Retrospective investigation of prophylactic tenofovir alafenamide USE in patients at risk of hepatitis B reactivation DUE to immunosuppressive therapy in Bursa Uludag University HEALTH practice and research center

The risk of HBV reactivation( HBVr) increases when HBV-infected individuals receive immunosuppressive or anticancer treatments. HBV reactivation can cause serious morbidity and mortality. The number of patients receiving antineoplastic agents, monoclonal antibodies, steroids, and biological agents is increasing. Hepatitis screening should be performed prior to immunosuppressive therapy, and prophylactic antiviral therapy should be initiated according to the risk of hepatitis B reactivation. Our study included 211 patients on immunosuppressive treatment and receiving prophylactic tenofovir alafenamide fumarate (TAF) between January 2019 and March 2022. Patients' demographic characteristics, hepatitis serology and laboratory results before and after treatment, underlying disease, immunosuppressive treatments, serological risks, and HBV reactivation risk status were evaluated. At the time of diagnosis, 26 (12.3%) patients tested positive for HBsAg, whereas 185 (87.7%) patients were HBsAg negative and anti-HBc total positive 23.70% of patients received anti-CD20 monoclonal antibodies, which are immunosuppressive agents with a significant risk of HBV reactivation. No statistically significant difference was found between pre-and post-treatment values in HBsAg, anti-HBc total, anti-HBs serology, or laboratory results. HBV DNA decreased significantly after treatment. No reactivation was observed in the retrospective analysis of 211 patients. In this study, TAF was shown to be as effective as other antivirals in preventing HBVr. TAF supresses HBV DNA, has a minimal side-effect profile, and may be used safely in prophylactic therapy in patients with renal impairment since it does not require renal dosage adjustment and has no detrimental effect on renal functions. Keywords: HBV, reactivation, immunosuppression, tenofovir alafenamide fumarate. The risk of HBV reactivation( HBVr) increases when HBV-infected individuals receive immunosuppressive or anticancer treatments. HBV reactivation can cause serious morbidity and mortality. The number of patients receiving antineoplastic agents, monoclonal antibodies, steroids, and biological agents is increasing. Hepatitis screening should be performed prior to immunosuppressive therapy, and prophylactic antiviral therapy should be initiated according to the risk of hepatitis B reactivation. Our study included 211 patients on immunosuppressive treatment and receiving prophylactic tenofovir alafenamide fumarate (TAF) between January 2019 and March 2022. Patients' demographic characteristics, hepatitis serology and laboratory results before and after treatment, underlying disease, immunosuppressive treatments, serological risks, and HBV reactivation risk status were evaluated. At the time of diagnosis, 26 (12.3%) patients tested positive for HBsAg, whereas 185 (87.7%) patients were HBsAg negative and anti-HBc total positive 23.70% of patients received anti-CD20 monoclonal antibodies, which are immunosuppressive agents with a significant risk of HBV reactivation. No statistically significant difference was found between pre-and post-treatment values in HBsAg, anti-HBc total, anti-HBs serology, or laboratory results. HBV DNA decreased significantly after treatment. No reactivation was observed in the retrospective analysis of 211 patients. In this study, TAF was shown to be as effective as other antivirals in preventing HBVr. TAF supresses HBV DNA, has a minimal side-effect profile, and may be used safely in prophylactic therapy in patients with renal impairment since it does not require renal dosage adjustment and has no detrimental effect on renal functions. Keywords: HBV, reactivation, immunosuppression, tenofovir alafenamide fumarate.