Evaluation of hepatitis B virus reactivation prevention measures in immunosuppressed patients: current status and effectiveness.

Background: Prevention of hepatitis B virus (HBV) reactivation is a very important issue, but there is still no clear strategy. This study aimd to develop and evaluate an in-hospital collaboration flow to prevent HBV reactivation, guided by the Japanese Society of Hepatology (JSH) guidelines. Methods: We have strengthened and implemented a screening system and for HBV reactivation from February 2022 to January 2023. We assessed the administration of nucleic acid analogs (NAs) in hepatitis B surface antigen (HBsAg) or HBV DNA-positive cases, the detection rate of HBs or hepatitis B core (HBc) antibodies in HBsAg or HBV DNA-negative cases, and the follow-up status of HBV DNA testing. A total of 1,195 patients were included, with exclusions based on the judgement of no need for testing by the attending physician. Results: Among 1,172 tested patients, 1.88% (n=22) were HBsAg or HBV DNA-positive, all of whom received NA therapy. Among 1,150 HBsAg or HBV DNA-negative cases, 9.91% (n=114) were HBs or HBc antibody-positive, with 82.5% (n=94) undergoing HBV DNA testing. Over the years, the HBV DNA measurement rates increased significantly to 82.5% in 2022. Conclusions: The implemented screening regimen resulted in high and improving testing rates over time. Most HBsAg or HBV DNA-positive cases were treated with tenofovir alafenamide (TAF), highlighting its potential benefits in terms of safety and adherence. Continued validation and adaptation of the screening system are necessary to further prevent HBV reactivation.