Hepatitis B core related antigen in relation to intrahepatic and circulating viral markers, before and after combination therapy

Predictive role of early treatment dynamics of HBV RNA and HBcrAg for HBeAg seroconversion in children with chronic hepatitis B

This study aimed to assess the predictive capacity of emerging serological markers, serum HBV RNA and HBcrAg, for HBeAg seroconversion in children with HBeAg-positive chronic hepatitis B (CHB). Treatment-naïve HBeAg-positive CHB children who admitted to the Liver Disease Center of Hunan Children's Hospital between April 2021 and September 2022 and received treatment with the combined entecavir and interferon-alpha treatment were recruited. Serum HBV RNA and HBcrAg were measured at baseline and Weeks 12, 24, and 48 of treatment. Our study showed that serum HBV RNA (HR = 0.71, 95% CI: 0.56-0.91, p = 0.006), HBcrAg (HR = 0.60, 95% CI: 0.43-0.84, p = 0.003), and HBsAg (HR = 0.49, 95%CI: 0.36-0.69, p < 0.001) at Week 12 were independent predictors of HBeAg seroconversion. ROC curve analysis presented that serum HBV RNA decline value (ΔHBV RNA) at Week 36 and HBcrAg decline value (ΔHBcrAg) at Week 12 (AUC = 0.871, p = 0.003 and AUC = 0.810, p = 0.003, respectively) could effectively predict HBeAg seroconversion. Furthermore, the optimal critical values were determined and the children with ΔHBV RNA > 3.759 log10 copies/mL at Week 36 or ΔHBcrAg >0.350 log10 U/mL at Week 12 more likely to achieve HBeAg seroconversion. The serum HBV RNA and HBcrAg provide new insights into the treatment of CHB in children. Early assessment of serum HBV RNA and HBcrAg during treatment can assist clinical decision-making and optimize individualized therapeutic approaches.

Hepatocellular carcinoma reduced, HBsAg loss increased, and survival improved after finite therapy in hepatitis B patients with cirrhosis

BACKGROUND AND AIMS

Long-term nucleos(t)ide analog (Nuc) treatment can reduce HCC in patients with HBV-related liver cirrhosis (HBV-LC). Earlier small cohort studies showed a comparable 5-year incidence of HCC in HBeAg-negative patients with HBV-LC who stopped and those continued Nuc therapy. This study aimed to validate these findings using a large cohort with 10-year follow-up.

APPROACH AND RESULTS

From 2 centers, 494 HBeAg-negative patients with HBV-LC who stopped (finite group) and 593 who continued (continuous group) Nuc therapy were recruited. HCC, HBsAg loss, liver-related mortality/transplantation, and overall survival rates were compared between 2 groups with 1:1 propensity score matching of sex, treatment history, types of Nuc, age, transaminases, platelet count, and HBsAg levels at end of therapy in finite group or 3-year on-therapy in continuous groups. During a median follow-up of 6.2 (3.4-8.9) years, the annual and 10-year HCC incidence were lower in finite group (1.6 vs. 3.3%/y and 10-y 15.7% vs. 26.8%, respectively; log-rank test, p <0.0001). The finite group showed greater HBsAg decline/year (-0.116 vs. -0.095 log 10 IU/mL, p =0.0026) and 7.6 times higher 10-year incidence of HBsAg loss (22.7% vs. 3%, p <0.0001). Multivariate Cox regression showed finite therapy an independent factor for HBsAg loss (adjusted HR: 11.79) but protective against HCC (adjusted HR: 0.593), liver-related mortality/transplantation (adjusted HR: 0.312), and overall mortality (adjusted HR: 0.382).

CONCLUSIONS

Finite Nuc therapy in HBeAg-negative HBV-LC may reduce HCC incidence, increase HBsAg loss, and improve survival. Greater HBsAg decline/loss may reflect enhanced immunity and contribute to the reduction of hepatic carcinogenesis.

A critique and systematic review of the clinical utility of hepatitis B core-related antigen

BACKGROUND & AIMS

Hepatitis B core-related antigen (HBcrAg) is a new biomarker for chronic hepatitis B (CHB) whose performance has not been critically or systematically appraised. Herein, we performed a systematic review to determine its clinical utility.

METHODS

We evaluated the biological pathway of HBcrAg and performed a systematic review of PubMed for clinical trials, cohort studies, and case-control studies that evaluated the clinical utility of HBcrAg. The effectiveness of HBcrAg in predicting HBV-specific clinical events (e.g. HBeAg seroconversion, phases of CHB, HBsAg loss, treatment response, and relapse after stopping therapy) was examined using receiver-operating characteristic curves. The correlation coefficients of HBcrAg with HBV DNA, quantitative HBsAg (qHBsAg), HBV RNA, and cccDNA were summarised from published studies. Median values were used as estimates.

RESULTS

HBcrAg consists of three precore/core protein products: HBcAg, HBeAg, and a 22 kDa precore protein. HBcrAg assays have been associated with false-positive rates of 9.3% and false-negative rates of between 12-35% for CHB. The new iTACT-HBcrAg is more sensitive but does not reduce the false-positive rate. A PubMed search found 248 papers on HBcrAg, of which 59 were suitable for analysis. The clinical performance of HBcrAg was evaluated using AUROC analyses, with median AUROCs of 0.860 for HBeAg seroconversion, 0.867 for predicting HBeAg(-) hepatitis, 0.645 for HBsAg loss, 0.757 for treatment response, and 0.688 for relapse after stopping therapy. The median correlation coefficient (r) was 0.630 with HBV DNA, 0.414 with qHBsAg, 0.619 with HBV RNA and 0.550 with cccDNA. Correlation decreased during antiviral therapy, but combined biomarkers improved performance.

CONCLUSIONS

HBcrAg has a mixed performance and has a poor correlation with HBsAg loss and antiviral therapy, hence HBcrAg results should be interpreted with caution.

IMPACT AND IMPLICATIONS

Hepatitis B core-related antigen (HBcrAg) has been used to assess management of patients with chronic hepatitis B (CHB) without a systematic and critical Sreview of its performance. Our finding that HBcrAg had a false-positive rate of 9% and a false-negative rate of 12-35% raises concerns, although larger studies are needed for validation. A systematic review showed that the performance of HBcrAg was variable depending on the CHB endpoint; it was excellent at predicting HBeAg seroconversion and HBeAg-negative chronic hepatitis (vs. chronic infection), which should be its main use, but it was poor for relapse after stopping antiviral therapy and for HBsAg loss. HBcrAg results should be interpreted with considerable caution, particularly by physicians, researchers, guideline committees and agencies that approve diagnostic tests.

Many Ways to Communicate-Crosstalk between the HBV-Infected Cell and Its Environment

Chronic infection with the hepatitis B virus (HBV) affects an estimated 257 million people worldwide and can lead to liver diseases such as cirrhosis and liver cancer. Viral replication is generally considered not to be cytopathic, and although some HBV proteins may have direct carcinogenic effects, the majority of HBV infection-related disease is related to chronic inflammation resulting from disrupted antiviral responses and aberrant innate immune reactions. Like all cells, healthy and HBV-infected cells communicate with each other, as well as with other cell types, such as innate and adaptive immune cells. They do so by both interacting directly and by secreting factors into their environment. Such factors may be small molecules, such as metabolites, single viral proteins or host proteins, but can also be more complex, such as virions, protein complexes, and extracellular vesicles. The latter are small, membrane-enclosed vesicles that are exchanged between cells, and have recently gained a lot of attention for their potential to mediate complex communication and their potential for therapeutic repurposing. Here, we review how HBV infection affects the communication between HBV-infected cells and cells in their environment. We discuss the impact of these interactions on viral persistence in chronic infection, as well as their relation to HBV infection-related pathology.

End-of-treatment HBcrAg and HBsAb levels identify durable functional cure after Peg-IFN-based therapy in patients with CHB

BACKGROUND & AIMS

Functional cure can be sustained in a proportion of patients with chronic hepatitis B (CHB) who lose hepatitis B surface antigen (HBsAg) after pegylated interferon alpha (Peg-IFN-ɑ)-based treatment. In this study, we aimed to identify biomarkers associated with a durable functional cure and to dissect potential immunological mechanisms.

METHODS

Of 257 nucleos(t)ide analogue-suppressed patients with CHB in the ANCHOR study, 80 patients randomly assigned to 96-week Peg-IFN-α-based therapy with 24-week off-treatment follow-up were included in this parallel study. Virologic and immunological biomarkers were examined dynamically. A response was defined as HBsAg loss or hepatitis B surface antibody (HBsAb) appearance at the end of treatment (EOT). Sustained response (SR) or durable functional cure was defined as sustained HBsAg loss with or without the appearance of HBsAb at the end of follow-up (EOF).

RESULTS

Thirty-six (45.0%) out of 80 patients achieved a response at EOT; 58.3% (21/36) of responders maintained SR at EOF. Quantitative hepatitis B core-related antigen (qHBcrAg) and HBsAb at EOT were associated with SR, with AUROCs of 0.697 (0.512-0.882, p = 0.047) and 0.744 (0.573-0.915, p = 0.013), respectively. A combination of HBcrAg <4 log₁₀U/ml and HBsAb >2 log₁₀IU/L at EOT had a positive predictive value of 100% for SR with an AUROC of 0.822 (0.684-0.961, p = 0.001). These patients showed maintained proportions of HBV envelope-specific CD8⁺T and B cells, a markedly increased proportion of T follicular helper cells after Peg-IFN-ɑ discontinuation, and significantly higher proportions of HBV polymerase-specific CD8⁺T and CD86⁺CD19⁺B cells at EOF.

CONCLUSIONS

Lower HBcrAg and higher HBsAb levels at EOT were associated with sustained cellular and humoral immune responses. They can be used to identify patients likely to achieve durable functional cure post Peg-IFN-based therapy.

GOV IDENTIFIER

NCT02327416 LAY SUMMARY: Functional cure can be sustained in a proportion of patients with chronic hepatitis B after pegylated interferon alpha-based treatment. However, predicting who will achieve durable functional cure remains challenging. Herein, we show that low levels of hepatitis B core-related antigen and higher levels of hepatitis B surface antibodies at the end of treatment are linked to immunological responses and are associated with durable functional cure.

Antigen Load and T Cell Function: A Challenging Interaction in HBV Infection

Current treatment for chronic HBV infection is mainly based on nucleos(t)ide analogues, that in most cases need to be administered for a patient’s lifetime. There is therefore a pressing need to develop new therapeutic strategies to shorten antiviral treatments. A severe dysfunction of virus-specific T cell responses contributes to virus persistence; hence, immune-modulation to reconstitute an efficient host antiviral response is considered a potential approach for HBV cure. In this perspective, a detailed understanding of the different causes of T cell exhaustion is essential for the design of successful functional T cell correction strategies. Among many different mechanisms which are widely believed to play a role in T cell dysfunction, persistent T cell exposure to high antigen burden, in particular HBsAg, is expected to influence T cell differentiation and function. Definitive evidence of the possibility to improve anti-viral T cell functions by antigen decline is, however, still lacking. This review aims at recapitulating what we have learned so far on the complex T cell–viral antigen interplay in chronic HBV infection.