Treatment with nucleoside analogue ( NA s) is now the most common treatment for chronic hepatitis B ( CHB ) and is recommended by all guidelines. Stopping NA s is a controversial issue in these patients, unless the clinical endpoints of HB eAg seroconversion or HB sAg seroclearance are achieved. While HB eAg seroconversion can occur in a significant number of patients, HB sAg seroclearance rates are low. HB sAg seroclearance is increasingly accepted as the ideal end of treatment, representing a func- tional cure. Treatment withdrawal leads to relapse in 50% of patients who achieve HB eAg seroconversion and complete at least 12 months of consolidation therapy. In HB eAg negative CHB , the Asian Pacific Association for the Study of the Liver ( APASL ) stopping rules show that although clinical relapse occurs in approximately 43% and virological relapse occurs in 70%, very few patients experience flare or decompensation. NA s treatment for >2 years was associated with a lower rate of relapse. Recently, stopping NA therapy was shown to be associated with HB sAg in 20%- 39% of HB eAg negative patients and more frequently in those with low quantitative HB sAg ( qHBsA g). However, the most optimal level is unclear. Quantitative HB sAg is becoming a useful tool to predict a sustained response or relapse before stopping therapy. In conclusion, stopping NA therapy is generally safe and can be an option in specific situa- tions such as HB eAg seroconversion. However, it is associated with disease relapse. Thus, patient selection based on qHB sA g may help identify patients who are more likely to achieve HB sAg seroclearance or a sustained response.
K E Y W O R D S
antiviral therapy , cessation , hepatitis B flares , nucleos(t)ide analogues , quantitative HB sAg ,
relapse , seroreversion , treatment withdrawal