Chronic hepatitis B (CHB) is a major cause of liver-related morbidity and mortality. Functional cure of CHB, defined as sustainable hepatitis B surface antigen (HBsAg) seroclearance, is associated with improved clinical outcomes. However, functional cure is rarely attainable by current treatment modalities. RNA interference (RNAi) by small-interfering RNA (siRNA) and anti-sense oligonucleotide (ASO) has been studied as a novel treatment strategy for CHB. RNAi targets post-transcriptional messenger RNAs and pregenomic RNAs to reduce hepatitis B virus (HBV) antigen production and viral replication. By reducing viral antigens, host immune reconstitution against HBV may also be attained. Phase I/II trials on siRNAs have demonstrated them to be safe and well-tolerated. siRNA is effective when given in monthly doses with different total number of doses according to different trial design, and can lead to sustainable dose-dependent mean HBsAg reduction by 2–2.5 log. Incidences of HBsAg seroclearance after siRNA therapy have also been reported. ASOs have also been studied in early phase trials, and a phase Ib study using frequent dosing regimen within 4 weeks could achieve similar HBsAg reduction of 2 log from baseline. Given the established efficacy and safety of nucleos(t) ide analogues (NAs), future RNAi regimens will likely include NA backbone. While the current evidence on RNAi appears promising, it remains undetermined whether the potent HBsAg reduction by RNAi can result in a high rate of HBsAg seroclearance with durability. Data on RNAi from phase IIb/III trials are keenly anticipated.

Chronic hepatitis B (CHB) infection leads to clinically heterogeneous disease outcomes. Different viral markers are utilized to monitor treatment effects and predict risk of complications in patients with CHB. Hepatitis B core-related antigen (HBcrAg) is a novel serum composite viral protein whose performance has been proven to be superior to that of existing viral markers. It showed good correlation with intrahepatic covalently closed-circular DNA. Its profile differs drastically in patients in different disease phases, and the level declines with antiviral therapies. HBcrAg may be helpful for predicting hepatocellular carcinoma development and hepatitis B virus (HBV) reactivation in immunosuppressed patients. Another emerging measurable serum marker, HBV RNA, exists in the form of pregenomic RNA-containing virions. Its profile differs between patients in different disease phases in a similar manner to that of HBcrAg. HBV RNA is present in serum at lower levels than HBV DNA in treatment-naive patients by 1–2 logs. In contrast, its level is higher than HBV DNA in patients receiving nucleos(t)ide analogues (NAs). A significant decline in serum RNA was observed in patients receiving novel antiviral therapies, including core protein allosteric modulators and RIG-1/NOD2 agonists. Both HBcrAg and HBV RNA may be helpful for predicting off-therapy sustained virological control in patients who stop long-term NA treatment.
Biomarkers ; Carcinoma, Hepatocellular ; DNA ; Hepatitis B ; Hepatitis B virus ; Hepatitis B, Chronic ; Hepatitis, Chronic ; Humans ; RNA ; Virion

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, affecting approximately 25% of the general population worldwide, and is forecasted to increase global health burden in the 21st century. With the advancement of non-invasive tests for assessing and monitoring of steatosis and fibrosis, NAFLD screening is now feasible, and is increasingly highlighted in international guidelines related to hepatology, endocrinology, and pediatrics. Identifying high-risk populations (e.g., diabetes mellitus, obesity, metabolic syndrome) based on risk factors and metabolic characteristics for non-invasive screening is crucial and may aid in designing screening strategies to be more precise and effective. Many screening modalities are currently available, from serum-based methods to ultrasonography, transient elastography, and magnetic resonance imaging, although the diagnostic performance, cost, and accessibility of different methods may impact the actual implementation. A two-step assessment with serum-based fibrosis-4 index followed by imaging test vibration-controlled transient elastography can be an option to stratify the risk of liverrelated complications in NAFLD. There is a need for fibrosis surveillance, as well as investigating the cost-effectiveness of different screening algorithms and engaging primary care for first-stage triage screening.

Chronic hepatitis B infection is a major public health challenge. With the advancement in technology, various components of the viral cycle can now be measured in the blood to assess viral activity. In this review article, we summarize the relevant data of how antiviral therapies impact viral biomarkers, and discuss their potential implications. Viral nucleic acids including hepatitis B virus (HBV) double-stranded deoxy-ribonucleic acid (DNA) and to a lesser extent, pre-genomic RNA, are readily suppressed by nucleos(t)ide analogues (NUCs). The primary role of these markers include risk prediction for hepatocellular carcinoma (HCC) and risk stratification for partial cure, defined as off-therapy virological control, or functional cure, defined as hepatitis B surface antigen (HBsAg) seroclearance plus undetectable serum HBV DNA for ≥6 months. Viral translational products including hepatitis e antigen, quantitative HBsAg and hepatitis B core-related antigen can be reduced by NUCs and pegylated interferon a. They are important in defining disease phase, delineating treatment endpoints, and predicting clinical outcomes including HCC risk and partial/ functional cure. As the primary outcome of phase III trials in chronic hepatitis B is set as HBsAg seroclearance, appropriate viral biomarkers can potentially inform the efficacy of novel compounds. Early viral biomarker response can help with prioritization of subjects into clinical trials. However, standardization and validation studies would be crucial before viral biomarkers can be broadly implemented in clinical use.

Serum hepatitis B core-related antigen (HBcrAg) was shown to predict the risk of hepatocellular carcinoma (HCC) in chronic hepatitis B (CHB) patients undergoing treatment. We investigated the longitudinal profile of HBcrAg in entecavir (ETV)-treated CHB patients with subsequent HCC develop-ment. We identified HCC cases diagnosed at ≥1 year after ETV initiation. CHB patients without HCC (matched for age, sex, cirrhosis status, baseline hepatitis B virus [HBV] DNA lev-el, and ETV treatment duration) were identified as controls at an HCC:non-HCC ratio of 1:2. Serum samples were retrieved at baseline (ETV initiation) and at 3 and 5 years of ETV therapy for HBcrAg measurement (log IU/mL). In total, 180 patients (60 HCC patients matched with 120 CHB patients without HCC; median age, 56.5 years; 80.6% male; baseline HBV DNA, 5.9 log IU/mL; median follow-up, 6.8 years) were recruited. The median time from ETV initiation to HCC de-velopment was 3.2 years. HBcrAg levels were higher in HCC cases than in controls at all three time points: 5.69 log IU/ mL versus 5.02 log IU/mL (p=0.025), 4.23 log IU/mL versus 3.36 log IU/mL (p=0.007), and 3.86 log IU/mL versus 3.36 log IU/mL (p=0.009), respectively. ETV led to similar rates of decline in HBcrAg from baseline to 3 years in both groups (0.34 log IU/mL/year vs 0.39 log IU/mL/year, p=0.774), al-though the decline from 3 to 5 years was slower in the nonHCC group (0.05 log IU/mL/year) than in the HCC group (0.09log IU/mL/year, p=0.055). ETV time-dependently reduced HBcrAg in HCC and non-HCC patients. HBcrAg interpretation should consider the antiviral treatment duration.

Background/Aims: We investigated the dynamics of serum HBV pre-genomic RNA (pgRNA) and hepatitis B core-related antigen (HBcrAg) in patients receiving nucleos(t)ide analogues (NAs) and their predictability for favourable suppression of serum hepatitis B surface antigen (HBsAg). Methods: Serum viral biomarkers were measured at baseline, weeks 4, 12, 24, 36, and 48 of treatment. Patients were followed up thereafter and serum HBsAg level was measured at end of follow-up (EOFU). Favourable HBsAg response (FHR) was defined as ≤100 IU/mL or HBsAg seroclearance upon EOFU. Results: Twenty-eight hepatitis B e antigen (HBeAg)-positive and 36 HBeAg-negative patients (median, 38.2 years old; 71.9% male) were recruited with median follow-up duration of 17.1 years (interquartile range, 12.8–18.2). For the entire cohort, 22/64 (34.4%) achieved FHR. For HBeAg-positive patients, serum HBV pgRNA decline at week 4 was significantly greater for patients with FHR compared to non-FHR (5.49 vs. 4.32 log copies/mL, respectively; P=0.016). The area under the receiver-operating-characteristic curve (AUROC) for week 4 HBV pgRNA reduction to predict FHR in HBeAg-positive patients was 0.825 (95% confidence interval [CI], 0.661–0.989). For HBeAg-negative patients, instead of increase in serum HBcrAg in non-FHR patients, FHR patients had median reduction in HBcrAg at week 4 (increment of 1.75 vs. reduction of 2.98 log U/mL; P=0.023). The AUROC for week 4 change of HBcrAg to predict FHR in HBeAg-negative patients was 0.789 (95% CI, 0.596–0.982). Conclusions Early on-treatment changes of serum HBV pgRNA and HBcrAg at 4 weeks predict HBsAg seroclearance or ≤100 IU/mL in NA-treated CHB patients upon long-term FU.

Background/Aims: Hepatitis B surface antigen (HBsAg) seroclearance remains uncommon in chronic hepatitis B (CHB) infection. During acute flares of CHB (AFOCHB), alanine aminotransferase elevation reflects a mounting immune response toward viral clearance. We hypothesized that severe AFOCHB is associated with a greater quantitative HBsAg (qHBsAg) decline and HBsAg seroclearance rate. Methods: A total of 75 patients with severe AFOCHB with alanine aminotransferase 10× the upper limit of normal were matched to a control group by age and sex in a 1:2 ratio. qHBsAg levels were measured at the time of flare and annually (for both cases and controls) until the last follow-up. Results: The median follow-up times for patients with severe AFOCHB and controls were 8.8 and 10.5 years, respectively. The cumulative rate of HBsAg seroclearance was higher in the severe AFOCHB group than in the control group (11.8% vs 5.0%, p=0.04) despite the former group having a trend of a higher baseline median qHBsAg (3,127 IU/mL vs 1,178 IU/mL, p=0.076). Compared with the control group, the severe AFOCHB group had a greater annual qHBsAg reduction (–242.4 IU/mL/yr vs –47.3 IU/mL/yr, p=0.002). Increasing age (p=0.049), lower baseline qHBsAg (p=0.002), and severe AFOCHB (p=0.014) were independently associated with HBsAg seroclearance. However, the cumulative rate of hepatocellular carcinoma was significantly higher in the severe AFOCHB group than in the control group (15.8% vs 1.9%, p<0.001). Conclusions Severe AFOCHB was associated with a greater incidence of HBsAg seroclearance and qHBsAg decline. However, it was associated with a higher incidence of hepatocellular carcinoma.