A historical perspective on the discovery and elucidation of the hepatitis B virus.

The discovery in 1965 of the "Australia antigen," subsequently identified as the hepatitis B virus surface antigen (HBsAg), was such a watershed event in virology that it is often thought to mark the beginning of hepatitis research, but it is more accurately seen as a critical breakthrough in a long effort to understand the pathogenesis of infectious hepatitis. A century earlier, Virchow provided an authoritative explanation of "catarrhal jaundice," which did not consider an infectious etiology, but the transmission of jaundice by human serum was clearly identified in two outbreaks in 1885, and the distinction between "infectious" and "serum" hepatitis was recognized by the early 1920s. The inability to culture a virus or reproduce either syndrome in laboratory animals led to numerous studies in human volunteers; by the end of World War II, it was known that the diseases were caused by different filterable agents, and the terms "hepatitis A" and "B" were introduced in 1947 (though some long-incubation cases then designated B must in retrospect have been hepatitis C). The development of a number of liver function tests during the 1950s led to the recognition of anicteric infections and the existence of chronic carriers, but little more could be done until an infectious agent had been identified. Once Blumberg and colleagues had found a specific viral marker, the vast amount of accumulated epidemiologic and clinical data, together with huge numbers of stored serum samples, enabled rapid progress in understanding hepatitis B, and revealed the existence of a vast population of chronically infected people in Asia, Oceania and Africa. In this article, we place the identification of the Australia antigen within the historical context of research on viral hepatitis. Following a chronological review from 1865 to 1965, we summarize how the discovery led to improved safety of blood transfusion, the development of a highly effective vaccine and the eventual identification of the hepatitis C, D and E viruses. This article forms part of a symposium in Antiviral Research on "An unfinished story: from the discovery of the Australia antigen to the development of new curative therapies for chronic hepatitis B."

Hepatitis-Associated Liver Cancer: Gaps and Opportunities to Improve Care.

The global burden of hepatocellular carcinoma (HCC; primary liver cancer) is increasing. HCC is often unaccompanied by clear symptomatology, causing patients to be unaware of their disease. Moreover, effective treatment for those with advanced disease is lacking. As such, effective surveillance and early detection of HCC are essential. However, current screening and surveillance guidelines are not being fully implemented. Some at-risk populations fall outside of the guidelines, and patients who are screened are often not diagnosed at an early enough stage for treatment to be effective. From March 17 to 19, 2015, the Hepatitis B Foundation sponsored a workshop to identify gaps and limitations in current approaches to the detection and treatment of HCC and to define research priorities and opportunities for advocacy. In this Commentary, we summarize areas for further research and action that were discussed throughout the workshop to improve the recognition of liver disease generally, improve the recognition of liver cancer risk, and improve the recognition that screening for HCC makes a life-saving difference. Participants agreed that primary prevention of HCC relies on prevention and treatment of viral hepatitis and other underlying etiologies. Earlier diagnosis (secondary prevention) needs to be substantially improved. Areas for attention include increasing practitioner awareness, better definition of at-risk populations, and improved performance of screening approaches (ultrasound, biomarkers for detection, risk stratification, targeted therapies). The heterogeneous nature of HCC makes it unlikely that a single therapeutic agent will be universally effective. Medical management will benefit from the development of new, targeted treatment approaches.

Hepatitis B knowledge among key stakeholders in Haimen City, China: Implications for addressing chronic HBV infection.

BACKGROUND: This article describes hepatitis B-related knowledge, attitudes and practices after completion of the Gateway to Care campaign, a citywide public health education program that targeted city residents, health care providers and individuals chronically infected with hepatitis B virus in Haimen City, China. METHODS: Pre/post questionnaires assessed hepatitis B knowledge change among health care providers and post-campaign surveys evaluated hepatitis B knowledge, attitudes and behaviors (including stigma-related beliefs and practices) among health care providers, city residents and chronically infected individuals. Focus groups were conducted to gain a more in-depth understanding of the needs of the target communities, and to identify future intervention strategies to improve hepatitis B testing and linkage to care and treatment. RESULTS: Results indicate high levels of hepatitis B knowledge among multiple stakeholders in Haimen City, with significant knowledge improvement among health care providers. Stigma-related beliefs and myths regarding separation of infected individuals from certain aspects of family life were common among all stakeholder groups, despite high levels of accurate knowledge about hepatitis B transmission and prevention. Self-report of hepatitis B screening was low among city residents, as was awareness of hepatitis B treatment. CONCLUSIONS: More efforts are needed to improve awareness of HBV treatment, decrease HBV-related stigma, improve screening rates, and reduce cost of antiviral treatment. Future interventions in Haimen City should be driven by behavioral change theory, to not only improve knowledge, but to improve screening behaviors and address hepatitis B-related stigma and discrimination.

Global epidemiology of hepatocellular carcinoma: an emphasis on demographic and regional variability.

Liver cancer is the second leading cause of global cancer mortality. The major risk factors for hepatocellular carcinoma (HCC) are being addressed with success by prevention efforts. Vaccination against hepatitis B virus has reduced incidence of HCC in Taiwan and is partly responsible for lower rates in China. New infections with hepatitis C virus are low in developed countries because of prevention of posttransfusion infections and reduced exposure to HCV by drug users. Aflatoxin exposure has been reduced by better grain storage and dietary changes. Obesity, metabolic syndrome, and diabetes are increasing in developed and developing countries and will lead to more cases of HCC.

Statin use and risk of primary liver cancer in the Clinical Practice Research Datalink.

BACKGROUND: Statins (3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors) are widely prescribed to reduce cholesterol levels. Studies have suggested that statins are associated with reduced risk of liver cancer, but much of the evidence is from regions of the world with high liver cancer incidence rates. The current study examined the statins-liver cancer relationship in a low-rate region and examined the effects of preexisting liver disease and diabetes on that association. METHODS: A nested case-control study was conducted within the United Kingdom's Clinical Practice Research Datalink (CPRD). Persons diagnosed with primary liver cancer between 1988 and 2011 were matched to controls at a four-to-one ratio. Matches stratified on liver disease and on diabetes were also completed. Odds ratios (ORs) and 95% confidence intervals (CIs) for associations of statins with liver cancer were estimated using conditional logistic regression. RESULTS: In total, 1195 persons with primary liver cancer were matched to 4640 control patients. Statin use was associated with a statistically significantly reduced risk of liver cancer (ORadj = 0.55, 95% CI = 0.45 to 0.69), especially among current users (ORadj = 0.53, 95% CI = 0.42 to 0.66). The reduced risk was statistically significant in the presence (ORadj = 0.32, 95% CI = 0.17 to 0.57) and absence of liver disease (ORadj = 0.65, 95% CI = 0.52 to 0.81) and in the presence (ORadj = 0.30, 95% CI = 0.21 to 0.42) and absence of diabetes (ORadj = 0.66, 95% CI = 0.51 to 0.85). CONCLUSIONS: In the current study in a low-rate area, statin use was associated with a statistically significantly reduced risk of liver cancer overall. Risk was particularly reduced among persons with liver disease and persons with diabetes, suggesting that statin use may be especially beneficial in persons at elevated risk of liver cancer.

Prevention of perinatal hepatitis B transmission in Haimen City, China: Results of a community public health initiative.

In regions where hepatitis B virus (HBV) is endemic, perinatal transmission is common. Infected newborns have a 90% chance of developing chronic HBV infection, and 1 in 4 will die prematurely from HBV-related liver disease. In 2010, the Hepatitis B Foundation and the Haimen City CDC launched the Gateway to Care campaign in Haimen City, China to improve awareness, prevention, and control of HBV infection citywide. The campaign included efforts to prevent perinatal HBV transmission by screening all pregnant women for hepatitis B surface antigen (HBsAg), following those who tested positive, and administering immunoprophylaxis to their newborns at birth. Of 5407 pregnant women screened, 185 were confirmed HBsAg-positive and followed until delivery. At age one, 175 babies were available for follow up testing. Of those, 137 tested negative for HBsAg and positive for antibodies to HBsAg, indicating protection. An additional 34 HBsAg-negative babies also tested negative for antibodies to HBsAg or had indeterminate test results, were considered to have had inadequate immune responses to the vaccine, and were given a booster dose. A higher prevalence of nonresponse to HBV vaccine was observed among babies born to hepatitis B e antigen (HBeAg)-positive mothers and mothers with high HBV DNA titers. The remaining 4 babies tested positive for HBsAg and negative for antibodies, indicative of active HBV infection. The mothers of all 4 had viral loads ≥8×10(6) copies/ml in the third trimester. Although inadequate response or nonresponse to HBV vaccine was more common among babies born to HBeAg-positive and/or high viral load mothers, these risk factors did not completely predict nonresponsiveness. All babies born to HBV-infected mothers should be tested upon completion of the vaccine series to ascertain adequate protection. Some babies of HBeAg-positive mothers with high viral load may still become HBV infected despite timely immunoprophylaxis with HBV vaccine and HBIG.

Chronic HBV infection outside treatment guidelines: is treatment needed?

BACKGROUND: There are now seven antivirals approved for use in the management of chronic HBV infection in the US. Current professional guidelines recommend the use of antiviral treatment in only a distinct subset of the total HBV chronically infected population, estimated to be more than 350 million worldwide. The subset of chronically HBV-infected individuals for whom the antivirals have been demonstrated to produce desirable outcomes are those with abnormal liver enzymes and a viral load above a defined threshold, presumably identifying those at highest risk for development of cirrhosis and hepatocellular carcinoma. However, some individuals whose clinical features place them outside these guidelines, for whom treatment is not recommended, are also at significant risk for liver disease complications and liver-related death. METHODS: In this report, we produce new estimates of the age-specific risks of liver-related death in people outside the current treatment guidelines using published data from multiple populations. RESULTS: Our results indicate that the age-specific 10-year risks of liver-related mortality in these individuals range from 0.3-4% in the West to 0.3-20% in Asia. CONCLUSIONS: The magnitude of these risks and the estimated size of the global population that falls outside of current treatment guidelines have led us to consider whether medical interventions are also needed for these individuals, either with currently approved therapeutics or yet-to-be-discovered medications targeting new mechanisms of antiviral effect. Potential targets for development of new medications are discussed.

Can propranalol prevent hepatocellular carcinoma?

ß-Adrenergic signaling is involved in many processes that may contribute to cancer progression. In this issue of the journal (beginning on page 1007), Nkontchou and colleagues report their retrospective observational finding that the ß-blocker propranolol was associated with a highly statistically significant reduction in the incidence of hepatocellular carcinoma in patients with advanced cirrhosis and related esophageal varices. This surprising finding requires confirmation, but the result is biologically plausible. Epidemiologic studies have linked ß-blockers with reduced rates of metastasis of other cancers and reduced cancer mortality. Laboratory studies suggest biologic mechanisms for anticancer effects of ß-blockers.

Dichlorodiphenyltrichloroethane and risk of hepatocellular carcinoma.

Dichlorodiphenyltrichloroethane (p,p'-DDT), an organochlorine pesticide known to have deleterious health effects in humans, has been linked to hepatocellular carcinoma (HCC) in rodents. A recent study has reported that p,p'-DDT and its most persistent metabolite, dichlorodiphenyldichloroethylene (p,p'-DDE), may also be associated with HCC in humans. To examine whether there is an association between p,p'-DDT and/or p,p'-DDE in a population at high-risk of developing HCC, a nested case-control study was conducted within the 83,794 person Haimen City Cohort in China. Sera and questionnaire data were collected from all participants between 1992 and 1993. This study included 473 persons who developed HCC and 492 who did not, frequency matched on sex, age and area of residence. p,p'-DDT and p,p'-DDE levels were determined by mass spectrometry. Hepatitis B viral infection status (based on hepatitis B virus surface antigen; HBsAg) was also determined. p,p'-DDT and/or p,p'-DDE serum levels were significantly associated with sex, area of residence, occupation, alcohol consumption and cigarette smoking. Adjusting for age, sex, area of residence, HBsAg, family history of HCC, history of acute hepatitis, smoking, alcohol, occupation (farmer vs. other) and levels of p,p'-DDT or p,p'-DDE, odds ratios (OR) and 95% confidence intervals (CI) were calculated via unconditional logistic regression. Overall, the highest quintile of p,p'-DDT was associated with an increased risk of HCC, OR = 2.96 95% CI; 1.19-7.40. There were no statistically significant associations with p,p'-DDE. Overall, these results suggest that recent exposure to p,p'-DDT may increase risk of HCC.

Quantitative dynamics of hepatitis B basal core promoter and precore mutants before and after HBeAg seroconversion.

BACKGROUND & AIMS: Hepatitis B e antigen (HBeAg) seroconversion is an important clinical and virological "landmark" during chronic hepatitis B virus (HBV) infection. Mutant viruses carrying the precore G1896A and/or the basal core promoter (BCP) A1762T/G1764A mutations are associated with HBeAg seroconversion. However, the exact role of these mutants in HBeAg seroconversion remains unclear, partly because the evolution of these mutant viruses before and after seroconversion has not been well studied. METHODS: Using our novel mutant quantification methods, the percentage of the mutant viruses was analyzed both cross-sectionally and longitudinally, before and after seroconversion. RESULTS: Cross-sectional analysis showed that the percentage of both precore and BCP mutants gradually increased with age in the HBeAg-positive population. Follow-up of 18 HBeAg-positive patients revealed that the mutant percentage may stay low and stable for many years, followed by a steady increase in the percentage of G1896A and/or A1762T/G1764A mutants, from <10% to 50-100%, within about 3 years prior to seroconversion. In all cases, increase of mutant percentage was preceded or accompanied by elevated serum alanine aminotransferase. After the seroconversion, the mutant percentage could remain high or decrease significantly, sometimes to below 20%. CONCLUSIONS: Levels of G1896A and A1762T/G1764A mutants (of genotypes B and C) in the HBeAg-positive patients may predict the time of HBeAg seroconversion. The dominance of these mutants in the HBeAg-positive phase is more likely the result of immune selection rather than the enhanced replication capability of the mutants. However, anti-HBe antibody may not be a major selection force for these mutants.

Fumonisin B1 and risk of hepatocellular carcinoma in two Chinese cohorts.

Fumonisin B1 (FB1), a mycotoxin that contaminates corn in certain climates, has been demonstrated to cause hepatocellular cancer (HCC) in animal models. Whether a relationship between FB1 and HCC exists in humans is not known. To examine the hypothesis, we conducted case-control studies nested within two large cohorts in China; the Haimen City Cohort and the General Population Study of the Nutritional Intervention Trials cohort in Linxian. In the Haimen City Cohort, nail FB1 levels were determined in 271 HCC cases and 280 controls. In the General Population Nutritional Intervention Trial, nail FB1 levels were determined in 72 HCC cases and 147 controls. In each population, odds ratios and 95% confidence intervals (95%CI) from logistic regression models estimated the association between measurable FB1 and HCC, adjusting for hepatitis B virus infection and other factors. A meta-analysis that included both populations was also conducted. The analysis revealed no statistically significant association between FB1 and HCC in either Haimen City (OR=1.10, 95%CI=0.64-1.89) or in Linxian (OR=1.47, 95%CI=0.70-3.07). Similarly, the pooled meta-analysis showed no statistically significant association between FB1 exposure and HCC (OR=1.22, 95%CI=0.79-1.89). These findings, although somewhat preliminary, do not support an associated between FB1 and HCC.

Chronic hepatitis B infection: a workshop consensus statement and algorithm.

Here, presented with an evidence-based algorithm, are workshop consensus recommendations on whom to screen for hepatitis B and when to pursue further evaluation and management.

The Australia antigen and role of the late Philadelphia General Hospital in reducing post-transfusion hepatitis and sequelae.

Baruch Blumberg, who received the Nobel Prize for Physiology or Medicine for his discovery of the Australia antigen, died on April 5, 2011. Arguably, that discovery has been the most important advance in the field of Hepatology. It led to the virtual elimination of transfusion related hepatitis B in most parts of the world and was essential to the identification of hepatitis A, C, D and E viruses. Credit for this is due Dr. Blumberg and teams in Philadelphia and Tokyo. In lieu of an Associate Editor commentary, Drs. Senior, London, and Sutnick, who were members of that remarkable team, tell us their inspiring story.

Quantification of complex precore mutations of hepatitis B virus by SimpleProbe real time PCR and dual melting analysis.

BACKGROUND: Hepatitis B virus (HBV) precore G1896A mutation is associated with Hepatitis B e antigen (HBeAg) seroconversion. This mutation and the adjacent G1899A mutation also appear to associate with increased risk of hepatocellular carcinoma. Quantitative mutant dynamics may help determine the potential of these mutants as clinical biomarkers. However, a reliable method to quantify either mutant is not available, partly because the viral genome has polymorphisms in general and the precore mutations are complex. OBJECTIVES: (1) To develop a reliable and ultrasensitive assay for the quantification of HBV G1896A and/or G1899A mutants. (2) To obtain preliminary data on the quantities of the precore mutants in patients. STUDY DESIGN: A SimpleProbe real time PCR assay was developed to quantify the HBV precore mutants. Dual melting analysis and a primer-probe partial overlap approach were used to increase detection accuracy. A wild-type selective PCR blocker was also developed to increase mutant detection sensitivity. RESULTS: The assay correctly identified the precore sequence from all 62 patient samples analyzed. More than 97% of precore sequences in the GenBank can be recognized. Mutant detection sensitivity reached 0.001% using a wild type-selective PCR blocker. At least one precore mutant can be detected from all 20 HBeAg-positive individuals who were negative for precore mutations by DNA sequencing. CONCLUSIONS: The reliability of this ultrasensitive mutation quantification assay was demonstrated. The same approaches may be useful for the detection of other clinically significant mutations. Evolution of the precore mutants warrants further studies.

The global epidemiology of hepatocellular carcinoma: present and future.

The global risk of hepatocellular carcinoma (HCC) has been largely driven by hepatitis B virus (HBV) infection for the past century, along with hepatitis C virus (HCV), aflatoxin, excessive alcohol consumption, and obesity/diabetes. The dominant effect of HBV on global HCC risk should decline as the population vaccinated against HBV grows older. Infection with HCV is also expected to decline. Projections of HCV-related HCC rates remaining high for another 30 years may be overly pessimistic. Alcohol may be less of a factor in HCC in coming years. However, obesity and diabetes may become even more important risk factors for HCC.

Ultrasensitive quantification of hepatitis B virus A1762T/G1764A mutant by a SimpleProbe PCR using a wild-type-selective PCR blocker and a primer-blocker-probe partial-overlap approach.

Hepatitis B virus (HBV) carrying the A1762T/G1764A double mutation in the basal core promoter (BCP) region is associated with HBe antigen seroconversion and increased risk of liver cirrhosis and hepatocellular carcinoma (HCC). Quantification of the mutant viruses may help in predicting the risk of HCC. However, the viral genome tends to have nucleotide polymorphism, which makes it difficult to design hybridization-based assays including real-time PCR. Ultrasensitive quantification of the mutant viruses at the early developmental stage is even more challenging, as the mutant is masked by excessive amounts of the wild-type (WT) viruses. In this study, we developed a selective inhibitory PCR (siPCR) using a locked nucleic acid-based PCR blocker to selectively inhibit the amplification of the WT viral DNA but not the mutant DNA. At the end of siPCR, the proportion of the mutant could be increased by about 10,000-fold, making the mutant more readily detectable by downstream applications such as real-time PCR and DNA sequencing. We also describe a primer-probe partial overlap approach which significantly simplified the melting curve patterns and minimized the influence of viral genome polymorphism on assay accuracy. Analysis of 62 patient samples showed a complete match of the melting curve patterns with the sequencing results. More than 97% of HBV BCP sequences in the GenBank database can be correctly identified by the melting curve analysis. The combination of siPCR and the SimpleProbe real-time PCR enabled mutant quantification in the presence of a 100,000-fold excess of the WT DNA.

Treatment of children with chronic hepatitis B virus infection in the United States: patient selection and therapeutic options.

Chronic hepatitis B virus (HBV) infection in children presents a therapeutic challenge for the practitioner. Decisions regarding selection of patients who may benefit from treatment, appropriate timing of treatment, and the choice of antiviral therapy are complex and are compounded by the limited number of drugs that have been studied in children. An expert panel of nationally recognized pediatric liver specialists was convened by the Hepatitis B Foundation on August 11, 2009, to consider clinical practice relative to the therapeutic options available for children. A detailed account of these discussions is provided, and the opinions expressed are based on consensus of the experts, as well as on published evidence when available. The panel concludes that, at this time, there is no established benefit of treatment of children in the immune tolerant phase, and there is a very high risk of development of drug resistance. In addition, there is no indication for treatment of children in the inactive carrier state. For children in the immune active or reactivation phases, liver histology can help guide treatment decisions, and family history of liver disease, especially hepatocellular carcinoma, may argue for early treatment in some cases. Outside of clinical trials, interferon is the agent of choice in most cases. Nucleos(t)ide analogues are secondary therapies, and children who receive these agents require careful monitoring for development of resistance. There are a few situations when treatment is indicated regardless of HBV DNA or alanine aminotransferase levels. There is still much to be elucidated about the appropriate use of HBV therapy in children. Until more clinical data and therapeutic options are available, a conservative approach is warranted.

Hepatocellular carcinoma of the liver.

Primary cancer of the liver, hepatocellular carcinoma (HCC), is an extremely deadly cancer, with very poor 5 year survivals, following diagnosis. The poor outcomes are believed to be due, in part, to the late times in which the cancers are usually first detected. Improved methods for early detection have thus become a top priority in the management of liver cancer. This Chapter reviews current methods of detection as well as leading new methods. Possible explanations as to why there are so many markers that are being discovered, but so few that make it to validation are discussed.

Recommendations for screening, monitoring, and referral of pediatric chronic hepatitis B.

Most children with chronic hepatitis B virus infection (persistent hepatitis B surface antigen-positive for >6 months) are asymptomatic and do not generally require treatment. These children are, however, at increased risk for severe complications later in life, including advanced liver disease and liver cancer. On November 11, 2008, the Hepatitis B Foundation, a nonprofit research and disease advocacy organization, convened a panel of nationally recognized North American pediatric liver specialists to consider and recommend an approach for the screening, monitoring, initial management, and referral of children with chronic hepatitis B. The panel developed recommendations to provide guidance to practitioners on determining what additional tests to conduct, how often to monitor on the basis of test results, and when to refer to a pediatric liver specialist to build a partnership between the practitioner and liver specialist to enhance the success of management of children with this lifelong infection.