Serum HBV DNA plus RNA shows superiority in reflecting the activity of intrahepatic cccDNA in treatment-naïve HBV-infected individuals

Usefulness of serum HBV RNA levels for predicting antiviral response to entecavir treatment in patients with chronic hepatitis B

BACKGROUND

Hepatitis B virus (HBV) RNA is an important serum biomarker of hepatic covalently closed circular DNA (cccDNA) transcriptional activity; however, its clinical characteristics remain unclear. This study evaluated the clinical utility of HBV RNA levels in patients with chronic hepatitis B (CHB).

METHODS

We studied 87 CHB patients with serum HBV DNA levels ≥ 5.0 log IU/mL who initiated entecavir (ETV) treatment between 2000 and 2018. Serum HBV RNA levels were measured at three-time points: before ETV treatment, at 12 weeks, and at 48 weeks after starting ETV treatment. Clinical markers associated with the antiviral effects of ETV treatment were analyzed.

RESULTS

Serum HBV RNA levels decreased in both HBeAg-positive and -negative patients during the observation period. In HBeAg-positive patients, multivariable analysis showed that lower HBV RNA levels at 48 weeks of ETV treatment were independently associated with HBeAg seroconversion. Additionally, lower baseline HBV RNA levels significantly predicted virologic response in those patients. In contrast, among HBeAg-negative patients, lower HBV core-related antigen (HBcrAg) levels and the FIB-4 index were independently associated with virologic response. In HBeAg-positive patients, those with higher baseline HBV RNA levels showed a more significant reduction in hepatitis B surface antigen levels.

CONCLUSION

Serum HBV RNA levels predicted HBeAg seroconversion and early HBV DNA reduction in HBeAg-positive patients, while HBcrAg was significantly associated with virologic response in HBeAg-negative patients. These findings highlight the different predictive roles of HBV RNA and HBcrAg based on HBeAg status, which may provide individualized treatment strategies.

Prediction of cccDNA dynamics in hepatitis B patients by a combination of serum surrogate markers

Quantification of intrahepatic covalently closed circular DNA (cccDNA) is a key for evaluating an elimination of hepatitis B virus (HBV) in infected patients. However, quantifying cccDNA requires invasive methods such as a liver biopsy, which makes it impractical to access the dynamics of cccDNA in patients. Although HBV RNA and HBV core-related antigens (HBcrAg) have been proposed as surrogate markers for evaluating cccDNA activity, they do not necessarily estimate the amount of cccDNA. Here, we employed a recently developed multiscale mathematical model describing intra- and intercellular viral propagation and applied it in HBV-infected patients under treatment. We developed a model that can predict intracellular HBV dynamics by use of extracellular viral markers, including HBsAg, HBV DNA, and HBcrAg in peripheral blood. Importantly, the model prediction of the amount of cccDNA in patients over time was confirmed to be well correlated with the data for quantified cccDNA by paired liver biopsy. Thus, our method combining classic and emerging surrogate markers enables us to predict the decay dynamics of cccDNA in patients undergoing treatment.

A case report: cccDNA and pgRNA remain positive in liver tissue in a chronic hepatitis B patient with functional cure

Hepatitis B surface antigen (HBsAg) seroclearance is recommended as the ideal endpoint for nucleos(t)ide analog (NA) treatments. Functional cure of chronic hepatitis B (CHB) is defined as having undetectable serum hepatitis B virus (HBV) deoxyribonucleic acid and serum HBsAg. We report a functional cure case of CHB with a family history of hepatocellular carcinoma (HCC) after long-term NA therapy. Despite achieving functional cure for over 7 years, both HBV covalently closed circular deoxyribonucleic acid (cccDNA) and pregenomic ribonucleic acid (pgRNA) remain positive in the liver tissue of the patient, indicating that a sterilizing cure has not been achieved. This case highlights the importance of active surveillance of HBV cccDNA and pgRNA for sterilizing the cure and risk of HCC.

Newer Diagnostic Virological Markers for Hepatitis B Virus Infection

Chronic Hepatitis B (CHB) remains a major public health problem, leading to various complications such as liver fibrosis, cirrhosis, and hepatocellular carcinoma. The existing diagnostic markers for Hepatitis B virus (HBV) are limited in distinguishing different CHB phases and intra-hepatic viral replication activity. In the past few years, several non-invasive potential blood markers that reflect viral intra-hepatic replicative state more accurately have been in progress and are gaining importance. Despite substantial efforts, the clinical utility of these new markers in CHB management is limited and unexplored. Therefore, in this review, we will discuss some of the newer HBV markers, their potential role in the diagnosis and monitoring of CHB patients.

How to cite this article

Agarwal R, Gupta E, Samal J, et al. Newer Diagnostic Virological Markers for Hepatitis B Virus Infection. Euroasian J Hepato-Gastroenterol 2024;14(2):214-220.

Clinical performance of Circulating HBV RNA and iTACT-HBcrAg Assays in HBeAg-negative and HBsAg-cleared Chronic Hepatitis B Patients

Hepatitis B virus (HBV) RNA and hepatitis B core-related antigen (HBcrAg) have been reported to reflect the transcriptional activity of covalently closed circular HBV DNA. We retrospectively investigated the proportions of quantifiable serum HBV RNA and immunoassay for total antigen including complex via pretreatment-hepatitis B core-related antigen (iTACT-HBcrAg) in chronic hepatitis B patients negative for hepatitis B e antigen (HBeAg) and/or with hepatitis B surface antigen (HBsAg) seroclearance. This study included 246 HBeAg-negative HBV-infected patients, who comprised 13 with liver cirrhosis (LC, the LC group), 118 chronic hepatitis (CH, the CH group), and 115 inactive carriers (IC, the IC group), and 44 patients with HBsAg seroclearance. iTACT-HBcrAg and HBV RNA levels were determined using stored serum samples. Higher proportions of the patients had quantifiable iTACT-HBcrAg than HBV RNA in all groups of HBeAg-negative patients (iTACT-HBcrAg: 84.6%, 90.7%, 35.7%, HBV RNA: 23.1%, 26.3%, 14.8%, for the LC, CH, IC groups). With HBsAg seroclearance (HBsAg <0.05 IU/mL), the proportions of quantifiable samples for HBV RNA were also lower than iTACT-HBcrAg (0% for HBV RNA). Thus, iTACT-HBcrAg was more often detectable than circulating HBV RNA in this study population. Further long-term prospective evaluation of iTACT-HBcrAg is desirable for its utilization in clinical practice.

Hepatitis B cure: Current situation and prospects

Achievement of a 'clinical cure' in chronic hepatitis B (CHB) implies sustained virological suppression and immunological control over the infection, which is the ideal treatment goal according to domestic and international CHB management guidelines. Clinical practice has shown encouraging results for specific patient cohorts using tailored treatment regimens. These regimens incorporate either nucleos(t)ide analogs, immunomodulatory agents such as pegylated interferon α, or a strategic combination of both, sequentially or concurrently administered. Despite these advancements in the clinical handling of hepatitis B, achieving a clinical cure remains elusive for a considerable subset of patients due to the number of challenges that preclude the realization of optimal treatment outcomes. These include, but are not limited to, the emergence of antiviral resistance, incomplete immune recovery, and the persistence of covalently closed circular DNA. Moreover, the variance in response to interferon therapy and the lack of definitive biomarkers for treatment cessation also contribute to the complexity of achieving a clinical cure. This article briefly overviews the current research progress and existing issues in pursuing a clinical cure for hepatitis B.

Biogenesis of serum HBV RNA and clinical phenomena of serum HBV RNA in chronic hepatitis B patients before and after receiving nucleos(t)ide analogues therapy

There are estimated 300 million people afflicted with chronic hepatitis B (CHB) worldwide. The risk of liver cirrhosis and hepatocellular carcinoma (HCC) increases considerably with chronic hepatitis B infection. While current therapeutics are effective in controlling hepatitis B virus (HBV) infection and disease progression, a cure for HBV infection remains unattainable due to an intranuclear replicative intermediate known as covalently closed circular DNA (cccDNA). It has recently been shown that serum HBV RNA is a non-invasive biomarker that reflects cccDNA transcriptional activity. This review provides a comprehensive overview and the latest updates on the molecular characteristics and clinical significance of serum HBV RNA, such as species of serum HBV RNA, forms of serum HBV RNA carriers and predictive value for relapses in CHB patients after nucleos(t)ide analogues (NAs) discontinuation and development of liver fibrosis and HCC. Furthermore, we summarize standardized assays for testing serum HBV RNA, the dynamic changes of serum HBV RNA levels in treatment-naïve CHB patients and those under NAs therapy, as well as the host and viral influencing factors of serum HBV RNA levels. Finally, we discuss the future perspectives in studies of serum HBV RNA.

[Predictive Value of Baseline Serum Marker Levels for the Effect of Interferon Therapy in Patients With Chronic Hepatitis B]

Objective

To study the changes in the serum markers in chronic hepatitis B patients who have had previous treatment with long-acting interferon therapy of nucleoside and those who have not and to assess the value of the serum markers for clinical prognosis evaluation.

Methods

The clinical data of 411 cases of chronic hepatitis B were collected. All cases were given the additional treatment of long-acting interferon between October 2019 to April 2022. The cases were divided into two groups, a previously treated group consisting of patients who had been treated with nucleoside and nucleotide analogues (NAs) for more than 6 months after they became infected with hepatitis B virus (HBV) for over 6 months and an initial treatment group, or treatment naïve group, consisting of patients who had HBV infection for over 6 months and received no treatment or patients who have stopped NAs therapy for more than 6 months. The serum marker levels of the previously treated group and the initial treatment group, i.e., the previously treatment-naïve patients, were compared, and the receiver operating characteristics (ROC) curve was used to evaluate the value of the baseline levels of hepatitis B surface antigen (HBsAg) and HBV pregenomic RNA (pgRNA) for predicting the rate of cured cases in the two groups.

Results

There was no significant difference in the rate of cured cases between the previously treated group and the initial treatment group. The baseline HBV DNA, HBsAg, and hepatitis B e antigen (HBeAg) levels of the cured cases in both groups were significantly lower than those in the uncured cases (P<0.0001). After 48 weeks of treatment, the serum HBsAb levels (mIU/mL) of the cured cases in both the previously treated and initial treatment groups were significantly higher than those of the uncured cases in the two groups (previously treated group: 78.97±22.57 vs. 0.99±0.38, P<0.0001; initial treatment group: 235.50±175.00 vs. 1.32±0.88, P<0.0001). The serum HBsAb levels (mIU/mL) of the cured cases in the initial treatment groups were significantly higher than that of cured cases in the previously treated group (235.50±175.00 vs. 78.97±22.57, P<0.0001). Within 0 to 60 weeks of treatment, HBV pgRNA levels of cured cases in both groups were significantly lower than those of the the uncured cases in both groups (P<0.0001). Multivariate logistic regression and ROC curve analysis showed that baseline serum HBsAg was the influencing factor and predictor of interferon efficacy in both the previously treated cases and the initial treatment cases, with the area under the curve (AUC) being 0.80 (95% confidence interval [CI]: 0.7423-0.8615, P<0.0001) and 0.74 (95% CI: 0.6283-0.8604, P=0.0079), respectively, and the optimal cut-off values being 244.60 IU/mL and 934.40 IU/mL, respectively. However, the baseline serum HBV pgRNA level of under 1340.00 copies/mL in the initial treatment cases led to better sensitivity and better specificity in efficacy prediction, with the AUC of the baseline HBV pgRNA being 0.9649 (95% CI: 0.9042-1.0000, P<0.0001).

Conclusion

Among the previously treated cases and the initial treatment cases, patients who achieve clinical cure have lower levels of HBV DNA, HBsAg, and HBeAg at baseline, lower level of HBV pgRNA over the course of their treatment, and higher level of HBsAb at week 48. Baseline HBsAg levels can be used to effectively predict the clinical cure outcomes in previously treated cases and initial treatment cases. Baseline HBV pgRNA levels also exhibit a high predictive value for treatment outcomes in initial treatment cases.

Quantification of circulating HBV RNA expressed from intrahepatic cccDNA in untreated and NUC treated patients with chronic hepatitis B

OBJECTIVE

A convenient, reproducible biomarker of hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) transcriptional activity is lacking. We measured circulating HBV RNA (cirB-RNA) in untreated and nucleos(t)ide analogues (NUC) treated chronic hepatitis B (CHB) patients to define its correlation with intrahepatic viral markers and HBV core-related antigen (HBcrAg).

DESIGN

Paired liver biopsy and serum samples were collected from 122 untreated and 30 NUC-treated CHB patients. We measured cirB-RNA, HBV DNA, hepatitis B surface antigen (HBsAg), HBcrAg and alanine aminotransferase levels. cirB-RNA was quantified using an investigational HBV RNA assay for use on the cobas 6800 system. The test detects a region spanning the HBV canonical polyadenylation site. cccDNA and 3.5 kb RNA in liver tissue were assessed by quantitative PCR and droplet digital PCR.

RESULTS

cirB-RNA was detectable in 100% of HBeAg(+) chronic hepatitis (CH), 57% and 14% of HBeAg(-) CH and chronic infection untreated patients and 47% of NUC-treated patients. cirB-RNA undetectability was associated with lower intrahepatic cccDNA transcriptional activity, as well as serum HBcrAg, but no significant differences in HBsAg, in both untreated and treated patients. In untreated HBeAg(-) patients, cirB-RNA correlated with intrahepatic 3.5 kb RNA and cccDNA transcriptional activity, serum HBV DNA and HBcrAg, but not with HBsAg or total cccDNA levels. Combined undetectability of both cirB-RNA and HBcrAg detection in untreated HBeAg(-) patients identified a subgroup with the lowest levels of intrahepatic transcriptionally active cccDNA.

CONCLUSION

Our results support the usefulness of quantification of circulating HBV RNA expressed from cccDNA as an indicator of intrahepatic active viral reservoir in both untreated and NUC-treated CHB patients.

TRIAL REGISTRATION NUMBER

NCT02602847.

Role of hepatitis B virus non-structural protein HBx on HBV replication, interferon signaling, and hepatocarcinogenesis

Hepatitis B, a global health concern caused by the hepatitis B virus (HBV), infects nearly 2 billion individuals worldwide, as reported by the World Health Organization (WHO). HBV, a hepatotropic DNA virus, predominantly targets and replicates within hepatocytes. Those carrying the virus are at increased risk of liver cirrhosis and hepatocellular carcinoma, resulting in nearly 900,000 fatalities annually. The HBV X protein (HBx), encoded by the virus's open reading frame x, plays a key role in its virulence. This protein is integral to viral replication, immune modulation, and liver cancer progression. Despite its significance, the precise molecular mechanisms underlying HBx remain elusive. This review investigates the HBx protein's roles in HBV replication, interferon signaling regulation, and hepatocellular carcinoma progression. By understanding the complex interactions between the virus and its host mediated by HBx, we aim to establish a solid foundation for future research and the development of HBx-targeted therapeutics.

Serum HBV RNA levels among untreated adults with chronic hepatitis B in distinct immune phases and liver histopathology statuses

HBV RNA is a novel serum biomarker that reflects intrahepatic HBV covalently closed circular DNA (cccDNA) transcription activity. Serum HBV RNA levels among treatment-naïve adults during the natural history of chronic hepatitis B (CHB) and distinct liver histopathology statuses remain elusive. In our study, we include a total of 411 treatment-naïve CHB patients, among which 43 patients were HBeAg-positive immune-tolerant [IT(e+)], 84 patients were HBeAg-positive immune active [IA(e+)], 65 patients in HBeAg-negative immune active phases [IA(e-)], 149 patients were HBeAg-negative inactive phases [IC(e-)], and 70 patients were in Gray Zone (GZ). HBV RNA was measured in this cohort and its potential correlation with traditional serological markers and liver histopathology were analyzed. Our data showed that HBV RNA was strongly correlated with HBV DNA, HBeAg, HBsAg and ALT. Further subgroup analysis revealed a close correlation between HBV RNA and HBV DNA in patients in the IA (e+) and IA (e-) phases, but neither in IT(e+) nor IC(e-) phase. HBV RNA levels were consistently increased with the advanced degrees of hepatic inflammation, but not hepatic fibrosis. Of note, HBV RNA from HBeAg-positive patients negatively correlated with liver fibrosis, whereas HBV RNA from HBeAg-negative patients was weakly associated with liver inflammation. To sum up, serum HBV RNA shows a distinct profile among CHB patients in different immune statuses and hepatic histopathology stages/grades. Simultaneous testing of HBV RNA and traditional indicators might provide a comprehensive clinical assessment of CHB patients.

Clinical cure of hepatitis B: Delight and anticipation

Chronic hepatitis B (CHB) patients achieving clinical cure represent individuals who have attained persistent virological suppression and immunological control. This is the ideal treatment goal in both domestic and international CHB management guidelines. Clinical practice has demonstrated promising outcomes for certain patient populations treated with optimized regimens involving nucleos(t)ide analogs (NAs) or immunomodulators (such as pegylated interferon α) administered sequentially or in combination. However, despite the gratifying progress in the clinical management of hepatitis B, a significant number of patients still cannot achieve the goal of clinical cure. Many challenges remain to be overcome to achieve better treatment outcomes. This article provides a brief overview of the current research progress and existing issues in the pursuit of clinical cure of hepatitis B.

Sera of Individuals Chronically Infected with Hepatitis B Virus (HBV) Contain Diverse RNA Types Produced by HBV Replication or Derived from Integrated HBV DNA

This study aimed to better characterize the repertoire of serum hepatitis B virus (HBV) RNAs during chronic HBV infection in humans, which remains understudied. Using reverse transcription-PCR (RT-PCR), real-time quantitative PCR (RT-qPCR), RNA-sequencing, and immunoprecipitation, we found that (i) >50% of serum samples bore different amounts of HBV replication-derived RNAs (rd-RNAs); (ii) a few samples contained RNAs transcribed from integrated HBV DNA, including 5'-HBV-human-3' RNAs (integrant-derived RNAs [id-RNAs]) and 5'-human-HBV-3' transcripts, as a minority of serum HBV RNAs; (iii) spliced HBV RNAs were abundant in <50% of analyzed samples; (iv) most serum rd-RNAs were polyadenylated via conventional HBV polyadenylation signal; (v) pregenomic RNA (pgRNA) was the major component of the pool of serum RNAs; (vi) the area of HBV positions 1531 to 1739 had very high RNA read coverage and thus should be used as a target for detecting serum HBV RNAs; (vii) the vast majority of rd-RNAs and pgRNA were associated with HBV virions but not with unenveloped capsids, exosomes, classic microvesicles, or apoptotic vesicles and bodies; (viii) considerable rd-RNAs presence in the circulating immune complexes was found in a few samples; and (ix) serum relaxed circular DNA (rcDNA) and rd-RNAs should be quantified simultaneously to evaluate HBV replication status and efficacy of anti-HBV therapy with nucleos(t)ide analogs. In summary, sera contain various HBV RNA types of different origin, which are likely secreted via different mechanisms. In addition, since we previously showed that id-RNAs were abundant or predominant HBV RNAs in many of liver and hepatocellular carcinoma tissues as compared to rd-RNAs, there is likely a mechanism favoring the egress of replication-derived RNAs. IMPORTANCE The presence of integrant-derived RNAs (id-RNAs) and 5'-human-HBV-3' transcripts derived from integrated hepatitis B virus (HBV) DNA in sera was demonstrated for the first time. Thus, sera of individuals chronically infected with HBV contained both replication-derived and integrant-transcribed HBV RNAs. The majority of serum HBV RNAs were the transcripts produced by HBV genome replication, which were associated with HBV virions and not with other types of extracellular vesicles. These and other above-mentioned findings advanced our understanding of the HBV life cycle. In addition, the study suggested a promising target area on the HBV genome to increase sensitivity of the detection of serum HBV RNAs and supported the idea that simultaneous detection of replication-derived RNAs (rd-RNAs) and relaxed circular DNA (rcDNA) in serum provides more adequate evaluation of (i) the HBV genome replication status and (ii) the durability and efficiency of the therapy with anti-HBV nucleos(t)ide analogs, which could be useful for improvement of the diagnostics and treatment of HBV-infected individuals.

Research progress on detection methods for hepatitis B virus covalently closed circular DNA

Hepatitis B virus (HBV) infection remains a serious global public health problem, and HBV covalently closed circular DNA (cccDNA) in the nucleus of infected cells cannot be eliminated by current treatments and is a major factor in the persistence and recurrence of hepatitis B. Efficient and scientific detection methods are important for clinical monitoring of cccDNA and targeted drug development. Western blotting is the gold standard for the quantitative detection of cccDNA, but it is time-consuming and complex. In recent years, new detection technologies have been continuously updated. There are new developments and breakthroughs in both next-generation polymerase chain reaction (PCR) and non-PCR methods such as in situ hybridization. Some HBV-related markers (such as hepatitis B core-related antigen) have also been shown to be closely related to cccDNA, and they can be used as surrogate markers to indirectly reflect cccDNA content. In this paper, the main detection methods of cccDNA and their improvements are reviewed, the advantages and limitations of these methods are analysed and summarized, and future development directions are proposed.

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.

A standardized assay for the quantitative detection of serum HBV RNA in chronic hepatitis B patients

Serum hepatitis B virus (HBV) pregenomic RNA (pgRNA) is a surrogate marker for reflecting the transcriptional activity of covalently closed circular DNA. However, there is still no standardized assay for the quantitative detection of serum HBV RNA in chronic hepatitis B patients. In this study, quantitative polymerase chain reactions for detecting the preC/C-RNA (preC/C region HBV pgRNA), SF-RNA (splicing variants-free pgRNA) and XR-RNA (X region remained pgRNA) regions were set up. The dynamic changes of serum pgRNA splicing variants and 3′ terminal truncations were analysed in three retrospective cohorts: 35 treatment-naive chronic HBV-infected patients (cohort A), 52 chronic hepatitis B (CHB) patients who received nucleos(t)ide analogs (NAs) therapy for 48 weeks (cohort B) and eight CHB patients who are under long-term NAs treatment (cohort C). The accuracy and sensitivity of HBV RNA detection were assessed by the National Standard of HBV RNA. We confirmed that high proportions of pgRNA splicing variants and 3′ terminal truncations were present and significantly affect the quantitative detection of serum HBV RNA in both treatment-naive and NAs-treated CHB patients. To achieve the higher accuracy and sensitivity on the detection of HBV RNA level, the primers and probes should be designed at the 5′ terminal region of HBV genome and outside the mainly spliced sequence of pgRNA, especially for CHB patients under long-term NAs treatment. This study would help to better understand the significance of the pgRNA splicing variants and 3′ terminal truncations, and further guide the clinical detection of serum HBV RNA.

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.

Review article: novel biomarkers in hepatitis B infection

BACKGROUND

Chronic hepatitis B remains a global health problem with an estimated 296 million people affected worldwide. Individuals are at risk of serious complications such as cirrhosis and hepatocellular carcinoma and accurately predicting these clinical endpoints has proven difficult. However, several viral biomarkers have recently been developed, including quantitative HBV surface antigen (qHBsAg), hepatitis B RNA (HBV RNA) and core-related antigen (HBcrAg), and shown promise in a range of clinical settings.

AIMS

To critically appraise these novel biomarkers, exploring their potential uses, availability of assays and areas for future development.

METHODS

We performed a literature search of PubMed, identifying articles published in the field of hepatitis B biomarkers between 2010 and 2022.

RESULTS

Novel biomarkers such as HBcrAg, HBV RNA and qHBsAg may be useful in predicting treatment outcomes, stratifying the risk of future complications and estimating off-treatment viral reactivation. Furthermore, HBV RNA and HBcrAg titres may accurately reflect cccDNA transcriptional activity, and this is particularly informative in the context of nucleoside analogue therapy. On a cautionary note, most studies have been performed in Caucasian or Asian populations, and methods for detecting HBV RNA lack standardisation.

CONCLUSION

Novel viral biomarkers have the potential to provide additional insights into the natural history of infection and allow a more bespoke, cost-effective framework of care. However, access remains limited, and further efforts are needed to validate their use in ethnically diverse populations, confirm predictive cut-off values, and establish their role in the era of novel antiviral therapies.

Ellagic acid modulates cisplatin toxicity in DMH induced colorectal cancer: Studies on membrane alterations

Systemic toxicity due to chemotherapy contributes to poor prognosis in patients receiving chemotherapy. The present study, therefore, explores the role of Ellagic acid, a phytochemical, in modulating cisplatin (CP) toxicity in dimethylhydrazine-induced colorectal cancer. Colons excised from DMH administered animals showed abnormal crypts and bulges over the mucosal surface. SEM revealed significant alterations and dysplastic lesions in DMH administered mice. Animals receiving combined treatment showed improvement in colonic epithelium with lesser irregularities. DMH and CP administration disturbed the membrane dynamics and integrity as observed with the fluorescent probes DPH and pyrene. However, EA co-supplementation with CP proved to be beneficial in normalizing the altered membrane. Ellagic acid co-supplementation along with CP; therefore, showed great promise and helped restore the membrane alterations in the colon caused due to CP-induced toxicity and DMH insult. These observations could pave way towards developing a combination therapy targeting colon carcinogenesis in future.

HBV pgRNA profiles in Chinese HIV/HBV coinfected patients under pre- and posttreatment: a multicentre observational cohort study

Data on hepatitis B virus (HBV) pregenomic (pgRNA) levels in HIV/HBV coinfected patients pre- and post-combined antiretroviral therapy (cART) are limited. This study aimed to evaluate the distribution of HBV pgRNA levels in treatment-naive coinfected patients and explore the changes that occur after the initiation of cART by examining patients from multicentre cohort studies performed in China. We included HIV/HBV coinfected subjects from the China AIDS Clinical Trial cohorts established from 2008 to 2014. Clinical and serological markers of HIV and HBV infection and biochemical data were acquired at baseline and after 96 and 240-480 weeks of cART. The correlations between HBV pgRNA and HBV DNA levels as well as HBsAg levels were calculated using Spearman's bivariate correlation analysis, and multivariate regression analysis was performed to determine factors associated with undetectable HBV pgRNA levels before cART and HBeAg loss after cART. A total of 132 HIV/HBV coinfected patients were enrolled, and 100 individuals were HBeAg-negative. A total of 34.4% (32/93) of patients were positive for HBV pgRNA, and the median HBV pgRNA level was 4.92 (IQR: 4.21-6.12) log₁₀ copies/mL before cART. The median HBV pgRNA level was significantly lower in HBeAg-negative individuals than in HBeAg-positive individuals (4.22 (IQR: 2.70-4.84) log₁₀ copies/mL vs. 5.77 (IQR: 4.63-6.55) log₁₀ copies/mL, p = 0.002). HBV pgRNA was moderately correlated with HBsAg (r = 0.594, p = 0.001), and positively associated with HBV DNA (r = 0.445, p = 0.011). The factors independently associated with undetectable HBV pgRNA level before cART were HBV DNA (OR: 5.61, 95% CI: 1.50-20.96, p = 0.01) and HBeAg status (OR: 5.95, 95% CI: 1.52-23.25, p = 0.01). A total of 87.5% (28/32) of patients were followed for a median duration of 138 (IQR: 54-240) weeks, and the HBV pgRNA levels became undetectable in seven patients. The 132 patients were observed for 695.5 person-years, and no HBsAg loss occurred. Thirteen individuals achieved HBeAg loss, four patients had undetectable levels of HBV pgRNA pre-cART, and the level of six individuals became undetectable during the 48-week (IQR: 48-264) follow-up period. HBeAg status was significantly associated with HBV pgRNA level in HIV/HBV coinfected patients pre- and post-cART. Additionally, undetectable HBV pgRNA level may be associated with HBeAg loss after cART.

Serum HBV RNA predicts HBeAg clearance and seroconversion in patients with chronic hepatitis B treated with nucleos(t)ide analogues

This study evaluated the predictive value of serum HBV DNA, HBV RNA, HBcrAg, HBsAg, intrahepatic HBV DNA and cccDNA for HBeAg clearance and seroconversion during long-term treatment with nucleos(t)ide analogues (NAs) in patients with chronic hepatitis B (CHB). A single centre, prospective cohort of CHB patients was used for this study. Serum HBV RNA levels were retrospectively measured at baseline, 6, 12, 24, 36, 48, 60, 72 and 84 months post-NAs treatment. Serum HBsAg and HBcrAg levels were quantified at baseline, month 6, 60 and 72. Histological samples from liver biopsy at baseline and month 60 were analysed for intrahepatic HBV DNA and cccDNA. Eighty-three HBeAg-positive patients were enrolled with a median follow-up time of 108 months (range 18-138 months). Of them, 53 (63.86%) patients achieved HBeAg clearance, and 37 (44.58%) achieved HBeAg seroconversion. Cox multivariate analysis showed that only baseline HBV RNA was independently associated with HBeAg clearance and seroconversion (<5.45 log₁₀ copies/mL, HR = 5.06, 95% CI: 1.87-13.71, p = .001; HR = 3.38, 95% CI: 1.28-8.91, p = .01). The independent association with HBeAg clearance and seroconversion remained for HBV RNA levels at month 6 (<4.72 log₁₀ copies/mL, HR = 4.16, 95% CI: 1.61-10.72, p = .003; HR = 6.52, 95% CI: 1.85-22.94, p = .003) and month 12 (<4.08 log₁₀ copies/mL, HR = 3.68, 95% CI: 1.96-6.90, p < .001; HR = 2.79, 95% CI: 1.31-5.94, p = .008). The AUCs of baseline HBV RNA for predicting the HBeAg clearance (0.83, 95% CI: 0.70-0.96, 0.83, 95% CI: 0.70-0.96 and 0.82, 95% CI: 0.69-0.95 respectively) and seroconversion (0.89, 95% CI: 0.77-1.00; 0.81, 95% CI: 0.66-0.95 and 0.84, 95% CI: 0.71-0.98 respectively) at month 36, 60 and 84 were higher than those of HBV DNA, HBsAg and HBcrAg. In conclusion, lower serum HBV RNA at baseline, month 6 and 12 post-NAs treatment could predict HBeAg clearance and seroconversion during long-term NAs treatment.

Impact of HCV viremia on HBV biomarkers in patients coinfected with HBV and HCV

BACKGROUNDS

Hepatitis B virus (HBV) biomarkers reflect the status of HBV infection; however, their role in patients with chronic hepatitis B and C (HBV/HCV) coinfection remains unknown. This study evaluated the characteristics of HBV biomarkers in patients with chronic HBV/HCV coinfection.

METHODS

One hundred untreated HBV/HCV coinfected patients were enrolled. Active viral infection was defined as viral load above 2000 U/L and 15 U/L for HBV and HCV, respectively. Blood samples were analyzed for HBV biomarkers, including hepatitis B surface antigen (HBsAg), hepatitis B core-related antigen (HBcrAg), HBV DNA, and HBV pregenomic RNA (HBV pgRNA). The impact of HCV viremia was also studied.

RESULTS

A total of 15 patients were HBV-inactive/HCV-inactive, 63 patients were HBV-inactive/HCV-active, 14 patients were HBV-active/HCV-inactive and 8 patients were HBV-active/HCV-active. A total of 71 (71%) patients were active HCV and 22 (22%) were active HBV. HBsAg, HBcrAg, and HBV DNA correlated with each other (P < 0.001). HBV pgRNA displayed no correlations with HBV DNA, HBsAg, or HBcrAg. Patients with HCV viremia had significantly lower HBV DNA, HBsAg, and HBcrAg levels as well as higher HBV pgRNA levels and lower HBV DNA:pgRNA ratio than those without viremia (HBV DNA, P < 0.001; HBsAg, P = 0.015; HBcrAg, P = 0.006; HBV pgRNA, P = 0.073; and HBV DNA:pgRNA ratio, P < 0.001).

CONCLUSIONS

In patients coinfected with HBV and HCV, HBsAg, HBcrAg, and HBV DNA significantly correlated with each other. HBV and HCV coinfected patients with HCV viremia have lower HBV DNA, HBsAg, HBcrAg, and HBV DNA:pgRNA ratio as well as higher HBV pgRNA levels.

Dynamics of Serum Pregenome RNA in Chronic Hepatitis B Patients Receiving 96-Month Nucleos(t)ide Analog Therapy

Background

Tissue covalently closed circular DNA (cccDNA) can reflect the activity of HBV replication. However, it is impractical to assess intrahepatic cccDNA in every outpatient. Serum pregenome RNA (pgRNA) is transcribed from intrahepatic cccDNA and may reflect the activity of intrahepatic cccDNA. We explored the dynamics and the potential role of serum pgRNA in patients receiving long-term NAs treatment.

Methods

Serum pgRNA, HBV DNA, HBsAg, HBeAg, and ALT levels were quantified, and the relationships between serum pgRNA and these common clinical indicators before and after the treatment were investigated.

Results

Serum pgRNA showed dynamic change during the 96-month NAs therapy, and serum pgRNA levels were positive and detectable in 19 patients with undetectable serum HBV DNA. Serum pgRNA showed strong and positive correlation with serum HBV DNA (r = 0.693, p < 0.001) and serum HBsAg levels (r = 0.621, p < 0.001) at baseline. Patients with HBeAg seroconversion had lower baseline serum pgRNA levels (p = 0.002). The area under the curve (AUC) of baseline serum pgRNA for predicting HBeAg seroconversion was 0.742 (95% CI: 0.606–0.850) with 63.16% sensitivity and 80.56% specificity. The cumulative HBeAg seroconversion rate was higher in patients with low serum pgRNA (p = 0.001).

Conclusion

Serum pgRNA of low level at baseline or great decline at month 6 may independently predict the high incidence of undetectable serum pgRNA at year 4 following NAs therapy, and the baseline serum pgRNA may serve as a novel predictor for HBeAg seroconversion during NAs therapy.

Approaches to quantifying Hepatitis B Virus covalently closed circular (ccc)DNA

Chronic hepatitis B is a major cause of liver disease worldwide and is currently incurable. Hepatitis B virus (HBV) covalently closed circular (ccc) DNA is a key form of the virus responsible for its persistence and is the transcriptional template for all viral transcripts. The field is focussed on methods to clear HBV cccDNA but this been limited by technical difficulties in its quantification due to: identical sequence to other forms of HBV DNA; low copy number per cell; and high resistance to denaturation by heat, leading to difficulty using polymerase chain reaction or hybridization methods for detection. A number of assays have been developed in order to overcome these hurdles either directly or detecting cccDNA levels indirectly via its transcriptional products. In this review, we summarize the approaches to cccDNA quantification that are currently used, and outline key open questions in the cccDNA biology field which remain to be answered due to the limitations of current methods.

Hepatitis B Core-Related Antigen and New Therapies for Hepatitis B

The hepatitis B core-related antigen (HBcrAg) is an unprecedented novel HBV biomarker that plays an essential role in reflecting covalently closed circular DNA (cccDNA) in chronic hepatitis B (CHB) because its levels correlate with intrahepatic cccDNA and serum HBV DNA. In this review, we describe the clinical application of serum HBcrAg in CHB patients, with a particular focus on new therapies targeting intrahepatic HBV replication. (1) HBcrAg can be detected in clinical cases where serum HBV DNA is undetectable during anti-HBV therapy. (2) A highly sensitive HBcrAg assay (iTACT-HBcrAg) may be useful for monitoring HBV reactivation, as an alternative to HBV DNA. (3) Decreased HBcrAg levels have been significantly associated with promising outcomes in CHB patients, reducing the risk of progression or recurrence of hepatocellular carcinoma. Additionally, we focus on and discuss several drugs in development that target HBV replication, and monitoring HBcrAg may be useful for determining the therapeutic efficacies of such novel drugs. In conclusion, HBcrAg, especially when measured by the recently developed iTACT-HBcrAg assay, may be the most appropriate surrogate marker, over other HBV biomarkers, to predict disease progression and treatment response in CHB patients.

HBxAg promotes HBV replication and EGFR activation in human placental trophoblasts

Hepatitis B virus (HBV) infection is a global epidemic. The main transmission route of chronic HBV infection is from mother to child, yet the mechanisms underlying HBV intrauterine infection remain unclear. In the present study, the effect and the mechanism underlying hepatitis B virus X antigen (HBxAg) on HBV replication and EGFR activation in trophoblasts was investigated. Serum samples from pregnant women with HBV infection were used to infect trophoblasts and HBxAg expression was detected using ELISA. HBV plasmids carrying either full length hepatitis B virus X (HBx) or HBx with a deletion mutation (ΔHBx) were transfected into trophoblasts and expression levels of HBV DNA, hepatitis B e-antigen and pregenomic (pg)RNA, and structural maintenance of chromosomes (Smc) 5/6 were assessed. The association between HBx and EGFR promoters was characterized using a luciferase reporter assay and EGFR/PI3K/phosphorylated (p)-AKT expression and apoptosis rate were also monitored. The results of the present study indicated that HBxAg expression increased with the increasing titre of HBV DNA (P<0.05). Compared with the wild-type group, the amount of HBV DNA in the supernatant and cells was significantly reduced (P<0.05) in the ΔHBx group and the intracellular HBeAg and pgRNA levels were also significantly decreased (P<0.05). In addition, Smc5/6 expression was also significantly decreased (P<0.05) when the intracellular HBx protein was expressed compared with mock-transfected cells. Co-transfection of HBx and EGFR promoter plasmids in JEG-3 and HTR-8 cells significantly elevated EGFR promoter driven luciferase expression relative to the control group (P<0.01). In EGFR overexpressing cells, the expression of PI3K/p-AKT was significantly increased, whereas the apoptosis rate was significantly decreased (P<0.05). These results were reversed in the EGFR-knockdown group. In conclusion, the present study demonstrated that HBx promotes HBV replication in trophoblasts via downregulation of Smc5/6, activates the EGFR promoter and inhibits trophoblast apoptosis via the PI3K/p-AKT downstream signalling pathway, thereby increasing the risk of HBV intrauterine infection.

The 96-week clinical outcomes after cessation of nucleos(t)ide analog treatment in chronic hepatitis B patients

Background

Chronic hepatitis B (CHB) patients have a high virological relapse rate after cessation of nucleos(t)ide analog (NA) treatment, but the clinical outcome remains unclear. This study aimed to investigate the 96-week clinical outcomes and the risk factors for relapse in CHB after cessation of NAs.

Methods

This study was a prospective trial; 74 eligible patients were enrolled. The patients underwent NA cessation and follow-up according to the 2012 Asian Pacific Association for the Study of the Liver Guideline. Symptoms, biochemical (aspartate aminotransferase [AST], alanine aminotransferase [ALT], total bilirubin, urea nitrogen, creatinine), virological data (hepatitis B surface antigen [HBsAg], hepatitis B e antigen [HBeAg], hepatitis B e antibody [HBeAb], hepatitis B virus [HBV] DNA levels), and color Doppler ultrasound examination results were recorded and analysed.

Results

After NA cessation, 19 cases were HBsAg-negative without relapse during the 96-week follow-up. Of the 55 cases of HBsAg-positive after cessation, four types of clinical outcomes were observed. Twelve patients had no relapse during the 96-week follow-up (type A, 21.8%), 7 patients underwent virological relapses but spontaneously had a non-virological relapse (type B, 12.7%), 10 patients maintained virological relapse (type C, 18.2%), and 26 patients turned to clinical relapse, received NA retreatment, and achieved ALT normalization and negative conversion of HBV DNA within 12 months (type D, 47.3%). The 2-year overall cumulative rates of virological and clinical relapses were 58.1% and 24.3%, respectively. Independent factors associated with virological relapse were duration of negative HBV DNA, EOT (end of treatment) HBsAg, and original status of HBeAg. The EOT HBsAg was also an independent factor for clinical relapse.

Conclusions

There are four types of clinical outcomes in patients with CHB after cessation of NA treatment. Further research is needed to explore the mechanism of different clinical outcomes. The EOT HBsAg level is an independent factor associated with both virological and clinical relapse.

On-treatment HBV RNA dynamic predicts entecavir-induced HBeAg seroconversion in children with chronic hepatitis B

BACKGROUND

Hepatitis B e antigen (HBeAg) seroconversion is an important intermediate outcome in HBeAg-positive chronic hepatitis B patients. This study aimed to explore whether hepatitis B virus (HBV) RNA serum levels can predict HBeAg seroconversion treated with entecavir.

METHODS

Serum samples from HBeAg-positive children previously treated with entecavir were retrospectively analyzed. HBV RNA levels were measured at baseline, weeks 12, 24, 48, 72 of therapy. Ability of individual biomarkers to predict HBeAg seroconversion was evaluated using receiver operating characteristics (ROC) analyzes.

RESULTS

Serum HBV RNA was detectable in 51 children with a median of 6.05 (4.04-8.29) log₁₀ IU/mL at baseline. Patients with subsequent HBeAg seroconversion showed a significantly larger decline in median HBV RNA levels during treatment from baseline to week 12 of 1.96 (0.30-3.38) and to week 24 of 2.27 (1.20-3.38) log₁₀ IU/mL, respectively, in comparison to HBeAg-positive patients without HBeAg seroconversion (P < 0.001). Levels of HBV RNA at treatment weeks 12 and 24 showed good ability to predict HBeAg seroconversion (area under ROC scores > 0.85, P < 0.001).

CONCLUSION

On-treatment HBV RNA dynamic predicts entecavir-induced HBeAg seroconversion in children with chronic hepatitis B living in China.

Novel viral markers and the prediction of off-treatment relapse in chronic hepatitis B patients: A systematic review

BACKGROUND AND AIM

Hepatitis B core-related antigen (HBcrAg) and hepatitis B virus RNA (HBV RNA) are novel markers that reflect intrahepatic cccDNA and could be useful in the prediction of relapse after nucleos(t)ide analogues (NA) discontinuation. The aim of the study is to perform a systematic review on this issue.

METHODS

Medline/Pubmed database was searched using text terms related to HBcrAg, RNA, NAs, discontinuation, and relapse. Included studies were those that enrolled adult patients who had been on NAs for more than 6 months with available information on end-of-treatment (EOT) HBcrAg and/or HBV RNA and relapse rates.

RESULTS

Sixteen studies were included. Virological and clinical relapse rates ranged from 11% to 100% and 11% to 73%, respectively. Low or undetectable EOT HBcrAg levels were associated with low off-treatment relapse rates in most studies with area under the receiver operating characteristic curve (AUROC) of 0.69-0.70 for predicting virological relapse (VR) and 0.61-0.77 for predicting clinical relapse (CR). Undetectable EOT HBV RNA was associated with a lower risk of off-treatment relapse with AUROC of 0.65-0.76 for predicting VR and 0.66-0.73 for predicting CR. Combined EOT HBcrAg and HBV RNA performed better in predicting off-treatment relapse than either test alone with AUROC of 0.816-0.846 for predicting CR. None of the patients with double-negative HBV RNA and HBcrAg developed CR.

CONCLUSION

Combining HBcrAg with HBV RNA or HBsAg improved the discriminating abilities in the prediction of off-treatment relapse of each test. Patients with double-negative HBcrAg and HBV RNA at EOT had low risks of relapse and could be considered for NA discontinuation.

Persistence of Hepatitis B Virus Infection: A Multi-Faceted Player for Hepatocarcinogenesis

Hepatitis B virus (HBV) infection has a multi-dimensional effect on the host, which not only alters the dynamics of immune response but also persists in the hepatocytes to predispose oncogenic factors. The virus exists in multiple forms of which the nuclear localized covalently closed circular DNA (cccDNA) is the most stable and the primary reason for viral persistence even after clearance of surface antigen and viral DNA. The second reason is the existence of pregenomic RNA (pgRNA) containing virion particles. On the other hand, the integration of the viral genome in the host chromosome also leads to persistent production of viral proteins along with the chromosomal instabilities. The interferon treatment or administration of nucleot(s)ide analogs leads to reduction in the viral DNA load, but the pgRNA and surface antigen clearance are a slow process and complete loss of serological HBsAg is rare. The prolonged exposure of immune cells to the viral antigens, particularly HBs antigen, in the blood circulation results in T-cell exhaustion, which disrupts immune clearance of the virus and virus-infected cells. In addition, it predisposes immune-tolerant microenvironment, which facilitates the tumor progression. Thus cccDNA, pgRNA, and HBsAg along with the viral DNA could be the therapeutic targets in the early disease stages that may improve the quality of life of chronic hepatitis B patients by impeding the progression of the disease toward hepatocellular carcinoma.

The relationship between hepatitis B virus serum DNA, RNA and quantitative hepatitis B surface antigen, and the predictive value for mother-to-child transmission: an observational cohort study

OBJECTIVE

To explore the relationships between hepatitis B virus (HBV) DNA, HBV RNA and hepatitis B surface antigen (HBsAg) and to evaluate their predictive value for mother-to-child transmission of HBV.

DESIGN

An observational cohort study.

SETTING

First Hospital of Jilin University.

POPULATION

HBsAg-positive and hepatitis B e antigen (HBeAg) -positive pregnant women were recruited.

METHODS

Blood samples were collected from mothers before delivery, and HBV infection of infants was evaluated at 7 months of age.

RESULTS

Overall, 268 mothers and 271 infants were enrolled. HBV DNA and HBsAg levels were correlated (r_s  = 0.699; P < 0.001), and HBV DNA (r_s  = 0.500; P < 0.001) and HBsAg (r_s  = 0.372; P < 0.001) were both correlated with HBV RNA. The areas under the curve for HBV DNA, HBsAg and HBV RNA for prediction of infection were 0.69 (95% CI 0.57-0.82), 0.63 (95% CI 0.51-0.76) and 0.65 (95% CI 0.52-0.78), respectively. Higher HBV DNA (odds ratio [OR] 4.77, 95% CI 1.44-15.86), higher HBsAg (OR 4.13, 95% CI 1.12-15.25) and higher HBV RNA (OR 3.19, 95% CI 1.09-9.32) were risk factors for HBV infection. Analysis of the HBV DNA-RNA-HBsAg Score revealed that it was an independent predictive factor for mother-to-child transmission (the OR of Score 3 was 8.81, 95% CI 2.79-27.82).

CONCLUSION

HBV DNA, HBV RNA and HBsAg were correlated in HBeAg-positive pregnant women. HBsAg could be considered as a substitute marker of HBV DNA for HBeAg-positive pregnant women in low-income regions. We should pay special attention to pregnant women with high levels of all three markers.

TWEETABLE ABSTRACT

HBsAg could be considered as a substitute marker of HBV DNA for HBeAg-positive pregnant women in low-income regions. Special attention should be given to pregnant women with high levels of all three markers (HBV DNA, HBV RNA and HBsAg).

Viral hepatitis update: Progress and perspectives

Viral hepatitis, secondary to infection with hepatitis A, B, C, D, and E viruses, are a major public health problem and an important cause of morbidity and mortality. Despite the huge medical advances achieved in recent years, there are still points of conflict concerning the pathogenesis, immune response, development of new and more effective vaccines, therapies, and treatment. This review focuses on the most important research topics that deal with issues that are currently being solved, those that remain to be solved, and future research directions. For hepatitis A virus we will address epidemiology, molecular surveillance, new susceptible populations as well as environmental and food detections. In the case of hepatitis B virus, we will discuss host factors related to disease, diagnosis, therapy, and vaccine improvement. On hepatitis C virus, we will focus on pathogenesis, immune response, direct action antivirals treatment in the context of solid organ transplantation, issues related to hepatocellular carcinoma development, direct action antivirals resistance due to selection of resistance-associated variants, and vaccination. Regarding hepatitis D virus, we describe diagnostic methodology, pathogenesis, and therapy. Finally, for hepatitis E virus, we will address epidemiology (including new emerging species), diagnosis, clinical aspects, treatment, the development of a vaccine, and environmental surveillance.

Baseline quantitative HBcAb strongly predicts undetectable HBV DNA and RNA in chronic hepatitis B patients treated with entecavir for 10 years

The predictive effect of quantitative anti-hepatitis B core on double-negative HBV DNA and RNA remains unstudied. We observed dynamic changes in this measure in chronic hepatitis B patients receiving entecavir for 10 years, evaluating its predictive value for double-negative HBV DNA and RNA. Twenty-seven chronic hepatitis B patients treated with entecavir for 10 years were enrolled in this study. Liver function, quantitative anti-hepatitis B core, hepatitis B surface and e antigens, HBV DNA and RNA were measured at baseline and each follow-up. Virological response was defined as double-negative HBV DNA and RNA; serological response was defined as hepatitis B e antigen seroconversion. After antiviral therapy, quantitative anti-hepatitis B core showed an overall downward trend. Patients with virological response had significantly higher quantitative anti-hepatitis B core levels than those without virological response at baseline. Patients with serological response also had higher quantitative anti-hepatitis B core levels than those without serological response at baseline and week 24. Baseline quantitative anti-hepatitis B core level was the only independent predictor for virological and serological responses. Baseline quantitative anti-hepatitis B core level was powerfully predictive of double-negative HBV DNA and RNA in chronic hepatitis B patients receiving long-term entecavir therapy.

Viral Biomarkers for Hepatitis B Virus-Related Hepatocellular Carcinoma Occurrence and Recurrence

Hepatocellular carcinoma (HCC) is the sixth most common cancer worldwide and the fourth leading cause of cancer-related death. The most common risk factor for developing HCC is chronic infection with hepatitis B virus (HBV). Early stages of HBV-related HCC (HBV-HCC) are generally asymptomatic. Moreover, while serum alpha-fetoprotein (AFP) and abdominal ultrasound are widely used to screen for HCC, they have poor sensitivity. Thus, HBV-HCC is frequently diagnosed at an advanced stage, in which there are limited treatment options and high mortality rates. Serum biomarkers with high sensitivity and specificity are crucial for earlier diagnosis of HCC and improving survival rates. As viral-host interactions are key determinants of pathogenesis, viral biomarkers may add greater diagnostic power for HCC than host biomarkers alone. In this review, we summarize recent research on using virus-derived biomarkers for predicting HCC occurrence and recurrence; including circulating viral DNA, RNA transcripts, and viral proteins. Combining these viral biomarkers with AFP and abdominal ultrasound could improve sensitivity and specificity of early diagnosis, increasing the survival of patients with HBV-HCC. In the future, as the mechanisms that drive HBV-HCC to become clearer, new biomarkers may be identified which can further improve early diagnosis of HBV-HCC.

Clinical Implications of Serum Hepatitis B Virus Pregenomic RNA Kinetics in Chronic Hepatitis B Patients Receiving Antiviral Treatment and Those Achieving HBsAg Loss

Serum hepatitis B virus (HBV) pregenomic RNA (pgRNA) is correlated with covalently closed circular DNA. We aimed to investigate the utility of serum HBV pgRNA in chronic hepatitis B patients receiving nucleos(t)ide analogue treatment and those achieving HBsAg loss. One hundred and eighty-five patients were enrolled for studying long-term HBV pgRNA kinetics during treatment. Twenty patients achieving HBsAg loss after treatment were enrolled for examining HBV pgRNA kinetics around HBsAg loss. HBV pgRNA significantly decreased in the high baseline HBV pgRNA (≥6 log copies/mL) group but significantly increased in the low baseline HBV pgRNA (<4 log copies/mL) group after 3-month entecavir treatment. Among the 20 patients achieving HBsAg loss, 13 (65%) patients had serum HBV pgRNA higher than the limit of detection (LOD, 1466 copies/mL) when they achieved HBsAg loss. Finally, all 20 patients had HBV pgRNA going below the LOD within 3 years after achieving HBsAg loss. In conclusion, baseline serum HBV pgRNA alone is insufficient for predicting the trajectory of HBV pgRNA. Most patients still had HBV pgRNA higher than the LOD when they achieved HBsAg loss. Further studies on HBV pgRNA kinetics around HBsAg loss would provide an enhanced basis for further applications of HBV pgRNA.

Hepatitis B Virus RNA as Early Predictor for Response to Pegylated Interferon Alpha in HBeAg-Negative Chronic Hepatitis B

BACKGROUND

Hepatitis B virus RNA (HBV-RNA) is a novel serum biomarker that correlates with transcription of intrahepatic covalently closed circular (cccDNA), which is an important target for pegylated interferon (PEG-IFN) and novel therapies for functional cure. We studied HBV-RNA kinetics following PEG-IFN treatment and its potential role as a predictor to response in HBeAg-negative chronic hepatitis B (CHB) patients.

METHODS

HBV-RNA levels were measured in 133 HBeAg-negative CHB patients treated in an international randomized controlled trial (PARC study). Patients received PEG-IFN α-2a for 48 weeks. HBV-RNA was measured from baseline through week 144. Response was defined as HBV-DNA <2000 IU/mL and ALT normalization at week 72. Kinetics of HBV-RNA were compared with HBV-DNA, HBsAg, and HBcrAg.

RESULTS

Mean HBV-RNA at baseline was 4.4 (standard deviation [SD] 1.2) log10 c/mL. At week 12, HBV-RNA declined by -1.6 (1.1) log10 c/mL. HBV-RNA showed a greater decline in responders compared to nonresponders early at week 12 (-2.0 [1.2] vs -1.5 [1.1] log10 c/mL, P = .04). HBV-RNA level above 1700 c/mL (3.2 log10 c/mL) had a negative predictive value of 91% at week 12 and 93% at week 24 (P = .01) for response. Overall, HBV-RNA showed a stronger correlation with HBV-DNA and HBcrAg (.82 and .80, P < .001) and a weak correlation with HBsAg (.25). At week 12, HBV-RNA was significantly lower among patients with lower HBsAg (<100 IU/mL) or HBsAg loss at week 144.

CONCLUSIONS

During PEG-IFN treatment for HBeAg-negative CHB, HBV-RNA showed a fast and significant decline that correlates with treatment response and HBsAg loss at long-term follow-up.

CLINICAL TRIALS REGISTRATION

NCT00114361.

Factors and virological significance of hepatitis B virus pregenomic RNA status after 5 years of antiviral therapy

OBJECTIVES

To investigate the factors and virological significance of serum hepatitis B virus (HBV) pregenomic RNA (pgRNA) status after long-term antiviral therapy with nucleos(t)ide analogues (NAs) in patients with chronic hepatitis B (CHB).

METHODS

In total, 51 treatment-naïve patients with CHB were included in the study. Clinical data were collected at baseline, during 5 years and at year 10 of NA treatment. Serum HBV pgRNA status of 51 patients was determined at year 5.

RESULTS

At year 5, 45% of the patients remained positive for HBV pgRNA. There were significant differences in baseline hepatitis B e antigen (HBeAg) status, HBV DNA load and hepatitis B surface antigen (HBsAg) levels between patients testing positive and negative for HBV pgRNA at year 5. Serum HBV pgRNA status and serum HBV DNA load were correlated after 5 years of NA treatment (r = 0.347, P = 0.013). Being HBV pgRNA positive at year 5 was an independent risk factor for sustainedly undetectable HBV DNA after 10 years of NA treatment (odds ratio 13.638, 95% confidence interval 1.32-140.81; P = 0.028). Furthermore, HBV pgRNA status at year 5 was associated with HBV DNA re-appearance at year 10 (P = 0.009).

CONCLUSIONS

HBV pgRNA status at year 5 can reveal HBV covalently closed circular DNA (cccDNA) activity, and HBV pgRNA positivity after long-term antiviral therapy may indicate higher transcriptional activity of HBV cccDNA. Long-term dynamic monitoring of HBV pgRNA should be considered.

Biomarkers for hepatitis B virus replication: an overview and a look to the future

INTRODUCTION

Hepatitis B virus (HBV) infection is a major public health issue but there are no powerful drugs to eradicate the virus. HBV markers including HBsAg, HBcrAg, HBV RNA, HBcAb, and HBV DNA are becoming promising biomarkers to reflect the natural phases of chronic HBV infection and predict the outcome of anti-HBV treatment.

AREAS COVERED

The authors summarized the biomarkers of HBV replication and presented the current advances of these biomarkers on predicting the outcome of anti-HBV treatment and identifying the progression of chronic HBV infection.

EXPERT OPINION

HBsAg, HBcrAg, HBV RNA, HBcAb, and HBV DNA are noninvasive and feasible biomarkers for monitoring the process of anti-HBV therapy and predicting the progress of HBV infection. However, there are still no strong biomarkers with high sensitivity and specificity for clinical application. Combination of two or more HBV biomarkers, new technique for measuring HBV cccDNA, and searching novel HBV biomarkers are essential for anti-HBV treatment in the future.

Serum HBV RNA Dynamic and Drug Withdrawal Predictor Value in Patients With Chronic HBV Infection on Long-term Nucleos(t)ide Analogue (NA) Therapy

AIMS

This study aimed to investigate the dynamic pattern of serum hepatitis B virus (HBV) RNA in chronic hepatitis B (CHB) patients on long-term nucleos(t)ide analogue (NA) therapy and evaluate predictor value of end-of-treatment (EOT) serum HBV RNA status on drug-withdrawal durability.

METHODS

We carried out a real-life cohort study of 326 CHB patients on NA treatment between February 12, 2016 and February 21, 2018. Thirty of these patients discontinued NA treatment after enrollment, and were included in 2-year off-therapy follow-up. Serum HBV RNA levels were determined using the RNA simultaneous amplification testing method.

RESULTS

Both serum HBV RNA and DNA levels declined significantly in long-term antiviral progress. When the treatment duration was longer than 3 years, the undetectable rates of HBV RNA and DNA were 55.10% and 97.0%, respectively. The serum HBV RNA-negative rate was 39.5%. The cumulative 2-year off-therapy viral and clinical relapse rate was 40.56%; 95% confidence interval (95% CI), 21.51-59.61 and 31.31%; 95% CI, 11.32-51.29 in all patients, respectively. Patients with EOT hepatitis B surface antigen (HBsAg)≤1000 IU/mL plus HBV RNA negativity had a relatively lower cumulative 2-year off-therapy viral relapse rate (23.01%; 95% CI, 0.17-45.99). EOT HBsAg≤1000 IU/mL plus HBV RNA negativity showed obvious superiority for the EOT HBsAg≤1000 IU/mL single in drug withdrawal durability prediction, with better specificity (18.18% vs. 72.73%, P=0.03), and the positive predictive value and negative predictive value were 76.92% and 47.06%, respectively.

CONCLUSIONS

In the long-term antiviral process, both serum HBV RNA and DNA levels declined significantly. EOT serum HBV RNA negativity was not an independent drug withdrawal marker, but can complement the HBsAg titer to monitor drug withdrawal in CHB patients on long-term NA therapy.

Disease burden of chronic hepatitis B and complications in China from 2006 to 2050: an individual-based modeling study

Background

Chronic hepatitis B has become a major public health problem in China. An accurate depiction of the disease burden has not yet been thoroughly conducted. We aimed to project the disease burden of chronic hepatitis B virus (HBV) infection and related complications by modeling various scenarios.

Method

An individual-based Markov model was used to predict disease burden from 2006 through 2050. We simulated 5 scenarios with different annual incidences, diagnoses and nucleotide analog (NA) treatment rates as well as treatment eligibility, which included a natural history without diagnosis or NA therapy, a base case, a World Health Organization (WHO)-proposed target case and two ideal cases.

Result

The natural history scenario is projected to have the fewest HBsAg losses (27.59 million) and highest number of HBV-related deaths (27.19 million). With improved diagnosis and treatment rates of NA therapy, ideal cases have fewer HBV-related deaths (14.46–14.77 million) than do WHO-proposed cases (15.13 million) and base cases (16.89 million), but the proportion of HBsAg loss is similar among them. With a reduction in new infections, the prevalence of chronic HBV in 2050 is expected to be a minimum of 27.03–27.49 million under WHO and ideal cases.

Conclusion

Ideal scenarios 1 and 2 contribute to the lowest disease burden of HBV and its complications in the future, in which new infection control is more effective than increasing diagnosis, treatment rate and treatment eligibility. However, considering the large existing chronic HBV infected population and the low HBsAg loss rate of NA therapy, it is still difficult to avert the increasing trend of cumulative cirrhosis, DC, HCC, LT, and HBV-related death in all scenarios. If new high-potency drugs are not developed, the disease burden of chronic HBV will remain high in the future.

Evaluation of HBV serological markers in treatment-naïve HBV mono-infected patients and HBV-HIV co-infected patients

OBJECTIVES

Many studies have investigated the utility of hepatitis B virus (HBV) serological markers in HBV-infected patients. However, only a few studies have examined HBV serological markers in HBV-human immunodeficiency virus (HIV) co-infected patients. Here, we conducted a cross-sectional study to evaluate correlations of HBV serological markers in treatment-naïve HBV mono-infected patients and HBV-HIV co-infected patients.

METHODS

HBsAg, HBV DNA, HBV RNA, and HBcrAg were quantified in 51 HBV mono-infected patients and 33 HBV-HIV co-infected patients recruited at Tianjin Second People's Hospital from 2016 to 2019.

RESULTS

There was no significant difference in serum levels of HBV DNA (P = 0.056), HBV RNA (P = 0.387), HBcrAg (P = 0.714) and HBsAg (P = 0.165) between the patient groups. In HBV mono-infected patients, strong positive correlations were confirmed between HBV RNA and HBV DNA (r=0.620, P < 0.01), HBcrAg and HBV DNA (r=0.802, P < 0.001), and HBcrAg and HBV RNA (r=0.727, P < 0.01). In HBV-HIV co-infected patients, serum HBsAg was very strongly correlated with HBcrAg (r=0.838, P < 0.001). In HBeAg-positive HBV mono-infected patients, all HBV serological markers correlated with each other, whereas only HBV RNA correlated with HBcrAg in HBeAg-negative HBV mono-infected patients (r=0.688, P = 0.007). In HBeAg-positive HBV-HIV co-infected patients, only HBsAg correlated with HBcrAg (r=0.725, P<0.001), whereas HBcrAg and HBV RNA correlated with each other in HBeAg-negative patients (r = 0.683, P=0.010). Moreover, CD4 T-cell counts were not significantly associated with HBsAg, HBV DNA, HBV RNA, and HBcrAg levels.

CONCLUSION

Compared with HBsAg and HBV DNA, which are widely used in clinical settings, our study confirmed that new HBV serological markers, such as HBV RNA and HBcrAg, have some utility in HBV mono-infected patients and HBV-HIV co-infected patients for monitoring the progression of liver disease.

Efficacy of a combination of HBV RNA and HBeAg in predicting HBeAg seroconversion in patients treated with entecavir for 144 weeks

BACKGROUND

In some previous studies, serum hepatitis B virus RNA (HBV RNA) was proposed as an HBV viral marker during therapy. However, the dynamic change of HBV RNA, the correlation of HBV RNA with cccDNA, and the combination of HBV RNA with known HBV markers in predicting entecavir (ETV) treatment outcome in the same cohort are rarely reported.

METHODS

A total of 111 HBeAg-positive patients were enrolled in our study. The dynamic changes of serum HBV RNA and the correlation of HBV RNA with other HBV markers were investigated in the early treatment period of 144-week ETV treatment. Intrahepatic cccDNA was detected at baseline and week 48. Receiver operating characteristic analyses were used to identify HBV RNA levels associated with HBeAg seroconversion.

RESULTS

The serum HBV RNA levels decreased more rapidly in patients with HBeAg seroconversion than those without HBeAg seroconversion. The levels of HBV RNA decreased slower compared with the serum HBV DNA, irrespective of whether the patients achieved HBeAg seroconversion or not. Although the serum HBV RNA was positively correlated with cccDNA at baseline among all patients, no significant correlation was observed in the patients with HBeAg seroconversion at week 48 (r=0.094, P=0.588). The area under the receiver operating characteristic (AUROC) of HBV RNA and HBeAg at week 24 was 0.754 and 0.800, respectively. The AUROC of the HBV RNA and HBeAg combination had a higher value (AUROC=0.821).

CONCLUSIONS

The level of HBV RNA at week 24 was a powerful predictor of HBeAg seroconversion in HBeAg-positive patients after 144-week ETV treatment, while the combination of HBV RNA and HBeAg was superior to HBV RNA alone in predicting HBeAg seroconversion.

Serum Hepatitis B Virus RNA Levels Predict HBeAg Seroconversion and Virological Response in Chronic Hepatitis B Patients with High Viral Load Treated with Nucleos(t)ide Analog

Background and Aim

Hepatitis B virus (HBV) RNA has attracted increasing attention as a novel serum marker for intrahepatic HBV replication. However, the predictive value of the serum level of HBV RNA for hepatitis B e-antigen (HBeAg) seroconversion and viral response among patients with a high viral load (HVL) is unclear. We evaluated the role of the serum level of HBV RNA as a predictor of treatment response in chronic HBV (CHB) patients with an HVL.

Patients and Methods

The study cohort was 66 HBeAg-positive CHB patients with an HVL (serum HBV DNA >1.9×10⁶ IU/mL) at baseline from our previous prospective cohort study treated with lamivudine (LAM) and adefovir dipivoxil(ADV) (N=31) or entecavir alone (N=35) for ≤96 weeks. The serum HBV RNA level was quantified by TaqMan^® probe-based reverse transcription real-time quantitative polymerase chain reaction at four time points.

Results

The baseline serum HBV RNA level (in log₁₀ copies/mL) in patients treated with LAM+ADV and ETV monotherapy was 8.97±1.22 and 9.15±0.92, respectively. After nucleos(t)ide analog (NA) therapy, the serum HBV RNA level decreased steadily in all patients (week 0 vs week 12, p<0.001; week 12 vs week 24, p=0.010; week 24 vs week 48, p<0.001). Fifty-three (80.3%) patients achieved a virologic response (VR), and 12 (18.2%) achieved HBeAg seroconversion after 96 weeks. Multivariate analyses revealed that the serum HBV RNA level at week 12 could predict HBeAg seroconversion (OR 3.560, 95% CI: 1.39–9.110, p=0.008) and VR (1.908, 1.115–3.265, 0.018) at 96 weeks. Analyses of receiver operating characteristic curves indicated that the serum HBV RNA level 12 weeks after NA treatment had predictive value for HBeAg seroconversion (AUC=0.847, p<0.001) and VR (AUC=0.736, p=0.011).

Conclusion

The serum level of HBV RNA at 12 weeks could predict HBeAg seroconversion and a VR during NA treatment in CHB patients with an HVL.

Monitoring of serum HBV RNA, HBcrAg, HBsAg and anti-HBc levels in patients during long-term nucleoside/nucleotide analogue therapy

BACKGROUND

This study was aimed at evaluating the clinical significance of serum HBV RNA, hepatitis B core-related antigen (HBcrAg) and hepatitis B core antibody (anti-HBc) levels in chronic hepatitis B patients with undetectable HBV DNA during nucleoside/nucleotide analogue (NA) treatment.

METHODS

Fifty-seven patients who received long-term NA treatment of median 5.83 (25%, 75% percentiles 4.67, 7.75) years were enrolled, and 285 serum samples at five time points for each patient were quantitatively analysed for the three serum markers together with serum HBV DNA and hepatitis B surface antigen (HBsAg) levels.

RESULTS

The HBV RNA level significantly correlated with HBcrAg (r=0.629; P<0.001) but not HBsAg levels (P=0.1460). Nonetheless, the HBcrAg level significantly correlated with the HBsAg level (r=0.469; P<0.001). Hepatitis B e antigen (HBeAg)-positive samples showed higher HBV RNA, HBcrAg and HBsAg levels than HBeAg-negative samples did (all P<0.05). Nine patients with HBeAg loss manifested a significantly greater decline in HBV RNA and HBcrAg levels (median 1.84 [25%, 75% percentiles 1.02, 2.12] log₁₀ copies/ml, 1.14 [0.62, 2.21] log₁₀ U/ml, respectively) compared with those in seven patients without HBeAg loss (0.74 [0.10, 1.08] log₁₀ copies/ml and 0.41 [0.21, 0.69] log₁₀ U/ml, respectively). Overall, serum HBV RNA, HBcrAg, HBsAg and anti-HBc levels gradually decreased with time during NA treatment. At the end of observation, HBV RNA and HBcrAg reached an undetectable level in 26 and 6 (46% and 11%) patients, respectively.

CONCLUSIONS

Monitoring of HBV RNA and HBcrAg levels is useful for NA-treated patients with undetectable HBV DNA. The attainment of HBV RNA undetectability usually occurs prior to HBcrAg undetectability.

Diagnostic Value of Detection of Pregenomic RNA in Sera of Hepatitis B Virus-Infected Patients with Different Clinical Outcomes

Pregenomic RNA (pgRNA) is a direct transcription product of hepatitis B virus (HBV) covalently closed circular DNA (cccDNA), and it plays important roles in viral genome amplification and replication. This study was designed to investigate whether serum pgRNA is a strong alternative marker for reflecting HBV cccDNA levels and to analyze the correlation between serum pgRNA, serum HBV DNA, and hepatitis B surface antigen (HBsAg). A total of 400 HBV-infected patients who received nucleos(t)ide analog (NA) therapy with different clinical outcomes were involved in this research. Case groups included asymptomatic hepatitis B virus carrier (ASC), chronic hepatitis B (CHB), liver cirrhosis (LC), and hepatocellular carcinoma (HCC) patients, with 100 patients in each group. The results showed that the levels of HBV pgRNA had significant differences between these 4 groups. Serum pgRNA levels correlated well with serum HBV DNA and HBsAg levels (HBV pgRNA levels versus HBV DNA levels, r = 0.58, P < 0.001; HBV pgRNA levels versus HBsAg levels, r = 0.47, P < 0.001). In addition, we focused on the 108 HBV-infected patients with HBV DNA levels of <500 IU/ml; it was surprising to find that in 17.57% (13/74) of cases, HBV pgRNA could be detected even when the HBV DNA level was below 20 IU/ml. In conclusion, HBV pgRNA levels in serum can be a surrogate marker for intrahepatic HBV cccDNA compared with serum HBV DNA and HBsAg. The detection of serum HBV pgRNA levels may provide a reference for clinical monitoring of cccDNA levels and the selection of appropriate timing for discontinuing antiviral therapy, especially when HBV DNA levels are below the detection limit.