Prospects for hepatitis B virus eradication and control of hepatocellular carcinoma

Hepatitis B virus infection is the most common cause of chronic hepatitis, liver cirrhosis and hepatocellular carcinoma worldwide. In areas hyperendemic for HBV infection, the related complications occur mostly during adulthood. However, nearly half of all primary infection in chronic carriers occurs in the perinatal period through maternal transmission, the other half arising from horizontal transmission mainly through intrafamilial spread or injection using unsterilized needles. A universal vaccination programme is better than immunization for at-risk groups. Hepatitis B vaccination should be integrated into the Expanded Programme on Immunization in children. Universal immunization against hepatitis B virus has proved to be effective in reducing the hepatitis B carrier rate to one-tenth of the prevalence before the vaccination programme in highly endemic areas, and the incidence of hepatocellular carcinoma in children has also been shown to be significantly reduced. Continued efforts to implement universal vaccination programmes worldwide will very likely reduce the incidence of hepatitis B virus-related diseases, particularly liver cirrhosis and hepatocellular carcinoma.     

Basal core-promoter mutant of hepatitis B virus and progression of liver disease in hepatitis B e antigen-negative chronic hepatitis B.

BACKGROUND/AIMS: The long-term outcomes in hepatitis B e antigen (HBeAg)-negative chronic hepatitis B are distinct from those in HBeAg-positive chronic hepatitis. However, the molecular virological factors that contribute to the progression of liver disease in this special clinical setting remain largely unknown. We thus investigated the association of hepatitis B virus (HBV) genotypes as well as precore/basal core-promoter mutations with the clinical and virological characteristics of patients with HBeAg-negative chronic hepatitis B in Taiwan. METHODS: HBV genotypes and sequences of precore and basal core-promoter regions of the HBV genome were determined in 174 HBeAg-negative chronic HBV infection patients including 62 inactive carriers and 112 with different stages of liver disease. RESULTS: HBV carriers with older age (> 50 years) (odds ratio, 9.09; 95% confidence interval (CI), 3.22-25, P < 0.001) and basal core-promoter mutant of HBV (odds ratio, 4.12; 95% CI, 1.41-12.03, P = 0.01) were associated with the development of liver cirrhosis and hepatocellular carcinoma (HCC). The gender-related risk factors associated with the development of liver cirrhosis and HCC were further analyzed, and basal core-promoter mutant was only associated with the development of liver cirrhosis and HCC in male carriers (odds ratio, 4.35; 95% CI, 1.30-14.52, P = 0.02). CONCLUSIONS: The risk of development of liver cirrhosis and HCC is significantly increased in patients with advanced age as well as with basal core-promoter mutant of HBV. In addition, basal core-promoter mutant might contribute to the gender difference of the progression of liver disease in HBeAg-negative chronic hepatitis B in Taiwan.     

Current and future directions for treating hepatitis B virus infection

Hepatitis B virus(HBV) persistently infects approximately 350 million people, and approximately 600000 liverrelated deaths are observed per year worldwide. HBV infection is also one of the major risk factors for hepatocellular carcinoma(HCC). The persistence of serum hepatitis B e antigen(HBe Ag) and high level of serum HBV DNA are thought to reflect a high HBV replication status in hepatocytes, causing cirrhosis, HCC and liver-related deaths. It has been reported that antiviral therapy, such as peginterferon and nucleos(t)ide analogues(NUCs), could suppress liver-related death by inhibiting the HBV DNA levels and inducing seroconversion from HBe Ag to antibody to HBe antigen. Currently, peginterferon is widely used, but there are also several disadvantages in the use of peginterferon, such as various adverse events, the administration route and duration. It is difficult to predict the effects of treatment and interferon is contraindicated for the patients with advanced fibrosis of the liver and cirrhosis. With respect to NUCs, entecavir and tenofovir disoproxil fumarate are current the first-choice drugs. NUCs can be administered orally, and their anti-viral effects are stronger than that of peginterferon. However, because cessation of NUC administration leads to high levels of viral replication and causes severe hepatitis, they must be administered for a long time. On the other hand, the use of both interferon and NUCs cannot eliminate covalently closed circular DNA of HBV. In this review, we evaluate the natural course of chronic HBV infection and then provide an outline of these representative drugs, such as peginterferon, entecavir and tenofovir disoproxil fumarate.     

Aflatoxin levels in chronic hepatitis B patients with cirrhosis or hepatocellular carcinoma in Balıkesir,Turkey

Aflatoxins, the secondary metabolites produced by species of naturally occurring Aspergilli, are commonly found in food such as cereals, dried fruits and juice, wine, beer and spices. They are hepatotoxic and are well known human carcinogens based on evidence from human studies. Aflatoxins are an environmental risk factor for the development of hepatocellular carcinoma (HCC). Chronic hepatitis B‐infected patients are at increased risk of cirrhosis, hepatic failure and liver cancer. This study was designed to determine the serum aflatoxin B₁ (AFB₁), aflatoxin B₂ (AFB₂), aflatoxin G₁ (AFG₁) and aflatoxin G₂ (AFG₂) concentrations using high‐pressure liquid chromatography (HPLC) in hepatitis B‐infected patients with or without cirrhosis and liver cancer, alongside healthy controls in Bal?kesir, Turkey. The mean AFB₁ and total AF levels in patients without liver cancer and cirrhosis were significantly higher than healthy controls. The mean AFB₁ and total AF levels in patients with chronic hepatitis B and HCC were significantly higher than infected patients with or without cirrhosis. These results suggest that patients with chronic hepatitis B who are exposed to AFs are at increased risk for developing HCC, which might be prevented by reducing consumption of contaminated foods.     

Chronic hepatitis B: a long-term retrospective cohort study of disease progression in Shanghai, China

BACKGROUND AND AIMS: The present study aimed to describe the disease progression of chronic hepatitis B patients without or with compensated cirrhosis at baseline, to estimate the risk of progression to decompensated cirrhosis, hepatocellular carcinoma and death, and to determine prognostic factors of disease progression in patients in Shanghai, China. METHODS: Stored medical records from 322 biopsy-confirmed chronic hepatitis B cases diagnosed between 1981 and 1993 were selected, and the status of patients was tracked in 1999-2000. Among consenting patients, ultrasound examination and laboratory tests were conducted. Person-year incidence rates, Kaplan-Meier analysis, log-rank tests, and Cox regression analysis were conducted. RESULTS: Among chronic hepatitis B patients without compensated cirrhosis, the incidence rates of decompensated cirrhosis, hepatocellular carcinoma, and death were 6.3, 2.8, and 7.6 per 1000 person-years, respectively, while for patients with compensated cirrhosis, the rates were 35.6, 8.2, and 35.2 per 1000 person-years, respectively. The 15-year survival rate was 88% for patients without compensated cirrhosis, compared with 56% for patients with compensated cirrhosis (P < 0.001). Cox regression analysis demonstrated that increased alpha-fetoprotein (AFP) (P < 0.01), gamma-globulin (P < 0.05), and high-level severity of hepatic fibrosis (P < 0.01) at baseline were risk factors of decompensated cirrhosis. Factors associated with a high risk of death included elevated AFP at baseline (P < 0.01), severity of hepatic fibrosis (P < 0.003), and sustained positivity for hepatitis B surface antigen (P < 0.004). CONCLUSION: Increased AFP and severity of hepatic fibrosis at baseline were associated with higher risk of decompensated cirrhosis and death. These data provide rare empirical estimates of the negative long-term outcomes for patients with chronic hepatitis B in Shanghai, China.     

Managing hepatitis B to prevent liver cancer: recent advances

Chronic hepatitis B (CHB) infection is a major cause of human mortality worldwide. The majority of people with CHB are infected early in life, and 20–40% of men and 15% of women with chronic infection will develop hepatocellular carcinoma (HCC). Antiviral therapy is recommended for patients with CHB who have cirrhosis or active disease with the aims of reducing disease progression to cirrhosis, liver failure and liver cancer, thereby preventing death. Evidence that treatment with interferon or with early nucleos(t)ide analogue therapy reduces HCC has been somewhat conflicting, however evidence is emerging to support a significant role in HCC prevention of the more effective antivirals, entecavir and tenofovir. Older patients, those with cirrhosis, and those undergoing curative treatments for HCC derive the greatest medium-term benefit in terms of HCC reduction, but HCC can still occur and long-term surveillance is recommended.     

Natural history of chronic hepatitis B REVEALed

Chronic hepatitis B is a worldwide public health challenge. Knowledge of natural history of chronic hepatitis B is important for the management of the disease. A community-based prospective cohort study was carried out to evaluate the risk predictors of progression of chronic hepatitis B in Taiwan. A total of 23,820 participants were enrolled in 1991-1992 from seven townships in Taiwan. Their serum samples were collected at study entry and tested for hepatitis B surface antigen (HBsAg) and e antigen (HBeAg), antibodies against hepatitis C virus (anti-HCV), alanine aminotransferase (ALT), and α-fetoprotein (AFP). A subcohort of 3653 male and female participants who were seropositive for HBsAg and seronegative for anti-HCV was included in the Risk Evaluation of Viral Load Elevation and Associated Liver Disease/Cancer-Hepatitis B Virus (REVEAL-HBV) study. Newly developed cases of cirrhosis and hepatocellular carcinoma (HCC) were ascertained through follow-up examination and data linkage with profiles of the National Cancer Registry, National Health Insurance Database and Death Certification System. The incidence of both HCC and cirrhosis were significantly associated with serum HBV DNA levels in a dose-response relationship from <300 (undetectable) to ≥1,000,000 copies/mL. The biological gradients remained significant (P<0.001) after adjustment for age, sex, habits of cigarette smoking and alcohol drinking, HBeAg serostatus, and serum ALT level at cohort entry. A significant association with risk of cirrhosis and HCC was also observed for HBV genotype, precore G1896A mutant and basal core promoter A1762T/G1764A double mutant. Nomograms have been developed for the long-term risk prediction of cirrhosis and HCC for patients with chronic hepatitis B. Inactive carriers of HBV have an increased HCC incidence and liver-related mortality than HBsAg-seronegative controls. Serum HBV DNA level at study entry is a major predictor of spontaneous seroclearance of HBeAg, HBV DNA and HBsAg. These findings may inform the effective and efficient management of chronic hepatitis B.     

Capacity to report on mortality attributable to chronic hepatitis B and C infections by Member States: An exercise to monitor progress towards viral hepatitis elimination

Viral hepatitis is globally leading causes of death, and 96% of these are due to hepatitis B and C (HBV/HCV) late outcomes. The first Global Health Sector Strategy (GHSS) aims to reduce by 65% the mortality associated with HBV/HCV, and an indicator (C10) is proposed to monitor progress. Data on viral hepatitis and liver‐related mortality are required, and different methods of estimation can be used, depending on availability and quality of sources. We aimed to understand the current situation and practicality of calculating C10, accessing available sources to estimate initial figure for Europe. We listed and compiled regional and national data sources reporting deaths from HCC, cirrhosis and chronic liver disease (CLD) and available estimates of attributable fraction. We critically appraised quality of data, highlighting gaps in current data and estimated mortality attributable to HBV and HCV, for 31 EU/EEA countries from 2010 to 2015. Mortality data are available for 30/31 countries. Quality varies but 60% of national sources report with specificity as required by WHO indicator. Attributable fraction is only available through the literature search. We estimated C10 for 87.6% country‐years. Deaths attributable to HBV/HCV for this period and region were 292 600, while HCV deaths were three times higher. Incomplete data for 2015 prevented calculation of time trends. Regional sources are outdated for monitoring C10, but national sources are capable of reporting mortality data. Sources for attributable fraction are sparse, outdated and much needed. We recommend improvement of death registration allowing measuring this indicator. Studies measuring attributable fraction on national and subnational levels are crucial.     

Systematic review of risk factors of hepatocellular carcinoma after hepatitis B surface antigen seroclearance

There is no consensus about factors that increase risk of hepatocellular carcinoma (HCC) among patients with chronic hepatitis B who have achieved seroclearance of hepatitis B surface antigen (HBsAg). To assess the available evidence about risk factors for HCC after HBsAg seroclearance, Scopus, EMBASE, PubMed and Cochrane Library databases were systematically searched for relevant studies published through 15 September 2017. A total of 28 studies involving more than 105 411 patients with chronic hepatitis B were included. HBsAg seroclearance occurred spontaneously in 7656, while it occurred after interferon or nucleos(t)ide analogue therapy in 1248. The rate of HBsAg seroclearance was 6.77%. Incidence of HCC was significantly lower among patients who experienced HBsAg seroclearance than among those who remained HBsAg‐positive (1.86% vs 6.56%, P < .001). Risk factors of HCC occurrence included cirrhosis (incidence with vs without: 9.51% vs 1.66%), male gender (2.34% vs 0.64%) and age ≥ 50 year at HBsAg seroclearance (2.34% vs 0.63%) (all P < .001). The available evidence suggests that HCC can develop at a low rate after HBsAg seroclearance, so periodic surveillance is recommended, especially for male patients, patients with cirrhosis and patients who experience HBsAg seroclearance when at least 50 years old.     

A paucity of liver disease in Canadian Inuit with chronic hepatitis B virus,subgenotype B6 infection

Clinical observations suggest that chronic hepatitis B virus (HBV) infections in the Canadian Inuit are less often associated with serious adverse outcomes than has been described in other HBV‐infected patient populations. The aim of this study was to document the clinical and biochemical features, liver‐related morbidity and all‐cause mortality in Canadian Inuit with chronic HBV infections. Administrative databases were reviewed for individuals identified as hepatitis B surface antigen (HBsAg) positive during a 1983–85 seroepidemiological survey of viral hepatitis in Baffin Island, Canada. An equal number of age‐ and gender‐matched HBsAg‐negative individuals from the same communities served as controls. Baseline HBV viral loads, genotypes and specific mutations were compared in HBsAg‐positive survivors and nonsurvivors. A subset of surviving HBsAg‐positive carriers were reassessed 25–30 years following their initial diagnosis for evidence of advanced liver disease and changes to their serological/virological findings. One hundred and forty four HBsAg‐positive individuals were identified. All were Canadian Inuit. The mean age at diagnosis was 38 ± 17 years and 69 (61%) were male. Median follow‐up was 23 years (range: 2–28 years). Viral quantitation from stored sera could be performed in 70 infected individuals. The median viral load was 4.3 log 10 IU/ml (range: 2.3–8.8 log 10 IU/ml), and all were genotype B, subgenotype B6. Liver biochemistry, morbidity and all‐cause mortality rates were similar in HBsAg‐positive carriers and controls. Following multivariate analyses, only age at diagnosis predicted mortality in HBsAg carriers. In a subset of 30 HBsAg‐positive survivors who underwent follow‐up assessments, clinical, biochemical and radiological examinations of the liver were essentially normal. 23/30 (77%) remained HBsAg positive and 17/19 (90%) HBV‐DNA positive. The genotype and prevalence of genomic mutations in this cohort remained largely unchanged, but quantifiable viral loads were significantly lower (P < 0.003). The results of this study suggest that chronic HBV infections in the Canadian Inuit are infrequently associated with serious adverse outcomes. Whether this finding reflects unique features of the host, presence or absence of external factors that influence the course of HBV and/or intrinsic properties of the HBV B6 subgenotype remains to be determined.     

Decreasing incidence of hepatocellular carcinoma among children following universal hepatitis B immunization

Abstract: Hepatocellular carcinoma (HCC) is one of the 10 most common malignant tumors worldwide. Chronic infection with hepatitis B or C virus is closely related to hepatocarcinogenesis. The outcome of current therapies for HCC is not satisfactory. Prevention is the best way to control HCC. Among the various strategies of HCC prevention, immunization against hepatitis B virus infection is the most effective. Universal hepatitis B immunization has proved to be effective in reducing the incidence of HCC to 1/4–1/3 of that in children born before the hepatitis B vaccination era in Taiwan. The problems we face in achieving global control of hepatitis‐related HCC include: (1) no effective vaccine for the prevention of hepatitis C and its related HCC; (2) no immunization program for hepatitis B in areas with inadequate resources; (3) poor compliance to the immunization program as a result of ignorance, anxiety, or poverty; and (4) vaccine failure. Integration of the hepatitis B vaccination program into the expanded program of immunization for all infants throughout the world will be most urgent and important for HCC control. The reduction of the incidence of HCC will be seen in adults 30–40 years of age after the launch of the universal hepatitis B vaccination program. This concept of cancer vaccine can be applied to other infectious agents and their related cancers.     

乙型及丙型肝炎患者发生肝细胞癌的风险预测：REVEAL-HBV/HCV研究的回顾

乙型肝炎病毒（HBV）及丙型肝炎病毒（HCV）的慢性感染是肝细胞癌（HCC）的主要致病原因。全球约有3亿5千万人为HBV的慢性感染者;HCV慢性感染者则有2亿人。全球每年约有50万人死于乙型肝炎引起的HCC,另有25万人死于丙型肝炎引起的HCC。乙型肝炎慢性感染者,其血中HBV DNA及ALT持续处于高水平是HCC最重要的预测因子。其他的危险因子还包括HBV C基因型、HBV基础核心促进子A1762T/G1764A双突变、男性、老年、肝癌家族史、酗酒习惯、以及与HCV或人类免疫不全病毒的合并感染等。根据REVEAL-HBV研究的资料,我们发展出简单易用的列线图,可利用非侵入性的临床特征准确地预测慢性乙型肝炎患者发生HCC的风险。丙型肝炎慢性感染患者发生HCC最重要的预测因子包括高血中HCV RNA水平、高ALT水平、HCV基因型以及老年等。REVEAL-HCV研究案例中,与HCV RNA水平低于检测范围且低ALT水平者相比,HCV RNA可测得、高ALT水平且感染第一型病毒的案例具有最高的HCC发生风险,其多变项调整后的风险比值（95%CI）为21.87（5.09～93.95）,这些发现对于慢性丙型肝炎的临床处置具有重要的意义。     

Occult hepatitis B virus infection and its clinical implications

Occult hepatitis B virus (HBV) infection is characterized by presence of HBV infection with undetectable hepatitis B surface antigen (HBsAg). Serum HBV level is usually less than 10⁴ copies/mL in these patients. Diagnosis of occult HBV infection requires sensitive HBV-DNA PCR assay. Several possibilities have been hypothesized as the mechanisms of occult HBV infection. These include: (i) mutations of HBV-DNA sequence; (ii) integration of HBV-DNA into host's chromosomes; (iii) infection of peripheral blood mononuclear cells by HBV; (iv) formation of HBV-containing immune complex; (v) altered host immune response; and (vi) interference of HBV by other viruses. The precise prevalence of occult HBV infection remains to be defined. The clinical implications of occult HBV infection involve different clinical aspects. First of all, occult HBV infection harbours potential risk of HBV transmission through blood transfusion, haemodialysis, and organ transplantation. Second, it may serve as the cause of cryptogenic liver disease, contribute to acute exacerbation of chronic hepatitis B, or even fulminant hepatitis. Third, it is associated with development of hepatocellular carcinoma. Fourth, it may affect disease progression and treatment response of chronic hepatitis C. Most of the previous studies utilized retrospective observation without control groups, and lacked direct association of occult HBV infection with specific pathological changes and disease progression. Highly sensitive, quantitative, and functional molecular analyses of HBV, combined with a well-designed prospective clinical assessment will provide the best approach for the future study of occult HBV infection.     

Guidelines for the treatment of chronic hepatitis and cirrhosis due to hepatitis B virus infection for the fiscal year 2008 in Japan

In the 2008 guidelines for the treatment of patients with cirrhosis, who are infected with hepatitis B virus (HBV), the main goal is to normalize levels of alanine and aspartate aminotransferases by eliminating HBV or reducing viral loads. In patients with compensated cirrhosis, the clearance of HBV from serum is aimed for by entecavir, as the main resort, for histological improvement toward the prevention of hepatocellular carcinoma (HCC). In patients with decompensated cirrhosis, by contrast, meticulous therapeutic strategies are adopted for the reversal to compensation, toward the eventual goal of decreasing the risk of HCC. For maintaining liver function and preventing HCC, branched chain amino acids and nutrient supplements are applied, in addition to conventional liver supportive therapies. For patients with chronic hepatitis B, separate guidelines are applied to those younger than 35 years and those aged 35 years or older. Even for patients with chronic hepatitis who are negative for hepatitis e antigen (HBeAg), but who harbor HBV DNA in titers of 7 log copies/mL or more, a "drug-free state" is aimed for by sequential treatment with interferon (IFN) plus entecavir as the first line. For patients with chronic hepatitis B aged 35 years or older, who are HBeAg-negative and carry HBV DNA in titers of less than 7 log copies/mL, long-term IFN for 24–48 weeks is adopted anew. To HBeAg-negative patients who have either or both platelet counts of less than 150 × 10³/mm³ and less than 7 log copies of HBV DNA, also, long-term IFN for 24–48 weeks is indicated.