Hepatitis B virus RNA decline without concomitant viral antigen decrease is associated with a low probability of sustained response and hepatitis B surface antigen loss

Achieving chronic hepatitis B functional cure: Factors and potential mechanisms

Chronic hepatitis B (CHB) is a significant global health issue affecting approximately 254 million individuals worldwide. Achieving the loss of hepatitis B surface antigen (HBsAg), either with or without seroconversion to hepatitis B surface antibody (HBsAb), is regarded as a functional cure and the optimal goal for addressing CHB, and can be achieved through various approaches, including induction with nucleos(t)ide analogues (NAs), induction with pegylated interferon alpha (PegIFNα), and spontaneous clearance of HBsAg. Spontaneous clearance of HBsAg is rare, while NAs can directly inhibit HBV DNA, they are unable to act on covalently closed circular DNA (cccDNA), hence inhibiting HBsAg production or clearing HBsAg is extremely challenging. On the other hand, functional cure based on PegIFNα shows good long-term durability, but over 10 % of patients still experience relapse, mostly within 48 weeks after functional cure. Factors related to CHB functional cure with antiviral therapy are complex, including host factors, viral factors, environmental factors, etc. The integration of HBV DNA into liver cells, persistence of HBV cccDNA, insufficient B cell responses and compromised T cell function pose significant barriers to HBV clearance. Therefore, this study systematically reviewed the relevant factors and potential mechanisms influencing functional cure CHB, which can provide a basis for personalized treatment, help predict treatment outcomes and assess prognosis, and provide theoretical support for the advancement of novel treatment strategies and medications.

[Research progress of biomarkers of hepatitis B virus and clinical significance]

The infection of Hepatitis B virus (HBV) can result in severe consequences, including chronic hepatitis, liver fibrosis, cirrhosis, and even liver cancer. Effective antiviral treatment has the potential to slow down the progression of the disease. HBV serum biomarkers play a crucial role in the dynamic management of chronic hepatitis B (CHB) patients. However, the conventional hepatitis B virus markers, such as hepatitis B serologic testing and HBV DNA, are insufficient to meet the clinical requirements. This review provided a comprehensive overview of the current research on the quantification of HBsAg and anti-HBc, HBV RNA and HBV core-associated antigen, which summarized the crucial role these markers play in the administration of antiviral medications, predicting the efficacy of treatment and anticipating the likelihood of virologic rebound following drug cessation, as well as assessing disease progression in CHB patients.

Interpreting Serogical Markers in Hepatitis B Virus Infection

Hepatitis B virus (HBV) is considered a global health-related problem. The World Health Organization estimates an incidence of approximately 1.5 million new cases annually despite an available effective vaccine, and approximately 296 million people worldwide are living with chronic hepatitis B. This large number of patients require continuous monitoring of the treatment efficacy, disease progression, and screening for the HBV-related liver complications. Recently, it has become more evident that we need better predictive markers to allow treatment cessation when there is a reduced risk of viral reactivation, in addition to the present need to predict disease outcome and improve the management of people living with chronic hepatitis B. Novel HBV biomarkers are focused on in this minireview. These new markers include quantification of serum HBV RNA, hepatitis B core–related antigen, quantitative hepatitis B surface antigen, quantitative anti–hepatitis B core antigen, and detection of HBV nucleic acid–related antigen. The target of finding new markers for HBV replication is to provide crucial clinical data in a noninvasive way for detecting the replicative and transcriptional activity of the virus. This may support better management of patients compared with the criterion-standard invasive marker for detecting the intrahepatic replication and transcription of HBV, which is the quantification of covalently closed circular DNA.

End-of-treatment anti-HBs levels and HBeAg status identify durability of HBsAg loss after PEG-IFN discontinuation

Background

Hepatitis B surface antigen (HBsAg) loss, namely, the functional cure, can be achieved through the pegylated interferon (PEG-IFN)-based therapy. However, it is an unignorable fact that a small proportion of patients who achieved functional cure develop HBsAg reversion (HRV) and the related factors are not well described.

Methods

A total of 112 patients who achieved PEG-IFN-induced HBsAg loss were recruited. HBV biomarkers and biochemical parameters were examined dynamically. HBV RNA levels were assessed in the cross-sectional analysis. The primary endpoint was HRV, defined as the reappearance of HBsAg after PEG-IFN discontinuation.

Results

HRV occurred in 17 patients during the follow-up period. Univariable analysis indicated that hepatitis B e antigen (HBeAg) status, different levels of hepatitis B surface antibody (anti-HBs), and hepatitis B core antibody (anti-HBc) at the end of PEG-IFN treatment (EOT) were significantly associated with the incidence of HRV through using the log-rank test. Additionally, time-dependent receiver operating characteristic (ROC) analysis showed that the anti-HBs was superior to anti-HBc in predictive power for the incidence of HRV during the follow-up period. Multivariable Cox proportional hazard analysis found that anti-HBs ≥1.3 log₁₀IU/L (hazard ratio (HR), 0.148; 95% confidence interval (CI), 0.044-0.502) and HBeAg negativity (HR, 0.183; 95% CI, 0.052-0.639) at EOT were independently associated with lower incidence of HRV. Cross-sectional analysis indicated that the HBV RNA levels were significantly correlated with the HBsAg levels in patients with HRV (r=0.86, p=0.003).

Conclusions

EOT HBeAg negativity and anti-HBs ≥1.3 log₁₀IU/L identify the low risk of HRV after PEG-IFN discontinuation.

Circulating HBV RNA: From biology to clinical applications

Chronic HBV infection can hardly be cured due to the persistence of an intrahepatic pool of viral covalently closed circular DNA (cccDNA) transcription template, which is refractory to current antivirals. The direct analyses of cccDNA quantity and transcriptional activity require an invasive biopsy. Recently, circulating HBV RNA has been identified as a promising noninvasive surrogate marker of cccDNA and can be used for monitoring disease progression and predicting prognosis of patients with chronic HBV infection. To better understand this surrogate biomarker of cccDNA, we reviewed the current knowledge about the molecular characteristics and potential clinical applications of circulating HBV RNA. Specifically, we summarized the reported species and existing forms of circulating HBV RNA and discussed their biogenesis and the capacity of de novo infection by RNA virions. Moreover, we described the potential applications of circulating HBV RNA in different clinical scenarios, such as classifying the phases of chronic HBV infection, analyzing sustained on-treatment and off-treatment outcomes of treated patients, as well as predicting HCC development. Perspectives on future research of circulating HBV RNA were also proposed in this review.

Management and Treatment of Patients with Chronic Hepatitis B: Towards Personalized Medicine

The currently available antiviral treatments (Peg-Interferon-α and Nucleos(t)ide Analogues, NA) for chronic hepatitis B (CHB) achieve a functional cure (serum HBsAg and HDV-DNA clearance) of HBV infection in a limited number of patients. Nevertheless, the continuous pharmacological suppression of viral replication by NA halts liver disease progression lowering the risk of HCC development and improving the survival. In the near future, to fully exploit the potential of old and new drugs for HBV treatment a personalized approach to the patients will be required according to an accurate definition of their virologic, immunologic and clinical profile.

Advances in treatment and prevention of hepatitis B

Chronic hepatitis B (CHB) continues to contribute to worldwide morbidity and mortality significantly. Scientists, clinicians, pharmaceutical companies, and health organizations have dedicated substantial Intellectual and monetary resources to finding a cure, increasing immunization rates, and reducing the global burden of CHB. National and international health-related organizations including the center for disease control, the national institute of health, the American Association for the study of liver disease (AASLD), The European association for the study of the Liver (EASL), The Asia Pacific association for the study of the Liver (APASL) and the world health organization release periodic recommendations for disease prevention and treatment. Our review of the most recent guidelines by EASL, AASLD, APASL, and Taiwan Association for the Study of the Liver revealed that an overwhelming majority of cited studies were published before 2018. We reviewed Hepatitis B-related literature published 2018 onwards to identify recent developments and current barriers that will likely direct future efforts towards eradicating hepatitis B. The breakthrough in our understanding of the hepatitis B virus life cycle and resulting drug development is encouraging with significant room for further progress. Data from high-risk populations, most vulnerable to the devastating effects of hepatitis B infection and reactivation remain sparse. Utilization of systems approach, optimization of experimental models, identification and validation of next-generation biomarkers, and precise modulation of the human immune response will be critical for future innovation. Within the foreseeable future, new treatments will likely complement conventional therapies rather than replace them. Most Importantly, pragmatic management of CHB related population health challenges must be prioritized to produce real-world results.

Novel Biomarkers of Hepatitis B Virus and Their Use in Chronic Hepatitis B Patient Management

Even though an approved vaccine for hepatitis B virus (HBV) is available and widely used, over 257 million individuals worldwide are living with chronic hepatitis B (CHB) who require monitoring of treatment response, viral activity, and disease progression to reduce their risk of HBV-related liver disease. There is currently a lack of predictive markers to guide clinical management and to allow treatment cessation with reduced risk of viral reactivation. Novel HBV biomarkers are in development in an effort to improve the management of people living with CHB, to predict disease outcomes of CHB, and further understand the natural history of HBV. This review focuses on novel HBV biomarkers and their use in the clinical setting, including the description of and methodology for quantification of serum HBV RNA, hepatitis B core-related antigen (HBcrAg), quantitative hepatitis B surface antigen (qHBsAg), including ultrasensitive HBsAg detection, quantitative anti-hepatitis B core antigen (qAHBc), and detection of HBV nucleic acid-related antigen (HBV-NRAg). The utility of these biomarkers in treatment-naïve and treated CHB patients in several clinical situations is further discussed. Novel HBV biomarkers have been observed to provide critical clinical information and show promise for improving patient management and our understanding of the natural history of HBV.