Association of HBsAg mutation patterns with hepatitis B infection outcome: Asymptomatic carriers versus HCC/cirrhotic patients

Characterization of a breakthrough vaccine escape strain associated with overt hepatitis B virus infection

Hepatitis B virus (HBV) vaccine is composed of the purified hepatitis B surface antigen (HBsAg) that is produced by recombinant DNA technology. The neutralizing antibodies induced by vaccination target mainly the "a" determinant, aa124-147, of the outer viral envelope (HBsAg). In the present work, we demonstrate a case study for vaccinated patient that is infected with a vaccine escape HBV strain (Eg200). Characterization of the isolate Eg200 showed that it belongs to the genotype D and an uncommon sub-genotype in Egypt; D9. The DNA sequence encoding HBsAg was sequenced. Mutational analysis of the HBsAg showed a double mutation in the "a" determinant of this HBV isolate; T125M and P127T. However, such substitutions were found to be conserved to the detected serotype, ayw3, of Eg200 isolate. This case report indicates that continuous characterization of breakthrough vaccine escape strains of HBV is essential to develop the immunization strategies against HBV infection.

An Ideal Hallmark Closest to Complete Cure of Chronic Hepatitis B Patients: High-sensitivity Quantitative HBsAg Loss

In the era of antiviral therapy, the main goal of treatment has shifted from the persistent inhibition of hepatitis B virus (HBV) replication to the pursuit of serological clearance of HBs surface antigen (HBsAg). Based on the life cycle of HBV, HBsAg originates from covalently closed circular DNA (cccDNA) and integrated HBV DNA, thus reflecting their transcriptional activity. Complete HBsAg loss may mean elimination or persistent inactivity of the HBV genome including cccDNA and integrated HBV DNA. HBsAg loss improves the recovery of abnormal immune function, which in turn, may further promote the clearance of residual viruses. Combined with functional cure and the great improvement of clinical outcomes, the continuous seroclearance of high-sensitivity quantitative HBsAg may represent the complete cure of chronic hepatitis B (CHB). For many other risk factors besides HBV itself, patients with HBsAg loss still need regular monitoring. In this review, we summarized the evolution of CHB treatment, the origin of serum HBsAg, the pattern of HBsAg seroclearance, and the effect of HBsAg loss on immune function and disease outcomes. In addition, we discuss the significance of high-sensitivity HBsAg detection and its possibility as a surrogate of complete cure.

Influence of C107R mutation from hepatitis B virus genotype H on in vitro hepatitis B surface antigen detection and IFN-β-1a treatment

Aim: Assess the in vitro effect of hepatitis B virus (HBV) genotype H (HBV/H) with the small surface HBV protein (HBs) C107R mutation on hepatitis B surface antigen (HBsAg) detection, TGFB1, CAT and IFNB1A expression, and the response to IFN-β-1a treatment. Methods: HBV/H wild-type and HBs  C107R variant replicons were constructed and transfected into hepatic stellate cells and/or Huh7 that were later treated with IFN-β-1a. HBsAg, HBV-DNA, pgRNA, TGFB1, CAT and IFNB1A expression was analyzed. 3D HBs structure from wild-type and C107R were foreseen by AlphaFold protein predictor, and IFN-β-1a antiviral effect was evaluated. Results: C107R mutation did not impact viral replication, but HBsAg serologic detection was affected. Wild-type and C107R similarly modified gene expression and responded to IFN-β-1a. Conclusion: C107R disrupts the Cys107/Cys138 disulfide bond and impairs HBsAg detection. Independently of the mutation, there were changes in TGFB1, CAT and IFNB1A expression, and a medium response to IFN-β-1a treatment compared with genotype A and C.

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.

Comparison of S gene mutations in patients with occult and chronic hepatitis B virus infection

BACKGROUND AND AIM

This study aimed to detect mutations in the HBV S gene and evaluate their relationship to occult hepatitis B virus (HBV) infection (OBI).

METHODS

The study included 32 patients with negative serum HBsAg and HBV DNA who underwent liver biopsy due to different clinical indications defined as the OBI group and 32 patients who underwent liver biopsy due to chronic hepatitis B (CHB) as the comparison group. The HBV S gene region was amplified by Nested PCR, and Sanger sequencing was performed.

RESULTS

At least one amino acid (aa) mutation was detected in the major hydrophilic region (MHR) of the HBV S gene in 14/32 (43.75%) of the patients with OBI and 8/32 (25.0%) with CHB. The genotype of all patients with OBI and CHB was HBV/D. Although 9 (28.1%) of the cases with OBI had sub-genotype HBV/D3, none of the patients with CHB had sub-genotype HBV/D3. Unlike patients with CHB, L15*, D33N, Q51P, V63F, L91I, P108S, T115I, P120L, T125M, Q129H, T189I, L216F, P217L mutations were detected in the HBV S gene in OBI cases. Also, P127T aa polymorphism was frequently detected. Mutation frequency in the HBV S gene in the major hydrophilic region (MHR) was higher in patients with OBI with sub-genotypes HBV/D3 and D2 than those with HBV/D1 and those with serotype HBV/ayw3 compared to those with HBV/ayw2 (p < 0.05).

CONCLUSIONS

Sub-genotypic-specific mutation patterns were seen in the "a" determinant region and T helper cell epitopes of HBsAg, especially in the C-terminus domain; this may be associated with OBI.

Role of S Protein Transmembrane Domain Mutations in the Development of Occult Hepatitis B Virus Infection

Occult HBV infection (OBI) is a special infection status during Hepatitis B virus (HBV) infection. The underlying mechanism of its occurrence remains unclear. This study conducted sequencing analysis on 104 OBI plasma samples and 524 HBsAg positive samples from 29 blood centres, and searched for high-frequency mutations in transmembrane domain (TMD) of S protein in the OBI population. Plasmids with TMD high-frequency mutations were constructed, in vivo and in vitro functional experiments were performed to investigate possible molecular mechanisms of OBI occurrence. We found 22 high-frequency TMD mutations in genotype B OBI strains. Among them, five mutations can lead to impairment of HBsAg secretion; seven mutations had accumulated intracellular HBsAg while extracellular HBsAg didn’t decrease compared to wildtype. This study chose C85R from TMD2, F220C, and F220Y from TMD4 for further exploration. Protein structure predication showed these three mutant HBsAg displayed changed hydrophilic properties and tended to accumulate in the phospholipid bilayer of cell membrane. Mutant HBsAg’s secretion disorder may induce OBI. On the other hand, V168A + V177A from TMD3 expressed increased HBsAg both in intracellular and extracellular levels. This mutation had most unstable natural conformation and may be inclined to transition into V177A or V168A + S174N + V177A. These three mutations were more prone to mixed infection, presenting a state of coexistence, thus approaching the impaired secretion pattern of OBI. This study demonstrated TMD mutations could contribute to the occurrence of OBI and provided a theoretical basis for OBI study and the functional cure of chronic hepatitis B virus infection.

Precore/core mutations of hepatitis B virus genotype D arising in different states of infection

Aim of the study

Precore/core variations and liver disease progression have been suggested. In this study, we aimed to determine the frequency of precore/core mutations in hepatitis B virus (HBV)-infected patients at various clinical stages.

Material and methods

In total, 73 HBV-infected patients including 26 inactive carriers (IC), 20 chronic active (CA), and 27 patients with liver cirrhosis/hepatocellular carcinoma (C/HCC) were randomly selected. The HBV DNA was extracted from the sera and subjected to nested PCR for amplification of precore/core region. The PCR product was then sequenced by the Sanger method.

Results

The stop codon of W28*(G1896A) was determined as the most prevalent mutation (55%) of the precore region. The comparison of groups also demonstrated that core substitutions at residues of S21, E40 and I105 (< 0.05) correlated with the development of the inactive carrier state. Furthermore, the total substitutions in Th epitopes (117-131) were significantly higher in the C/HCC group than the IC and CA groups (p = 0.001).

Conclusions

Our results indicated a high frequency of W28* mutation in HBV studied patients. Moreover, variations including S21, E40 and I105 and R151 that were mapped onto cellular epitopes might be related to inactive state development.

Mutations in the HBV PreS/S gene related to hepatocellular carcinoma in Vietnamese chronic HBV-infected patients

Background

Chronic hepatitis B virus (CHB) infection is a major health problem and leading cause of hepatocellular carcinoma (HCC) worldwide. Several point and deletion mutations on the PreS/S gene have been intensively considered associated with HCC. This study aimed to describe the characteristics of HBV PreS/S mutations in Vietnamese CHB-infected patients and their association with HCC.

Methods

This cross-sectional study was conducted from 02/2020 to 03/2021, recruited Vietnamese CHB-infected patients with HBV-DNA >3 log₁₀-copies/mL and successful PreS/S gene sequencing. Mutations were detected by direct Sanger sequencing.

Results

247 CHB-infected patients were recruited, characterized by 68.8% males, 54.7% HBV genotype B, 57.5% HBeAg positive, 23.1% fibrosis score ≥F3 and 19.8% HCC. 61.8% amino acid replacements were detected throughout the PreS1/PreS2/S genes. The most common point-mutations included N/H51Y/T/S/Q/P (30.4%), V68T/S/I (44.9%), T/N87S/T/P (46.2%) on PreS1 gene; T125S/N/P (30.8%), I150T (42.5%) on PreS2 gene; S53L (37.7%), A184V/G (39.3%), S210K/N/R/S (39.3%) on S gene. The rates of case(s) with any point-mutation on the Major Hydrophylic Region (MHR) and the "a" determinant region were 63.6% and 39.7%, respectively. Most of S point-mutations were presented with low rates such as T47A/E/V/K (9.3%), P120S/T (8.5%), G145R (2%). On multivariable analysis, males (OR = 4.51, 95%CI 1.78–11.4, p = 0.001), age≥40 (OR = 5.5, 95%CI 2.06–14.68, p = 0.001), W4P/R/Y on PreS1 (OR = 11.56, 95%CI 1.99–67.05, p = 0.006) and 4 S point-mutations as: T47A/E/V/K (OR = 3.67, 95%CI 1.19–11.29, p = 0.023), P120S/T (OR = 3.38, 95%CI 1.09–10.49, p = 0.035), S174N (OR = 29.73, 95%CI 2.12–417.07, p = 0.012), P203R (OR = 8.45, 95%CI 1.43–50.06, p = 0.019) were associated with HCC.

Conclusions

We detected 61% amino acid changes on PreS/S regions in Vietnamese CHB patients. One point-mutation at amino acid 4 on PreS1 gene and 4 point-mutations at amino acids 47, 120, 174, and 203 on S gene were associated with HCC. Further investigations are recommended to further clarify the relationship and interaction between mutations in HBV genome and HCC progression.

Hepatocellular Carcinoma in Hepatitis B Virus-Infected Patients and the Role of Hepatitis B Surface Antigen (HBsAg)

Hepatocellular carcinoma (HCC) is the fifth most common cancer and the second leading cause of cancer-related death worldwide. Hepatitis B virus (HBV) infection is among the main risk factors for HCC. The risk of HCC is not eliminated completely after viral suppression, due to HBV DNA integrated into human chromosomes. Cirrhosis, HBV viral DNA levels, age, male gender, the immune response of the host against HBV, and a combination of obesity and diabetes are among the main risk factors for HCC. Active viral replication and long-standing active disease with inflammation are associated with a higher risk of HCC. Treatment of HBV with nucleos(t)ide analogues (NAs) decreased HCC risk by effectively decreasing viral load and inflammation. Similar risk factors have been reported in hepatitis B patients after seroclearance. Studies have reported decreased risk of HCC after seroclearance, but there were also conflicting results from a few studies indicating no difference in risk of developing HCC. The difference in HCC rates could be because of other factors such as coinfection, occult HBV infection, family history, HBV genotype, and other comorbidities. Due to the persistent risk of HCC after seroclearance, HCC surveillance is critical for early detection, especially in high-risk patients. However, long-term studies might be needed to further validate the results.

State of the art treatment of hepatitis B virus hepatocellular carcinoma and the role of hepatitis B surface antigen post-liver transplantation and resection

Chronic hepatitis B virus (HBV) infection is the major aetiology of hepatocellular carcinoma (HCC). The optimal goal of therapy, hepatitis B surface antigen (HBsAg) loss and anti-HBs production, is achieved rarely and HBsAg-associated HCC risk is well recognized. Here we review the role of HBsAg in HCC, the link between HBsAg and HCC recurrence post-liver transplantation or resection, and the implications for therapy. HBV-associated carcinogenesis is a multifactorial process. The observation that HBV-related HCC can occur in the absence of cirrhosis is compatible with a direct oncogenic effect of the virus, which may occur via multiple mechanisms, including those mediated by both mutated and unmutated HBsAg. HCC recurrence in HBsAg-positive patients post-liver transplantation has been reported in 10%-15% of patients and is likely to be because of expansion of residual HCC tumour cell populations containing integrated HBV DNA, which expand and independently replicate HBV, leading to the recurrence of both HCC and HBV. The direct role of HBsAg in HCC recurrence post-liver resection is less clear. Cirrhosis is the most important risk factor for HCC development, and precancerous cirrhotic liver remains after resection, with the potential to undergo malignant transformation regardless of the existence of HBV-derived oncogenic drivers. The role of HBsAg in the development of HCC and its recurrence post-surgical intervention has multiple implications for therapy and suggests a potential role for immunotherapy in the future management of HCC, in particular post-liver transplantation. Use of hepatitis B immunoglobulins that target HBsAg directly, alongside immune-oncology therapies, may be relevant in this setting.

48 weeks outcome after cessation of nucleos(t)ide analogue therapy in chronic hepatitis B patients

INTRODUCTION AND OBJECTIVE

The aim of the present study was to investigate the significance of serum HBsAg levels in treatment cessation of nucleoside analogues (NAs) in patients with chronic hepatitis B (CHB) infection.

METHODS

In 158 CHB patients with long-term NAs treatment, 74 patients were in HBeAg negative and had a HBsAg level <1500IU/mL, 36 of whom were informed and consented to cease NAs. HBsAg, HBV DNA and liver function were examined in the 1st, 3rd, 6th, 9th and 12th month after treatment cessation.

RESULTS

The sustained response rate was 88.89% (32/36) within one year after NAs cessation. Sub-group analysis was based on HBsAg levels of patients with NAs cessation, there was no relapse case in 11 patients whose HBsAg <50IU/mL, and the negative predictive value (NPV) was 100%. Seroconversion of HBsAg occurred in 3 patients. 2 patients from 21 cases whose HBsAg was between 50IU/mL and 1000IU/mL relapsed. 2 of 4 patients whose in HBsAg >1000IU/mL relapsed. HBsAg of patients with a sustained response decreased slowly. In contrast, HBsAg levels increased gradually in relapsed patients, and the increase of HBsAg was precedent to relapses of HBV DNA and ALT. Multivariate analysis suggested that only HBsAg level showed a close correlation with HBV DNA relapses. ROC curve analysis suggested that the increase of HBsAg level in the 3rd and 6th month after NAs cessation had a great predictive value for relapses.

CONCLUSION

Monitoring of base line HBsAg level can predict outcomes of NAs cessation in HBeAg-negative chronic hepatitis B. HBsAg <50IU/mL has higher predictive values of better sustained responses in HBeAg-negative CHB patients.

Natural variability in surface antigen and reverse transcriptase domain of hepatitis B virus in treatment-naïve chronic HBV-infected Egyptian patients

Hepatitis B virus (HBV) infection is a serious health problem not only in Egypt, but also worldwide. We collected 57 serum samples from treatment-naïve chronic HBV-infected Egyptians. The DNA segment encoding HBV surface antigen (HBsAg) and reverse transcriptase (RT) domain was partially sequenced. Our data revealed that all viral isolates belonged to genotype D with ayw2 as the predominant serotype (89 %). Regarding HBsAg, 45 substitutions were detected in the collected isolates. Eleven substitutions were found in the major hydrophilic region, including two novel ones (M103T and G130E) that were not correlated before with genotype D. Additionally, 11 occult samples (19 %) were detected, in which the predominant mutations of HBsAg were S143L (7 samples) followed by D144A and T125M (4 samples each). Concerning the RT domain, 26 isolates (45 %) harbored 19 natural mutations that were reported to be associated with antiviral resistance. Eleven different mutations were not correlated previously with genotype D. The most predominant mutation was Y124H (47 samples, 82 %). Interestingly, such mutation was detected in 91 % of the previous reported sequences of HBV isolates collected in Egypt (157 sequences). Furthermore, our study illustrated the presence of viral quasispecies in the HBsAg (10 samples, 17.5 %) and RT domain (9 samples, 15.7 %). In conclusion, we elucidated the presence of natural substitutions in HBsAg and RT domain of HBV isolates obtained from treatment-naïve chronic HBV-infected Egyptian patients. Additionally, we detected viral quasispecies and revealed Y124H as a characteristic substitution in the RT domain for HBV isolates in Egypt. Moreover, novel substitutions in HBsAg and RT domain were reported with genotype D.

A recombinant human immunoglobulin with coherent avidity to hepatitis B virus surface antigens of various viral genotypes and clinical mutants

The hepatitis B virus (HBV) envelope is composed of a lipid bilayer and three glycoproteins, referred to as the large (L), middle (M), and small (S) hepatitis B virus surface antigens (HBsAg). S protein constitutes the major portion of the viral envelope and an even greater proportion of subviral particles (SVP) that circulate in the blood. Recombinant S proteins are currently used as a preventive vaccine, while plasma fractions isolated from vaccinated people, referred to as hepatitis B immune globulin (HBIG), are used for short-term prophylaxis. Here, we characterized a recombinant human IgG1 type anti-S antibody named Lenvervimab regarding its binding property to a variety of cloned S antigens. Immunochemical data showed an overall consistent avidity of the antibody to S antigens of most viral genotypes distributed worldwide. Further, antibody binding was not affected by the mutations in the antigenic ‘a’ determinant found in many clinical variants, including the immune escape mutant G145R. In addition, mutations in the S gene sequence that confer drug resistance to the viral polymerase did not interfere with the antibody binding. These results support for a preventive use of the antibody against HBV infection.

Knowledge and Awareness Regarding Hepatitis B, Hepatitis C, and Human Immunodeficiency Viruses Among College Students: A Report From Iran

Globally, high-risk illnesses including Hepatitis B, Hepatitis C, and human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) are major health problems causing considerable impact on health systems. Knowledge and awareness are very important factors for controlling these illnesses in society. Regarding the transmission routes of these viruses, young people are at the highest risk of infection. Therefore, our objectives were to determine the college students' awareness of hepatitis B virus (HBV), hepatitis C virus (HCV), and HIV/AIDS with regard to basic information, transmission, and prevention. A total of 810 students from 7 universities, from September to March 2017, were included in the study. All participants were categorized into three groups (medical, biology, and other fields). The subjects were evaluated by a standardized questionnaire and results analyzed in SPSS software using the χ² test. In total, 43% of respondents were male and the majority of them were 20 to 25 years old. Our results showed the suitable level of awareness about HBV and remarkable about HIV. In contrast, insufficient level of awareness was indicated about HCV. Given the low levels of awareness or knowledge about HCV, it can be suggested that educational programs for this important disease are necessary especially for university students. On the other hand, high awareness of participants about HBV and HIV/AIDS might be the results of the proper functioning of educational programs for students in Iran.

A chronic hepatitis B patient infected with HBsAg diagnostic-escape strain in the presence of anti-HBs positivity

Hepatitis B virus (HBV) is an important pathogen responsible for serious diseases like chronic hepatitis, cirrhosis and liver cancer. Turkey is located in the intermediate endemic region based on the average HBV surface antigen positivity. The high replication capacity of HBV and the lack of proofreading activity of the reverse transcriptase (RT) enzyme makes the virus prone to mutations. In this study, S gene mutation which is detected in a chronic HBV case without any follow-up and treatment is presented. Although patient was HBsAg negative and anti-HBs positive in the examinations, the mutation analysis was performed upon the high level of HBV DNA load and sG145R (vaccine escape) mutation in S gene region and rtI169F, rtV173L, rtA181G and rtT184R mutations in pol gene region were detected. S gene region mutations may cause false negatives in diagnostic assays that detect HBsAg. At the same time, it is a public health problem because these HBV variants can also be transmitted by vertical and horizontal routes. Therefore, when atypical serological profiles are encountered, it is of utmost importance to remember S gene mutations and perform necessary analyses.