Hepatitis B Reactivation in a US Cohort of People With HIV and Hepatitis B Core Antibody After Switch to Antiretroviral Therapy Without Hepatitis B Activity

BACKGROUND: One in 3 people with human immunodeficiency virus (HIV-1; PWH) are hepatitis B (HBV) core antibody positive (anti-HBc+) and surface antigen negative (HBsAg-) suggesting prior exposure. HBV reactivation can occur in this group if nucleos(t)ide reverse transcriptase inhibitor antiretrovirals (ARV) active against both HIV and HBV are stopped. We describe HBV reactivation in anti-HBc+/HBsAg- PWH following switch from ARV with HBV activity to ARV without HBV activity. METHODS: We identified an at-risk cohort of 5986 anti-HBc+ participants switched from HBV-active to non-HBV-active ARV on or before 31 December 2023 and HBsAg- on the most recent result preceding switch from 63 153 PWH in the Veterans Aging Cohort Study. We defined HBV reactivation as HBV DNA detection or HBsAg+ result at any time following switch. HBV-active ARV included lamivudine, emtricitabine, or tenofovir. RESULTS: Forty (0.67%) anti-HBc+/HBsAg- PWH experienced HBV reactivation after switch to non-HBV-active ARV, with median time to reactivation 8.9 months (interquartile range 5.5-26.7). The rate of HBV reactivation was 25.1 per 10 000 person-years (95% confidence interval [CI], 18.4-34.3). Prespecified subgroup analyses revealed higher rates per 10 000 person-years of HBV reactivation in those HBsAg+ in the remote past with no hepatitis B surface antibody positive (anti-HBs+) result (321; 95% CI, 120-855) versus subgroups never previously HBsAg+ or anti-HBs+ (38.0; 95% CI, 22.9-63.0), or anti-HBs+ but never HBsAg+ (17.4; 95% CI, 11.2-27.0). CONCLUSIONS: Overall risk of HBV reactivation appears low after switch from HBV-active to non-HBV-active ARV among anti-HBc+ PWH with no prior HBsAg+. Our results inform provider-patient discussion about HBV reactivation risk when considering ARV switching.