Liver and Bile
J Hepatol. 2022;76(5):1042–50
Probability of HBsAg loss after nucleo(s)tide analogue withdrawal depends on HBV genotype and viral antigen levels
Background and aims: Nucleo(s)tide analogue (NA) withdrawal may result in hepatitis B surface antigen (HBsAg) clearance in a subset of patients. However, predictors of HBsAg loss after NA withdrawal remain ill-defined.
Methods: The authors studied predictors of HBsAg loss in a global cohort of hepatitis B e antigen (HBeAg)-negative patients with undetectable hepatitis B virus (HBV) DNA who discontinued long-term NA therapy. Patients requiring retreatment after treatment cessation were considered non-responders.
Results: They enrolled 1216 patients (991 with genotype data); 98 (8.1%) achieved HBsAg loss. The probability of HBsAg loss was higher in non-Asian patients (adjusted hazard ratio [aHR] = 8.26, p < 0.001), and in patients with lower HBsAg (aHR = 0.243, p < 0.001) and HBV core-related antigen (HBcrAg) (aHR = 0.718, p = 0.001) levels. Combining HBsAg (< 10, 10–100 or > 100 IU/ml) and HBcrAg (< 2 log vs. ≥ 2 log) levels improved prediction of HBsAg loss, with extremely low rates observed in patients with HBsAg > 100 IU/ml with detectable HBcrAg. HBsAg loss rates also varied with HBV genotype; the highest rates were observed for genotypes A and D, and none of the patients with HBV genotype E experienced HBsAg loss (p < 0.001 for the overall comparison across genotypes; p < 0.001 for genotypes A/D vs. genotypes B/C). HBV genotype C was independently associated with a higher probability of HBsAg loss when compared to genotype B among Asian patients (aHR = 2.494; 95% confidence interval: 1.490-4.174, p = 0.001).
Conclusions: The probability of hepatitis B surface antigen (HBsAg) loss after nucleo(s)tide analogue cessation varies according to patient ethnicity, hepatitis B virus (HBV) genotype and end-of-treatment viral antigen levels. Patients with low HBsAg (< 100 IU/ml) and/or undetectable hepatitis core-related antigen levels, particularly if non-Asian or infected with HBV genotype C, appear to be the best candidates for treatment withdrawal.