Incidence and Predictors of Hepatitis B Surface Antigen Clearance in HIV Patients: A Retrospective Multisite Study

BACKGROUND: New therapies to achieve hepatitis B surface antigen (HBsAg) clearance are under development. However, gaps in knowledge exist in understanding the incidence and predictors of HBsAg clearance in a racially diverse HIV population. METHODS: We examined the incidence and risk of HBsAg clearance in a retrospective cohort of people with HIV/hepatitis B virus (HBV). Included patients had sufficient data to establish chronic infection based on Centers for Disease Control and Prevention guidelines. We examined the incident rate for HBsAg loss and hazard rate ratios to evaluate predictors for HBsAg clearance in a multivariable model. RESULTS: Among 571 HIV/HBV patients, 87% were male, 61% were Black, 45% had AIDS, 48% were HBeAg positive, and the median follow-up was 88 months. Incident HBsAg clearance was 1.5 per 100 person-years. In the multivariate model, those with AIDS at baseline (adjusted hazard ratio [aHR], 2.43; 95% CI, 1.37–4.32), Hispanics (aHR, 3.57; 95% CI, 1.33–9.58), and those with injection drug use as an HIV risk factor (aHR, 3.35; 95% CI, 1.26–8.89) were more likely to lose HBsAg, whereas those who were HBeAg positive (aHR, 0.34; 95% CI, 0.19–0.63) were less likely to lose HBsAg. The median change in CD4 cell count during the observation period was 231 cells/mm(3) in those with HBsAg loss vs 112 cells/mm(3) in those with HBsAg persistence (P = .004). CONCLUSIONS: HBsAg loss occurs in about 10% of those with chronic HBV infection. Being Hispanic, having AIDS at baseline, having an injection drug use history, and having HBeAg-negative status at baseline predicted the likelihood of HBsAg loss. Immune restoration may be a mechanism through which HBsAg loss occurs in HIV patients.