Stopping Antiviral Treatment and Subsequent Flare in Chronic Hepatitis B Infection: Immunological and Virological Profiling

Chronic hepatitis B infection (CHB) affected 292 million individuals in the world in 2016 according to the Polaris Observatory estimation, translating to about 3.9% global prevalence. Up to 40% of patients with CHB will develop liver-related complications and there were 890,000 deaths from these complications in 2015. Current antiviral therapy is aimed to achieve effective viral suppression, biochemical remission, histological improvement, and risk reductions in liver-related complications including cirrhosis and liver cancer. Many patients require long-term oral nucleos(t)ide analogues (NA) since off-treatment sustained virological control can only be achieved in a minority of patients. For HBeAg-negative CHB patients, variable rates of durable virological response were observed after cessation of NA. Only a small proportion of HBeAg-negative Asian patients (<10%) can successfully stop NA without virological breakthrough, compared to more than 60% of Caucasian patients maintaining a durable virologic response and even HBsAg seroclearance in up to 30%. Therefore, current guidelines in general recommend indefinite duration of NA therapy in HBeAg-negative patients, unless guaranteed close monitoring could be provided after cessation of NA in suitable subjects. Favourable factors predictive of partial cure include lower baseline HBV DNA, lower HBsAg titre or hepatitis B core-related antigen at NA cessation and longer duration of consolidation therapy in HBeAg-negative patients. There is lack of data in the immunological and virological profile in patients who stop their long-term NA, and in those who developed post-NA cessation flare.

The investigators aim to study the virological and immunological profile in patients who stopped long-term NA therapy, with or without post-NA cessation flare. In addition, the investigators would like to investigate the effect of mild flare after monitored NA-cessation on subsequent virological activity and HBsAg seroclearance.