Brian J. McMahon

Chronic hepatitis B

These guidelines have been written to assist physicians and other health care providers in the recognition, diagnosis, and management of patients chronically infected with the hepatitis B virus (HBV). They are intended to suggest preferable approaches to the clinical management of chronic hepatitis B. The recommendations are flexible and are not intended as the only acceptable approach to management and treatment. As the appropriate course of treatment will vary in light of the relevant facts and circumstances surrounding each individual patient with chronic hepatitis B, guidelines are not intended to define the applicable standard of medical care and may be updated periodically as new information becomes available. These guidelines were developed under the auspices of, and approved by, the Practice Guidelines Committee of the American Association for the Study of Liver Diseases. They should be taken as guidelines and not “standards of care.” Data used to support the recommendations made were obtained by a literature search of peer-reviewed articles concerning the natural history, diagnosis, and treatment of chronic hepatitis B. In addition, the proceedings of a recent National Institutes of Health workshop on the “Management of Hepatitis B” were considered in the development of these guidelines.1 The strength of each recommendation is categorized based on the quality of evidence in the literature according to the rating system indicated in Table 1.2

Chronic hepatitis B: Update 2009

The 2009 update of the American Association for the Study of Liver Diseases (AASLD) Practice Guidelines for Management of Chronic Hepatitis B are now posted online at www.aasld.org. This is the fourth version of this guideline; the last version was published in 2007.1 The key changes in the 2009 version are new recommendations for first-line and second-line antiviral agents. Since the last update, tenofovir disoproxil fumarate (Viread) was approved by the U.S. Food and Drug Administration for treatment of chronic hepatitis B based on the results of two double-blind randomized trials showing a superiority of tenofovir compared to adefovir. In the trial on patients positive for hepatitis B e antigen (HBeAg), 48 weeks of treatment with tenofovir resulted in a significantly higher proportion of patients with undetectable serum hepatitis B virus (HBV) DNA assay by polymerase chain reaction (76% versus 13%), alanine aminotransferase normalization (68% versus 54%), and hepatitis B surface antigen loss (3% versus 0%), with similar rates of histologic response (74% versus 68%) and HBeAg seroconversion (21% versus 18%) compared to treatment with adefovir.2 In the trial on HBeAg-negative patients, 48 weeks of treatment with tenofovir resulted in significantly more patients with undetectable serum HBV DNA by polymerase chain reaction assay (93% versus 63%) than adefovir and similar proportions of patients achieving alanine aminotransferase normalization (76% versus 77%) or histologic response (72% versus 69%).2 Tenofovir resistance was not detected in any of the patients after up to 96 weeks treatment, but patients at the greatest risk of drug resistance—those who remained viremic at week 72—received additional therapy with emtricitabine. Therefore, data on resistance to tenofovir monotherapy beyond 72 weeks cannot be determined from the two pivotal trials. The primary resistance mutation has not been determined. An alanine-to-threonine substitution at position 194 (rtA194T) has been reported to be associated with tenofovir resistance,3 but additional studies are needed to confirm the association. Tenofovir had similar safety profile as adefovir in the phase III trials. Tenofovir has been reported to cause Fanconi syndrome and renal insufficiency, as well as osteomalacia and decrease in bone density. Monitoring of serum creatinine and phosphorus is recommended.4 The recommended dose of tenofovir is 300 mg daily. Dose adjustments should be made in patients with impaired renal function. Based on these new findings, the recommendation for first-line oral antiviral medications has been changed to tenofovir or entecavir, and adefovir has been moved to second-line oral antiviral medication. Interferon remains one of the first-line options for patients who do not have cirrhosis. Please refer to recommendations 15, 16, 20-24, 31 and 40, and tables 8, 9, 10e, and 11-13. Since the last update in 2007, additional data on activity of entecavir against human immunodeficiency virus (HIV) became available.5 Therefore, entecavir is no longer recommended in persons with HBV/HIV coinfection, who are receiving treatment for HBV alone. Please refer to recommendations 34 and 35. The guidelines were also updated to include recent changes in Centers for Disease Control and Prevention recommendations on HBV screening.6 The new recommendations expanded HBV screening to persons born in intermediate endemic areas and those who will be receiving cancer chemotherapy or long-term immunosuppressive therapy. Please refer to recommendations 1 and 39, and table 2.

The natural history of chronic hepatitis B virus infection.

Chronic hepatitis B virus (HBV) infection has a complicated course. Three phases are identified: an immune tolerant phase with high HBV DNA and normal alanine aminotransferase (ALT) levels associated with minimal liver disease; an immune active phase with high HBV DNA and elevated ALT levels with active liver inflammation; and an inactive phase with HBV DNA levels < 2000 IU/mL and normal ALT levels with minimal inflammation and fibrosis on liver biopsy. Affected persons can move progressively from one phase to the next and may revert backward. The primary adverse outcomes of chronic HBV infection are hepatocellular carcinoma (HCC) and cirrhosis. Published natural history studies were reviewed and ranked by the strength of evidence regarding the study design. Factors with the highest evidence of risk for development of HCC or cirrhosis from population‐based prospective cohort studies include male sex, family history of HCC, HBV DNA level above 2000 IU/mL in persons above age 40, HBV genotypes C and F, and basal core promoter mutation. Those with the next highest level of evidence include aflatoxin exposure, and heavy alcohol and tobacco use. Improved methods to identify persons at highest risk of developing HCC or cirrhosis are needed to allow intervention earlier with antiviral therapy in appropriate patients. Future studies should include prospective follow‐up of established population‐based cohorts as well as new cohorts recruited from multiple centers stratified by HBV genotypes/subgenotypes and clinical phase to determine the incidence of the various HBV phases, HCC, and cirrhosis. Also, nested case‐control studies assessing immunological and host genetic factors among persons with active and inactive disease phases, HCC, and cirrhosis could be conducted using these types of cohorts. (HEPATOLOGY 2009;49:S45–S55.)

Chronic hepatitis B: update of recommendations.

An estimated 350 million persons worldwide and 1.25 million in the United States are infected with hepatitis B virus (HBV). Hepatitis B carriers are at risk for development of cirrhosis and hepatocellular carcinoma (HCC). The natural history of chronic HBV infection is variable. Persons with chronic HBV infection need lifelong monitoring to determine if and when intervention with antiviral therapy is needed and to observe for serious sequelae. These guidelines were developed under the auspices of, and approved by, the Practice Guidelines Committee of the American Association for the Study of Liver Diseases. The original guidelines were published in HEPATOLOGY 2001;34:1225–1241.1 In light of recent progress, particularly in the treatment of chronic hepatitis B, these guidelines were updated in September of 2003. A complete version of the updated guidelines, including a review of recently published literature, can be found at the AASLD web site, www.aasld.org. Following is a summary of the updated recommendations for treatment of chronic hepatitis B. The recommendations were graded as I (randomized controlled trials), II-1 (controlled trials without randomization), II-2 (cohort or case-control analytic studies), II-3 (multiple time series, dramatic uncontrolled experiments), and III (opinions of respected authorities, descriptive epidemiology).

Negative Immune Regulator Tim-3 Is Overexpressed on T Cells in Hepatitis C Virus Infection and Its Blockade Rescues Dysfunctional CD4+ and CD8+ T Cells

ABSTRACT A number of emerging molecules and pathways have been implicated in mediating the T-cell exhaustion characteristic of chronic viral infection. Not all dysfunctional T cells express PD-1, nor are they all rescued by blockade of the PD-1/PD-1 ligand pathway. In this study, we characterize the expression of T-cell immunoglobulin and mucin domain-containing protein 3 (Tim-3) in chronic hepatitis C infection. For the first time, we found that Tim-3 expression is increased on CD4+ and CD8+ T cells in chronic hepatitis C virus (HCV) infection. The proportion of dually PD-1/Tim-3-expressing cells is greatest in liver-resident T cells, significantly more so in HCV-specific than in cytomegalovirus-specific cytotoxic T lymphocytes. Tim-3 expression correlates with a dysfunctional and senescent phenotype (CD127low CD57high), a central rather than effector memory profile (CD45RAnegative CCR7high), and reduced Th1/Tc1 cytokine production. We also demonstrate the ability to enhance T-cell proliferation and gamma interferon production in response to HCV-specific antigens by blocking the Tim-3-Tim-3 ligand interaction. These findings have implications for the development of novel immunotherapeutic approaches to this common viral infection.

Antibody Levels and Protection after Hepatitis B Vaccination: Results of a 15-Year Follow-up

Context Although administration of hepatitis B vaccine for infants is routine practice in many countries, we do not know whether the protection that this vaccine offers lasts beyond 10 years. Such information is essential to develop policies about booster vaccination. Contribution Of 841 Alaska Natives who received 3 doses of hepatitis B vaccination during 19811982 and were followed for 15 years, 84% had protective levels of antibody to hepatitis B surface antigen that indicated continued protection. The greatest decline in antibody levels occurred in people who received vaccine before 4 years of age. Definite asymptomatic breakthrough infections occurred in 16 participants. Cautions Only about half of the initial cohort of 1578 was available for testing at 15 years. The Editors Universal vaccination of infants with hepatitis B vaccine is included in the immunization programs of most countries and has been shown to be effective in reducing the rate of chronic hepatitis B virus (HBV) infection (1, 2). Protection has been demonstrated in persons and populations vaccinated for 5 to 10 years, and rates of asymptomatic breakthrough HBV infection have been extremely low (3-9). However, the duration of protection afforded by hepatitis B vaccination beyond 10 years and the possible need for booster doses of this vaccine are unknown. Alaska Natives have a high prevalence of chronic HBV infection, primarily acquired during early childhood (10). Between November 1981 and May 1982, Alaska Natives residing in 15 villages in southwest Alaska were enrolled in a cohort study to ascertain the immunogenicity and long-term effectiveness of hepatitis B vaccination (11-14). We report data on the persistence of antibodies to hepatitis B surface antigen (anti-HBs), incidence of HBV infection, and the genetic characteristics of the HBV isolates in persons with breakthrough infections 15 years after initial vaccination of this cohort. Methods Participants and Data Collection A total of 1578 Alaska Natives who were serologically negative for hepatitis B surface antigen (HBsAg) and antibody to hepatitis B core antigen (anti-HBc) were vaccinated on a 0-, 1-, and 6-month schedule with 3 doses of plasma-derived hepatitis B vaccine (Heptavax, Merck & Co., Inc., West Point, Pennsylvania) beginning in 1981 (11). Persons younger than 20 years of age received the 10-g dose, and adults received the 20-g dose. Of the 1578 persons vaccinated, 1436 (91%) were tested for an anti-HBs response 6 months after the last vaccine dose. From 1982 to 1992, serum specimens were obtained annually and once again during 1996 from as many of the 1578 consenting participants as possible. The Institutional Review Boards of the Alaska Area Native Health Service, the Indian Health Service, the Centers for Disease Control and Prevention, and the Yukon-Kuskokwim Health Corporation and the Norton Sound Regional Alaska Native health boards approved this study. All participants 18 years of age and older and parents of children younger than 18 years of age had provided signed informed consent to participate in the study; children older than 7 years of age gave verbal assent. The number of HBsAg-positive persons in each village was obtained from a registry used to follow patients with chronic HBV infection (15). Serologic Testing All serum specimens were tested for HBsAg, anti-HBs, and anti-HBc by radioimmunoassay using commercial test kits (Abbott Laboratories, Abbott Park, Illinois). At the initial testing of the cohort for anti-HBs, results were reported in sample ratio units. However, subsequent anti-HBs results were reported in milli international units (mIU) per mL using a World Health Organization reference standard (12-14). To ensure comparability of results over time, all serum specimens from each participant with sufficient volume (99.9% of all specimens collected during the study) were retested to determine anti-HBs levels in mIU/mL. Detection of HBV DNA and Nucleic Acid Sequencing Hepatitis B virus DNA was extracted from serum specimens (50 L) of participants with serologic markers of HBV infection by using commercially available reagents (MasterPure Complete DNA and RNA Purification Kit, Epicentre Technologies, Madison, Wisconsin), as described previously (16, 17). The HBsAg genomic region was then amplified by dilution cloning polymerase chain reaction by using previously described primers and methods to identify circulating variants of HBsAg (16, 17). The polymerase chain reaction products were purified and the nucleic acid sequence of the amplified region were determined by using prism dye or dRhodamine terminator cycle reactions (Applied Biosystems, Foster City, California) and automated sequencing (ABI Model 373 or 377, Applied Biosystems) (18). Sequence data were further analyzed by Sequence Navigator (ABI) and GCG software (19). Definitions The initial anti-HBs level was measured 6 months after the third dose of vaccine and 1 year after the first dose of vaccine. Participants with an initial anti-HBs level of at least 10 mIU/mL were considered vaccine responders. An anti-HBs level of 2 mIU/mL or greater was considered a positive result on subsequent specimens. A booster response was defined as a 2-fold or greater increase in anti-HBs levels between serologic test results. A definite HBV infection in a participant was defined as 1) 2 or more consecutive serum specimens positive for anti-HBc more than 1 year after the initial vaccine dose, 2) a single positive anti-HBc result with a positive HBV DNA result, or 3) any HBsAg-positive test result. A possible HBV infection was defined as a single positive or 2 nonconsecutive positive anti-HBc results. Participants who developed anti-HBc were interviewed for history of icterus or other clinical signs or symptoms compatible with acute hepatitis, and village and hospital medical records were reviewed for evidence of an illness compatible with viral hepatitis. Statistical Analysis Among persons who inadvertently received additional doses of hepatitis B vaccine during the follow-up period, anti-HBs results after the additional vaccine dose or doses were excluded from the analyses. Results for anti-HBs among persons with definite HBV infections were excluded from analyses after anti-HBc appeared. The primary outcomes in this study were the cumulative number of persons with a definite HBV infection during all follow-up years and the anti-HBs levels at the 15-year follow-up. The definitions of age classes (0 to 4 years, 5 to 19 years, 20 to 49 years, 50 years) were similar to those in a previously published analysis of this cohort (14). Although these data have been presented previously (11-14), we have provided the proportion of persons initially responding to vaccination. Quantitative anti-HBs levels are presented as geometric mean concentrations (GMCs). In bivariate analyses, analysis of variance was used to test the 15-year anti-HBs concentrations (log-transformed). Incidence rates of definite HBV infection were compared by using the Fisher exact test. We analyzed factors associated with anti-HBs levels over the 15 years after the first vaccine dose by using a linear mixed model (PROC MIXED in SAS version 9.1, SAS Institute, Inc., Cary, North Carolina) (19). We chose a longitudinal mixed linear model because it makes inferences by using information from the entire cohort collected at all follow-up time points. Levels of anti-HBs were log-transformed before analysis, and concentrations of 0 mIU/mL were assigned a value of 1.0 mIU/mL. Factors considered in the model were time (entered as a continuous covariate; linear and quadratic term were considered), age class at initial vaccination, sex, the log of the initial anti-HBs level, presence of an HBsAg-infected person in the household at the start of the study, and the proportion of village residents with chronic HBV infection at the end of follow-up, along with interaction terms involving time. Significance of 1 factor alone, such as age or sex, is called a main effect and is not of primary interest for this presentation. Of primary interest are the interaction terms between time and other factors. A significant interaction of time with another variable, such as sex, indicates that the decline in anti-HBs level differed between males and females. We obtained parameter estimates by using restricted maximum likelihood. We used an unstructured covariance matrix to account for dependence of observations across time within individuals. Backward elimination of statistically nonsignificant terms yielded a final model of main effects and time interaction terms. If the time interaction term was statistically significant, the main effect term remained in the model regardless of statistical significance. We used the Wald chi-square statistic to test covariates. Contrast tests were 2-sided, and an level of 0.05 was required. We used residual plots to evaluate model fit. A secondary outcome was a boost in anti-HBs level at the 11- or 15-year follow-up among persons without additional doses of vaccine. We used the chi-square test or the CochranMantelHaenszel test to compare age and sex of persons with a booster response to those of persons without a booster response at both follow-up years. All P values were exact where appropriate and were 2-sided; results were considered statistically significant at the 0.05 level. We conducted analyses by using StatXact4 (Cytel Software Corp., Cambridge, Massachusetts) and SAS software, version 9.1 (SAS Institute, Inc.). Missing Data Throughout the entire study, anti-HBs determinations were observed for 68% of all potential observational time points (Appendix Table 1). The 15 remote rural Alaskan study villages are accessible only by airplane. During each year, study personnel flew into each village for 1 to 2 days and attempted to recruit all available participants. Persons not available or out of the village for the day were considered miss

Tim-3 expression on PD-1+ HCV-specific human CTLs is associated with viral persistence, and its blockade restores hepatocyte-directed in vitro cytotoxicity

Having successfully developed mechanisms to evade immune clearance, hepatitis C virus (HCV) establishes persistent infection in approximately 75%-80% of patients. In these individuals, the function of HCV-specific CD8+ T cells is impaired by ligation of inhibitory receptors, the repertoire of which has expanded considerably in the past few years. We hypothesized that the coexpression of the negative regulatory receptors T cell immunoglobulin and mucin domain-containing molecule 3 (Tim-3) and programmed death 1 (PD-1) in HCV infection would identify patients at risk of developing viral persistence during and after acute HCV infection. The frequency of PD-1-Tim-3- HCV-specific CTLs greatly outnumbered PD-1+Tim-3+ CTLs in patients with acute resolving infection. Moreover, the population of PD-1+Tim-3+ T cells was enriched for within the central memory T cell subset and within the liver. Blockade of either PD-1 or Tim-3 enhanced in vitro proliferation of HCV-specific CTLs to a similar extent, whereas cytotoxicity against a hepatocyte cell line that expressed cognate HCV epitopes was increased exclusively by Tim-3 blockade. These results indicate that the coexpression of these inhibitory molecules tracks with defective T cell responses and that anatomical differences might account for lack of immune control of persistent pathogens, which suggests their manipulation may represent a rational target for novel immunotherapeutic approaches.

Antibody Levels and Protection after Hepatitis B Vaccine: Results of a 22-Year Follow-Up Study and Response to a Booster Dose

BACKGROUND The duration of protection in children and adults (including health care workers) resulting from the hepatitis B vaccine primary series is unknown. METHODS To determine the protection afforded by hepatitis B vaccine, Alaska Native persons who had received plasma-derived hepatitis B vaccine when they were >6 months of age were tested for antibody to hepatitis B surface antigen (anti-HBs) 22 years later. Those with levels <10 mIU/mL received 1 dose of recombinant hepatitis B vaccine and were evaluated on the basis of anti-HBs measurements at 10-14 days, 30-60 days, and 1 year. RESULTS Of 493 participants, 60% (298) had an anti-HBs level >or=10 mIU/mL. A booster dose was administered to 164 persons, and 77% responded with an anti-HBs level >or=10 mIU/mL at 10-14 days, reaching 81% by 60 days. Response to a booster dose was positively correlated with younger age, peak anti-HBs response after primary vaccination, and the presence of detectable anti-HBs before boosting. Considering persons with an anti-HBs level >or=10 mIU/mL at 22 years and those who responded to the booster dose, protection was demonstrated in 87% of the participants. No new acute or chronic hepatitis B virus infections were identified. CONCLUSIONS The protection afforded by primary immunization with plasma-derived hepatitis B vaccine during childhood and adulthood lasts at least 22 years. Booster doses are not needed.

Hepatitis B Virus Genotypes in Alaska Native People with Hepatocellular Carcinoma: Preponderance of Genotype F

BACKGROUND The development of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B virus (HBV) infection has been associated with specific HBV genotypes and the presence of specific mutations. METHODS From a cohort of Alaska Native people with chronic HBV infection, we genotyped 47 patients with HCC and 1129 patients without HCC, and we tested patients with HCC and control patients for mutations in the basal core promoter and precore regions. RESULTS Genotype F was found in 68% of patients with HCC, versus 18% of those without HCC (P<.001). For patients with genotype F, the median age at diagnosis of HCC was lower than that for patients with other genotypes (22.5 vs. 60 years, respectively; P=.002). Overall, there were no significant differences in the number of basal core promoter and precore region mutations between patients with HCC and control patients. CONCLUSIONS We found a significant association between genotype F and the development of HCC among Alaska Native people with chronic HBV infection but no significant association between HCC and basal core promoter or precore mutations in genotype F.

The influence of hepatitis B virus genotype and subgenotype on the natural history of chronic hepatitis B

BackgroundChronic infection with hepatitis B virus (HBV) is associated with a high lifetime risk of developing hepatocellular carcinoma (HCC) and cirrhosis of the liver.PurposeTo review the studies published to date regarding the association of HBV genotypes and subgenotypes in the development of adverse sequelae from HBV.MethodsReview of the literature for articles describing studies of HBV genotype/subgenotypes and development of HCC, cirrhosis, and liver-related death.ResultsEight 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.ConclusionsStudies 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.