Hepatitis B core antibody positivity is not associated with risk of transaminase elevation following switch to dual antiretroviral therapy

Objective: To evaluate whether hepatitis B core antibodies, indicative of possible occult hepatitis B virus (HBV) infection (pOBI), are associated with an increased risk of transaminase elevation in people with HIV (PWH) switching to two-drug regimens (2DR). Design: Cohort study. Methods: We included PWH who switched to 2DR since 2018, if they discontinued at least one anti-HBV drug and were HBsAg-negative at baseline. Two cohorts were analyzed: cohort 1 discontinued tenofovir (TFV) but continued lamivudine (3TC), Cohort 2 switched to regimens without HBV-active drugs. Survival analysis, including Cox regression adjusting for potential confounders, was conducted to compare time to grade ≥1 transaminase increase in those with and without pOBI. Results: Among 167 patients in cohort 1 (35.2% with pOBI), the rate of transaminitis was 4.59 vs. 7.47 per 100 person-years for those with and without pOBI [incidence rate ratio (IRR) 0.61; 95% confidence interval (CI) 0.17-1.83; P = 0.259]. Cox multivariable analysis found no significant association between pOBI and transaminitis (hazard ratio 0.56; 95% CI 0.2-1.5; P = 0.266), with adjusted models confirming these results. Among 118 individuals in cohort 2 (33.9% with pOBI), transaminitis rates were 8.04 vs. 8.68 per 100 person-years for those with and without pOBI (IRR 0.93; 95% CI 0.19-3.91; P = 0.763). Cox regression showed no significant association between pOBI and transaminitis (hazard ratio 1.18; 95% CI 0.4-3.6; P = 0.769), with consistent findings in adjusted models. No HBV reactivation occurred in either cohort. Conclusion: pOBI was not associated with risk of transaminase elevation in PWH switching to dual therapies lacking anti-HBV agents.