| The disappearance of HBs antigen (HBsAg) and the annual decline in HBs antigen levels were examined in the long-term observation group and the treatment intervention group. In the long-term natural history observation group, HBsAg negativity was confirmed in 50 of 392 cases over a mean observation period of 14 years. The annual HBsAg negativity rate was 0.91%/year. In multivariate analysis, significant factors related to HBsAg negativity were HBsAg levels at first visit < 3.3 log IU/ml (hazard ratio) HR; 2.2: P = 0.008) and the presence or absence of NA therapy (HR; 0.12, P = 0.001). The median HBsAg levels 20, 10, and 5 years before HBsAg negativity in HBsAg-negative cases were 3.89, 2.84, and 1.84 log IU/ml, respectively. In a study of the treatment intervention groups (entecavir group N=177, tenofovir group N=30, peginterferon group N=26), the extent of HBsAg decay from the start of treatment to one year was -0.07log IU/mL in the entecavir group (N=177), -0.24log IU/mL in the tenofovir group (N=30), and -0.56log IU/mL in the peginterferon group (N=26), with the extent of HBsAg decay differing depending on the type of treatment drug. In the future, it will be necessary to aim for early HBs antigen disappearance by treatment using new antiviral agents, such as siRNA or Anti-Sense Oligo, or by using several types of drugs in combination. |
