Frequent hepatitis B surface antigen (HBsAg) clearance during tenofovir therapy in persons with HIV/hepatitis B virus coinfection
Long-term antiretroviral therapy (ART) with tenofovir has proven effective not only in controlling HIV but also in suppressing hepatitis B virus (HBV) replication in people living with HIV (PWH) who are coinfected with HBV. However, achieving functional cure of HBV—defined as the loss of hepatitis B surface antigen (HBsAg)—remains an elusive goal. In a recent study published in HIV Medicine, Béguelin et al. examined the frequency and predictors of HBsAg loss among PWH with chronic HBV infection receiving tenofovir-containing ART within the Swiss HIV Cohort Study.
The study included 272 participants with a median follow-up of 8.4 years. HBsAg clearance occurred in 7% of individuals within the first 2 years of tenofovir therapy, increasing to 16% over long-term follow-up. Importantly, among those with HBsAg loss, 59% developed anti-HBs antibodies, indicating seroconversion.
The key predictor of HBsAg loss was a low quantitative HBsAg (qHBSAg) level (<1000 IU/mL) at the start of tenofovir therapy (OR 5.3; 95% CI 1.6–17.8). No significant association was found between HBsAg clearance and CD4 count, HIV transmission mode, or HBeAg status. Notably, individuals receiving tenofovir as part of their initial ART regimen had a higher early HBsAg loss rate (10%) compared to those switching to tenofovir later (5%).
In summary, HBsAg clearance was more frequent than historically observed in HBV monoinfection and was primarily predicted by low baseline qHBsAg. These findings highlight the potential of tenofovir-containing ART to promote functional HBV cure in HIV/HBV-coinfected individuals and suggest that quantitative HBsAg measurement could help identify patients most likely to benefit from intensified monitoring or novel curative strategies.