High level of hepatitis B virus DNA after HBeAg-to-anti-HBe seroconversion is related to coexistence of mutations in its precore and basal core promoter

Impact of Hepatitis B Virus Genetic Variation, Integration, and Lymphotropism in Antiviral Treatment and Oncogenesis

Chronic Hepatitis B Virus (HBV) infection poses a significant global health burden. Although, effective treatment and vaccinations against HBV are available, challenges still exist, particularly in the development of curative therapies. The dynamic nature and unique features of HBV such as viral variants, integration of HBV DNA into host chromosomes, and extrahepatic reservoirs are considerations towards understanding the virus biology and developing improved anti-HBV treatments. In this review, we highlight the importance of these viral characteristics in the context of treatment and oncogenesis. Viral genotype and genetic variants can serve as important predictive factors for therapeutic response and outcomes in addition to oncogenic risk. HBV integration, particularly in coding genes, is implicated in the development of hepatocellular carcinoma. Furthermore, we will discuss emerging research that has identified various HBV nucleic acids and infection markers within extrahepatic sites (lymphoid cells). Intriguingly, the presence of hepatocellular carcinoma (HCC)-associated HBV variants and viral integration within the lymphoid cells may contribute towards the development of extrahepatic malignancies. Improved understanding of these HBV characteristics will enhance the development of a cure for chronic HBV infection.

Systematic review and meta-analysis: Development of hepatocellular carcinoma in chronic hepatitis B patients with hepatitis e antigen seroconversion

Hepatitis B e antigen (HBeAg) seroconversion is considered to have significantly favourable clinical outcomes for patients with chronic hepatitis B (CHB). However, inconsistent study results suggest that hepatocellular carcinoma (HCC) still occurs in patients with HBeAg seroconversion. We performed a systematic review and meta-analysis to determine the incidence of HCC in patients with CHB after HBeAg seroconversion. Web of Science, PubMed and Embase databases were searched through January 2017. The incidence of HCC in CHB patients after HBeAg seroconversion was pooled using a random-effects model or fix-effects model. Sixteen studies were finally included, involving 4910 patients with HBeAg seroconversion. The overall pooled proportion suggested that 3.33% (95% confidence interval (CI): 2.28%-4.58%) of patients with CHB develop HCC despite HBeAg seroconversion. In patients with HBeAg seroconversion without cirrhosis, the pooled proportion of HCC development was 0.94% (95% CI: 0.15%-2.4%). Moreover, patients with cirrhosis, active hepatitis, or aged greater than 40 years at the time of HBeAg seroconversion were at significantly higher risk for HCC development. HBeAg seroconversion was significantly associated with a reduced risk of HCC compared with persistently positive HBeAg (RR = 0.58, 95% CI: 0.35-0.97, P = .04). Despite the reduced risk with HBeAg seroconversion, HCC can still occur in a proportion of patients with CHB after HBeAg seroconversion. Long-term monitoring is needed for patients with established cirrhosis, active hepatitis or those older than 40 years at the time of HBeAg seroconversion.

Influence of the basal core promoter and precore mutation on replication of hepatitis B virus and antiviral susceptibility of different genotypes

Mutations in the basal core promoter (BCP) and precore (PC) regions of the hepatitis B virus (HBV) are more common in genotypes B and C than in genotype A, suggesting that these mutations might affect replication competency depending on genotype. The purpose of the study was to investigate the influence of these mutations on the capacity of HBV for replication and antiviral drug susceptibility according to genotype. Genotypes A, B, and C of HBV strains with a BCP mutation, PC mutation, or BCP + PC mutation were made by site-directed mutagenesis. Replication competency of each construct and susceptibility to nucleos(t) ide analogues were tested in an Huh7 cell line. In genotype A, the BCP and BCP + PC mutations increased the viral replication around 6.5 times compared with the wild type, and the PC mutation alone similarly increased the viral replication around three times. In genotypes B and C, all three mutant types increased viral replication to a similar extent, regardless of mutation pattern. Interestingly, the BCP mutation appeared to have a greater effect on viral replication in genotype A than in genotypes B and C. This finding was unexpected because the BCP mutation is more common in HBV genotypes B and C. Moreover, the BCP, PC, and BCP + PC mutations decreased the sensitivity of HBV to antiviral agents to various degrees (2- to 10-fold) regardless of genotype. In conclusion, BCP and PC mutations increased viral replication regardless of HBV genotype and decreased in vitro antiviral susceptibility to the nucleos(t) ide analogues.

Atypical serological profiles in hepatitis B virus infection

During hepatitis B virus (HBV) infection, at least four antigen-antibody systems are observed: HBsAg and anti-HBs; preS antigen and anti-preS antibody; HBcAg and anti-HBc; and HBeAg and anti-HBe. Through the examination of these antigen-antibody systems, hepatitis B infection is diagnosed and the course of the disorder may be observed. Although the serologic findings that allow both the diagnosis of HBV infection as well as assessing of its clinical course are already well established, the dynamics of viral proteins expression and of the antibodies production may vary during the infection natural course. This causes the HBV infection to be occasionally associated with the presence of uncommon serological profiles, which could lead to doubts in the interpretation of results or suspicion of a serological result being incorrect. This paper is dedicated to the discussion of some of these profiles and their significance.

The relationship between core promoter mutation of hepatitis B virus, viral load and hepatitis B e antigen status in chronic hepatitis B patients

The aim of this study is to detect the possible association of hepatitis B virus (HBV) core mutation, hepatitis B e antigen (HBeAg) status and the viral load in chronic hepatitis B (CHB) patients. Sixty-six patients with CHB were enrolled. Hepatitis markers and hepatitis C virus antibody (HCV-Ab) were tested using micro particle enzyme immunoassay kits. Viral load was measured by real-time polymerase chain reaction (PCR) and the mutation was analyzed by nested PCR followed by restriction fragment length polymorphism. Most of CHB patients were HBeAg (-ve). The HBeAg status did not have an influence on the presence or absence of T1762/A1764 mutation. HBV-DNA serum level was not significantly different in patients with core mutation and patients without core mutation in HBeAg (-ve) group, while in HBeAg (+ve) group HBV-DNA serum level was significantly higher in patients with core mutation. This study reports the predominance of HBeAg (-ve) and HBV core promoter mutation.

A336C/A336T/T337C variations in HBV core gene and spontaneous hepatitis B e antigen loss in chronic hepatitis B patients

BACKGROUND

A336C/A336T/T337C variations in HBV core gene were demonstrated to relate to the decreases in serum HBV DNA levels and HBV replication in chronic hepatitis B patients. Usually the drastic decrease in serum HBV DNA levels correlates with spontaneous HBeAg loss during the course of chronic HBV infection. The aim of the present study was to investigate whether there was correlation between A336C/A336T/T337C variations and spontaneous HBeAg loss

METHODOLOGY/PRINCIPAL FINDINGS

A modified PCR-RFLP assay and ELISA were adopted to determine A336C/A336T/T337C variations and serum HBeAg levels in chronic hepatitis B patients without any antiviral therapy, respectively, whereas G1896A variation and HBV genotype were detected using Taqman-PCR assay. RFLP pattern C, E, G, C/G mixture and a new pattern C' were found in this study. A336C/A336T/T337C variations occurred in 40/166(24.1%) chronic hepatitis B patients. Chi-square test showed that C336/T336/C337 variants was more frequent in chronic hepatitis B patients with A1896 variants than those with the wild type G1896 (χ2 = 4.7, P = 0.03), and moreover, patients with C336/T336/C337 variants had a significantly lower HBeAg-positive percentage than those with the wild type A336/T337. Binary logistic regression identified genotype B (OR = 4.1, 95%CI = 1.8-9.2, P = 0.001), the presence of C336/T336/C337 variants (OR = 3.2, 95%CI = 1.2-8.5, P = 0.02) and A1896 variants (OR = 7.8, 95%CI = 3.3-18.5, P < 0.001) as independent factors associated with spontaneous HBeAg loss.

CONCLUSION/SIGNIFICANCE

A336C/A336T/T337C were naturally occurring polymorphisms in HBV core gene, and moreover, the presence of C336/T336/C337 variants was first demonstrated to be an independent factor associating with spontaneous HBeAg loss in chronic hepatitis B patients.

Association of core promoter mutations of hepatitis B virus and viral load is different in HBeAg(+) and HBeAg(-) patients

AIM: To identify the prevalence of hepatitis B e antigen (HBeAg) and to assess the association of hepatitis B virus (HBV) core promoter mutations and viral load in Indonesian patients.

METHODS: Sixty-four patients with chronic hepatitis, 65 with liver cirrhosis and 50 with hepatocellular carcinoma were included in this study. HBeAg and hepatitis B e antibody (HBeAb) tests were performed using enzyme-linked immunosorbent assay and the mutations were analyzed by sequencing. Viral load was measured by real-time polymerase chain reaction.

RESULTS: Of 179 patients, 108 (60.3%) were HBeAg(-) and 86 (79.6%) of these HBeAg(-) patients had been seroconverted. The A1896 mutation was not found in HBeAg(+) patients, however, this mutation was detected in 70.7% of HBeAg(-) patients. This mutation was frequently found when HBeAg was not expressed (87.7%), compared to that found in HBeAg seroconverted patients (65.1%). The A1899 mutation was also more prevalent in HBeAg(-) than in HBeAg(+) patients (P = 0.004). The T1762/A1764 mutation was frequently found in both HBeAg(+) and HBeAg(-) patients, however, the prevalence of this mutation did not significantly differ among the two groups (P = 0.054). In HBeAg(+) patients, the T1762/A1764 mutation was correlated with lower HBV DNA (P < 0.001). The A1899 mutation did not correlate with HBV DNA (P = 0.609). In HBeAg(-) patients, the T1762/A1764 mutation alone was not correlated with HBV DNA (P = 0.095), however, the presence of either the T1762/A1764 or A1896 mutations was associated with increased HBV DNA (P < 0.001).

CONCLUSION: The percentage of HBeAg(-) patients is high in Indonesia, and most of the HBeAg(-) patients had been seroconverted. The A1896 mutation was most likely the major cause of HBeAg loss. The T1762/A1764 mutation alone was associated with lower viral loads in HBeAg(+) patients, but not in HBeAg(-) patients.

Seroprevalence of hepatitis B virus and hepatitis C virus among blood donors in Nyala, South Dar Fur, Sudan

The objective of this study was to determine the seroprevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections and the possible risk factors among blood donors in Nyala, South Dar Fur State of western Sudan, which has never been studied before. A total of 400 male blood donors were tested for the detection of HBsAg and anti-HCV antibodies, (6.25%) were found reactive for HBsAg and (0.65%) were reactive for anti-HCV antibodies. The highest seroprevalence (30.8%) was found in those between 19-24 and 37-42 years for HBsAg, whereas it was (50%) in those between 31-36 years for anti-HCV antibodies. Unprotected sexual activities (20%) was the most apparent predisposing risk factor for both HBV and HCV seroreactors, followed by razor sharing (13.3%), parenteral drug injections (10%), history of migration to Egypt and alcoholism (6.6%) for each, tattooing and surgical procedures (3.3%) for each and (36.6%) were not aware for their condition. Serum alanine aminotansferase (ALT) was elevated in (30.7%) of HBV seroreactors and in (50%) of HCV seroreactors. Serum albumin was reduced in (23.1%) HBV and in (50%) HCV seroreactors. The study concluded that the seroprevalence of HBV and HCV was in an intermediate and low rates respectively and unprotected sexual activities was the major risk factor for infection in the population studied.

Seroprevalence of hepatitis B virus and hepatitis C virus among blood donors in Nyala, South Dar Fur, Sudan

The objective of this study was to determine the seroprevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections and the possible risk factors among blood donors in Nyala, South Dar Fur State of western Sudan, which has never been studied before. A total of 400 male blood donors were tested for the detection of HBsAg and anti-HCV antibodies, (6.25%) were found reactive for HBsAg and (0.65%) were reactive for anti-HCV antibodies. The highest seroprevalence (30.8%) was found in those between 19-24 and 37-42 years for HBsAg, whereas it was (50%) in those between 31-36 years for anti-HCV antibodies. Unprotected sexual activities (20%) was the most apparent predisposing risk factor for both HBV and HCV seroreactors, followed by razor sharing (13.3%), parenteral drug injections (10%), history of migration to Egypt and alcoholism (6.6%) for each, tattooing and surgical procedures (3.3%) for each and (36.6%) were not aware for their condition. Serum alanine aminotansferase (ALT) was elevated in (30.7%) of HBV seroreactors and in (50%) of HCV seroreactors. Serum albumin was reduced in (23.1%) HBV and in (50%) HCV seroreactors. The study concluded that the seroprevalence of HBV and HCV was in an intermediate and low rates respectively and unprotected sexual activities was the major risk factor for infection in the population studied.

Correlation between hepatitis B virus DNA levels and HBeAg quantity in patients under 20 years old with chronic hepatitis B virus infection

AIM: To investigate the relationshipt between hepatitis B virus (HBV) DNA contents and HBeAg quantity in HBV-infected patients under 20 years old.

METHODS: The serum HBV DNA contents and HBeAg quantity in 339 patients (age 1-20) with chronic HBV infection were examined by real time fluorescence quantitative polymerase chain reaction (FQ-PCR) and time-resolved fluoroimmunoassay (TRFIA) respectively, and the level of anine aminotransferase (ALT) was detected by rate method.

RESULTS: The patients with HBV DNA contents more than 10⁵ copies/mL, HBeAg quantity more than 0.3 NCU/mL, and normal ALT level accounted for 92.3% of the total cases. Positive correlation (r = 0.769, P < 0.001) and linear regression (b = 0.32, R² = 0.59, P < 0.001) existed between HBV DNA contents (on a log scale) and HBeAg quantity in the patients under 20 years old.

CONCLUSION: Serum HBV DNA contents and HBeAg quantity are changed simultaneously in HBV-infected patients under 20 years old, except in quite a few cases, so combined examination of HBV DNA and HBeAg may help to evaluate the state of chronic HBV infection more exactly.

Low HBV-DNA levels in end-stage renal disease patients with HBeAg-negative chronic hepatitis B

In end-stage renal disease patients treated by hemodialysis with HBeAg-negative chronic hepatitis B virus (HBV) infection, the evaluation of the presence of viral replication is essential in the assessment for renal transplantation. Data on HBV viral load, prevalence of precore mutations, as well as the influence of HCV coinfection on HBV-DNA levels in this group of patients is scarce. The aim of this study was to determine the HBV viral load in HBsAg-positive/HBeAg-negative hemodialysis patients; to compare HBV-DNA levels between isolated HBV infection carriers and HBV-HCV coinfected patients, and to evaluate the prevalence of precore mutations in these patients. Fifty hemodialysis patients with chronic HBeAg-negative HBV infection were studied. Viral load was determined by PCR (Amplicor HBV Monitor-Roche). The detection of precore mutations was made by sequencing. Of a total of 50 patients, 76% were male, with a mean age of 44 +/- 11 years. Anti-HCV was positive in 56% of patients. HBV-DNA was undetectable in 58% of patients; 24% had HBV-DNA <10,000 copies/ml, 12% between 10,000-100,000 copies/ml, and only 6% had HBV-DNA >100,000 copies/ml. There was no difference in the viral load of patients infected only by HBV and HBV-HCV co-infected patients (P = 0.96). Precore mutations were detected in only 8% of cases. In conclusion, hemodialysis patients with HBeAg-negative HBV infection had a low viral load. Precore mutations were infrequent and the presence of anti-HCV has not influenced the levels of HBV-DNA.