Patients with and without loss of hepatitis B virus DNA after hepatitis B e antigen seroconversion have different virological characteristics

The Role of Hepatitis B Core-Related Antigen

Hepatitis B virus (HBV) cannot be completely eliminated from infected hepatocytes due to the existence of intrahepatic covalently closed circular DNA (cccDNA). Serological biomarkers reflect intrahepatic viral replicative activity as non-invasive alternatives to liver biopsy. Hepatitis B core-related antigen (HBcrAg) is a novel biomarker that has an important role in chronic hepatitis B (CHB), because it correlates with serum HBV DNA and intrahepatic cccDNA. In clinical cases with undetectable serum HBV DNA or loss of HBsAg, HBcrAg still can be detected and the decrease in HBcrAg levels is significantly associated with promising outcomes for CHB patients. HBcrAg can predict spontaneous or treatment-induced hepatitis B envelope antigen (HBeAg) seroconversion, persistent responses before and after cessation of nucleos(t)ide analogues, potential HBV reactivation, HBV reinfection after liver transplantation, and risk of hepatocellular carcinoma progression or recurrence. In this review, the clinical applications of HBcrAg in CHB patients based on its virological features are described. Furthermore, new potential therapeutic anti-HBV agents that affect intrahepatic cccDNA are under development, and the monitoring of HBcrAg might be useful to judge therapeutic effects. In conclusion, HBcrAg might be a suitable surrogate marker beyond other HBV markers to predict the disease progression and treatment responses of CHB patients.

Review article: hepatitis B core-related antigen (HBcrAg): an emerging marker for chronic hepatitis B virus infection

BACKGROUND

Chronic hepatitis B (CHB) cannot be completely eradicated due to the presence of covalently closed circular DNA (cccDNA) in the nuclei of infected hepatocytes. While quantification of intrahepatic cccDNA requires liver biopsies, serological markers can be non-invasive alternatives to reflect intrahepatic viral replicative activity. Recently, hepatitis B core-related antigen (HBcrAg) has been advocated as a novel serum marker for disease monitoring and prognostication of CHB.

AIM

To examine the virological aspect and clinical application of HBcrAg with respect to the natural history and treatment of CHB.

METHODS

We reviewed all papers published in the PubMed journal list and abstracts from major international meetings that included the keyword "HBcrAg" or "hepatitis B core-related antigen" until March 2017. Selected studies were compared and summarised on the basis of existing theories, as well as the authors' experience.

RESULTS

HBcrAg exhibited good correlation with intrahepatic (ih) cccDNA, ih total hepatitis B virus (HBV) DNA, serum HBV DNA and to a lesser extent HBV surface antigen (HBsAg). In situations where serum HBV DNA levels become undetectable or HBsAg loss is achieved, HBcrAg can still be detectable. This marker is helpful in differentiation of HBeAg-negative chronic hepatitis from HBeAg-negative chronic infection, predicting spontaneous or treatment-induced HBeAg seroconversion, sustained response to nucleos(t)ide analogue (NA), risk of HBV reactivation in occult HBV infection under immunosuppressive therapies, and risk of hepatocellular carcinoma (HCC) development as well as post-operative HCC recurrence.

CONCLUSIONS

HBcrAg is a potential surrogate marker of cccDNA. It may soon become a useful marker for disease monitoring, predicting treatment response and disease outcome of chronic hepatitis B.

The role of interleukin-27 in predicting spontaneous HBeAg seroconversion in chronic hepatitis B infection

BACKGROUND AND AIMS

Hepatitis B e seroconversion, associated with preceding hepatic inflammation, marks the transition from immune active to residual phase in the natural disease history of chronic hepatitis B. Recently, interleukin-27 has been reported to be associated with hepatic inflammation in hepatitis B infection. We aimed to evaluate the role of interleukin-27 in predicting spontaneous e seroconversion in chronic hepatitis B.

METHODS

A total of 142 treatment-naive hepatitis B patients with positive e antigen were recruited. Interleukin-27, hepatitis B viral DNA levels and liver function parameters, were measured on presentation. Patients who had spontaneous e seroconversion within 3 years of follow-up were compared with those without e seroconversion within the same period of time. Factors predictive of spontaneous e seroconversion were identified.

RESULTS

Of the 142 patients (M:F=80:62, median age: 31), 44 (31%) had spontaneous e seroconversion within 3 years of follow-up. Multivariate analyses revealed that younger age, lower viral DNA and lower interleukin-27 levels on presentation independently predicted spontaneous e seroconversion: the rate was significantly higher in patients aged <31 (OR: 11.022, 95% CI: 3.658-33.205; P<.001), viral DNA <5 log IU/mL (OR: 2.311, 95% CI: 1.049-5.091; P=.038) and interleukin-27 <67.3 pg/mL (OR: 3.276, 95% CI: 1.257-8.536; P=.015). Among patients with all these three favourable factors on presentation, 77% of them underwent spontaneous e seroconversion within 3 years.

CONCLUSIONS

Low interleukin-27 levels were associated with early e seroconversion. The combination of baseline interleukin-27 <67.3 pg/mL and viral DNA <5 log IU/mL in young patients was useful for predicting early spontaneous e seroconversion in treatment-naïve chronic hepatitis B patients.

Serum HBV core-related antigen is a good predictor for spontaneous HBeAg seroconversion in chronic hepatitis B patients

Early prediction of spontaneous hepatitis B virus e antigen (HBeAg) seroconversion is pivotal in the prevention of unnecessary drug prescription, corresponding financial burden, and adverse reactions. One hundred and thirteen chronic hepatitis B patients with HBeAg-positive in the immune active phase were followed up for about 1.5 years. Patients were classified into two groups: spontaneous HBeAg seroconversion group (group A, n = 18) and non-spontaneous HBeAg seroconversion group. Among the non-spontaneous HBeAg seroconversion group, 35 patients were selected as controls (group B, n = 35). At week 12, there was a significant difference in hepatitis B core-related antigen (HBcrAg) levels between the two groups (group A 4.32 ± 1.05 log₁₀  kU/ml, and group B 5.16 ± 0.53 log₁₀  kU/ml, P = 0.004), and this significance magnified at week 28. Only two variables, HBcrAg level and the reduction in the HBcrAg levels (ΔHBcrAg) at week 28 were enrolled, with the odds ratio of 4.19 and 0.21, respectively. The optimal cutoffs of HBcrAg levels and the ΔHBcrAg at week 28 were 4.90 and 2.00 log₁₀  kU/ml, respectively. The positive predictive value and negative predictive value of HBcrAg levels at week 28 were 73.9% and 96.7%, respectively. The positive predictive value and negative predictive value of the ΔHBcrAg at week 28 were 76.2% and 93.8%, respectively. The measurement of HBcrAg is useful for monitoring the natural course of chronic hepatitis B virus infection. The dynamics of HBcrAg levels could accurately predict the spontaneous HBeAg seroconversion. J. Med. Virol. 89:463-468, 2017. © 2016 Wiley Periodicals, Inc.

Profiles of HBV DNA in a large population of Chinese patients with chronic hepatitis B: implications for antiviral therapy

BACKGROUND & AIMS

We determined the virological profile in Chinese chronic hepatitis B (CHB) subjects and its implications regarding current treatment guidelines.

METHODS

A total of 1400 treatment-naïve CHB patients had their HBV DNA levels determined using the Cobas Taqman assay. Patient demographics, HBeAg status, and liver biochemistry were also recorded.

RESULTS

The subjects were predominantly male (62%), had a median age of 45 years, and 301 (22%) were HBeAg-positive. In subjects aged ≤ 25, 26-35, 36-45, 46-55, and >55 years, there was a decreasing trend of HBV DNA levels of 9.9, 9.3, 8.2, 7.4, and 7.3 log copies/ml, respectively (p<0.001), in HBeAg-positive subjects, while the pattern was reversed with HBV DNA levels of 3.7, 4.4, 4.7, 4.9, and 5.2 log copies/ml, respectively, in HBeAg-negative subjects (p<0.001). In HBeAg-negative subjects, the proportion of patients with elevated ALT compared to those with normal ALT was significantly higher in older age groups (p<0.001). In our study population, by applying the AASLD, EASL, and APASL guidelines, 64%, 99%, and 64% would be eligible for antiviral therapy, respectively, in HBeAg-positive patients (with elevated ALT), and 38%, 72%, and 43%, respectively, in HBeAg-negative patients (with elevated ALT). Up to 54% of patients over the age of 40 years would be recommended for liver biopsy to determine further eligibility for treatment.

CONCLUSIONS

For HBeAg-negative CHB, more patients had elevated ALT and a higher viral load with increasing age. Close monitoring is recommended in this group so that treatment may be considered. By applying the current treatment guidelines, a wide discrepancy can be observed in the proportion of patients eligible for treatment in the absence of histological data.

The loss of HBeAg without precore mutation results in lower HBV DNA levels and ALT levels in chronic hepatitis B virus infection

BACKGROUND

The aim of this study was to investigate the correlation between precore (PC)/basal core promoter (BCP) mutations and the viral loads or activity of hepatitis in patients with chronic hepatitis B virus (HBV) infection.

METHODS

HBV genotypes, PC mutations, BCP mutations, HBV DNA levels, and serological markers of HBV were analyzed in all the patients with chronic HBV infection seen in Fujita Health University Hospital from June 2004 to November 2008 (n=215).

RESULTS

HBV genotype was C in 169 patients, B in 16, A in 3, F in 1, and unclassifiable in 5. Among the patients with genotype C, the prevalence of PC wild type was significantly lower in hepatitis B envelope antigen (HBeAg)(-) patients than in HBeAg(+) patients (9.5% versus 49.0%, P<0.0001). Among HBeAg(-) patients, the patients with PC wild type had significantly lower serum viral loads and alanine aminotransferase (ALT) levels compared with those with PC mutant (P<0.001). Among HBeAg(-) patients, the patients with genotype B had lower serum viral loads compared with those with genotype C (3.6+/-0.9 versus 4.6+/-1.6, P<0.05), and the prevalence of BCP wild type was significantly higher in those with genotype B than in those with genotype C (58.3% versus 10.8%, P<0.05).

CONCLUSIONS

Among HBeAg(-) patients with genotype C, the patients with PC wild type had significantly lower viral loads and ALT levels than those with PC mutant. This suggests that the patients with PC wild type may have better prognosis than those with PC mutant among HBeAg(-) patients with genotype C.

Evidence that methylation of hepatitis B virus covalently closed circular DNA in liver tissues of patients with chronic hepatitis B modulates HBV replication

Epigenetic factors may modulate chronic Hepatitis B viral infection by affecting virion gene transcription. The aim of this study was to compare the methylation status of the intrahepatic covalently closed circular DNA (cccDNA) CpG island 2 and HBV replication capability. HBV cccDNA was extracted from liver biopsies of 55 HBsAg-positive patients with chronic hepatitis B (32 HBeAg-positive and 23 HBeAg-negative), and was analyzed for methylation status and quantity. The two Hpa II recognition sequences CCpGG in the CpG island 2 were methylated in infected liver tissues from 24 (43.6%) of 55 patients. Positive ratios of cccDNA methylation were significantly higher in HBeAg-negative patients (15/23, 65.2%) than HBeAg-positive patients (9/32, 28.1%) (P < 0.05). The percentage of methylated-cccDNA/total-cccDNA of HBeAg-negative samples (a median of 48%, ranging from 5% to 83%) was significantly higher (P < 0.001) than HBeAg-positive samples (a median of 14%, ranging from 0.26% to 35%). Ratios of relaxed circular DNA (rcDNA) to cccDNA molecules revealed that cccDNA methylation correlated with impaired virion productivity in HBeAg-positive individuals (P < 0.05). The bisulfite DNA sequencing showed that methylation density was significantly higher in HBeAg-negative than in HBeAg-positive patients (P < 0.05). The methylation level of the CpG island 2 of the cccDNA in HBeAg-negative patients was higher than that in HBeAg-positive patients, suggesting that HBV cccDNA methylation may be relevant to replication capability of HBV.

The significance of enzyme immunoassay for the assessment of hepatitis B virus core-related antigen following liver transplantation

PURPOSE

Recently, a new enzyme immunoassay for the detection of hepatitis B virus (HBV) core-related antigen (HBcrAg) has been reported. In this study, we proposed to account for feasibility of HBcrAg assay, and discuss the dynamics of HBV seen in patients following HBV-related living donor liver transplantation (LDLT).

METHODS AND RESULTS

This study involved 12 patients; 11 patients had positive serum HBcrAg, and 6 patients had negative HBV-DNA. In the post-operation period, all cases were negative for HBV-DNA and HBsAg in sera under prophylaxis therapy. At post-operation, 5 of the 12 had positive serum HBcrAg, and at stable state, 6 had positive serum HBcrAg postoperatively. The mean levels of HBcrAg following LDLT were significantly lower than those seen in the preoperative-operation stage.

CONCLUSION

This enzyme immunoassay is a readily utilizable marker of HBV replication in the post transplantation stage. Furthermore, the evaluation of HBV activity by HBcrAg assay must be studied to determine the appropriate prophylaxis for controlling replication of HBV following LDLT.

Hepatitis B virus core-related antigens as markers for monitoring chronic hepatitis B infection

A sensitive chemiluminescence enzyme immunoassay has been developed for hepatitis B virus (HBV) core-related antigen (HBcrAg) detection. We aimed to investigate the usefulness of HBcrAg measurement for monitoring chronic hepatitis B disease. HBcrAg levels were measured by a chemiluminescence enzyme immunoassay in 54 untreated patients and 39 patients treated with either entecavir or lamivudine. The HBcrAg concentration correlated positively with the levels of serum HBV DNA (r = 0.820), intrahepatic total HBV DNA (r = 0.700), and covalently closed circular DNA (cccDNA) (r = 0.664; for all, P values were <0.001). A higher HBcrAg concentration was associated with a greater proportion of hepatitis B core antigen immunostaining. Although the differences were not statistically significant, patients with higher Knodell necroinflammation and fibrosis scores tended to have higher serum HBcrAg concentration levels. In the treated patients, the logarithmic reduction in HBcrAg at week 48 correlated positively with the logarithmic reduction of serum HBV DNA, intrahepatic total HBV DNA, and cccDNA. Of the 31 patients with undetectable serum HBV DNA (<300 copies/ml) at the end of treatment, 20 (65%) still had detectable HBcrAg. A greater reduction in posttreatment HBcrAg concentration was associated with histological improvement and a decrease in hepatitis B core antigen immunostaining. HBcrAg concentrations of <40,000 kU/ml at baseline and <200 kU/ml at week 24 were associated with a higher chance of having undetectable HBV DNA at week 48. In conclusion, serum HBcrAg levels correlated with HBV virological markers and reflected the chronic hepatitis B disease activity in the liver.

Presence of hepatitis B virus core promoter mutations pre-seroconversion predict persistent viral replication after HBeAg loss

BACKGROUND

In patients with chronic hepatitis B virus (HBV) infection DNA levels do not always fall after anti-hepatitis B e (anti-HBe) seroconversion.

OBJECTIVES

To follow longitudinally through HB e antigen (HBeAg) loss HBV DNA levels and core promoter/precore sequences in a cohort of 21 chronic HBV carriers.

STUDY DESIGN

Treatment-naïve HBeAg seropositive HBV carriers were monitored through HBeAg loss for between 2 and 22 years (mean 9.3). Core promoter/precore sequences, genotypes, HBV DNA levels and HBe status were determined.

RESULTS

Patients were grouped into those in whom serum/plasma HBV DNA remained high after HBeAg loss (group 1, n=11; HBV DNA>5log(10)IU/ml) and those in whom HBV DNA declined (group 2, n=10). Re-appearance of HBeAg was seen in seven group 1 patients. Pre-seroconversion mutations in the core promoter region including A1762T and/or G1764A were detected more frequently in group 1 (P=0.031). Overall sequence changes at sites other than 1762/1764 were more common post-seroconversion in group 1 than group 2 patients (P=0.037).

CONCLUSIONS

The presence of core promoter mutations prior to HBeAg loss identified those patients in whom HBV DNA persisted at high levels and was associated with temporary re-emergence of serum HBeAg. These patients may benefit from early anti-viral treatment.

Viral factors correlate with hepatitis B e antigen seroconverson in patients with chronic hepatitis B

BACKGROUND/AIMS

Seroconversion (SC) from hepatitis B envelope antigen (HBeAg) to anti-HBe usually indicates lower viral loads, resolved hepatitis activity and improved long-term outcomes. However, the role of viral factors in the development of SC remains largely unknown. We thus comprehensively studied these factors in 25 patients with sustained HBeAg SC and seven control patients with sustained loss of HBeAg.

METHODS

We determined viral factors in serum samples obtained 1 year before, 6 months before, 3 months before, at the time of, 6 months after and 1 year after HBeAg SC or HBeAg loss. Precore A1896 and basal core promoter T1762/A1764 mutants were determined by polymerase chain reaction (PCR)-based assays. Serum HBV levels were determined by a real-time PCR assay.

RESULTS

We found that decline of serum viral load, frequently accompanied by hepatitis exacerbation, occurred within 1 year before HBeAg SC. The proportions of precore and BCP mutations also increased gradually throughout the process of HBeAg SC. The virologic features were similar between HBeAg SC group and HBeAg loss group. Before HBeAg SC or loss, genotype B patients had higher serum viral loads and lower proportions of BCP mutation compared with genotype C patients.

CONCLUSION

Our findings suggested that viral factors correlate with the development of sustained HBeAg SC or loss.