The clinical outcome of hepatitis B virus (HBV) infection is variable, ranging from spontaneous recovery to an inactive carrier state, chronic hepatitis, occult HBV infection, liver cirrhosis, or hepatocellular carcinoma.
This variable pattern and clinical outcomes of the infection were mainly determined by virological and host genetic factors. Since the most of host genetic factors associated with HBV infection have currently focused on human leukocyte antigen (HLA) associations and interleukin (IL)-10 gene polymorphisms, this review focuses on the recent progresses in these issues to provide prognostic markers for the outcome of HBV infection.
A study on serum levels of IL-10 in occult HBV infected patients reported that the higher level of IL-10 production may suppress function of the immune system against HBV in patients with occult HBV infection. IL-10 promoter polymorphism at position -592 is associated with susceptibility to occult HBV infection.
Findings of this study suggest that the host HLA polymorphism is an important factor in determining outcome of HBV infection but regarding IL-10 gene promoter polymorphisms, we are still have a long way to achieve a deﬁnite conclusion.
Hepatitis B Virus; Interleukin (IL)-10 gene; HLA Antigens
Variants near the HLA-DP gene show the strongest genome-wide association with chronic hepatitis B virus (HBV) infection and HBV recovery/persistence in Asians. To test the effect of the HLA-DP region on outcomes to HBV infection, we sequenced the polymorphic HLA-DPB1 and DPA1 coding exons and the corresponding 3′ untranslated regions (3′UTRs) in 662 individuals of European-American and African-American ancestry. The genome-wide association study (GWAS) variant (rs9277535; 550A/G) in the 3′UTR of the HLA-DPB1 gene that associated most significantly with chronic hepatitis B and outcomes to HBV infection in Asians had a marginal effect on HBV recovery in our European- and African-American samples (odds ratio [OR] = 0.39, P = 0.01, combined ethnic groups). However, we identified a novel variant in the HLA-DPB1 3′UTR region, 496A/G (rs9277534), which associated very significantly with HBV recovery in both European and African-American populations (OR = 0.37, P = 0.0001, combined ethnic groups). The 496A/G variant distinguishes the most protective HLA-DPB1 allele (DPB1*04:01) from the most susceptible (DPB1*01:01), whereas 550A/G does not. 496A/G has a stronger effect than any individual HLA-DPB1 or DPA1 allele and any other HLA alleles that showed an association with HBV recovery in our European-American cohort. The 496GG genotype, which confers recessive susceptibility to HBV persistence, also associates in a recessive manner with significantly higher levels of HLA-DP surface protein and transcript level expression in healthy donors, suggesting that differences in expression of HLA-DP may increase the risk of persistent HBV infection.
A recent genome-wide study showed that the single nucleotide polymorphisms (SNPs) in the HLA-DP region were associated with chronic hepatitis B virus (HBV) infection in Japanese and Thai persons. We tested the effects of HLA-DP SNPs for all major HBV outcomes in Han Chinese (n = 1742): HBV resistance, clearance, chronic infection, cirrhosis, and hepatocellular carcinoma. HLA - DPA1 rs3077 T was strongly associated with decreased risk of chronic HBV infection (odds ratio, .62; P = .001), consistent with the previous report. We showed for the first time to our knowledge that it is a predictor for HBV clearance (odds ratio, 2.41; P < .001). However, rs3077 was not associated with the development of cirrhosis or hepatocellular carcinoma.
Although safe and effective vaccines for hepatitis B virus (HBV) have been available for nearly three decades, this virus kills at least 600,000 people annually worldwide and remains the leading global cause of chronic hepatitis, cirrhosis, and hepatocellular carcinoma. Because the HBV reverse transcriptase lacks a proofreading function, many HBV genotypes, subgenotypes, mutants, and recombinants exist. At least 10 HBV genotypes (HBV-A through J) with distinct geographic distributions have been identified; by definition, their complete genomic sequences diverge by more than 8%. HBV genotype is increasingly becoming recognized as an important factor in the progression and clinical outcome of HBV-induced disease. Infections by HBV-C or -D are significantly more likely to lead to cirrhosis and hepatocellular carcinoma than are infections by HBV-A or -B. Additionally, the hepatitis B e antigen seroconversion response to standard or pegylated interferon is more favorable in patients with HBV-A or -B than in those with HBV-C or -D. However, therapeutic responses to nucleos(t)ide analogues are generally comparable among HBV genotypes. In conclusion, genotyping of HBV is useful in identifying chronic hepatitis B patients who are at increased risk of disease progression, thereby enabling physicians to optimize antiviral therapy for these patients.
Antiviral agents; Genotype; Hepatitis B virus; Hepatocellular carcinoma; Molecular epidemiology
Hepatitis B virus (HBV) infection is a global health problem that causes a wide spectrum of liver disease, including acute or fulminant hepatitis, inactive carrier state, chronic hepatitis, cirrhosis, and hepatocellular carcinoma (HCC). The pathogenesis of hepatocyte damage associated with HBV is mainly through immune-mediated mechanisms. On the basis of the virus and host interactions, the natural history of HBV carriers who are infected in early life can be divided into four dynamic phases. The frequency, extent, and severity of hepatitis flares or acute exacerbation in the second immune clearance and/or fourth reactivation phase predict liver disease progression in HBV carriers. In the past decade, hepatitis B viral factors including serum HBV DNA level, genotype, and naturally occurring mutants predictive of clinical outcomes have been identified. The higher the serum HBV DNA level after the immune clearance phase, the higher the incidence of adverse outcomes over time. In addition, high viral load, genotype C, basal core promoter mutation, and pre-S deletion correlate with increased risk of cirrhosis and HCC development. As to the treatment of chronic hepatitis B, patients with high HBV DNA level and genotype C or D infection are shown to have a worse response to interferon therapy. In conclusion, serum HBV DNA level, genotype, and naturally occurring mutants are identified to influence liver disease progression and therapy of chronic hepatitis B. More investigations are needed to clarify the molecular mechanisms of the viral factors involved in the pathogenesis of each stage of liver disease and the response to antiviral treatments.
Chronic hepatitis B; HBV DNA; Genotype; Mutant; HBeAg seroconversion; Hepatocellular carcinoma; Therapy
Hepatitis B virus (HBV) infects more than 300 million people worldwide and is a common cause of liver disease and liver cancer. HBV, a member of the Hepadnaviridae family, is a small DNA virus with unusual features similar to retroviruses. HBV replicates through an RNA intermediate and can integrate into the host genome. The unique features of the HBV replication cycle confer a distinct ability of the virus to persist in infected cells. Virological and serological assays have been developed for diagnosis of various forms of HBV-associated disease and for treatment of chronic hepatitis B infection. HBV infection leads to a wide spectrum of liver disease ranging from acute (including fulminant hepatic failure) to chronic hepatitis, cirrhosis, and hepatocellular carcinoma. Acute HBV infection can be either asymptomatic or present with symptomatic acute hepatitis. Most adults infected with the virus recover, but 5%–10% are unable to clear the virus and become chronically infected. Many chronically infected persons have mild liver disease with little or no long-term morbidity or mortality. Other individuals with chronic HBV infection develop active disease, which can progress to cirrhosis and liver cancer. These patients require careful monitoring and warrant therapeutic intervention. Extrahepatic manifestations of HBV infection are rare but can be difficult to diagnose and manage. The challenges in the area of HBV-associated disease are the lack of knowledge in predicting outcome and progression of HBV infection and an unmet need to understand the molecular, cellular, immunological, and genetic basis of various disease manifestations associated with HBV infection.
Hepatitis B virus (HBV) is a common viral pathogen that causes a substantial health burden worldwide. Remarkable progress has been made in our understanding of the natural stages of chronic HBV infection. A dynamic balance between viral replication and host immune response is pivotal to the pathogenesis of liver disease. Knowledge of the HBV genome organization and replication cycle can unravel HBV genotypes and molecular variants, which contribute to the heterogeneity in outcome of chronic HBV infection. Most HBV infections are spontaneously resolved in immunocompetent adults, whereas they become chronic in most neonates and infants at a great risk of developing complications such as cirrhosis and hepatocellular carcinoma (HCC). Those with chronic HBV infection may present in one of the four phases of infection: immune tolerance, immune clearance [hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB)], inactive carrier state, and reactivation (HBeAg-negative CHB). Understanding the dynamic nature of chronic HBV infection is crucial in the management of HBV carriers. Long-term monitoring and optimal timing of antiviral therapy for chronic HBV infection help to prevent progression of HBV-related liver disease to its later stage, particularly in patients with higher risk markers of HCC, such as serum DNA concentration, HBeAg status, serum aminotransferase, HBV genotypes, and pre-core or core mutants.
Hepatitis B virus; Pathology; Immune tolerance; Immune clearance; Inactive hepatitis B surface antigen carriers; Reactivation; T-cell response; Cytokines
Epidemiological studies have clearly validated the association between hepatitis B virus (HBV) infection and hepatocellular carcinoma (HCC). Patients with chronic HBV infection are at increased risk of HCC, in particular those with active liver disease and cirrhosis.
We catalogued all published interactions between HBV and human proteins, identifying 250 descriptions of HBV and human protein interactions and 146 unique human proteins that interact with HBV proteins by text mining.
Integration of this data set into a reconstructed human interactome showed that cellular proteins interacting with HBV are made up of core proteins that are interconnected with many pathways. A global analysis based on functional annotation highlighted the enrichment of cellular pathways targeted by HBV.
By connecting the cellular proteins targeted by HBV, we have constructed a central network of proteins associated with hepatocellular carcinoma, which might be to regard as the basis of a detailed map for tracking new cellular interactions, and guiding future investigations.
Hepatitis B virus (HBV), a small and economically packaged double-stranded DNA virus, represents an enormous global health care burden. In spite of an effective vaccine, HBV is endemic in many countries. Chronic hepatitis B (CHB) results in the development of significant clinical outcomes such as liver disease and hepatocellular carcinoma (HCC), which are associated with high mortality rates. HBV is a non-cytopathic virus, with the host's immune response responsible for the associated liver damage. Indeed, HBV appears to be a master of manipulating and modulating the immune response to achieve persistent and chronic infection. The HBV precore protein or hepatitis B e antigen (HBeAg) is a key viral protein involved in these processes, for instance though the down-regulation of the innate immune response. The development of new therapies that target viral proteins, such as HBeAg, which regulates of the immune system, may offer a new wave of potential therapeutics to circumvent progression to CHB and liver disease.
Hepatitis B e antigen; precore protein; chronic hepatitis B; intrabody
Forty years ago in 1967, Professor Blumberg discovered the Australian Antigen, later known as the hepatitis B surface antigen, and was awarded the Nobel Prize. This discovery enables the diagnosis of hepatitis B virus (HBV) infection and defines its epidemiology. Viral hepatitis B infection affects global health situation, and chronic hepatitis B (CHB) is particularly serious in the Asia-Pacific region. HBV vaccines created the first breakthrough in HBV prevention. Through universal HBV vaccination program for the newborns, promoted since the mid-1980s, the main route that perpetuates chronic infection from mother to child is curbed. Most children and young adults now have immunity against HBV infection. The next breakthrough comes with therapy for CHB. This prevents progression to cirrhosis and hepatocellular carcinoma. Standard interferon therapy with modest efficacy has been largely replaced by therapy with nuclos(t)ide analogues or pegylated interferons alfa-2a and -2b. Lamivudine was approved by the FDA USA in 1998, followed by adefovir dipivoxil in 2002, entecavir in 2005, and telbivudine in 2006. Clevudine, tenofovir, and many promising candidates are in different stages of development and clinical trial. This paper critically reviews recent data published or presented since the APASL Consensus and Guideline Update of 2005. Clinical efficacy mostly in patients with raised serum alanine aminotransferase will be analyzed.
Chronic hepatitis B; Therapy; Nucleos(t)ide analogues
Despite the existence of Hepatitis B vaccination, hepatitis B virus (HBV) infection is still prevalent worldwide and accounts for significant morbidity and mortality. It is encouraging that majority of patients do recover from the acute infection, however, those that progress to chronic disease state is at great risk of developing complications such as hepatocellular carcinoma, cirrhosis and liver failure. Hepatitis B virus infection can be influenced by many factors such as host immune status, age at infection, and level of viral replication. The discovery about the existence of various genotypes and its association with different geographic distribution as well as the knowledge regarding mutant species has aid us in better understanding the nature of HBV infection and in delivering better care for patients. It is especially important to recognize those individuals with HBeAg-negative chronic HBV as they have a poorer prognosis compare with their counterparts, HBeAg-positive. Tremendous progress has been made over the years in understanding the behavior and clinical course of the disease; however, the natural history of HBV is complex and we still have much to explore and learn.
Hepatitis B; natural history; cirrhosis; hepatocellular carcinoma
Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections constitute a major global health problem. About 60,000 and 350,000 deaths occur as the results of HBV and HCV infections, respectively. Chronic hepatitis B and C infections are leading causes of cirrhosis and hepatocellular carcinoma (HCC) which are considered as the third cancer-associated cause of deaths worldwide. Iran suffers from the same problem but to a lesser extent as it is considered as a low endemic area for HBV and HCV infections and also as a low incidence area of HCC. This study was conducted to assess and provide a clear picture about epidemiology of HBV and HCV infections in Iran and worldwide, with the consequence on HCC distribution all over the world including Iran, and to analyze current literature regarding the modes of transmission and risk factors of HBV and HCV infections.
In this review, we performed electronic and manual searches on available databases such as MEDLINE, PubMed, Ovid, Embase, and the Iranian databases such as IranMedex. We also performed a Google search to find related articles.
HBV and HCV infections are the most common risk factors of hepatocellular carcinoma. The epidemiology of HCC usually follows that of HBV and HCV infections. With the introduction of HBV national vaccine in Iran and worldwide, there is a noticeable effect on reduction in HBV prevalence in most countries, and we expect that HCV will replace HBV as a major risk factor of HCC in Iran and worldwide. Alcohol plays a minor role as a risk factor for cirrhosis and HCC in Iran, Asia, and Africa, despite its noticeable role in Europe and the USA.
Vaccination against HBV remains the most effective approach against HBV infection with consequence decrease in HBV-related HCC. There is a need to improve the awareness about epidemiology of HBV and HCV infections, modes of transmission, and their complications, specifically HCC among population.
Hepatitis B Virus; Hepatitis C; Iran
Hepatitis B virus (HBV) infection is a serious clinical problem affecting approximately 2 billion people worldwide. An estimated 350 million live with chronic hepatitis B (CHB) infection and are at an increased risk for serious liver sequelae and death from acute or chronic consequences of CHB infection. Individuals with CHB have a 20–30% risk of early death from complications, including liver cirrhosis and hepatocellular carcinoma. In the Asia-Pacific region, half of the CHB burden results from vertical or mother-to-child transmission, with early childhood horizontal transmission accounting for the remaining half. Screening and vaccination are key factors in the successful prevention and control of HBV infection. Over the last 20 years, the implementation of screening programs and universal HBV vaccination for all individuals born in endemic areas have reduced the prevalence of HBV infection and HBV-related liver diseases among individuals younger than 30 years. Women of childbearing age are key stakeholders in preventing HBV infection and, as such, play a critical role in reducing the vertical and horizontal transmission of HBV. Further efforts are needed to implement screening and educational programs for women of childbearing age, particularly those with CHB, to prevent the transmission of HBV to newborns, spouses, other household members, and sexual partners. In addition, healthcare workers need to learn how to avoid iatrogenic transmission in the healthcare setting. This article reviews these issues and highlights areas in which their engagement with public health efforts serves to improve quality of life and society as a whole.
Chronic hepatitis B; Women of childbearing age; Hepatitis B virus; Pregnancy
Worldwide, an estimated 350 million people are chronically infected with the Hepatitis B Virus (HBV); chronic infection with HBV is associated with the development of severe liver diseases including hepatitis and cirrhosis. Individuals who are chronically infected with HBV also have a significantly higher risk of developing hepatocellular carcinoma (HCC) than uninfected individuals. The HBV X protein (HBx) is a key regulatory HBV protein that is important for HBV replication, and likely plays a cofactor role in the development of HCC in chronically HBV-infected individuals. Although some of the functions of HBx that may contribute to the development of HCC have been characterized, many HBx activities, and their putative roles during the development of HBV-associated HCC, remain incompletely understood. HBx is a multifunctional protein that localizes to the cytoplasm, nucleus, and mitochondria of HBV‑infected hepatocytes. HBx regulates numerous cellular signal transduction pathways and transcription factors as well as cell cycle progression and apoptosis. In this review, we will summarize reports in which the impact of HBx expression on cellular apoptotic pathways has been analyzed. Although various effects of HBx on apoptotic pathways have been observed in different model systems, studies of HBx activities in biologically relevant hepatocyte systems have begun to clarify apoptotic effects of HBx and suggest mechanisms that could link HBx modulation of apoptotic pathways to the development of HBV-associated HCC.
hepatitis B virus; HBx protein; hepatocellular carcinoma; apoptosis
Chronic infection with hepatitis B virus (HBV) is associated with a high lifetime risk of developing hepatocellular carcinoma (HCC) and cirrhosis of the liver.
To review the studies published to date regarding the association of HBV genotypes and subgenotypes in the development of adverse sequelae from HBV.
Review of the literature for articles describing studies of HBV genotype/subgenotypes and development of HCC, cirrhosis, and liver-related death.
Eight genotypes of HBV (A through H), which differ from each other in viral genome sequence by more than 8%, and multiple subgenotypes, which differ from each other by 4–8% have been identified. Recently, studies investigating the association between the risks of developing HCC and cirrhosis by specific HBV genotypes and subgenotypes have reported marked differences in outcome. Certain HBV genotypes and subgenotypes, including genotype C, B2-5, and F1, appear to be associated with a higher risk of developing HCC, and others, including genotypes B1, B6, and A2, appear to be associated with a lower risk of complications of HBV. Our understanding of the role of HBV genotypes and subgenotypes on the outcome of HBV infection is limited, as few population-based prospective studies have been performed and most studies compare only the outcome in areas where two genotypes predominate whereas others have not examined subgenotypes.
Studies to date suggest that HBV genotypes/subgenotypes have important influences on the outcome of chronic HBV infection, but more population-based prospective studies examining multiple genotypes are needed.
Hepatitis B virus genotypes; Clinical outcome
The glutathione S-transferase (GST) supergene family is made up of four gene families responsible for the biotransformation of drugs and other xenobiotics. Genetic variations in this supergene family influence individual detoxification levels and may contribute to the development of cancer. A hospital-based case-control study was conducted to evaluate the association between GST polymorphism among Filipino patients positive for hepatitis B virus (HBV DNA) and clinically diagnosed as either with chronic active hepatitis, liver cirrhosis, and hepatocellular carcinoma as well as normal individuals negative for HBV infection. Multiplex PCR was used to detect the presence or absence of the GSTT1 and GSTM1 polymorphisms in peripheral blood. DNA sequencing of the S gene region of the virus was used to determine the predominant genotype found among HBV-infected patients. Our results showed that the odds of having a chronic liver disease is only 0.95 (95% CI 0.58-1.57) among those with GSTT1 null genotype compared to those with GSTT1+ genotype. On the other hand, the odds of chronic liver disease is 17.85 times (95% CI 7.34-43.45) for those with GSTM1 null genotype compared to those with GSTM1+ genotype. Using the GSTT1+/GSTM1+ genotype as the reference, both GSTT1+/GSTM1- (OR 16.61; 95% CI 6.69-41.22) and GSTT1-/GSTM1- (OR 11.91; 95% CI 4.48-31.66) genotypes seem to be risk factors for chronic liver disease. From our observations, we conclude that polymorphism in GSTM1 null genotype (OR 17.85; 95% CI 7.34-43.45) seem to be associated with an increased risk of chronic liver disease among Filipinos.
GSTT1; GSTM1; chronic liver disease; hepatitis B virus; polymorphism; Filipino
Recovery from hepatitis B virus (HBV) infection depends on the cellular immune responses. Chemokines and their receptors play significant roles in immune defense. This study was undertaken to investigate the association between HBV infection and single nucleotide polymorphisms (SNPs) of genes for the chemokines and their receptors. Between March 2002 and February 2004, a total of 957 single ethnic Korean patients were enrolled into two different groups; "HBV clearance group" (n=350), who have recovered from HBV infection, and "HBV persistence group" (n=607), who were repeatedly HBsAg-positive. The HBV persistence group was subdivided into "inactive carrier" and "HBV progression group (chronic hepatitis and cirrhosis)". We assessed polymorphisms in regulated and normal T-cell expressed and secreted (RANTES) at position -403, monocyte chemoattractant protein-1 (MCP-1) at position -2518, CCR2 V64I, CCR5 -2459, CXCR1 S276T and CXCR4 I138I using single primer extension assay. Genotype distributions of the "HBV clearance versus persistence group" and "inactive carrier versus HBV progression group" were compared. On the basis of unconditional logistic regression analysis with adjustment for age and sex, no statistically significant association with susceptibility to persistent HBV infection was observed with RANTES -403, MCP-1 -2518, CCR2 V64I, CCR5 -2459, CXCR1 S276T, and CXCR4 I138I polymorphisms. In addition, no association of analyzed SNPs with HBV disease progression was found.
Hepatitis B; Single Nucleotide Polymorphism (SNP); Chemokines; Chemokine Receptors
Summary: Chronic hepatitis B virus (HBV) infection is a complex clinical entity frequently associated with cirrhosis and hepatocellular carcinoma (HCC). The persistence of HBV genomes in the absence of detectable surface antigenemia is termed occult HBV infection. Mutations in the surface gene rendering HBsAg undetectable by commercial assays and inhibition of HBV by suppression of viral replication and viral proteins represent two fundamentally different mechanisms that lead to occult HBV infections. The molecular mechanisms underlying occult HBV infections, including recently identified mechanisms associated with the suppression of HBV replication and inhibition of HBV proteins, are reviewed in detail. The availability of highly sensitive molecular methods has led to increased detection of occult HBV infections in various clinical settings. The clinical relevance of occult HBV infection and the utility of appropriate diagnostic methods to detect occult HBV infection are discussed. The need for specific guidelines on the diagnosis and management of occult HBV infection is being increasingly recognized; the aspects of mechanistic studies that warrant further investigation are discussed in the final section.
Hepatitis B virus (HBV) is one of leading causes of various hepatic diseases including acute and chronic hepatitis, cirrhosis, and hepatocellular carcinoma. Hundreds of million people worldwide are infected by HBV, chronically.
This study in conducted to investigate the inﬂuence of Hepatitis B virus (HBV) genotypes and type I IFN-αreceptor β subunit (IFNAR2) expression in liver on response to treatment with pegylated IFN-α-2a (Peg-IFN-α-2a) for chronic hepatitis B infection.
Patients and Methods
In this study, 65 eligible patients with chronic hepatitis B disease were enrolled. HBV genotypes of these patients were analyzed by using PCR-RFLP of the surface gene of HBV. The expression of IFNAR2 in the liver was immune histochemically investigated using anti-IFNAR2 antibody. All immune histochemical slides were read semi-quantitatively by image analysis. Chronic hepatitis B patients were treated with Peg-IFN-α2a therapy for a 48-week period and followed up for 24 weeks. Baseline characteristics and sustained viral response (SVR) to Peg-IFN-α-2a therapy were evaluated.
55 % of patients exhibited HBV genotype B and 31.7 % patients exhibited HBV genotypes C infections. After treatment with Peg-IFN-α-2a, SVR was achieved in 66.7 % of patients with HBV genotype B and in 26.3 % of patients with HBV genotype C (P = 0.009). Semiquantitative and the image analysis indicated by gray level values revealed a higher IFNAR2 expression in the group with severe inﬂammation (P < 0.001). Patients’ high IFNAR2 protein expression had a signiﬁcant impact on SVR to Peg-IFN-α-2a therapy (P = 0.028).
HBV genotype B and high expression of IFNAR2 in the liver of chronic hepatitis B patients are closely associated with better response to Peg-IFN-α-2a therapy in chronic hepatitis B disease.
Hepatitis B, Chronic; IFNAR2 Protein, Human; Peginterferon alfa-2a
Hepatitis B vaccination strategies may vary from country to country depending on hepatitis B virus (HBV) endemicity, predominant modes of infection, age of infection, and health care resources. In areas with high endemicity like Korea, transmission of virus from carrier mothers to infants during the perinatal period, and from other horizontal sources to infants and children, account for most cases of HBV infection. The consequences of HBV infection at an early age are serious, as more than 70% remain chronic carriers of the virus. These chronic carriers are the principal source of infection for other susceptible people, and are themselves at high risk of developing other serious diseases, such as chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. Theoretically, therefore, routine infant immunisation supplemented with prenatal screening of pregnant women for HBsAg or HBeAg and mass immunisation of children is the appropriate strategy for control of hepatitis B in these countries. To prevent primary liver cancer associated with HBV infection, however, immunisation of adults at high risk would also be prudent. Mandatory vaccination of all neonates is recommended in highly endemic areas, together with hepatitis B immune globulin in babies born to HBsAg carrier mothers.
The reasons for the viral persistence of hepatitis B virus (HBV) infection are unknown, but are probably related to host immune factors. Several matrix metalloproteinases (MMPs) can regulate an inflammatory response. The aim of this study was to assess the effects of the single nucleotide polymorphisms (SNPs) of MMP-3 and -9 genes on the susceptibility to persistent HBV infection. We studied 489 Korean patients with HBV infection (144 inactive carriers, 182 chronic hepatitis, and 163 liver cirrhosis) and 174 healthy individuals who had recovered from HBV infection. MMP-3 gene SNPs were identified at two polymorphic sites (codon 45 [E45K] and codon 96 [D96D]) and MMP-9 gene SNPs at three polymorphic sites (codon 279 [R279Q], codon 607 [G607G], and codon 668 [Q668R]) in study subjects. The frequency of T allele at third position of codon 96 in the MMP-3 gene was higher in HBV persistence patients when analyzed by co-dominant model (age- and sex-adjusted OR=1.242, 95% CI=1.001-1.540, p=0.049). In conclusion the T allele at the third position of codon 96 in the MMP-3 gene might be associated with persistent HBV infection.
Hepatitis B; Matrix Metalloproteinase; Polymorphism; Single Nucleotide
Hepatitis B virus (HBV) infection may cause acute, fulminant, or chronic hepatitis, leading to liver cirrhosis or hepatocellular carcinoma. Despite the availability of effective vaccine, HBV infection during infancy or early childhood is common in areas of high endemicity. In these regions, mother-to-infant transmission accounts for approximately 50% of chronic infections. Although the natural history of HBV infection in adults is well characterized, little information is available in the literature regarding the natural history of HBV infection in children. Similar to infection in adults, chronic HBV infection in children can be divided into distinct phases: immune tolerant, immune clearance, and inactive carrier state. However, acute exacerbation, with reactivation of HBV replication and re-elevation of alanine aminotransferase levels after hepatitis B e antigen seroconversion, is relatively rare in children, in comparison to adults. Although several potent antiviral agents are now available for the treatment of chronic hepatitis B, experience with these agents in the pediatric setting is limited. To date, conventional interferon α and lamivudine are the only two antiviral agents approved to treat chronic hepatitis B in children. The rapid emergence of resistant HBV associated with long-term lamivudine therapy, as well as poor tolerability associated with conventional interferon α, are factors that should be considered before initiating antiviral therapy. This article reviews current knowledge regarding the natural history and treatment of chronic hepatitis B in children. Factors that affect the natural history of HBV infection in children are also reviewed.
Hepatitis B virus; Chronic hepatitis B; Hepatitis B e antigen; Children; Adolescents
MHC class I polypeptide-related chain A (MICA) molecule is induced in response to viral infection and various types of stress. We recently reported that a single nucleotide polymorphism (SNP) rs2596542 located in the MICA promoter region was significantly associated with the risk for hepatitis C virus (HCV)-induced hepatocellular carcinoma (HCC) and also with serum levels of soluble MICA (sMICA). In this study, we focused on the possible involvement of MICA in liver carcinogenesis related to hepatitis B virus (HBV) infection and examined correlation between the MICA polymorphism and the serum sMICA levels in HBV-induced HCC patients. The genetic association analysis revealed a nominal association with an SNP rs2596542; a G allele was considered to increase the risk of HBV-induced HCC (P = 0.029 with odds ratio of 1.19). We also found a significant elevation of sMICA in HBV-induced HCC cases. Moreover, a G allele of SNP rs2596542 was significantly associated with increased sMICA levels (P = 0.009). Interestingly, HCC patients with the high serum level of sMICA (>5 pg/ml) exhibited poorer prognosis than those with the low serum level of sMICA (≤5 pg/ml) (P = 0.008). Thus, our results highlight the importance of MICA genetic variations and the significance of sMICA as a predictive biomarker for HBV-induced HCC.
Our previous study indicated that a common variant (rs430397 G>A) in the intron 5 of glucose-regulated protein 78 (GRP78) gene was associated with risk and prognosis of primary hepatocellular carcinoma (HCC), including HBV- and cirrhosis-related HCC. rs430397 polymorphism may be a contributing factor or biomarker of HBV infection or HBV-related cirrhosis.
539 non-HBV-infected individuals, 205 self-limited infection and 496 persistent HBV infection were recruited between January 2001 and April 2005 from the hospitals in Southern China. Genomic DNA was genotyped for rs430397. The associations between the variation and susceptibility to liver cirrhosis (LC) in persistent HBV infection were examined. We observed that individuals carrying allele rs430397A were more likely to become HBV-related LC. When persistently infected patients were divided into four subgroups, patients with phase IV had an increased allele A and genotype AG compared with phase I and/or phase III. Decreased serum albumin and prolonged plasma prothrombin time (PT) were showed in LC patients carrying genotype AA. Furthermore, rs430397 genotype had an increased susceptibility to LC with dose-dependent manners (P-trend = 0.005), and the genotype did constitute a risk factor for the development of advanced LC (Child–Pugh classification C and B, P-trend = 0.021).
rs430397 polymorphism may be a contributing factor to LC in persistent HBV carriers.
Hepatitis B virus (HBV) chronically infects approximately 250,000 Canadians and 350 million people worldwide. Without intervention, approximately 15% to 40% of chronically infected individuals will eventually develop cirrhosis, end-stage liver disease or hepatocellular carcinoma, or require liver transplantation. The availability and extensive use of the HBV vaccine has dramatically reduced the number of incident infections in Canada and worldwide. Effective therapeutic agents have been and continue to be developed to treat chronic infection. The present review provides a comprehensive overview of diagnostic tests for HBV infection and immunity, and elaborates on HBV risk factors, vaccine prevention and therapeutic monitoring. HBV diagnosis is accomplished by testing for a series of serological markers of HBV and by additional testing to exclude alternative etiological agents such as hepatitis A and C viruses. Serological tests are used to distinguish acute, self-limited infections from chronic HBV infections and to monitor vaccine-induced immunity. Nucleic acid testing for HBV-DNA is increasingly being used to quantify HBV viral load and measure the effectiveness of therapeutic agents. Given the multitude of available tests and the complexity of clinical management, there is a critical need for greater coordination among clinicians, diagnostic laboratory personnel and researchers to define optimal laboratory diagnostic and monitoring assays so that the appropriate tests are used to maximize prevention and optimize treatment outcomes.
Diagnosis; Hepatitis B virus; Monitoring; Prevention; Treatment