune escape mutations were detected in 10.7% of the sequences, the most common being I/T126S (1.8%), G145R (1.2%), M133T (1.2%), and Q129R (1.0%). HBV genotype B showed the highest rate of escape mutations (14.7%) while genotype H had no mutations (P < 0.001). HCC-associated mutations were detected in 33.7% of the sequences, with significantly higher frequency of C1653T, T1753V and A1762T/G1764A in genotype G than C (P < 0.001). The overall frequencies of lamivudine-, telbivudine-, adefovir-, and entecavir-resistant mutants were 7.3, 7.2, 0.5, and 0.2%, respectively, while only 0.05% showed reduced susceptibility to tenofovir. In particular, the highest frequency of lamivudine-resistant mutations was observed in genotype G and the lowest frequency in genotype E (32.5 and 0.3%; P < 0.001). The prevalence of HBV mutants was also biased by geographic location, with North America identified as one of the regions with the highest rates of immune escape, antiviral resistance, and HCC-associated mutants. The collective findings were discussed in light of natural selection and the known characteristics of HBV (sub)genotypes. Our data provide relevant information on the prevalence of clinically relevant HBV mutations, which may contribute to further improvement of diagnostic procedures, immunization programs, therapeutic protocols, and disease prognosis.

The distribution of hepatitis B virus surface antigen polymorphisms at positions associated with vaccine escape

Hepatitis B virus (HBV) infects over 250 million people worldwide. Vaccination is effective at preventing infection, although several mutations within the "a" determinant region of the HBV surface antigen (HBsAg) are associated with vaccine escape. We evaluated the frequency, genotype, and global distribution of polymorphisms at sites associated with vaccine escape in 4244 unique full-length HBV genomes. The "a" determinant within the Surface gene was inspected for polymorphisms at sites identified previously associated with vaccine escape. Nearly, 268 (6.3%) sequences from 36 countries contained a polymorphism at a site associated with vaccine escape including 22 genotype A, 99 genotype B, 93 genotype C, 32 genotype D, 14 genotype E, 3 genotype F, 2 genotype G, and 3 genotype I. In genotype A, the most common polymorphism occurred at M133. In genotype B, Q129 and M133 occurred 45 and 51 times, respectively, accounting for 94% of polymorphisms. Polymorphisms at G145 were most frequent in genotype C, while P120 was most common in genotype D. Among all genotypes, polymorphisms at M133 were the most common and accounted for 30.9% of polymorphisms. Polymorphisms at T116, P120, F134, K141, and P142 occurred in geographically diverse locations, whereas polymorphisms at Q129, M133, D144, and G145 were concentrated in East Asia. While the sample size is large, this approach relied on convenience sampling within each country, and many countries have no data available, thereby highlighting the need for additional routine surveillance of surface antigen mutations associated with vaccine escape.

Using Quasispecies Patterns of Hepatitis B Virus to Predict Hepatocellular Carcinoma With Deep Sequencing and Machine Learning

BACKGROUND

Hepatitis B virus (HBV) infection is one of the main leading causes of hepatocellular carcinoma (HCC) worldwide. However, it remains uncertain how the reverse-transcriptase (rt) gene contributes to HCC progression.

METHODS

We enrolled a total of 307 patients with chronic hepatitis B (CHB) and 237 with HBV-related HCC from 13 medical centers. Sequence features comprised multidimensional attributes of rt nucleic acid and rt/s amino acid sequences. Machine-learning models were used to establish HCC predictive algorithms. Model performances were tested in the training and independent validation cohorts using receiver operating characteristic curves and calibration plots.

RESULTS

A random forest (RF) model based on combined metrics (10 features) demonstrated the best predictive performances in both cross and independent validation (AUC, 0.96; accuracy, 0.90), irrespective of HBV genotypes and sequencing depth. Moreover, HCC risk scores for individuals obtained from the RF model (AUC, 0.966; 95% confidence interval, .922-.989) outperformed α-fetoprotein (0.713; .632-.784) in distinguishing between patients with HCC and those with CHB.

CONCLUSIONS

Our study provides evidence for the first time that HBV rt sequences contain vital HBV quasispecies features in predicting HCC. Integrating deep sequencing with feature extraction and machine-learning models benefits the longitudinal surveillance of CHB and HCC risk assessment.

Recent Advances in Understanding, Diagnosing, and Treating Hepatitis B Virus Infection

Chronic hepatitis B virus (HBV) infection affects 292 million people worldwide and is associated with a broad range of clinical manifestations including cirrhosis, liver failure, and hepatocellular carcinoma (HCC). Despite the availability of an effective vaccine HBV still causes nearly 900,000 deaths every year. Current treatment options keep HBV under control, but they do not offer a cure as they cannot completely clear HBV from infected hepatocytes. The recent development of reliable cell culture systems allowed for a better understanding of the host and viral mechanisms affecting HBV replication and persistence. Recent advances into the understanding of HBV biology, new potential diagnostic markers of hepatitis B infection, as well as novel antivirals targeting different steps in the HBV replication cycle are summarized in this review article.

Association of the Hepatitis B Virus Large Surface Protein with Viral Infectivity and Endoplasmic Reticulum Stress-mediated Liver Carcinogenesis

Hepatitis B is the most prevalent viral hepatitis worldwide, affecting approximately one-third of the world’s population. Among HBV factors, the surface protein is the most sensitive biomarker for viral infection, given that it is expressed at high levels in all viral infection phases. The large HBV surface protein (LHBs) contains the integral pre-S1 domain, which binds to the HBV receptor sodium taurocholate co transporting polypeptide on the hepatocyte to facilitate viral entry. The accumulation of viral LHBs and its prevalent pre-S mutants in chronic HBV carriers triggers a sustained endoplasmic reticulum (ER) overload response, leading to ER stress-mediated cell proliferation, metabolic switching and genomic instability, which are associated with pro-oncogenic effects. Ground glass hepatocytes identified in HBV-related hepatocellular carcinoma (HCC) patients harbor pre-S deletion variants that largely accumulate in the ER lumen due to mutation-induced protein misfolding and are associated with increased risks of cancer recurrence and metastasis. Moreover, in contrast to the major HBs, which is decreased in tumors to a greater extent than it is in peritumorous regions, LHBs is continuously expressed during tumorigenesis, indicating that LHBs serves as a promising biomarker for HCC in people with CHB. Continuing efforts to delineate the molecular mechanisms by which LHBs regulates pathological changes in CHB patients are important for establishing a correlation between LHBs biomarkers and HCC development.

Biological features of hepatitis B virus strains associated with fulminant hepatitis

Accumulating evidence suggests that hepatitis B virus (HBV) biological features may influence the course and clinical manifestations of infection and possibly the development of fulminant hepatitis (FH). Since HBV is not a cytocidal virus, virus-induced liver damage results from an interplay between the virus replication and the host's defense. Therefore, viral factors contributing to enhanced replication, induction of a stronger immune attack or apoptosis of hepatocytes could be crucial in development of FH. Numerous mutations in basal core promoter, pre-C, C and S regions of the HBV genome contribute to development of FH by different mechanisms, including enhanced viral replication, the loss of a decoy for immune response, unbalanced expression of viral proteins and retention of unprocessed cytotoxic proteins in hepatocytes.

Characterization of occult hepatitis B in high-risk populations in Kenya

Occult hepatitis B infection (OBI) is defined as the presence of hepatitis B virus (HBV) DNA in the liver or serum in the absence of detectable HBV surface antigen (HBsAg). OBI poses a risk for the development of cirrhosis and hepatocellular carcinoma. The prevalence of OBI in Kenya is unknown, thus a study was undertaken to determine the prevalence and molecular characterization of OBI in Kenyan populations at high risk of HBV infection. Sera from two Nairobi cohorts, 99 male sex workers, primarily having sex with men (MSM-SW), and 13 non-MSM men having HIV-positive partners, as well as 65 HBsAg-negative patients presenting with jaundice at Kenyan medical facilities, were tested for HBV serological markers, including HBV DNA by real-time PCR. Positive DNA samples were sequenced and MSM-SW patients were further tested for hepatitis C virus (HCV) infection. Of the 166 HBsAg-negative samples tested, 31 (18.7%; 95% confidence interval [CI] 13.5–25.3) were HBV DNA positive (i.e., occult), the majority (20/31; 64.5%) of which were HBV core protein antibody positive. HCV infection was not observed in the MSM-SW participants, although the prevalence of HBsAg positivity was 10.1% (10/99; 95% CI 5.6–17.6). HBV genotype A was predominant among study cases, including both HBsAg-positive and OBI participants, although the data suggests a non-African network transmission source among MSM-SW. The high prevalence of HBV infection among MSM-SW in Kenya suggests that screening programmes be instituted among high-risk cohorts to facilitate preventative measures, such as vaccination, and establish entry to treatment and linkage to care.

Role of hepatitis B antibody in predicting reactivation of resolved hepatitis B virus infection in leukemia patients

BACKGROUND & AIMS

Quantification of anti-HBs and anti-HBc predicts the risk of HBV reactivation (HBVr) in lymphoma patients receiving rituximab treatment. However, it remains unclear whether the quantification is predictive of HBVr in leukemia patients undergoing immunosuppression.

METHODS

and patients: Clinical and laboratory data of the leukemia patients with resolved HBV infection diagnosed between January 2013 and March 2018 were retrospectively collected. Data series of HBV seromarkers and HBV DNA levels before the patients receiving chemotherapy and/or hematopoietic stem cell transplantation (HSCT) and during follow-up duration were analyzed.

RESULTS

In total, 533 leukemia patients with resolved HBV infection were included. The incidences of HBVr were 5.7% (25/441) and 2.2% (2/92) in patients receiving HSCT and chemotherapy, respectively. In patients receiving HSCT, acute lymphoid leukemia had a significantly higher incidence of HBVr than acute myeloid leukemia (8.9% vs 3.9%, P < 0.05). The incidence varied almost zero to 40% due to the differences in the profiles of HBV antibodies. High anti-HBs (cut-off of 79.2 IU/L) or low anti-HBc levels (cut-off of 4.475, S/CO) at baseline were associated with a low risk of HBVr. Anti-HBe status did not affect the incidence of HBVr. However, the cut-offs were only predictive of HBVr in the patients who had negative anti-HBe.

CONCLUSION

The baseline profiles of HBV antibodies are predictive of the risk of HBVr in leukemia patients undergoing immunosuppression. However, seronegative anti-HBe is a prerequisite for using baseline anti-HBs and anti-HBc quantification to predict HBVr risk.