Table 1 Responses to antiviral treatment of patients with chronic hepatitis B.

Category of response
Biochemical	Decrease in serum ALT to within the normal range
Virological	Decrease in serum HBV DNA to undetectable levels in unamplified assays (<105 copies/ml) and loss of HBeAg in patients who were initially HBeAg positive
Histological	Decrease in histology activity index by at least 2 points compared with pretreatment liver biopsy
Complete	Fulfil criteria of biochemical and virological response and loss of HBsAg
Time of assessment
On therapy
Maintained: Persist throughout the course of treatment
End of treatment: At the end of a defined course of treatment
Off therapy: After discontinuation of treatment
Sustained (SR6): 6 months after discontinuation of treatment
Sustained (SR12): 12 months after discontinuation of treatment

ALT, alanine aminotransferase; HBsAg, hepatitis B surface antigen; HBV, hepatitis B virus.