When HBV was suppressed by NA therapy, the immune tolerance may also be suppressed. The post treatment relapse is an indirect evidence of losing immune tolerance in such patients (29-31). The post treatment clinical relapse is associated with enhanced Th1 response (35-37). T regulatory (Treg) cells, macrophages and other unidentified factors may play important roles on HBV tolerance (19, 38-41). One of an important phenomenon for patients receiving NA therapy is decrease of Treg cells level (42,43). The post treatment relapse of hepatic necroinflammation is an evidence of the restored HBV specific immune response (44,45).