Pegylated Interferon Treatment for the Effective Clearance of Hepatitis B Surface Antigen in Inactive HBsAg Carriers: A Meta-Analysis

BackgroundExpanding antiviral therapy to benefit more populations and optimizing treatment to improve prognoses are two main objectives in current guidelines on antiviral therapy. However, the guidelines do not recommend antiviral therapy for inactive hepatitis B surface antigen (HBsAg) carriers (IHCs). Recent studies have shown that antiviral therapy is effective with good treatment outcomes in IHC populations. We conducted a systematic review and meta-analysis of HBsAg clearance and conversion in IHCs.MethodsWe searched PubMed, Embase, Medline, and Web of Science to retrieve articles on HBsAg clearance in IHCs published between January 2000 and August 2021. Data were collected and analysed using the random-effects model for meta-analysis.ResultsA total of 1029 IHCs from 11 studies were included in this analysis. The overall HBsAg clearance rate was 47% (95% confidence interval (CI): 31% - 64%), with a conversion rate of 26% (95% CI: 15% - 38%) after 48 weeks of Pegylated interferon (Peg-IFN) treatment. In the control group (including nucleos(t)ide analogue (NA) treatment or no treatment), the overall HBsAg clearance rate was only 1.54% (95% CI: 0.56% - 3.00%), which was markedly lower than that in the Peg-IFN group. Further analysis showed that a low baseline HBsAg level and long treatment duration contributed to a higher HBsAg clearance rate.ConclusionThis study showed that treatment of IHCs can be considered to achieve a clinical cure for chronic hepatitis B virus (HBV) infection. After Peg-IFN treatment, the HBsAg clearance rate was 47%, and the conversion rate was 26%, which are markedly higher than those reported by previous studies on Peg-IFN treatment in patients with chronic hepatitis B (CHB). A low baseline HBsAg level and long treatment duration were associated with HBsAg clearance in IHCs. Therefore, antiviral therapy is applicable for IHCs, a population who may be clinically cured.Systematic Review Registrationhttp://www.crd.york.ac.uk/PROSPERO, CRD): CRD42021259889.

An improved droplet digital PCR assay reveals the stability of intrahepatic hepatitis B virus cccDNA.

The persistence of covalently closed circular DNA (cccDNA) poses a major obstacle to curing chronic hepatitis B (CHB). Here, we used droplet digital PCR (ddPCR) for cccDNA quantitation. ddPCR measured a less than two-fold difference in the intrahepatic cccDNA content more accurately than conventional real-time PCR (qPCR), (R2=0.9416 and R2=0.8963, respectively) and had also higher sensitivity and specificity than qPCR. The results of ddPCR correlated closely with serum HB core-related antigen and HB surface antigen (HBsAg) in 24 HBV-infected human-liver-chimeric mice (PXB-mice). We demonstrated that the total cccDNA content did not change during liver repopulation, although the cccDNA content per hepatocyte was reduced in PXB-mice after entecavir treatment. In the 6 patients with HBV-related hepatocellular carcinoma, ddPCR detected cccDNA in both tumor and non-tumor tissues. In 13 HBeAg-negative CHB patients with pegylated interferon alpha-2a, cccDNA contents from paired biopsies were more significantly reduced in virological response (VR) than in non-VR at week 48 (p=0.0051). Interestingly, cccDNA levels were the lowest in VR with HBsAg clearance but remained detectable after the treatment. Collectively, ddPCR revealed that cccDNA content is stable during hepatocyte proliferation and persists at quantifiable levels, even after serum HBsAg clearance.

Novel monkey mAbs induced by a therapeutic vaccine targeting the hepatitis B surface antigen effectively suppress hepatitis B virus in mice

Background We have previously obtained a mouse anti-hepatitis B surface antigen (HBsAg) antibody E6F6 with long-lasting serum HBsAg clearance effects. The E6F6 epitope-based protein CR-T3-SEQ13 (HBsAg aa 113–135) vaccination therapy in cynomolgus monkeys induced long-term polyclonal antibodies-mediated clearance of HBsAg in the HBV transgenic (HBV-Tg) mice. Methods We isolated monoclonal antibodies from CR-T3-SEQ13 vaccinated cynomolgus monkeys, compared their therapeutic effects with E6F6, identified their epitopes on HBsAg, determined the pharmacokinetics, and studied their physical property. Results A panel of anti-HBsAg mAbs was generated through memory B cell stimulatory culture. Two lead monkey-human chimeric antibodies, C1–23 and C3–23, effectively suppressed HBsAg and HBV DNA in HBV-Tg mice. The humanized antibodies and humanized-mouse reverse chimeric antibodies of two antibodies exhibited comparable HBsAg clearance and viral suppression efficacy as those versions of E6F6 in HBV-Tg mice. Humanized antibody hu1–23 exhibited more efficacy HBsAg-suppressing effects than huE6F6–1 and hu3–23 in HBV-Tg mice at dose levels of 10 mg/kg and 20 mg/kg. Evaluation of the binding sites indicates that the epitope recognized by hu1–23 is located in HBsAg aa 118–125 and 121–125 for hu3–23. Physical property study revealed that hu1–23 and hu3–23 are stable enough for further development as a drug candidate. Conclusions Our data suggest that the CR-T3-SEQ13 protein is a promising HBV therapeutic vaccine candidate; and hu1–23 and hu3–23 are therapeutic candidates for the treatment of CHB. Moreover, the generation of antibodies from the epitope-based vaccinated subjects may be an alternative approach for novel antibody drug discovery. Statement of Significance Cynomolgus monkey mAbs were generated from an HBsAg-epitope-based-protein vaccination through memory B cell stimulatory culture. The humanized antibodies can efficiently mediate HBsAg clearance in HBV-Tg mice and may serve as anti-HBsAg therapeutic candidates. Generation of mAbs from the epitope-based vaccinated subjects is an alternative approach for novel antibody discovery.

Highly Accurate, Specific And Sensitive Quantitation By Droplet Digital PCR Reveals The Stability of Intrahepatic Hepatitis B Virus cccDNA

The persistence of covalently closed circular DNA (cccDNA) poses a major obstacle to curing chronic hepatitis B (CHB). Here, we used droplet digital PCR (ddPCR) for cccDNA quantitation. ddPCR measured a less than two-fold difference in the intrahepatic cccDNA content more accurately than conventional real-time PCR (qPCR), (R2=0.9416 and R2=0.8963, respectively) and had also higher sensitivity and specificity than qPCR. The results of ddPCR correlated more closely with serum HB core-related antigen (R2=0.9843) than HB surface antigen (HBsAg) (R2=0.9742) in 24 HBV-infected human-liver-chimeric mice (PXB-mice). We demonstrated that the total cccDNA content did not change during liver repopulation, although the cccDNA content per hepatocyte was reduced in PXB-mice after entecavir treatment. In the 6 patients with HBV-related hepatocellular carcinoma, ddPCR detected cccDNA in both tumor and non-tumor tissues. In 13 HBeAg-negative CHB patients with pegylated interferon alpha-2a, cccDNA contents from paired biopsies were more significantly reduced in virological response (VR) than in non-VR at week 48 (p=0.0051). Interestingly, cccDNA levels were the lowest in VR with HBsAg clearance but remained detectable after the treatment. Collectively, ddPCR revealed that cccDNA content is stable during hepatocyte proliferation and persists at quantifiable levels, even after serum HBsAg clearance.

Functional cure for chronic hepatitis B: accessibility, durability, and prognosis

Hepatitis B surface antigen (HBsAg) clearance is regarded as the ideal endpoint for antiviral treatment in terms of drug withdrawal safety and improvements in prognosis. However, the overall rate of HBsAg clearance is low and differs based on treatment method and course. The recent application of combined and extended treatment strategies have improved the HBsAg clearance rate, and several patients achieved HBsAg clearance in clinical treatment. In addition, the durability of and clinical outcomes after HBsAg clearance have become the focus of both researchers and clinicians. This article reviews HBsAg clearance in terms of accessibility, durability, improvements in prognosis and relevant advances.

Incidence and predictors of hepatitis B surface antigen clearance in HIV patients: a retrospective multi-site study

Background New therapies to achieve hepatitis B surface antigen (HBsAg) clearance are under development. However, gaps in knowledge exist in understanding the incidence and predictors of HBsAg clearance in a racially diverse HIV population. Methods We examined the incidence and risk of HBsAg clearance in a retrospective cohort of people living with HIV/HBV. Included patients had sufficient data to establish chronic infection based on CDC guidelines. We examined the incident rate for HBsAg loss and hazard rate ratios to evaluate predictors for HBsAg clearance in a multivariable model. Results Among the 571 HIV/HBV, 87% were male, 61% Black, 45% had AIDS, 48% HBeAg-positive, and median follow-up was 88 months. Incident HBsAg clearance was 1.5 per 100 person-years. In multivariate model, AIDS at baseline [adjusted hazard ratio [(aHR) 2.43, 95% CI:1.37,4.32 ], Hispanics (aHR 3.57, 95% CI: 1.33, 9.58), and those with injection drug use as an HIV risk factor (aHR, 3.35, 95% CI: 1.26, 8.89) were more likely to lose HBsAg whereas those who were HBeAg-positive (aHR 0.34, 0.19, 0.63) were less likely to lose HBsAg. Median change in CD4 cell count during the observation period was 231 cells/mm 3 in those with HBsAg loss vs. 112 cells/mm 3 in those with HBsAg persistence (p=0.004). Conclusion HBsAg loss occurs in about 10% of those with chronic HBV-infection. Hispanics, AIDS at baseline, injection drug use history, and HBeAg-negative status at baseline predicted the likelihood of HBsAg loss. Immune restoration may be a mechanism through which HBsAg loss occurs in HIV patients.

Resolved Hepatitis B: Achieved or Imaginary Wellbeing?

Aim. Assessment of the clinical impact of previous hepatitis B infection (PHB).Key points. PHB is characterized by the presence of viral DNA in the organism (including intrahepatic cccDNA and integrated DNA). Possible virus persistence in the PHB patient's hepatocytes potentiates the agent transmission risk via haemotransfusion, organ transplantation and haemodialysis. Occult HBV infection in PHB individuals can reactivate at background immunosuppressive or chemotherapies. PHB with chronic liver diseases of various aetiology significantly rises the risk of cirrhosis and hepatic cancer. The PHB association with autoimmune liver diseases and extrahepatic gastrointestinal cancer needs a careful research to confirm the possible involvement of hepatitis B virus in morbid genesis.Conclusion. No clinical signs of acute or chronic disease, HBsAg clearance and negative viral DNA load in blood of PHB individuals do not necessarily imply a complete disease eradication.PHB elicitation improves accuracy of the overall prognosis, reduces the virus transmission risk and prevents the reactivation of HBV infection.

Cytokines and Chemokines Involved in Hepatitis B Surface Antigen Loss in Human Immunodeficiency Virus/Hepatitis B Virus Coinfected Patients

It has been reported that hepatic flare (HF), attributable to the development of immune reconstitution inflammatory syndrome (IRIS) in human immunodeficiency virus (HIV)/hepatitis B virus (HBV) coinfected patients, occurs frequently after the start of anti-retroviral therapy (ART). We have observed several cases of hepatitis B surface antigen (HBsAg) loss after IRIS. However, the factors leading to HBsAg clearance remain unknown. We measured CD4+ and CD8+ T cells, cytokines and chemokines in 16 patients coinfected HIV-1 and HBV with IRIS, and analyzed the factors leading to HBsAg clearance after IRIS. There was no significant difference in the CD4+ and CD8+ T cell counts between the HBsAg clearance and non-clearance groups, while the serum concentrations of almost all cytokines and chemokines in the HBsAg clearance group were higher than in the HBsAg non-clearance group at any time of observation. In particular, IP-10 at the ALT peak, GM-CSF and IL-12 one month after the ALT peak and TNF-α and GM-CSF after the ALT concentrations fell to within normal limits, were significantly higher in the HBsAg clearance group. It seems that HBsAg loss after IRIS requires continued immune responses against HBV, involving Th1 cytokines.