Uncover the immune biomarkers underlying hepatitis B e antigen (HBeAg) seroconversion: a need for more translational study

Efficacy and safety of a nanoparticle therapeutic vaccine in patients with chronic hepatitis B: A randomized clinical trial

BACKGROUND AND AIM

HBV DNA can be reduced using antiviral drugs in patients with chronic hepatitis B (CHB); however, the rate of HBeAg seroconversion remains low. A clinical trial was conducted to assess the efficacy and safety of a de novo designed liposome-based nanoparticle lipopeptide vaccine, εPA-44, for CHB.

APPROACH AND RESULTS

A two-stage phase 2 trial, which included a 76-week, randomized, double-blind, placebo-controlled trial (stage 1) and a 68-week open-label extension (stage 2), was conducted in 15 centers across China (Clinicaltrials.gov No. NCT00869778). In stage 1, 360 human leukocyte antigen A2 (HLA-A2)-positive and HBeAg-positive patients were randomly and equally distributed to receive six subcutaneous injections of 600 µg or 900 µg εPA-44 or placebo at week 0, 4, 8, 12, 20, and 28. In stage 2, 183 patients received extended 900 µg εPA-44, and 26 patients were observed for relapse without further treatment. The primary endpoint was the percentage of patients with HBeAg seroconversion at week 76. At week 76, patients receiving 900 µg εPA-44 achieved significantly higher HBeAg seroconversion rate (38.8%) versus placebo (20.2%) (95% CI, 6.9-29.6%; p = 0.002). With a combined endpoint of HBeAg seroconversion, alanine aminotransferase normalization and HBV DNA < 2,000 IU/mL, both 900 µg (18.1%) and 600 µg (14.3%), resulted in significantly higher rate versus placebo (5.0%) (p = 0.002 and p = 0.02, respectively) at week 76. In stage 2, none (0 of 20) of 900 µg εPA-44-treated patients experienced serologic relapse. The safety profile of εPA-44 was comparable to that of placebo.

CONCLUSIONS

Among HLA-A2-positive patients with progressive CHB, a finite duration of 900 µg εPA-44 monotherapy resulted in significantly higher HBeAg seroconversion rate than placebo and sustained off-treatment effect. A phase 3 trial is ongoing (ChiCTR2100043708).

Humoral Immune Responses and Hepatitis B Infection

BACKGROUND

Chronicity or seroclearance of hepatitis B virus (HBV) antigens is determined by the host immune responses. Current approaches to treat HBV patients are based on inhibition of replication using different antivirals (nucleoside or nucleotide analogs) as monotherapy, or along with immune modulators as combination therapy is being used worldwide for reducing the viral load. Understanding the role of immune cellular therapies with currently available treatments for persistent viral-mediated responses in HBV patients is unexplored. However, the generation of antibodies against a surface (HBs) and envelop (HBe) antigen of hepatitis B remains an issue for future studies and needs to be explored.

SUMMARY

Humoral immunity, specifically T follicular helper (TFh) cells, may serve as a target for therapy for HBsAg seroconversion. In this review, we have been engrossed in the importance and role of the humoral immune responses in CHBV infection and vertical transmission. Key Message: TFh cells have been suggested as the potential target of immunotherapy which lead to seroconversion of HBe and HBs antigens of HBV. HBsAg seroconversion and eradication of covalently closed circular DNA are the main challenges for existing and forthcoming therapies in HBV infection.

Less liver fibrosis marker increment in overweight chronic hepatitis B patients observed by age-adjusted Fibrosis-4 Index

Background and aims

Chronic hepatitis B patients in Taiwan with no or limited liver injury are not reimbursed for antiviral treatment by the Taiwan National Health Insurance (NHI). Innovative fibrosis marker, age-adjusted Fibrosis-4 Index (FIB4-AA), was implemented to evaluate the tendency of liver fibrosis in these patients.

Methods

The FIB-4 indices of 256 antiviral treatment-naïve chronic hepatitis B patients at Kaohsiung Medical University Hospital from 2003 to 2019 were reviewed. The difference in initial FIB-4 and last FIB4-AA was treated as a categorical variable, representing the tendency of liver fibrosis in each individual aside from ageing. Logistic regression was implemented to evaluate the three parameters most dependent on increment of FIB4-AA: e seroconversion, body mass index (BMI) and initial FIB-4 index.

Results

The yearly FIB-4 growth rate of an individual without chronic hepatitis was lower than that of the study group (0.0237 vs 0.0273 for males, 0.02 vs 0.0288 for females). Patients undergoing or completing e seroconversion were less prone to increment of FIB4-AA (p=0.036, OR 0.524). Logistic regression revealed that BMI ≥25 kg/m² significantly less increment of FIB4-AA (p=0.001, OR 0.383, 95% CI 0.212 to 0.690), while patients with initial FIB-4 <1.29 were prone to increasing liver FIB4-AA (p=0.000, OR 3.687, 95% CI 1.999 to 6.797).

Conclusion

Chronic hepatitis B patients not meeting the reimbursement criteria of the Taiwan NHI are prone to increment of liver fibrosis marker. Overweight is associated with less increment of fibrosis marker, while initial FIB-4 <1.29 is associated with increasing fibrosis marker.

Lower Expression of MicroRNA-155 Contributes to Dysfunction of Natural Killer Cells in Patients with Chronic Hepatitis B

MicroRNAs have been reported to be regulated in different ways in a variety of liver diseases. As a key modulator of cellular function in both innate and adaptive immunity, the role of miR-155 in chronic hepatitis B virus infection remains largely unknown. Here, we investigated the expression and function of miR-155 in chronic hepatitis B (CHB) patients. It was found that miR-155 expression in peripheral blood mononuclear cells (PBMCs) was lower in CHB patients than healthy controls (HC). Among CHB infection, immune-active (IA) patients with abnormal alanine aminotransferase (ALT) levels had relatively higher miR-155 expression in PBMCs and serum than immune-tolerant carriers, but were comparable to inactive carriers. Moreover, there was a positive correlation between miR-155 expression and ALT levels in CHB patients. Particularly, miR-155 expression in natural killer (NK) cells was significantly downregulated in IA patients compared with HC. Inversely, suppressor of cytokine signaling 1 (SOCS1), a target of miR-155, was upregulated in NK cells of IA patients. Overexpression of miR-155 in NK cells from IA patients led to a decrease in SOCS1 expression and an increase of IFN-γ production. Finally, accompanied by the normalization of ALT, miR-155 expression in PBMCs gradually decreased during telbivudine or peg-IFN-α-2a therapy. Interestingly, higher miR-155 expression at baseline was associated with better response to telbivudine therapy, but not peg-IFN-α-2a. In conclusion, our data suggested that miR-155 downregulation in NK cells of IA patients impaired IFN-γ production by targeting SOCS1, which may contribute to immune dysfunction during CHB infection. Additionally, baseline miR-155 expression could predict the treatment response to telbivudine therapy.

A scoring model predicts hepatitis B e antigen seroconversion in chronic hepatitis B patients treated with nucleos(t)ide analogs: real-world clinical practice

AIM

This study developed and validated a non-invasive scoring model to predict 1-year hepatitis B e antigen (HBeAg) seroconversion in response to nucleos(t)ide analog (NA) treatment in NA-naïve patients with HBeAg-positive chronic hepatitis B (CHB).

METHODS

Baseline data from 1014 patients visiting the outpatient and inpatient clinics of Beijing Ditan Hospital, Capital Medical University, China between October 2008 and April 2015 were included. These patients received NAs for HBeAg-positive CHB. The patients were assigned randomly to the derivation (n=710) and validation (n=304) cohorts in a 7:3 ratio. A prediction scoring model was established based on univariate and multivariate Cox proportional hazards regression analyses to identify independent prediction factors. In the derivation cohort, the odds ratio of the predictors were converted to integer risk scores by rounding the quotient from dividing the odds ratio, and the final score was the sum of these values. The predictive accuracy of the scoring model was further assessed using Harrell's concordance index (C-index).

RESULTS

The 1-year cumulative HBeAg seroconversion rates were 11.83% and 8.55% in the derivation and validation cohorts, respectively. In the derivation cohort, baseline pretreatment alanine aminotransferase (ALT), gamma-glutamyl transpeptidase (GGT), globulin (GLO), and quantitative HBeAg (qHBeAg) levels were independently associated with HBeAg seroconversion and were included in the scoring system. The model had good discrimination in the derivation and validation cohorts (C-index=0.750, 95% confidence interval 0.694-0.806 and C-index=0.776, 95% confidence interval 0.698-0.855, respectively). The prediction scores ranged from 0 to 4; scores of 0-1 and 2-4 identified patients with lower and higher levels of HBeAg seroconversion, respectively. Kaplan-Meier analysis was used to determine the 1-year cumulative HBeAg seroconversion rates in the two groups (scores of 0-1 and 2-4) of the primary cohort, and log-rank tests revealed a significant difference (4.87% vs. 20.9%, p<0.0001).

CONCLUSIONS

The 1-year prediction scoring model based on baseline levels of ALT, GGT, GLO, and qHBeAg offered a reliable predictive value for the response to NA therapy in a Chinese cohort.

Role of interleukin-21 in HBV infection: friend or foe?

Interleukin (IL)-21, a cytokine produced by activated CD4(+) T cells, has broad pleiotropic actions that affect the functions of a variety of lymphoid cells. The roles of IL-21 in modulating immunity to infections are currently being defined. Notably, IL-21-mediated cellular and humoral immune responses play an important role in determining the outcome of viral infection. This article reviews the current knowledge on the critical role of IL-21 in hepatitis B virus (HBV) infection. As a competent intermediary, IL-21 derived from virus-specific CD4(+) T cells plays key roles in sustaining CD8(+) T cells and promoting B-cell responses that are essential for effective viral control. However, as a mediator of inflammation, IL-21 is also involved in the development of HBV-induced liver cirrhosis and exacerbating liver injury. Overall, the current data point to IL-21 as an immunomodulatory cytokine in HBV infection. Immunotherapeutic strategies aimed at optimizing the beneficial effects of IL-21 in HBV infection may prove to be a rigorous challenge in the future, as they should foster the strengths of IL-21 while circumventing potential drawbacks.

TCRγδ(+)CD4(-)CD8(-) T cells suppress the CD8(+) T-cell response to hepatitis B virus peptides, and are associated with viral control in chronic hepatitis B

The immune mechanisms underlying failure to achieve hepatitis B e antigen (HBeAg) seroconversion associated with viral control in chronic hepatitis B (CHB) remain unclear. Here we investigated the role of CD4(-)CD8(-) T (double-negative T; DNT) cells including TCRαβ(+) DNT (αβ DNT) and TCRγδ(+) DNT (γδ DNT) cells. Frequencies of circulating DNT cell subsets were measured by flow cytometry in a retrospective cohort of 51 telbivudine-treated HBeAg-positive CHB patients, 25 immune tolerant carriers (IT), 33 inactive carriers (IC), and 37 healthy controls (HC). We found that γδ DNT cell frequencies did not significantly change during treatment, being lower at baseline (P = 0.019) in patients with HBeAg seroconversion after 52 weeks of antiviral therapy (n = 20) than in those without (n = 31), and higher in the total CHB and IT than IC and HC groups (P<0.001). αβ DNT cell frequencies were similar for all groups. In vitro, γδ DNT cells suppressed HBV core peptide-stimulated interferon-γ and tumor necrosis factor-α production in TCRαβ(+)CD8(+) T cells, which may require cell-cell contact, and could be partially reversed by anti-NKG2A. These findings suggest that γδ DNT cells limit CD8(+) T cell response to HBV, and may impede HBeAg seroconversion in CHB.

CXCL-10, interleukin-12 and interleukin-21 are not immunological predictors of HBeAg seroconversion in HIV-1-HBV coinfection following HBV-active antiretroviral therapy

BACKGROUND

Interferon stimulated chemokine CXCL-10, interleukin (IL)-12 (p70) and IL-21 have been associated with HBsAg and HBeAg loss following treatment of HBV monoinfection. The aim of this study was to determine whether these factors were also associated with HBsAg and HBeAg loss in HIV-HBV-coinfected patients following HBV-active combination antiretroviral therapy (cART).

METHODS

HIV-HBV-coinfected patients with HBeAg seroconversion (n=12; seroconverters [SC]) were compared to patients who did not seroconvert (n=13; non-seroconverters [NSC]). CXCL-10, IL-12 and IL-21 (Luminex Bead Array, Life Technologies, Grand Island, NY, USA) were measured in plasma prior to initiation of HBV-active cART (baseline), at the time of seroconversion (T0) and at the closest time point before (T-1) and after (T+1) seroconversion.

RESULTS

Levels of CXCL-10 declined significantly in all patients following HBV-active cART (P<0.05 for both SC and NSC; Kruskall-Wallis, Dunn's post-test). There was no difference between SC and NSC in the level of CXCL-10, IL-12 and IL-21 at any time point.

CONCLUSIONS

We found no evidence that CXCL-10, IL-12 or IL-21 were associated with HBeAg seroconversion following HBV-active cART. Other immunological determinants should be explored in this setting.

Frequency-dependent selection drives HBeAg seroconversion in chronic hepatitis B virus infection

HBeAg seroconversion is an important stage in the evolution of a chronic hepatitis B virus (HBV) infection that usually leads to control of viral replication and a reduced risk for liver cirrhosis and cancer. Since current therapies for the HBV-associated liver inflammation that is known as chronic hepatitis B (CHB). Rarely induce permanent HBeAg seroconversion, there is a need to understand the mechanisms responsible for the purpose of identifying new therapeutic targets. Currently, the most widely accepted hypothesis is that the patient’s humoral and cellular immune responses to the HBV initiate HBeAg seroconversion. Although we accept that this hypothesis cannot be excluded, we propose an alternative that is consistent with published data on HBeAg seroconversion. We postulate, as others have, that the HBeAg suppresses the immune response to the HBV. However, production of the HBeAg incurs a metabolic cost to the hepatocyte which reduces the replicative capacity of the virus. Consequently, HBeAg-negative viruses replicate faster than HBeAg-positive viruses. HBeAg-negative variants arise de novo; and when their frequency in the population is low they have a replicative advantage. However, they also benefit from the immunosuppressive effects of the HBeAg-positive viruses in the population. As HBeAg-negative variants increase in frequency and HBeAg levels fall, the immune system recognizes the HBV, and HBeAg seroconversion occurs as a consequence of frequency-dependent selection acting on HBeAg-negative variants. This hypothesis explains the wide inter-individual variation in age of seroconversion, the increased rate of seroconversion during anti-viral treatment and the phenomena of both spontaneous and post-treatment HBeAg reversions (in which patients cycle between the HBeAg-positive and negative phases of their infection).

Forty-eight-week retrospective study of telbivudine and lamivudine treatment in patients with hepatitis B-related cirrhosis

The aim of this study was to evaluate the efficacy and safety of telbivudine 600 mg/day compared with lamivudine 100 mg/day for 48 weeks of treatment in patients with hepatitis B-related cirrhosis. Data were reviewed retrospectively from 165 hepatitis B-related cirrhotic patients (55 compensated patients and 110 decompensated) who received antiviral therapy with telbivudine or lamivudine. Serum alanine aminotransferase (ALT) and hepatitis B virus (HBV) DNA levels, hepatitis B e antigen (HBeAg) loss and seroconversion, histological improvement and various adverse events (AEs) were evaluated. Baseline characteristics were comparable. ALT levels declined but showed no significant difference in treatment with telbivudine or lamivudine (P > 0.05). Reduction in serum HBV DNA levels was evident by week 4 in compensated HBV-related cirrhosis patients (telbivudine, 2.34 log10 copies/mL; lamivudine, 2.07 log10 copies/mL; P = 0.02) and persisted by week 8. Patients administrated with telbivudine had slightly greater HBeAg loss and seroconversion than patients with lamivudine, but the difference was not statistically significant (P > 0.05). Accumulative HBeAg loss was seen at week 48 (25.0% vs 25.0% and 13.3% vs 10.0% for telbivudine vs lamivudine in compensated and decompensated cirrhotic groups, respectively), as well as HBeAg seroconversion (15.0% vs 8.3% and 8.9% vs 6.7%). Mean Knodell Histologic Activity Index scores decreased in both compensated and decompensated cirrhotic patients (3.92 vs 3.64, 3.85 vs 3.73, for telbivudine vs lamivudine). Telbivudine and lamivudine were both well tolerated with minor AEs. The results of this study support telbivudine as an effective therapy for patients with both compensated and decompensated HBV-related cirrhosis.