Longitudinal profiles of highly sensitive hepatitis B surface antigen levels: re-evaluation of HBsAg seroclearance

The impact of hepatitis B surface antigen seroconversion on the durability of functional cure induced by pegylated interferon alpha treatment

BACKGROUND

Hepatitis B surface antigen (HBsAg) loss is regarded as a pivotal criterion for assessing functional cure in patients diagnosed chronic hepatitis B (CHB). We conducted the research to investigate the real-world performance of HBsAg seroconversion in sustaining HBsAg loss.

METHODS

This retrospective analysis confirmed 295 patients who attained HBsAg loss through combination therapy involving nucleos(t)ide analogues (NAs) and pegylated interferon alpha (peg-IFNα). Employing Kaplan-Meier estimates method to conduct survival analysis. The forest plot was used to visualize the results of multivariate Cox regression, and selected variables were included in the nomogram.

RESULTS

HBsAg seroreversion was observed in 45 patients during follow-up periods, with a lower recurrence risk in patients with HBsAg seroconversion at the end of peg-IFNα therapy (EOT) (10.3% vs 37.3% at 96-week, P < 0.0001). Moreover, the sustainability of hepatitis B surface antibody (anti-HBs) in participants continuing therapy after HBsAg seroconversion was superior to those discontinued prematurely (72.5% vs 54.5% at 96 weeks, P = 0.012). Additionally, the former group was also relatively less likely to experience HBsAg reversion during long-term observation (8.4% vs 14.3% at 96 weeks, P = 0.280). Hepatitis B envelope antigen (HBeAg) status, anti-HBs status and consolidation treatment screened by multivariable analysis were utilized to construct a predictive model for HBsAg reversion. The concordance index(C-index = 0.77) and calibration plots indicated satisfactory discrimination and consistency of nomogram.

CONCLUSIONS

HBsAg seroconversion was beneficial for sustaining functional cure in patients treated with peg-IFNα. Continuing consolidation therapy after HBsAg seroconversion also contributed to maintain HBsAg seroconversion and improve the durability of HBsAg loss. The nomogram illustrated its efficacy as a valuable instrument in showcasing survival probability of functional cure.

Clinical Consequences of Hepatitis B Surface Antigen Loss in Chronic Hepatitis B Infection: A Systematic Literature Review and Meta-Analysis

Background and Aims

Functional cure, which requires sustained hepatitis B surface antigen (HBsAg) loss after treatment cessation, is currently the optimal treatment endpoint for chronic hepatitis B virus infection. We performed a systematic literature review (SLR) and meta-analyses to assess the association between HBsAg loss and long-term clinical outcomes.

Methods

We performed a SLR of scientific literature published in Medline and Embase reporting the incidence of cirrhosis, hepatic decompensation (HD), hepatocellular carcinoma (HCC), liver-related mortality (LRM), and all-cause mortality (ACM) in relation to HBsAg status. Bayesian hierarchical commensurate prior meta-analyses synthesized evidence on the association between HBsAg loss and each outcome.

Results

Thirty-eight studies, comprising 50,354 patients with 350,734 patient-years of follow-up, were included in the meta-analyses, reporting on cirrhosis (n = 12), HD (n = 12), HCC (n = 36), LRM (n = 12), and ACM (n = 16). Pooled incidence rate ratios (IRRs; vs HBsAg persistence) and respective credible intervals (Crls) were 0.28 (0.060-1.070) for cirrhosis, 0.13 (0.013-0.38) for HD, 0.27 (0.11-0.53) for HCC, 0.17 (0.028-0.61) for LRM, and 0.64 (0.24-1.17) for ACM. Single-predictor-adjusted IRRs remained consistent with those from the primary analyses for all outcomes except cirrhosis and LRM. Outcome incidence rates were modified by selected study, patient and infection characteristics, but trended in the same direction of reduced risk after loss.

Conclusion

Overall, HBsAg loss was associated with a reduced risk of most clinically relevant outcomes. While the magnitude of the effect differed across subgroups, the direction of the association remained similar. Our results validate the need to develop new strategies to achieve HBsAg loss.

Role of serum HBV RNA and hepatitis B surface antigen levels in identifying Asian patients with chronic hepatitis B suitable for entecavir cessation

BACKGROUND

Treatment cessation in chronic HBV infection may be durable in certain patient subgroups before hepatitis B surface antigen (HBsAg) seroclearance. The role of serum HBV RNA in determining treatment cessation suitability has not been well-investigated.

METHODS

Nucleos(t)ide analogue (NUC) treatment was discontinued in non-cirrhotic patients with chronic HBV with serum HBsAg <200 IU/mL and fulfilling internationally recommended criteria for treatment cessation. Patients were monitored till 48 weeks with baseline and serial measurements of serum HBsAg, HBV RNA and hepatitis B core-related antigen. NUCs were resumed when HBV DNA reaches >2000 IU/mL regardless of alanine aminotransferase (ALT) levels.

RESULTS

114 entecavir-treated patients (median age 58.4 years, median serum HBsAg 54.4 IU/mL) with median treatment duration of 6.7 years were recruited. The 48-week cumulative rate of HBV DNA >2000 IU/mL was 58.1%. End-of-treatment serum HBV RNA and off-treatment serial HBV RNA were both independently associated with HBV DNA >2000 IU/mL (HR 2.959, 95% CI 1.776 to 4.926, p<0.001; HR 2.278, 95% CI 1.151 to 4.525, p=0.018, respectively). Patients with HBV RNA ≥44.6 U/mL had a cumulative 48-week rate of 93.2%, while combining HBV RNA undetectability and HBsAg <10 IU/mL had a cumulative 48-week rate of 9.1%. 24 patients (38.7%) developed off-treatment ALT elevation, highest peak ALT was 1515 U/L. 8 patients (median serum HBsAg 2.6 IU/mL) developed HBsAg seroclearance.

CONCLUSION

Serum HBV RNA measurement is essential for deciding on entecavir cessation in patients with chronic HBV, especially with low HBsAg levels. Patients can be stratified on their risk of off-treatment relapse based on both viral determinants.

TRIAL REGISTRATION NUMBER

NCT02738554.

Pregenomic HBV RNA and Hepatitis B Core-Related Antigen Predict Outcomes in Hepatitis B e Antigen-Negative Chronic Hepatitis B Patients Suppressed on Nucleos(T)ide Analogue Therapy

BACKGROUND AND AIMS

A dichotomous separation of hepatitis B viral DNA and hepatitis B surface antigen (HBsAg) concentrations occurs during the natural history and treatment of chronic hepatitis B. We have evaluated the ability of hepatitis B virus (HBV) RNA and hepatitis B core-related antigen (HBcrAg) as surrogates of silencing of covalently closed circular DNA (cccDNA), to characterize this dissociation, and virological outcomes.

APPROACH AND RESULTS

Three cohorts of hepatitis B e antigen (HBeAg)-negative patients were studied: cohort A: 66 HBeAg-negative patients on long-term nucleos(t)ide analogue (NA) therapy; cohort B: 23 antibodies against hepatitis B e antigen (anti-HBe)-positive patients who stopped treatment; and Cohort C: 19 anti-HBe-positive patients on long-term NA treatment who achieved HBsAg loss and in whom treatment was withdrawn. Concentrations of HBV serological/virological biomarkers (HBV DNA, HBsAg, HBcrAg, and HBV RNA) were measured in sequential samples at different time points on/off therapy. Cohort A: After 3 years of antiviral therapy, 33% and 30% had detectable HBcrAg and HBV RNA, respectively, despite all being HBV-DNA negative. After 5 years' therapy with NA, 27% and 14% had detectable HBcrAg and HBV RNA. Detectable HBcrAg and HBV RNA at the time of treatment withdrawal was only observed in those patients who developed a severe aminotransferase flare. Only those patients with HBV reactivation in cohort C had detectable HBV RNA at treatment withdrawal, but HBcrAg and HBV DNA were not detected.

CONCLUSIONS

HBcrAg and HBV RNA are sensitive biomarkers of continued transcription of cccDNA in HBeAg-negative patients despite marked HBV-DNA suppression by NA. These markers were predictors of severe alanine transaminase flares, after treatment withdrawal, and HBV-DNA reactivation. Their measurement during the natural history of hepatitis B, and on treatment with current and new agents, could characterize residual HBV-RNA transcription from cccDNA and assist drug development and disease management.

Systematic review of risk factors of hepatocellular carcinoma after hepatitis B surface antigen seroclearance

There is no consensus about factors that increase risk of hepatocellular carcinoma (HCC) among patients with chronic hepatitis B who have achieved seroclearance of hepatitis B surface antigen (HBsAg). To assess the available evidence about risk factors for HCC after HBsAg seroclearance, Scopus, EMBASE, PubMed and Cochrane Library databases were systematically searched for relevant studies published through 15 September 2017. A total of 28 studies involving more than 105 411 patients with chronic hepatitis B were included. HBsAg seroclearance occurred spontaneously in 7656, while it occurred after interferon or nucleos(t)ide analogue therapy in 1248. The rate of HBsAg seroclearance was 6.77%. Incidence of HCC was significantly lower among patients who experienced HBsAg seroclearance than among those who remained HBsAg-positive (1.86% vs 6.56%, P < .001). Risk factors of HCC occurrence included cirrhosis (incidence with vs without: 9.51% vs 1.66%), male gender (2.34% vs 0.64%) and age ≥ 50 year at HBsAg seroclearance (2.34% vs 0.63%) (all P < .001). The available evidence suggests that HCC can develop at a low rate after HBsAg seroclearance, so periodic surveillance is recommended, especially for male patients, patients with cirrhosis and patients who experience HBsAg seroclearance when at least 50 years old.

Review of Laboratory Tests used in Monitoring Hepatitis B Response to Pegylated Interferon and Nucleos(t)ide Analog Therapy

There are only two currently approved classes of hepatitis B virus (HBV) antiviral agents, pegylated interferon (Peg-IFN), and nucleos(t)ide analogs (NAs) for chronic HBV infection. Although Peg-IFN is used for a finite 48-week duration and offers a greater chance of sustained off-treatment virological response, it is poorly tolerated and can only be offered to selected patients. The NAs are well tolerated but require prolonged therapy due to risk of relapse with treatment cessation. There is evolving data that novel virological assays (e.g., quantitative hepatitis B surface antigen, quantitative hepatitis B core antigen, quantitative antibody to core protein) in combination with hepatitis B genotype and more sensitive HBV DNA polymerase chain reaction (PCR) assays may be useful to predict response to IFN as well as off-treatment NA durability. Utilization of these clinical laboratory tests may be important given the development of novel anti-HBV therapies, hoping to achieve a cure for chronic hepatitis B infection.