Abstract
Chronic hepatitis B (CHB) is a major global health concern. Guidelines for the management of hepatitis B virus (HBV) indicate that the loss of hepatitis B surface antigen (HBsAg) is a key endpoint of interest. The present study aimed to examine long-term changes in HBsAg levels in HBV-DNA-negative, hepatitis B e-antigen (HBeAg)-negative patients treated with peginterferon (Peg-IFN) α-2a and nucleos(t)ide analog (NA), and to examine the conditions that make them susceptible to HBsAg decline. A total of 17 patients with CHB treated with NA and Peg-IFN were observed for 96 weeks (48 weeks of Peg-IFN therapy and 48 weeks of post-treatment follow-up). In this study, responders were defined as those with a 50% or greater decrease in HBsAg levels from baseline at week 96. Beginning at week 16 of Peg-IFN therapy, there was a significant difference in the decrease in HBsAg levels from baseline between the responders and non-responders. In responders, HBsAg levels tended to be >60% lower 16 weeks after Peg-IFN initiation than before initiation. Age at the start of NA use and the duration of NA use before Peg-IFN treatment initiation were significant pretreatment factors associated with HBsAg response. In conclusion, Peg-IFN was revealed to be more effective in HBeAg-negative patients with CHB who started NA at a young age and have been on long-term treatment, particularly if the HBsAg levels decreased to less than 60% of the starting level at week 16 after starting Peg-IFN treatment.