Time-varying serum gradient of hepatitis B surface antigen predicts risk of relapses after off-NA therapy

Hepatitis B core-related antigen dynamics and risk of subsequent clinical relapses after nucleos(t)ide analog cessation

BACKGROUND/AIMS

Finite nucleos(t)ide analog (NA) therapy has been proposed as an alternative treatment strategy for chronic hepatitis B (CHB), but biomarkers for post-treatment monitoring are limited. We investigated whether measuring hepatitis B core-related antigen (HBcrAg) after NA cessation may stratify the risk of subsequent clinical relapse (CR).

METHODS

This retrospective multicenter analysis enrolled adults with CHB who were prospectively monitored after discontinuing entecavir or tenofovir with negative HBeAg and undetectable HBV DNA at the end of treatment (EOT). Patients with cirrhosis or malignancy were excluded. CR was defined as serum alanine aminotransferase > two times the upper limit of normal with recurrent viremia. We applied time-dependent Cox proportional hazard models to clarify the association between HBcrAg levels and subsequent CR.

RESULTS

The cohort included 203 patients (median age, 49.8 years; 76.8% male; 60.6% entecavir) who had been treated for a median of 36.9 months (interquartile range [IQR], 36.5-40.1). During a median post-treatment follow-up of 31.7 months (IQR, 16.7-67.1), CR occurred in 104 patients with a 5-year cumulative incidence of 54.8% (95% confidence interval [CI], 47.1-62.4%). Time-varying HBcrAg level was a significant risk factor for subsequent CR (adjusted hazard ratio [aHR], 1.53 per log U/mL; 95% CI, 1.12-2.08) with adjustment for EOT HBsAg, EOT anti-HBe, EOT HBcrAg and time-varying HBsAg. During follow-up, HBcrAg <1,000 U/mL predicted a lower risk of CR (aHR, 0.41; 95% CI, 0.21-0.81).

CONCLUSION

Dynamic measurement of HBcrAg after NA cessation is predictive of subsequent CR and may be useful to guide post-treatment monitoring.

Safety considerations for withdrawal of nucleos(t)ide analogues in patients with chronic hepatitis B: First, do no harm

Nucleos(t)ide analogues (NA) are widely used to treat hepatitis B virus (HBV) infection, but they cannot eradicate the virus and treatment duration can be lifelong if the endpoint is set at seroclearance of the hepatitis B surface antigen (HBsAg). As an alternative strategy, finite NA therapy without the prerequisite of HBsAg seroclearance has been proposed to allow treatment cessation in patients with sustained undetectable HBV viremia for two to three years. However, reactivation of viral replication almost always follows NA withdrawal. Whereas HBV reactivation might facilitate HBsAg seroclearance in some, it could lead to serious acute flare-ups in a certain proportion of patients. Occurrence and consequences of NA withdrawal flares are complicated with various factors involving the virus, host, and treatment. Accurate risk prediction for severe flares following NA cessation is essential to ensure patient safety. The risks of life-threatening flares in patients who discontinued NA according to the stopping rules of current guidelines or local reimbursement policies have recently been quantitatively estimated in large-scale studies, which also provided empirical evidence to help identify vulnerable patients at risk of devastating outcomes. Moreover, risk predictors were further explored and validated to hopefully aid in patient selection and management. In this narrative review with a focus on patient safety, we summarize and discuss current literature on the incidence of severe flares following NA cessation, risk stratification for candidate selection, rules of posttreatment monitoring, and indications for treatment resumption. We also share our thoughts on the limitations of existing knowledge and suggestions for future research.

Biomarkers for predicting nucleos(t)ide analogs discontinuation and hepatitis B virus recurrence after drug withdrawal in chronic hepatitis B patients

AIM

To summarize HBV-related biomarkers predicting nucleos(t)ide analogs (NAs) discontinuation and hepatitis B virus (HBV) recurrence after drug withdrawal in chronic hepatitis B (CHB) patients, providing references for clinical medication, so as to manage CHB patients more scientifically.

METHODS

Related pieces of literature were retrieved in PubMed and the results were sorted out. We then analyzed and summarized these articles.

RESULTS

We found that HBV related biomarkers maybe could predict NAs withdrawal safely and the possibility of relapse after treatment cessation, including hepatitis B e antigen (HBeAg), hepatitis B surface antigen (HBsAg), HBV DNA, HBV RNA, pregenomic-RNA (pgRNA), hepatitis B core-related antigen (HBcrAg), hepatitis B core antibody (anti-HBc), and models containing several indicators for predicting the effectiveness of treatment.

CONCLUSIONS

HBV DNA, HBV RNA, pgRNA, HBcrAg, anti-HBc, as well as the prediction models formed by several biomarkers could predict the safe discontinuation of NAs before HBsAg loss and recurrence.

Combining hepatitis B core-related and surface antigens at end of nucleos(t)ide analogue treatment to predict off-therapy relapse risk

BACKGROUND

There remains an unmet need for convenient biomarkers to assess the risks of discontinuing nucleos(t)ide analogues (NAs) in chronic hepatitis B (CHB).

AIM

To investigate if hepatitis B core-related antigen (HBcrAg) is an independent of surface antigen (HBsAg) for risk prediction of NA cessation.

METHODS

This prospective multicentre study enrolled 135 CHB patients who stopped entecavir or tenofovir after achieving viral remission for a median of 25.2 months. All patients stopped NA with negative HBeAg and undetectable viral DNA, and were then observed for clinical relapse and HBsAg loss. Predictors including HBsAg and HBcrAg levels were explored using Cox proportional hazard model and weighted to develop a risk score.

RESULTS

During a median follow-up of 25.9 months, clinical relapse and HBsAg loss occurred in 66 and eight patients, respectively, with a 5-year cumulative incidence of 56.1% (95% CI 46.7-66.0%) and 8.8% (95% CI 4.3-17.4%), respectively. HBcrAg was an independent relapse predictor, as well as HBsAg, age, ALT and tenofovir use. A score (SCALE-B) was calculated by the equation of 35*HBsAg (log IU/mL) + 20*HBcrAg (log U/mL) + 2*age (year) + ALT (U/L) + 40 for tenofovir use. The concordance rates for clinical relapse were 0.87, 0.88, 0.87, 0.85 and 0.90 at 1, 2, 3, 4 and 5 years, respectively. Moreover, HBsAg loss occurred exclusively in low-risk patients predicted by the score.

CONCLUSIONS

Serum HBcrAg and HBsAg levels were independent predictors of off-NA relapse and can be factored into a risk score to guide treatment cessation in patients with CHB.