Hepatitis C coinfection was the strongest independent risk factor for serious liver outcomes in a Swiss cohort of people living with HIV, according to an analysis presented at HIV Glasgow 2026. People with isolated hepatitis B core antibodies experienced more liver complications in the initial comparison, but the association weakened after researchers accounted for other risk factors.
The investigators used data from the Swiss HIV Cohort Study to examine whether an isolated antibody to hepatitis B core antigen, known as anti-HBc, was independently associated with liver complications. The analysis included 9,595 people receiving antiretroviral therapy who had a complete hepatitis B serology panel and at least two visits six or more months apart between 1997 and 2018. Median follow-up was 13.6 years.
At baseline, 1,334 participants had isolated anti-HBc, 2,734 had evidence of resolved hepatitis B infection and 5,527 had been vaccinated or had no evidence of prior exposure. Researchers tracked a combined outcome of advanced liver fibrosis or cirrhosis, hepatocellular carcinoma or liver-related death. They used a competing-risk approach to estimate the 10-year incidence. The isolated antibody pattern was present in about 14% of participants at baseline.
At 10 years, the cumulative incidence of the combined outcome was 15.7% among those with isolated anti-HBc, 10.4% among those with resolved hepatitis B and 7.2% in the unexposed or vaccinated group. In the initial comparison, the group with isolated anti-HBc had approximately twice the subdistribution hazard of the reference group (subdistribution HR: 1.99, 95% CI: 1.73–2.29).
After adjustment for established risk factors, the association with isolated anti-HBc weakened and was no longer statistically significant (adjusted HR: 1.12, 95% CI: 0.95–1.31). Resolved hepatitis B was also unassociated with the combined outcome after adjustment (adjusted HR: 0.99, 95% CI: 0.88–1.11). Hepatitis C coinfection had the strongest independent association with the outcome, at more than three times the hazard (adjusted HR: 3.15, 95% CI: 2.79–3.55).
The researchers interpreted the higher observed incidence among people with isolated anti-HBc as largely explained by concomitant hepatitis C. The absolute rates describe what happened within each serology group over time. The adjusted estimates address a different clinical question, whether the marker still distinguishes people at higher risk once other factors are taken into account.
The authors suggested that the findings could help refine liver disease surveillance in people with HIV, including those switching to antiretroviral regimens without hepatitis B activity. The study assessed longer-term liver complications in an observational cohort, so its findings support interpreting hepatitis B serology alongside hepatitis C status and other liver risk factors when planning follow-up.
Reference
Calame A, Aymes E, Begré L, et al. Isolated hepatitis B core antibody and liver-related outcomes in people living with HIV enrolled in the Swiss HIV Cohort Study. Abstract O34. Presented at: HIV Glasgow 2026; 8–11 November 2026; Glasgow, UK. J Int AIDS Soc. 2026;29(Suppl 6):e70211. doi:10.1002/jia2.70211
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