Acute exacerbations of chronic type B hepatitis are accompanied by increased T cell responses to hepatitis B core and e antigens. Implications for hepatitis B e antigen seroconversion

Effect of immune checkpoint inhibitors on patients with hepatitis B virus infection

Hepatitis B virus (HBV) infection is regarded as a major health concern worldwide. In patients with chronic HBV infection, exhausted virus-specific CD8+ T cells, resulting from the activation of the programmed cell death protein 1 and programmed death ligand 1 axis, play a key role in the chronicity of infection. Functional cure for HBV, defined as the seroclearance of hepatitis B surface antigen (HBsAg), is viewed as the optimal goal of chronic HBV infection treatment because HBsAg loss is associated with a low risk of hepatocellular carcinoma and a relatively favorable prognosis. Both interferon treatment and finite antiviral therapy are associated with positive HBV outcomes. Overall, combining immune checkpoint inhibitors with nucleos(t)ide analogs appears to be a promising approach for achieving HBsAg loss, particularly in patients with low HBsAg levels.

HBV shows different levels of adaptation to HLA class I-associated selection pressure correlating with markers of replication

BACKGROUND & AIMS

Immune responses by CD8 T cells are essential for control of HBV replication. Although selection of escape mutations in CD8 T-cell epitopes has been previously described in HBV infection, its overall influence on HBV sequence diversity and correlation with markers of HBV replication remain unclear.

METHODS

Whole-genome sequencing was applied to HBV isolates from 532 patients with chronic HBV infection and high-resolution HLA class I genotyping. Using a Bayesian model (HAMdetector) for identification of HLA-associated mutational states (HAMs), the frequency and location of residues under CD8 T-cell selection pressure were determined and the levels of adaptation of individual isolates were quantified.

RESULTS

Using previously published thresholds for the identification of HAMs, a total of 295 residues showed evidence of CD8 T-cell escape, the majority of which were located in previously unidentified epitopes. Interestingly, HAMs were highly enriched in the HBV core protein compared to all other proteins. When individual HBV isolates were compared, different levels of adaptation to HLA class I immune pressure were noted. The level of adaptation increased with patient age and correlated with markers of replication, with low levels of adaptation in HBeAg-positive infection. Furthermore, the levels of adaptation negatively correlated with HBV viral load and HBsAg levels, consistent with high levels of HLA class I-associated selection pressure in patients with low replication levels.

CONCLUSIONS

HBV sequence diversity is shaped by HLA class I-associated selection pressure with the HBV core protein being a predominant target of selection. Importantly, different levels of adaptation to immune pressure were observed between HBV infection stages, which need to be considered in the context of T-cell-based therapies.

IMPACT AND IMPLICATIONS

The immune response mediated by CD8 T cells plays a critical role in controlling HBV infection and shows promise for therapeutic strategies aimed at achieving a functional cure. This study demonstrates that mutational escape within CD8 T-cell epitopes is common in HBV and represents a key factor in the failure of immune control. Notably, the HBV core protein emerges as the primary target of CD8 T-cell selection pressure. Additionally, the observed correlation between HBV adaptation levels and viral replication markers indicates that CD8 T-cell immunity may influence transitions between phases of chronic HBV infection.

HBeAg induces neutrophils activation impairing NK cells function in patients with chronic hepatitis B

BACKGROUND

The role of neutrophils in hepatitis B virus (HBV) infection has been a subject of debate due to their involvement in antiviral responses and immune regulation. This study aimed to elucidate the neutrophil characteristics in patients with chronic hepatitis B (CHB).

METHODS

Through flow cytometry and ribonucleic acid-sequencing analysis, the phenotypes and counts of neutrophils were analyzed in patients with CHB. Moreover, the effects of HBeAg on neutrophils and the corresponding pattern recognition receptors were identified. Simultaneously, the cross-talk between neutrophils and natural killer (NK) cells was investigated.

RESULTS

Neutrophils were activated in patients with CHB, characterized by higher expression levels of programmed death-ligand 1 (PD-L1), cluster of differentiation 86, and interleukin-8, and lower levels of CXC motif chemokine receptor (CXCR) 1 and CXCR2. Hepatitis B e antigen (HBeAg) partially induces neutrophil activation through the Toll-like receptor 2 (TLR2). A consistent upregulation of the TLR2 and HBeAg expression was observed in patients with CHB. Notably, the genes encoding molecules pivotal for NK-cell function upon NK receptor engagement enriched in neutrophils after HBeAg activation. The HBeAg-activated neutrophils demonstrated the ability to decrease the production of interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) in NK cells, while the PD-1 and PD-L1 pathways partially mediated the immunosuppression.

CONCLUSIONS

The immunosuppression of neutrophils induced by HBeAg suggests a novel pathogenic mechanism contributing to immune tolerance in patients with CHB.

Use of HBV RNA and to predict change in serological status and disease activity in CHB

BACKGROUND AND AIMS

Predicting changes in disease activity and serological endpoints is necessary for the management of patients with chronic hepatitis B (CHB). We examined whether HBV RNA and hepatitis B core-related antigen (HBcrAg), two specialized virological markers proposed to reflect the activity of covalently closed circular DNA, may improve the ability to predict not sustained inactive carrier phase, spontaneous alanine aminotransferase (ALT) flare, HBeAg loss, and HBsAg loss.

APPROACH AND RESULTS

Among eligible participants enrolled in the North American Hepatitis B Research Network Adult Cohort Study, we evaluated demographic, clinical, and virologic characteristics, including HBV RNA and HBcrAg, to predict not sustained inactive carrier phase, ALT flare, HBeAg loss, and HBsAg loss through a series of Cox proportional hazard or logistic regression models, controlling for antiviral therapy use. Among the study population, 54/103 participants experienced not sustained inactive carrier phase, 41/1006 had a spontaneous ALT flare, 83/250 lost HBeAg, and 54/1127 lost HBsAg. HBV RNA or HBcrAg were predictive of all 4 events. However, their addition to models of the readily available host (age, sex, race/ethnicity), clinical (ALT, use of antiviral therapy), and viral factors (HBV DNA), which had acceptable-excellent accuracy (e.g., AUC = 0.72 for ALT flare, 0.92 for HBeAg loss, and 0.91 for HBsAg loss), provided only small improvements in predictive ability.

CONCLUSION

Given the high predictive ability of readily available markers, HBcrAg and HBV RNA have a limited role in improving the prediction of key serologic and clinical events in patients with CHB.

Systemic cytokine and viral antigen-specific responses in hepatitis D virus RNA positive versus HDV RNA negative patients

Background

Hepatitis B virus (HBV)/Hepatitis D Virus (HDV) co-infection increases the risk of severe liver disease compared to HBV mono-infection. Adaptive immune responses to HDV are weakly detectable, and the involvement of innate immunity in the progression of HDV-related liver fibrosis is suggested. We hypothesize that an overall innate immune activation in HBV/HDV co-infection plays a role in liver disease progression and also impacts virus specific T cell response.

Methods

Sixteen HBV/HDV-co-infected-patients (median age 42y/7F/6 Asian/4 White/6 Black/15 HBeAg-) and 8 HBV monoinfected-patients (median age 39y/4F/4 Asian/3 Black/1 White/HBeAg-) with median follow-up of 5 years were enrolled. Liver fibrosis was assessed by liver stiffness measurement (LSM, FibroScan®). Proliferation of CD3 + CD4+ T cells in response to viral antigens using CFSE assays and cytokine secreting monocytes was analyzed by flow cytometry.

Results

Of 16 HBV/HDV, 11 were HDV-RNA+ (HBV-DNA 0-1,040 IU/mL), 5/11 Interferon (IFN) + Nucleos/tide Analog (NA), 3/11 NA monotherapy, median ALT 77 U/L at the time of sample collection, median LSM of 9.8. In 5 HDV RNA-, median HBV DNA 65 IU/mL, 4/5 prior IFN and/or NA, ALT 31 U/L, and median LSM 8.5 kPa. In 8 HBV controls, median HBV-DNA, ALT, LSM was 69 IU/mL, 33 U/L,5 kPa, respectively. PBMC stimulation with HBV core antigen (HBcAg) and HDV antigen (HDAg) showed weaker CD3 + CD4 + T-cell proliferation in HDV-RNA+ vs. HDV RNA- and HBV-mono-infected patients (p < 0.05). In HDV-RNA+ patients, a correlation between ALT and TNF-α (r = 0.76, p = 0.008), higher IL-10 levels and increased proportion of CD14 + TNF-α+ cells were found.

Conclusion

In summary, during HBV/HDV coinfection, HDV RNA+ patients had weaker HBV and HDV specific responses, associated with increased TNF-α + monocytes irrespective of IFN treatment.

HBeAg-Negative/Anti-HBe-Positive Chronic Hepatitis B: A 40-Year-Old History

Hepatitis B “e” antigen (HBeAg) negative chronic hepatitis B (CHB), 40 years since discovery in the Mediterranean area, has become the most prevalent form of HBV-induced liver disease worldwide and a major health care burden caused by HBV infection. A great deal of knowledge accumulated over the last decades provides consistent evidence on the bimodal dynamics of the expression of structural and non-structural forms of the viral core proteins which associate with different virologic and clinic–pathologic outcomes of HBV infection. In absence of serum HBeAg, the presence and persistence of HBV replication causes and maintains virus-related liver injury. Thus, in clinical practice it is mandatory to screen HBV carriers with HBeAg-negative infection for the early diagnosis of HBeAg-negative CHB since antiviral therapy can cure HBV-induced liver disease when started at early stages.

Longitudinal characterization of phenotypic profile of T cells in chronic hepatitis B identifies immune markers associated with HBsAg loss

Background

The current desirable endpoint of treatment against chronic hepatitis B virus infection (cHBV) is to achieve a functional cure, which is defined as HBsAg loss (sAg-L) with or without anti-HBs seroconversion. However, the immunological features that are associated with functional cure have not been studied in detail.

Methods

172 cHBV patients (67 HBeAg+ and 105 HBeAg-), including 141 HBsAg retained (sAg-R) patients (115 chronic hepatitis and 26 asymptomatic carriers), 31 sAg-L patients, and 24 healthy individuals (vaccinated but not infected with HBV) were examined for their T cell phenotypic profile and HBV-specific T cell responses by flow cytometry. 18 cHBV patients with low serum HBsAg levels were also longitudinally followed for their T cell phenotypic profile and HBV-specific T cell responses up to 60 weeks.

Findings

sAg-L patients showed distinct CD4⁺ and CD8⁺ T cell phenotype fingerprints compared to those of sAg-R patients, as mainly indicated by the upregulation of HLA-DR on both CD4⁺ and CD8⁺ T cells, and a potent HBcAg-specific CD8⁺ T cell response. The changes in the T cell phenotype in cHBV patients were even more profound during rapid HBsAg decrease and was associated with interferon α treatment. The expression of HLA-DR (r = 0·3269, p = 0·0037), CD95 (r = 0·2796, p = 0·0151), CD40L (r = 0·2747, p = 0·0156), CTLA-4 (r = 0·2786, p = 0·0148), TIM-3 (r = 0·3082, p = 0·0068), CD107a (r = 0·3597, p = 0·0013) on CD4⁺ T cells, and HLA-DR (r = 0·3542, p = 0·0016), CD69 (r = 0·2507, p = 0·0279), CD107a (r = 0·2875, p = 0·0112) on CD8⁺ T cells were positively correlated with the rate of HBsAg decrease. The expression of HLA-DR (r = 0·2846, p = 0·0009) and CD95 (r = 0·2442, p = 0·0049) on CD8⁺ T cells were positively correlated with the magnitude of the HBcAg-specific T cell responses in cHBV patients. Importantly, CTLA-4, CD95 and CD107a expression on CD4⁺ T cells, as well as HLA-DR and TIM-3 expression on CD8⁺ T cells in combination with HBsAg quantification were identified as potential predictive factors for sAg-L within 48 weeks in cHBV patients.

Interpretation

The onset of HBsAg decrease and subsequent loss in cHBV patients on treatment is associated with significant alterations of both CD4⁺ and CD8⁺ T cell phenotypes. Characterization of the T cell phenotype in cHBV patients may present predicative value for sAg-L.

Funding

National Natural Science Foundation of China, National Scientific and Technological Major Project of China, Integrated Innovative Team for Major Human Diseases Program of Tongji Medical College, “Double-First Class” Project for the International Cooperation Center on Infection and Immunity, HUST.

Transaminase Elevations during Treatment of Chronic Hepatitis B Infection: Safety Considerations and Role in Achieving Functional Cure

While current therapies for chronic HBV infection work well to control viremia and stop the progression of liver disease, the preferred outcome of therapy is the restoration of immune control of HBV infection, allowing therapy to be removed while maintaining effective suppression of infection and reversal of liver damage. This “functional cure” of chronic HBV infection is characterized by the absence of detectable viremia (HBV DNA) and antigenemia (HBsAg) and normal liver function and is the goal of new therapies in development. Functional cure requires removal of the ability of infected cells in the liver to produce the hepatitis B surface antigen. The increased observation of transaminase elevations with new therapies makes understanding the safety and therapeutic impact of these flares an increasingly important issue. This review examines the factors driving the appearance of transaminase elevations during therapy of chronic HBV infection and the interplay of these factors in assessing the safety and beneficial nature of these flares.

[Natural History and Treatment Indications of Chronic Hepatitis B]

HBV is the most common etiology of both liver cirrhosis and hepatocellular carcinoma in Korea. Despite much progress made, the currently available antiviral therapies cannot eradicate or eliminate this virus. Hence, the benefits and risks of antiviral therapy should be carefully evaluated on an individual basis and within the context of the clinical situation. The ultimate goals of treatment are to decrease the mortality from liver disease. The benefits of antiviral therapy come from prevention of progression of liver disease. Understanding the natural history of chronic HBV infection is a key step in the decision making process to treat patients with chronic HBV infection. Generally, chronic hepatitis B patients in the immune tolerant phase and immune inactive phase are not recommended to undergo antiviral treatment, except for those patients in special conditions (e.g., immunosuppression or anticancer chemotherapy). Chronic hepatitis B patients in the immune active phase are recommended for antiviral therapy. For patients with liver cirrhosis, treatment should be considered when serum HBV DNA is detectable regardless of the serum level of ALT.

Diagnosis and management of toxicities of immune checkpoint inhibitors in hepatocellular carcinoma

Immune checkpoint inhibitors (ICIs) have reshaped cancer therapy. ICIs enhance T cell activation through various mechanisms and may help reverse the exhausted phenotype of tumour-infiltrating lymphocytes. However, disrupting the key role that checkpoint molecules play in immune homeostasis may result in autoimmune complications. A broad range of immune-related adverse events (irAEs) involve almost every organ but mostly affect the skin, digestive system, lung, endocrine glands, nervous system, kidney, blood cells, and musculoskeletal system. They are usually manageable but can be life-threatening. The incidence of irAEs is not very different in patients with hepatocellular carcinoma (HCC) compared to other tumour types, although there is a trend towards a higher incidence of hepatic irAEs. HCC usually develops on a background of cirrhosis with associated systemic manifestations. Extrahepatic organ dysfunction in cirrhosis may cause signs and symptoms that overlap with irAEs or increase their severity. Available guidelines for the management of irAEs have not specifically considered the assessment of toxicities in the context of patients with liver cancer and cirrhosis. This review addresses the toxicity profile of ICIs in patients with HCC, focusing on the challenges that the underlying liver disease poses to their diagnosis and management. Challenges include late recognition, inadequate work-up and delayed treatment, overdiagnosis and inappropriate interruption of ICIs, complications caused by immunosuppressive therapy, and increased cost. A specific algorithm for the management of hepatic irAEs is provided.

TNF-α/IFN-γ profile of HBV-specific CD4 T cells is associated with liver damage and viral clearance in chronic HBV infection

BACKGROUND & AIMS

The role of hepatitis B virus (HBV)-specific CD4 T cells in patients with chronic HBV infection is not clear. Thus, we aimed to elucidate this in patients with chronic infection, and those with hepatitis B flares.

METHODS

Through intracellular IFN-γ and TNF-α staining, HBV-specific CD4 T cells were analyzed in 68 patients with chronic HBV infection and alanine aminotransferase (ALT) <2x the upper limit of normal (ULN), and 28 patients with a hepatitis B flare. HBV-specific HLA-DRB1*0803/HLA-DRB1*1202-restricted CD4 T cell epitopes were identified.

RESULTS

TNF-α producing cells were the dominant population in patients' HBV-specific CD4 T cells. In patients with ALT <2xULN, both the frequency and the dominance of HBV-specific IFN-γ producing CD4 T cells increased sequentially in patients with elevated levels of viral clearance: HBV e antigen (HBeAg) positive, HBeAg negative, and HBV surface antigen (HBsAg) negative. In patients with a hepatitis B flare, the frequency of HBV core-specific TNF-α producing CD4 T cells was positively correlated with patients' ALT and total bilirubin levels, and the frequency of those cells changed in parallel with the severity of liver damage. Patients with HBeAg/HBsAg loss after flare showed higher frequency and dominance of HBV-specific IFN-γ producing CD4 T cells, compared to patients without HBeAg/HBsAg loss. Both the frequency and the dominance of HBV S-specific IFN-γ producing CD4 T cells were positively correlated with the decrease of HBsAg during flare. A differentiation process from TNF-α producing cells to IFN-γ producing cells in HBV-specific CD4 T cells was observed during flare. Eight and 9 HBV-derived peptides/pairs were identified as HLA-DRB1*0803 restricted epitopes and HLA-DRB1*1202 restricted epitopes, respectively.

CONCLUSIONS

HBV-specific TNF-α producing CD4 T cells are associated with liver damage, while HBV-specific IFN-γ producing CD4 T cells are associated with viral clearance in patients with chronic HBV infection.

LAY SUMMARY

TNF-α producing cells are the dominant population of hepatitis B virus (HBV)-specific CD4 T cells in patients with chronic HBV infection. This population of cells might contribute to the aggravation of liver damage in patients with a hepatitis B flare. HBV-specific IFN-γ producing CD4 T cells are associated with HBV viral clearance. Differentiation from HBV-specific TNF-α producing CD4 T cells into HBV-specific IFN-γ producing CD4 T cells might favor HBV viral clearance.

Association Between Severe Serum Alanine Aminotransferase Flares and Hepatitis B e Antigen Seroconversion and HBV DNA Decrease in Untreated Patients With Chronic HBV Infection

BACKGROUND & AIMS

The incidence and outcomes of alanine aminotransferase (ALT) flares during the natural history of chronic HBV infection has not been determined in a large, racially heterogeneous group of patients in North America.

METHODS

We collected data from the Hepatitis B Research Network-an observational cohort study of untreated adults with chronic HBV infection enrolled at 21 sites in the United States and Canada. Clinical and laboratory data were collected from 1587 participants (49.9% male, 73.7% Asian, 35.2% genotype B infection, mean age of 42.6 years) at enrollment, at weeks 12 and 24, and every 24 weeks thereafter for a planned 5 years of follow up (from January 2011 through May 2016). Participants were excluded if they had a history of hepatic decompensation, hepatocellular carcinoma, solid organ or bone marrow transplantation, chronic immune suppression, or antiviral therapy within 6 months before enrollment. Levels of ALT were measured in serum samples and flares were defined as at least 10 times the upper limit of normal (300 U/L in males and 200 U/L in females).

RESULTS

ALT flares occurred in 102 participants (6%), with 31 flares (30%) occurring at baseline. The 4-year cumulative incidence of ALT flares was 5.7%. The median peak level of ALT was 450 U/L (25th-75th percentile, 330 U/L to 747 U/L) with a maximum of 2578 U/L. In multivariable analysis, factors associated with the occurrence of an ALT flares were: male sex (odds ratio [OR], 3.02; P=.0007), higher baseline HBV DNA values (OR per log10, 1.41; P<.0001), at risk alcohol use (OR, 2.27 vs none or moderate; P=.02), and higher FIB-4 values (OR, 1.85 per log2; P<.0001). Older age was associated with lower odds of an ALT flare (OR, 0.63 per 10 years; P=.004). Rate of decrease in level of HBV DNA by 1 log10 or more (59 vs 23 per 100 person-years for HB e antigen (HBeAg)-positive vs HBeAg-negative patients; P=.003) and HBeAg loss (47 vs 15 per 100 person-years; P=.002) were higher in patients with an ALT flare than in patients without, but the rate of HBsAg loss was similar (4 vs 2 per 100 person-years; P=.26). No hepatic decompensation, liver transplants, or deaths were observed in participants with ALT flares.

CONCLUSION

In a large racially heterogeneous cohort of adults with chronic HBV infection, the cumulative incidence of severe ALT flares was low and associated with greater decreases in HBV DNA and loss of HBeAg, but not with loss of HBsAg.

Persistence of Hepatitis B Virus DNA and the Tempos between Virion Secretion and Genome Maturation in a Mouse Model

Chronic infection with human hepatitis B virus (HBV) could lead to cirrhosis and hepatoma. At present, there is no effective treatment to eradicate the virus from patients. HBV in chronic carriers does not exist as a single homogeneous population. The most frequent naturally occurring mutation in HBV core protein occurs at amino acid 97, changing an isoleucine to leucine (I97L). One dogma in the field is that only virions containing a mature genome are preferentially secreted into the medium. Here, we demonstrated that mutant I97L can secrete immature genome in mice. Although viral DNA of mutant I97L with immature genome is less persistent than wild-type HBV in time course experiments, viral DNA of mutant P130T with genome hypermaturation, surprisingly, is more persistent. Therefore, virion secretion regulated by genome maturity could influence viral persistence. It remains an open issue whether virion secretion could be a drug target for HBV therapy.

Hepatitis B virus (HBV) core protein (HBc) accumulates frequent mutations in natural infection. Wild-type HBV is known to secrete predominantly virions containing mature DNA genome. However, a frequent naturally occurring HBc variant, I97L, changing from an isoleucine to a leucine at amino acid 97, exhibited an immature secretion phenotype in culture, which preferentially secretes virions containing immature genomes. In contrast, mutant P130T, changing from a proline to a threonine at amino acid 130, exhibited a hypermaturation phenotype by accumulating an excessive amount of intracellular fully mature DNA genome. Using a hydrodynamic delivery mouse model, we studied the in vivo behaviors of these two mutants, I97L and P130T. We detected no naked core particles in all hydrodynamically injected mice. Mutant I97L in mice exhibited pleiotropic phenotypes: (i) excessive numbers of serum HBV virions containing immature genomes, (ii) significantly reduced numbers of intracellular relaxed-circle and single-stranded DNAs, and (iii) less persistent intrahepatic and secreted HBV DNAs than wild-type HBV. These pleiotropic phenotypes were observed in both immunocompetent and immunodeficient mice. Although mutant P130T also displayed a hypermaturation phenotype in vivo, it cannot efficiently rescue the immature virion secretion of mutant I97L. Unexpectedly, the single mutant P130T exhibited in vivo a novel phenotype in prolonging the persistence of HBV genome in hepatocytes. Taken together, our studies provide a plausible rationale for HBV to regulate envelopment morphogenesis and virion secretion via genome maturity, which is likely to play an important role in the persistence of viral DNA in this mouse model.

IMPORTANCE Chronic infection with human hepatitis B virus (HBV) could lead to cirrhosis and hepatoma. At present, there is no effective treatment to eradicate the virus from patients. HBV in chronic carriers does not exist as a single homogeneous population. The most frequent naturally occurring mutation in HBV core protein occurs at amino acid 97, changing an isoleucine to leucine (I97L). One dogma in the field is that only virions containing a mature genome are preferentially secreted into the medium. Here, we demonstrated that mutant I97L can secrete immature genome in mice. Although viral DNA of mutant I97L with immature genome is less persistent than wild-type HBV in time course experiments, viral DNA of mutant P130T with genome hypermaturation, surprisingly, is more persistent. Therefore, virion secretion regulated by genome maturity could influence viral persistence. It remains an open issue whether virion secretion could be a drug target for HBV therapy.

Management of Fulminant Hepatitis B

Purpose of Review

Acute HBV infection and acute exacerbations of chronic HBV infection can cause acute liver injury (ALI) or fulminant hepatitis (FH). At this stage, spontaneous survival is poor, less than 25%. The purpose of this review is to provide an overview of specific management of patients with HBV-ALI/FH.

Recent Findings

Acute HBVinfection and acute exacerbations of chronic HBVinfection can cause acute liver injury (ALI) or fulminant hepatitis (FH). Spontaneous survival at this stage is poor. It is urgent to distinguish between these two entities so that antiviral therapy can be initiated rapidly. Although the indications for antiviral therapy are clear for HBV reactivation, there is no true consensus regarding ALI/FH related to acute HBV infection. The global management of HBV-related FH does not differ from that implemented for other causes of FH, i.e. close cardiorespiratory and neurological monitoring, treatment with acetylcysteine, organ support in the event of organ failure (haemodynamic, renal, respiratory) and albumin dialysis. Liver transplantation remains the only alternative when certain criteria for a poor prognosis are met. A recurrence of HBV infection on the graft can be prevented post-transplant by the administration of HBIG and antiviral therapy for HBV, the modalities varying depending on the risk of recurrence.

Risk factors for progression to acute-on-chronic liver failure during severe acute exacerbation of chronic hepatitis B virus infection

BACKGROUND

Acute exacerbation in patients with chronic hepatitis B virus (HBV) infection results in different severities of liver injury. The risk factors related to progression to hepatic decompensation (HD) and acute-on-chronic liver failure (ACLF) in patients with severe acute exacerbation (SAE) of chronic HBV infection remain unknown.

AIM

To identify risk factors related to progression to HD and ACLF in compensated patients with SAE of chronic HBV infection.

METHODS

The baseline characteristics of 164 patients with SAE of chronic HBV infection were retrospectively reviewed. Independent risk factors associated with progression to HD and ACLF were identified. The predictive values of our previously established prediction model in patients with acute exacerbation (AE model) and the model for end-stage liver disease (MELD) score in predicting the development of ACLF were evaluated.

RESULTS

Among 164 patients with SAE, 83 (50.6%) had compensated liver cirrhosis (LC), 43 had progression to HD without ACLF, and 29 had progression to ACLF within 28 d after admission. Independent risk factors associated with progression to HD were LC and low alanine aminotransferase. Independent risk factors for progression to ACLF were LC, high MELD score, high aspartate aminotransferase (AST) levels, and low prothrombin activity (PTA). The area under the receiver operating characteristic of the AE model [0.844, 95% confidence interval (CI): 0.779-0.896] was significantly higher than that of MELD score (0.690, 95%CI: 0.613-0.760, P < 0.05) in predicting the development of ACLF.

CONCLUSION

In patients with SAE of chronic HBV infection, LC is an independent risk factor for progression to both HD and ACLF. High MELD score, high AST, and low PTA are associated with progression to ACLF. The AE model is a better predictor of ACLF development in patients with SAE than MELD score.

Is the function of the HBeAg really unknown?

The immune response to the hepatitis B virus (HBV) vaccine in newborns of hepatitis B e antigen (HBeAg)-positive or HBeAg-negative mothers is the subject of Huang et al. The authors report no correlation between the HBeAg status of the mothers/cord blood and the newborns immune response to the vaccine, but, unfortunately, draw unfounded conclusions regarding the tolerogenic potential of in utero exposure to HBeAg. In this reply, I address the possible influence of in utero exposure to the HBeAg, and briefly review other characteristics of the HBeAg, that may promote HBV chronicity. I argue that the function of HBeAg should no longer be considered "unknown" and that immunotolerance/immunomodulation represent the dominant functions of the HBeAg in viral-host interactions.

INASL Guidelines on Management of Hepatitis B Virus Infection in Patients receiving Chemotherapy, Biologicals, Immunosupressants, or Corticosteroids

Hepatitis B Virus (HBV) reactivation in patients receiving chemotherapy, biologicals, immunosupressants, or corticosteroids is emerging to be an important cause of morbidity and mortality in patients with current or prior exposure to HBV infection. These patients suffer a dual onslaught of illness: one from the primary disease for which they are receiving the culprit drug that led to HBV reactivation, and the other from HBV reactivation itself. The HBV reactivation not only leads to a compromised liver function, which may culminate into hepatic failure; it also adversely impacts the treatment outcome of the primary illness. Hence, identification of patients at risk of reactivation before starting these drugs, and starting treatment aimed at prevention of HBV reactivation is the best strategy of managing these patients. There are no Indian guidelines on management of HBV infection in patients receiving chemotherapy, biologicals, immunosupressants, or corticosteroids for the treatment of rheumatologic conditions, malignancies, inflammatory bowel disease, dermatologic conditions, or solid-organ or bone marrow transplantation. The Indian National Association for Study of the Liver (INASL) had set up a taskforce on HBV in 2016, with a mandate to develop consensus guidelines for management of various aspects of HBV infection, relevant to India. In 2017 the taskforce had published the first INASL guidelines on management of HBV infection in India. In the present guidelines, which are in continuation with the previous guidelines, the issues on management of HBV infection in patients receiving chemotherapy, biologicals, immunosupressants, or corticosteroids are addressed.

Long-term outcomes and predictive scores for hepatocellular carcinoma and hepatitis B surface antigen seroclearance after hepatitis B e-antigen seroclearance

The significance of hepatitis B e-antigen (HBeAg) seroclearance (ESC) in the long term is not well defined. The current study aimed to determine the clinical outcomes, the factors and predictive scores for hepatocellular carcinoma (HCC), and hepatitis B surface antigen (HBsAg) seroclearance of a large cohort of patients undergoing ESC. Patients with documented ESC were followed up 3- to 6-monthly. Baseline characteristics and longitudinal laboratory results were recorded. Predictive scores for HCC (HCC-ESC) and HBsAg seroclearance (HBsAg-ESC) were derived from multivariate Cox regression models. A total of 723 patients underwent ESC with a median ESC age and follow-up of 36.0 and 18.3 years, respectively. Only 3.5% and 3.0% had persistently normal alanine aminotransferase (ALT) and HBV DNA <2logs IU/mL, respectively, after ESC. For patients with 100%, 100%-90%, 90%-50%, 50%-10%, 10%-0%, and 0% normal ALT after HBeAg seroclearance, the rate of HCC was 4.3%, 2.2%, 3.6%, 3.9%, 17.3%, and 37.2% at 20 years after ESC, respectively (P < 0.001). At 20 years after ESC, the cumulative incidence of HCC and HBsAg seroclearance was 7.9% and 13.5%, respectively, with an overall survival of 91.5%. ESC age, male sex, cirrhosis, hypoalbuminemia, viral load, and ALT were significant factors for HCC, whereas ESC age, male sex, viral load, and antiviral therapy were significant factors for HBsAg seroclearance. The area under receiver operating characteristics for HCC-ESC and HBsAg-ESC scores to predict HCC and HBsAg seroclearance at 20 years after ESC was 0.92 and 0.74, respectively.

CONCLUSION

Male sex, older age at ESC, ALT, and higher level of HBV DNA were associated with higher rates of HCC after ESC. HCC-ESC and HBsAg-ESC predictive scores can determine the likelihood of developing HCC and achieving HBsAg seroclearance. (Hepatology 2018).

A Randomized Controlled Trial of Glycyrrhizin Plus Tenofovir vs. Tenofovir in Chronic Hepatitis B with Severe Acute Exacerbation

Objectives:

Severe acute exacerbation (SAE) of chronic hepatitis B (CHB) may progress to liver failure with high potential mortality despite the prompt treatment with nucleos(t)ide analogs. This study aimed to evaluate the efficacy and safety of glycyrrhizin in the treatment of CHB with SAE.

Methods:

Sixty patients with SAE of CHB were randomly treated with tenofovir plus intravenous glycyrrhizin (group A, n=30) or with tenofovir alone (group B, n=30). Primary end points were the improvement of serum levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) and model for end-stage liver disease (MELD) score. Secondary end point was overall mortality or receipt of liver transplantation by week 24.

Results:

Patients in group A had significant reductions of serum AST and ALT levels from baseline at days 3, 5, 8, and 15 than those in group B (all P<0.05). The MELD score significantly decreased since week 1 in the group A patients, whereas there were no changes relative to baseline in group B patients at weeks 1 and 2. By week 24, one (3.3%) of group A patients and four (13.3%) of group B patients died (n=3) or received liver transplantation (n=1) (P=0.177). Multivariate analysis identified baseline MELD score (P=0.021) as an independent factor for mortality or receipt of liver transplantation. There were no differences in the rates of grade 3 hypertension, hypokalemia and ascites between two groups.

Conclusions:

Early introduction of glycyrrhizin can be safe and helpful for patients with SAE of CHB.

Flares during long-term entecavir therapy in chronic hepatitis B

BACKGROUND AND AIM

The incidence and consequences of flares during first-line nucleos(t)ide analogue therapy are largely unknown. We aimed to investigate the incidence and outcome of alanine aminotransferase (ALT) flares during long-term entecavir (ETV) in chronic hepatitis B (CHB).

METHODS

CHB patients treated with ETV monotherapy from 11 European centers were studied. Flare was defined as > 3× increase in ALT compared with baseline or lowest on-treatment level and an absolute ALT > 3× ULN. Flares were designated as host-induced (preceded by hepatitis B virus (HBV)-DNA decline), virus-induced (HBV-DNA increase), or indeterminate (stable HBV-DNA).

RESULTS

Seven hundred and twenty-nine patients were treated with ETV for median of 3.5 years. Thirty patients developed a flare with cumulative incidence of 6.3% at year 5. Baseline hepatitis B e antigen (HBeAg)-positivity (HR 2.84; P = 0.005) and high HBV-DNA (Hazard ratio (HR) 1.30; P = 0.003) predicted flares. There were 12 (40%) host-induced, 7 (23%) virus-induced, and 11 (37%) indeterminate flares. Host-induced flares occurred earlier than virus-induced (median: 15 vs 83 weeks; P = 0.027) or indeterminate flares (15 vs 109 weeks; P = 0.011). Host-induced flares were associated with biochemical remission, and HBeAg (n = 3) and hepatitis B surface antigen (n = 2) seroconversions were exclusively observed among patients with these flares. Virus-induced flares were associated with ETV resistance (n = 2) and non-compliance (n = 1).

CONCLUSION

The incidence of ALT flares during ETV was low in this real-life cohort. ETV can be safely continued in patients with host-induced flares. Treatment adherence and drug resistance must be assessed in patients with virus-induced flares.

Current role of transient elastography in the management of chronic hepatitis B patients

Liver fibrosis is an important prognostic factor for chronic hepatitis B (CHB), and accurate evaluation of the stage of liver fibrosis is crucial in establishing management strategies. While liver biopsy is still considered the gold standard for staging liver fibrosis or cirrhosis, transient elastography (TE), a noninvasive means of assessing liver fibrosis, has come to play an increasing role in this process. After extensive validation, TE is now regarded as a reliable surrogate maker for grading the severity of liver fibrosis in CHB patients. It can detect the extent of fibrosis in a patient and can also be used to evaluate longitudinal changes in liver fibrosis over time with or without interventional management, such as antiviral therapy. However, several confounders hinder the effective assessment of liver fibrosis using TE, such as extensive liver necroinflammation, hepatic congestion, and cholestasis. TE has limited use in obese patients or patients with ascites. Although TE has several limitations, due to its accessibility and safety, it is a valuable tool for the initial evaluation and follow-up in patients with CHB.

Dynamic of Immune Response induced in Hepatitis B Surface Antigen-transgenic Mice Immunized with a Novel Therapeutic Formulation

The development of therapeutic vaccines against chronic hepatitis B requires the capacity of the formulation to subvert a tolerated immune response as well as the evaluation of histopathological damage resulting from the treatment. In the present study, the dynamicity of induced immune response to hepatitis B surface antigen (HBsAg) was evaluated in transgenic mice that constitutively express the HBsAg gene (HBsAg-tg mice). After immunization with a vaccine candidate containing both surface (HBsAg) and core (HBcAg) antigens of hepatitis B virus (HBV), the effect of vaccination on clearance of circulating HBsAg and the potential histological alterations were examined. Transgenic (tg) and non-transgenic (Ntg) mice were immunized by intranasal (IN) and subcutaneous (SC) routes simultaneously. A control group received phosphate-buffered saline (PBS) by IN route and aluminum by SC route. Positive responses, at both humoral and cellular levels, were obtained after five immunizations in HBsAg-tg mice. Such responses were delayed and of lower intensity in tg mice, compared to vaccinated Ntg mice. Serum IgG response was characterized by a similar IgG subclass pattern. Even when HBsAg-specific CD8⁺ T cell responses were clearly detectable by gamma-interferon ELISPOT assay, histopathological alterations were not detected in any organ, including the liver and kidneys. Our study demonstrated, that it is possible to subvert the immune tolerance against HBsAg in tg mice, opening a window for new studies to optimize the schedule, dose, and formulation to improve the immune response to the therapeutic vaccine candidate. These results can be considered a safety proof to support clinical developments for the formulation under study.

How to cite this article

Freyre FM, Blanco A, Trujillo H, Hernández D, García D, Alba JS, Lopez M, Merino N, Lobaina Y, Aguilar JC. Dynamic of Immune Response induced in Hepatitis B Surface Antigen-transgenic Mice Immunized with a Novel Therapeutic Formulation. Euroasian J Hepato-Gastroenterol 2016;6(1):25-30.

Chronic Hepatitis B Virus Infection: Disease Revisit and Management Recommendations

Chronic hepatitis B virus (HBV) infection evolves from immune-tolerance phase, through immune clearance phase to a quiescent phase or reactivation as hepatitis B e antigen-negative hepatitis. Persistent infection may result in the development of cirrhosis and hepatocellular carcinoma (HCC). Host factors including gender, age, family history, HLA-DP, and viral factors including HBV DNA, genotypes, precore mutations, pre-S deletions, and hepatitis B surface antigen (HBsAg) level are associated with the development of these complications. Risk scores for the development of HCC have been derived. Patients with persistently elevated alanine aminotransferase levels (>30 for males; >19 U/L for females) and HBV DNA levels >2000 IU/mL should be treated. Patients with established cirrhosis with detectable HBV DNA should also be treated. The recommended first-line agents include pegylated interferon and 2 nucleos(t)ide analogs, entecavir and tenofovir. NAs require long-term treatment to maintain suppression of HBV DNA. They have been shown to decrease hepatic fibrosis, or reverse cirrhosis and to reduce the development of HCC. They have very low rates (0% to 1.2%) of resistance. HBsAg seroclearance, although the ideal endpoint, is only achievable in 10% to 12% of patients by multicenter trials usually studying relatively young patients. Patients on long-term treatment should be monitored for viral breakthrough that may be due to noncompliance or the development of resistance. Newer agents are under trials to enhance the rate of HBsAg seroclearance. However, even with the current NAs, long-term treatment of >6 years can markedly reduce the covalently closed circular DNA, the viral component responsible for initiation of viral replication.

Asian-Pacific clinical practice guidelines on the management of hepatitis B: a 2015 update

Worldwide, some 240 million people have chronic hepatitis B virus (HBV), with the highest rates of infection in Africa and Asia. Our understanding of the natural history of HBV infection and the potential for therapy of the resultant disease is continuously improving. New data have become available since the previous APASL guidelines for management of HBV infection were published in 2012. The objective of this manuscript is to update the recommendations for the optimal management of chronic HBV infection. The 2015 guidelines were developed by a panel of Asian experts chosen by the APASL. The clinical practice guidelines are based on evidence from existing publications or, if evidence was unavailable, on the experts' personal experience and opinion after deliberations. Manuscripts and abstracts of important meetings published through January 2015 have been evaluated. This guideline covers the full spectrum of care of patients infected with hepatitis B, including new terminology, natural history, screening, vaccination, counseling, diagnosis, assessment of the stage of liver disease, the indications, timing, choice and duration of single or combination of antiviral drugs, screening for HCC, management in special situations like childhood, pregnancy, coinfections, renal impairment and pre- and post-liver transplant, and policy guidelines. However, areas of uncertainty still exist, and clinicians, patients, and public health authorities must therefore continue to make choices on the basis of the evolving evidence. The final clinical practice guidelines and recommendations are presented here, along with the relevant background information.

Chronic Hepatitis B with Spontaneous Severe Acute Exacerbation

Chronic hepatitis B virus (HBV) infection is a major global health problem with an estimated 400 million HBV carriers worldwide. In the natural history of chronic hepatitis B (CHB), spontaneous acute exacerbation (AE) is not uncommon, with a cumulative incidence of 10%–30% every year. While exacerbations can be mild, some patients may develop hepatic decompensation and even die. The underlying pathogenesis is possibly related to the activation of cytotoxic T lymphocyte-mediated immune response against HBV. An upsurge of serum HBV DNA usually precedes the rise of alanine aminotransferase (ALT) and bilirubin. Whether antiviral treatment can benefit CHB with severe AE remains controversial, but early nucleos(t)ide analogues treatment seemed to be associated with an improved outcome. There has been no randomized study that compared the effects of different nucleos(t)ide analogues (NA) in the setting of CHB with severe AE. However, potent NAs with good resistance profiles are recommended. In this review, we summarized current knowledge regarding the natural history, pathogenetic mechanisms, and therapeutic options of CHB with severe AE.

Adaptation of the hepatitis B virus core protein to CD8(+) T-cell selection pressure

Activation of hepatitis B virus (HBV)-specific CD8 T cells by therapeutic vaccination may promote sustained control of viral replication by clearance of covalently closed circular DNA from infected hepatocytes. However, little is known about the exact targets of the CD8 T-cell response and whether HBV reproducibly evades CD8 T-cell immune pressure by mutation. The aim of this study was to address if HBV reproducibly selects substitutions in CD8 T-cell epitopes that functionally act as immune escape mutations. The HBV core gene was amplified and sequenced from 148 patients with chronic HBV infection, and the human leukocyte antigen (HLA) class I genotype (A and B loci) was determined. Residues under selection pressure in the presence of particular HLA class I alleles were identified by a statistical approach utilizing the novel analysis package SeqFeatR. With this approach we identified nine residues in HBV core under selection pressure in the presence of 10 different HLA class I alleles. Additional immunological experiments confirmed that seven of the residues were located inside epitopes targeted by patients with chronic HBV infection carrying the relevant HLA class I allele. Consistent with viral escape, the selected substitutions reproducibly impaired recognition by HBV-specific CD8 T cells.

CONCLUSION

Viral sequence analysis allows identification of HLA class I-restricted epitopes under reproducible selection pressure in HBV core; the possibility of viral escape from CD8 T-cell immune pressure needs attention in the context of therapeutic vaccination against HBV.

Re-evaluation of hepatitis B virus clinical phases by systems biology identifies unappreciated roles for the innate immune response and B cells

To identify immunological mechanisms that govern distinct clinical phases of a chronic hepatitis B virus (HBV) infection-immune tolerant (IT), immune active (IA), inactive carrier (IC), and hepatitis B e antigen (HBeAg)-negative (ENEG) hepatitis phases-we performed a systems biology study. Serum samples from untreated chronic HBV patients (n = 71) were used for multiplex cytokine measurements, quantitative hepatitis B surface antigen (HBsAg), HBeAg levels, HBV genotype, and mutant analysis. Leukocytes were phenotyped using multicolor flow cytometry, and whole-blood transcriptome profiles were generated. The latter were compared with liver biopsy transcriptomes from IA (n = 16) and IT (n = 3) patients. HBV viral load as well as HBeAg and HBsAg levels (P < 0.001), but not leukocyte composition, differed significantly between distinct phases. Serum macrophage chemotactic protein 1, interleukin-12p40, interferon (IFN)-gamma-inducible protein 10, and macrophage inflammatory protein 1 beta levels were different between two or more clinical phases (P < 0.05). Comparison of blood transcriptomes identified 64 differentially expressed genes. The gene signature distinguishing IA from IT and IC patients was predominantly composed of highly up-regulated immunoglobulin-encoding genes. Modular repertoire analysis using gene sets clustered according to similar expression patterns corroborated the abundant expression of B-cell function-related genes in IA patients and pointed toward increased (ISG) transcript levels in IT patients, compared to subsequent phases. Natural killer cell activities were clustered in clinical phases with biochemical liver damage (IA and ENEG phases), whereas T-cell activities were higher in all phases, compared to IT patients. B-cell-related transcripts proved to be higher in biopsies from IA versus IT patients.

CONCLUSION

HBV clinical phases are characterized by distinct blood gene signatures. Innate IFN and B-cell responses are highly active during the IT and IA phases, respectively. This suggests that the presumed immune tolerance in chronic HBV infections needs to be redefined.

Manifestations of perihepatic lymph nodes in acute flare of chronic hepatitis B: association with HBeAg status and with HBeAg seroconversion

It has been observed that enlargement of perihepatic lymph nodes may be seen in patients with chronic hepatitis B, particularly during acute flares of CHB. We hypothesized that there may be a correlation between the nodal change patterns in CHB patients with acute flare and HBeAg status. Perihepatic lymph node sizes of 87 patients with acute flares of CHB were documented, with a median follow up of 43 months. Patients were separated into 3 groups, HBeAg-positive with HBe seroconversion (group 1), HBeAg-positive without HBe seroconversion (group 2), and HBeAg-negative (group 3). Group 1 has the highest incidence of enlarged lymph nodes (92.3%) compared with group 2 (75.8%) and group 3 (46.8%) (p = 0.003). And if nodal width at acute flare was > 8mm and interval change of nodal width was >3mm, the incidence of HBeAg seroconversion will be 75% (p<0.001).

Serum HBsAg and HBeAg levels are associated with liver pathological stages in the immune clearance phase of hepatitis B virus chronic infection

The association between hepatitis B surface antigen (HBsAg) and hepatitis B 'e' antigen (HBeAg) levels and liver inflammation and fibrosis in patients with chronic hepatitis B (CHB) in the immune clearance (IC) remains elusive. The aim of the present study was to investigate whether HBsAg and HBeAg levels were associated with liver inflammation and fibrosis in CHB patients during the IC phase. Kendall's rank correlation analysis and receiver operating characteristic curves were used to determine the correlation between HBsAg, HBeAg and liver pathological stages. Multivariate analysis by forward logistic regression was used to analyze significant predictors of cirrhosis. A liver pathology‑predicting model (IC model), which used routinely assessed markers in combination with HBsAg and HBeAg levels, was constructed. There were significantly positive correlations between the HBsAg and HBeAg levels (γ=0.317, P<0.001), and between the HBsAg and HBV‑DNA levels (γ=0.489, P<0.001). However, there was no correlation between the HBsAg and alanine aminotransferase levels. HBsAg and HBeAg levels differed significantly at various liver pathological stages and declined progressively in advanced liver pathological stages. Multivariate logistic regression analysis showed that age, HBsAg and HBeAg levels as well as the international normalized ratio (INR) were independent predictors of liver fibrosis during the IC phase. The IC model had a specificity and sensitivity of 88.64 and 78.24%, respectively, a positive predictive value of 48.15% and negative predictive value of 96.79%. In conclusion, HBsAg and HBeAg levels were negatively and indirectly correlated with liver inflammation and fibrosis in CHB patients in the IC phase. The IC model reliably predicted the probability of liver cirrhosis.

Is it necessary to delay antiviral therapy for 3-6 months to anticipate HBeAg seroconversion in patients with HBeAg-positive chronic hepatitis B in endemic areas of HBV genotype C?

Background/Aims

Spontaneous HBeAg seroconversion occurs frequently in the immune reactive phase in HBeAg-positive chronic hepatitis B (CHB). Therefore, observation for 3-6 months before commencing antiviral therapy is recommended in patients with alanine aminotransferase (ALT) levels that exceed twice the upper limit of normal (ULN). However, HBeAg seroconversion occurs infrequently in patients infected with hepatitis B virus (HBV) genotype C. The aim of the present study was to determine whether the waiting policy is necessary in endemic areas of HBV genotype C infection.

Methods

Ninety patients with HBeAg-positive CHB were followed prospectively without administering antiviral therapy for 6 months. Antiviral therapy was initiated promptly at any time if there was any evidence of biochemical (i.e., acute exacerbation of HBV infection or aggravation of jaundice) or symptomatic deterioration. After 6 months of observation, antiviral therapy was initiated according to the patient's ALT and HBV DNA levels.

Results

Only one patient (1.1%) achieved spontaneous HBeAg seroconversion. Biochemical and symptomatic deterioration occurred before 6 months in 17 patients (18.9%) and 5 patients, respectively. High ALT and HBV DNA levels were both independent risk factors for biochemical deterioration. Of 15 patients with HBV DNA ≥5.1×10⁷ IU/mL and ALT ≥5×ULN, biochemical deterioration occurred in 7 (46.7%), including 1 patient receiving liver transplantation due to liver failure.

Conclusions

Spontaneous HBeAg seroconversion in patients with HBeAg-positive CHB is rare within 6 months. Biochemical deterioration was common and may lead to liver failure. Immediate antiviral therapy should be considered, especially in patients with high ALT and HBV DNA levels in endemic areas of genotype C infection.

Hepatitis B flares in chronic hepatitis B: pathogenesis, natural course, and management

Hepatitis B flare, defined as an event with abrupt rise of alanine aminotransferase (ALT) levels to >5 times the upper limit of normal during chronic hepatitis B virus (HBV) infection, is considered to be the result of a human leukocyte antigen-I restricted, cytotoxic T lymphocyte mediated immune response against HBV and its downstream mechanisms. It may occur spontaneously, during or after antiviral therapy and in the setting of immunosuppression and/or chemotherapy. The clinical spectrum of hepatitis B flares varies from asymptomatic to symptomatic and typical overt acute hepatitis, even with hepatic decompensation or failure. Flares may also occur in viraemic patients with cirrhosis with higher incidence of decompensation/mortality, hence requiring immediate antiviral therapy. An upsurge of serum HBV DNA and hepatitis B surface antigen levels usually precedes the abrupt rise of ALT levels. Rising or stable and high HBV DNA during flares represent ineffective immune clearance and further hepatocytolysis, even hepatic decompensation, may occur. Such patients require immediate antiviral therapy. In contrast, bridging hepatic necrosis and/or alpha-fetoprotein levels >100 ng/ml or decreasing HBV DNA during flares represent a more effective immune clearance and frequently leads to seroclearance of HBV DNA and/or hepatitis B e antigen with remission. If patients are non-cirrhotic and there is no concern of developing decompensation, patients may be observed for 3-6 months before deciding on the need of antiviral therapy. Severe and repeated flares are prone to develop into decompensation or lead to the development of cirrhosis, thus a timely treatment to prevent the hepatitis B flare is better than to cope with the flare. Screening, monitoring and prophylactic or pre-emptive antiviral therapy is mandatory for patients who are going to receive immunosuppressants or chemotherapy.

Decline in intrahepatic cccDNA and increase in immune cell reactivity after 12 weeks of antiviral treatment were associated with HBeAg loss

Viral load reduction facilitates recovery of antiviral T-cell responses. Dynamic alterations in intrahepatic viraemia clearance and immune cell reactivity during the early phase of nucleoside analogue (NA) therapy and the impact of these changes on HBeAg seroconversion are unknown. Fifteen HBeAg-positive chronic hepatitis B (CHB) patients were treated with adefovir dipivoxil. T-cell reactivity to HBV core and surface antigens were tested using ELISPOT assay from baseline to week 48 post-treatment (at 4-week intervals). Before and at week 12 of treatment, paired liver biopsies were analysed for intrahepatic HBV-DNA and cccDNA via real-time fluorescent PCR. In situ detection of CD4(+) , CD8(+) T cells and NK cells was analysed by immunohistochemistry. With viral load reduction, HBV-specific IFN-γ-producing CD4(+) T cells in patients with HBeAg loss were greatly enhanced and reached the highest level at week 12, with further increase observed between week 36 and week 48. After 12 weeks of treatment, total intrahepatic HBV-DNA and cccDNA had significantly decreased; however, there was no difference in the viral loads or extent of reduction between patients with and without HBeAg loss. Paralleling reduction in viral load, intrahepatic CD8(+) T lymphocytes increased in patients with HBeAg loss compared with baseline values. Only one patient without HBeAg loss exhibited similar results. Increased immune cells were observed in certain patients along with reduced hepatic viral loads during the second phase of HBV-DNA decline, which could promote the recovery of antiviral immunity and facilitate HBeAg loss.

Potent antiviral therapy improves survival in acute on chronic liver failure due to hepatitis B virus reactivation

Acute on chronic liver failure (ACLF) is a disease entity with a high mortality rate. The acute event arises from drugs and toxins, viral infections, bacterial sepsis, interventions (both surgical and non-surgical) and vascular events on top of a known or occult chronic liver disease. ACLF secondary to reactivation of chronic hepatitis B virus is a distinct condition; the high mortality of which can be managed in the wake of new potent antiviral therapy. For example, lamivudine and entecavir use has shown definite short-term survival benefits, even though drug resistance is a concern in the former. The renoprotective effects of telbivudine have been shown in a few studies to be useful in the presence of renal dysfunction. Monotherapy with newer agents such as tenofovir and a combination of nucleos(t)ides is promising for improving survival in this special group of liver disease patients. This review describes the current status of potent antiviral therapy in patient with acute on chronic liver failure due to reactivation of chronic hepatitis B, thereby providing an algorithm in management of such patients.

Serum cytokine/chemokine profiles in acute exacerbation of chronic hepatitis B: clinical and mechanistic implications

BACKGROUND AND AIMS

Acute exacerbation (AE) of chronic hepatitis B virus (HBV) infection is common and negatively impacts the clinical outcome. Although upsurge of viral load always precedes or coincides with AE, the underlying immunological mechanisms remain unclear and were investigated.

METHODS

We prospectively followed the serum cytokine/chemokine profiles, viral load, and alanine aminotransferase (ALT) levels in 250 patients and identified 44 consecutive patients (male: 72.7%; age: 40.4 ± 9.7 years; hepatitis B e antigen [HBeAg] positivity: 63.6%; genotype B/C: 75%/25%) who developed AE during the follow-up in a medical center. The impact of clinical characteristics (age, gender, HBeAg, ALT, HBV genotype), cytokines (tumor necrosis factor-alpha, interferon gamma, interleukin [IL]-2, IL-4, IL-6, and IL-10), and chemokines (CXCL10/interferon gamma-induced protein [IP]-10, CCL2/MCP-1, CXCL9/MIG, CCL5/RANTES, and CXCL8/IL-8) on the serum HBV DNA dynamics at different time points (baseline, peak of serum HBV DNA level, peak of serum ALT level, and after AE) were analyzed.

RESULTS

Of 44 patients, serum HBV DNA level surged before the peak of serum ALT level in 23 (52.3%), and coincided with the peak of ALT in 21 (47.7%). The upsurge of serum viral load significantly correlated with the increase of IL-10 (P = 0.0037) and CXCL10/IP-10 (P = 0.0044). Upsurge of serum viral load was preceded by an increase in serum IL-4 (P < 0.05), IL-6 (P < 0.05), and IL-10 (P < 0.05). Combination of HBV genotype, IL-6 level at baseline, and ALT level at the peak of serum HBV DNA reliably predicted subsequent AE pattern (P = 0.0116).

CONCLUSIONS

Enhanced Th2 activity is likely involved in the surge of HBV DNA level before hepatitis exacerbation.

Immunotherapy for Chronic Hepatitis B using HBsAg-based Vaccine Formulations: From Preventive Commercial Vaccines to Therapeutic Approach Julio Cesar Aguilar

Despite the existence of effective prophylactic vaccines, hepatitis B virus (HBV) infections remain a major public health problem. It has been estimated that about 370 million people are chronically infected with this virus worldwide. These individuals act as a reservoir for viral spread and chronic infection also increases the risk of liver diseases, such as cirrhosis and hepatocellular carcinoma. Current antiviral therapies fail to control viral replication in the long term in most patients. Viral persistence has been associated with a defect in the development of HBV-specific cellular immunity. The limitations of the current available therapies underline the need for alternative therapies. Specific immunotherapeutic strategies target not only the induction or stimulation of CD4(+) and CD8(+) T-cell responses but also the induction of proinflammatory cytokines capable of controlling viral replication. Therapeutic vaccination has been extensively studied in chronic hepatitis B (CHB) based in the properties of hepatitis B surface antigen (HBsAg) and taking advantage of its previous use in preventive vaccination. In this sense, pioneer studies were carried out employing HBsAg-based vaccines, including prophylactic commercial vaccines and HBsAg-based formulations with novel adjuvants. The results and general knowledge coming from these studies are discussed in the present review. The decision on developing new generations of vaccines including new antigens or formulations should take into account the experience with HBsAg-based vaccine formulations in order to decide about changing the vaccine antigen or adding new antigens to improve the composition. How to cite this article: Aguilar JC, Lobaina Y. Immunotherapy for Chronic Hepatitis B using HBsAg-based Vaccine Formulations: From Preventive Commercial Vaccines to Therapeutic Approach. Euroasian J Hepato-Gastroenterol 2014;4(2):92-97.

Long-term prognosis of chronic hepatitis B virus infection in the childhood

AIM

It was aimed to investigate the modes of transmisson and long-term prognosis of the disease in patients who were followed up with a diagnosis of chronic hepatitis B infection.

MATERIAL AND METHODS

The files of the patients who presented to our outpatient clinic between January 2002 and May 2013 and were being followed up with a diagnosis of chronic hepatitis B virus infection were examined retrospectively and the information related with the age, gender, age at the time of diagnosis, mode of transmission, follow-up period, transaminase levels, the amount of hepatitis B virus-deoxyribonucleic acid and treatment and responses to the treatment given were recorded.

RESULTS

The age at the time of diagnosis of 150 patients (97 males, 64%) included in the study was 14.95±2.94 years. 59 (39.3%) of the patients were inactive carriers, 61 (40.7%) were in the immunotolerant stage and 30 (20%) were in the immunoreactive stage. Vertical transmission was present in 86 (57.3%) patients, horizontal transmission was present in 41 patients (27.3%) and the mode of transmission was not known in 23 patients (15.3%). Response to treatment was obtained in 26 (72.2%) of 36 patients who received treatment. Lamivudine (4 mg/kg/day) was given to 29 of the patients who were given treatment, interferon-α (IFN-α) (6 MU/m(2), three days a week) was given to 3 patients at the same dose and both IFN-α and lamivudine were given to 4 patients. The time to give response to treatment was 24.23±15.23 months (6-50 months). Spontaneous anti-HBe seroconversion occured in four (7.2%) of 55 immuntolerant children who were followed up without treatment. The time to development of seroconversion in these children was 2.50±1.91 years (1-5 years).

CONCLUSIONS

Chronic hepatitis B virus infection has a more benign prognosis in children compared to adults, though it may lead to development of hepatic failure, cirrhosis and hepatocellular cancer. In addition, a decrease in the frequency of infection is expected in children in the years ahead owing to vaccination programs. However, we think that studies related with use of different drugs in patients who do not respond to treatment should be performed.

Identification of serum cytokine profiles associated with HBeAg seroconversion following antiviral treatment interruption

The major shortcoming of nucleos(t)ide analogue therapy for chronic hepatitis B (CHB) is the frequent requirement for indefinite therapy. Withdrawal of treatment can result in viral rebound with an alanine aminotransferase (ALT) flare leading to hepatic decompensation, while in others this can lead to hepatitis B e antigen (HBeAg) seroconversion. The aim of the study was to identify host immune profiles associated with these different outcomes. Eighteen HBeAg(+) patients, enrolled on a phase III trial with the nucleoside analogue adefovir dipivoxil, were followed for up to 128 weeks. For the first 48 weeks, all patients received continuous therapy. Subsequently, patients experienced cycles of treatment interruptions due to random drug/placebo misallocations. Host immune profiles were characterized by measuring a panel of serum cytokines before, during, and after each cycle of treatment withdrawal. Virus-specific T-cell responses were also determined at these time points in a subset of patients to elucidate the mechanisms utilized to control hepatitis B virus (HBV) replication post-treatment. Significantly, elevated levels of IFN-γ, IP-10, and IL-2 on-treatment were associated with HBeAg seroconversion after treatment withdrawal. In these patients, treatment interruption induced further increases in serum IFN-γ levels and marked increases in virus-specific T-cells producing IFN-γ, but minimal alterations in viremia and ALT. In HBeAg(+) patients with low on-treatment levels of serum IFN-γ, the interruption of therapy induced significant elevations in HBV-DNA, ALT, IP-10, and increases in virus-specific T-cells producing IL-10. Evaluating on-treatment serum cytokines in concert with virologic and clinical parameters may help to identify CHB patients who can successfully discontinue nucleos(t)ide analogue therapy.

Management of hepatitis B virus-related acute liver failure

Hepatitis B virus (HBV) is the most important cause of acute liver failure (ALF) in Eastern countries. HBV-related ALF may occur after acute HBV infection (A-ALF) or during acute exacerbation (flare) of chronic HBV infection (C-ALF). C-ALF may occur spontaneously or as a result of the effect of immunosuppression due to chemotherapeutic or immunosuppressive agents. The definition of HBV-related ALF is uncertain, because different diagnostic criteria are used in C-ALF, which may present as acute-on-chronic liver failure. Although the pathogenesis differs in the two subgroups of ALF, the symptoms and biochemical parameters can be similar. High titers of immunoglobulin M hepatitis B core antibody and lower viral loads are frequent in A-ALF as compared with C-ALF. The prognosis of C-ALF is significantly poor as compared with that of A-ALF. In C-ALF, most immunosuppression-mediated reactivation of hepatitis B results in fatality. Many case series or case-control studies have not demonstrated the survival benefit of nucleos(t)ide treatment. This treatment failure is probably related to delayed initiation of nucleos(t)ide treatment and viral suppression. Treatment with nucleos(t)ide analogs should be started immediately and should be continued regardless of subgroups of HBV-related ALF. Liver transplantation is the only treatment option that improves the prognosis of HBV-related ALF. Patients under consideration for transplantation should be given nucleos(t)ide analogs as prophylaxis to reduce the likelihood of post-transplant HBV recurrence.

Acute exacerbation of chronic hepatitis B: the dilemma of differentiation from acute viral hepatitis B

Exacerbations of chronic hepatitis B are common in endemic countries. Acute exacerbation of chronic hepatitis B virus (CHB-AE) causing derangement of liver functions may be seen in a flare of HBV in immune clearance phase or as a reactivation of HBV in patients with inactive or resolved HBV infection. While reactivation of HBV is usually seen in HBsAg positive patients, it is being increasingly recognized in patients with apparently resolved HBV infection who do not have HBsAg in serum but have IgG antibody to core antigen (anti-HBc) in the serum, especially so in patients on chemotherapy, immunosuppressive therapy or undergoing hematopoietic stem cell transplantation. In an icteric patient who is HBsAg positive, it may be difficult to differentiate CHB-AE from acute viral hepatitis B (AVH-B). Both may have similar clinical presentation and even IgM anti-HBc, the traditional diagnostic marker of AVH-B, may also appear at the time of exacerbation of CHB. The differentiation between CHB-AE and AVH-B is important not only for prognostication but also because management strategies are different. Most cases of AVH-B will resolve on their own, HBsAg clearance is achieved spontaneously in 90-95% of adults and treatment is rarely indicated except in the few with severe/fulminant disease. In contrast, in CHB-AE, the onset of jaundice may lead to decompensation of liver disease and treatment is warranted. The mechanisms of acute exacerbation and the differentiating features between AVH-B and CHB-AE are reviewed.

Virus-specific immune response in HBeAg-negative chronic hepatitis B: relationship with clinical profile and HBsAg serum levels

BACKGROUND AIMS

The immune impairment characterizing chronic hepatitis B (cHBV) infection is thought to be the consequence of persistent exposure to viral antigens. However, the immune correlates of different clinical stages of cHBV and their relation with different levels of HBsAg have not been investigated. The aim of the present study was to evaluate the relationship between HBV-specific T cells response and the degree of in vivo HBV control and HBsAg serum levels in HBeAg-HBeAb+ cHBV.

METHODS

Peripheral blood mononuclear cells from 42 patients with different clinical profiles (treatment-suppressed, inactive carriers and active hepatitis) of cHBV, 6 patients with resolved HBV infection and 10 HBV-uninfected individuals were tested with overlapping peptides spanning the entire HBV proteome. The frequency and magnitude of HBV-specific T cell responses was assessed by IFNγ ELISPOT assay. Serum HBsAg was quantified with a chemiluminescent immunoassay.

RESULTS

The total breadth and magnitude of HBV-specific T cell responses did not differ significantly between the four groups. However, inactive carriers targeted preferentially the core region. In untreated patients, the breadth of the anti-core specific T cell response was inversely correlated with serum HBsAg concentrations as well as HBV-DNA and ALT levels and was significantly different in patients with HBsAg levels either above or below 1000 IU/mL. The same inverse association between anti-core T cell response and HBsAg levels was found in treated patients.

CONCLUSIONS

Different clinical outcomes of cHBV infection are associated with the magnitude, breadth and specificity of the HBV-specific T cell response. Especially, robust anti-core T cell responses were found in the presence of reduced HBsAg serum levels, suggesting that core-specific T cell responses can mediate a protective effect on HBV control.