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This retrospective study of 256 HIV patients in Japan found that 58% of HIV/HBV-coinfected individuals cleared hepatitis B surface antigen (HBsAg), with most clearance occurring within 3-4 years of antiretroviral therapy. Clearance was significantly associated with higher CD4 counts and lower HIV viral loads, indicating better immune function. In cases of occult HBV infection, researchers identified a rare amino acid substitution (N131K) in the HBsAg 'a' determinant region that may cause false-negative HBsAg test results.
Why it matters
These findings have important implications for managing HIV/HBV-coinfected patients, particularly as newer NRTI-sparing antiretroviral regimens become more common. The identification of rare mutations causing occult HBV infection highlights the need for careful monitoring and alternative testing strategies to prevent HBV reactivation when switching treatment regimens.
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⚠️ Preprint – Noch nicht peer-reviewed
Dieser Artikel wurde noch nicht von unabhängigen Experten begutachtet. Die Ergebnisse sind vorläufig und sollten mit Vorsicht interpretiert werden.
Background: HBV coinfection is more common among people with HIV than in the general population. Nucleotide reverse transcriptase inhibitors (NRTIs) in antiretroviral therapy (ART) are also active against HBV. Growing use of NRTI-sparing regimens raises concern about HBV reactivation. Objectives: To determine the rate, cumulative incidence, and factors associated with HBsAg clearance in HIV/HBV-coinfected patients, and to characterize the genetic/structural basis of occult HBV infection (OBI) in the same cohort. Study design: We retrospectively reviewed 256 people with HIV at Kumamoto University Hospital in Japan (1986-2025), stratified by HBsAg clearance status; clinical factors were compared and cumulative incidence estimated by Kaplan-Meier analysis. OBI cases underwent HBsAg-region sequencing. Results: Fifteen patients were analyzed (12 HBsAg-positive, 3 OBI). HBsAg clearance occurred in 7/12 (58%). The Kaplan-Meier estimated cumulative incidence reached 25% by 2 years and 64.3% at approximately 4.4 years, after which no additional clearance events were observed during follow-up. Clearance was associated with higher CD4 ([≥]200 cells/L: 71% vs 0%) and lower HIV-RNA (<105 copies/mL: 86% vs 20%); HBV-DNA was significantly higher in the clearance group than OBI (adjusted p=0.007). All OBI sequences matched genotype C2; one also carried a rare genotype A2 'a' determinant substitution, N131K (0.23% of genotype A sequences in HBVdb). Conclusions: HBsAg clearance was frequent, concentrated within 3-4 years of ART, and associated with preserved immune status and HBV replicative activity. A rare 'a' determinant substitution may cause false-negative HBsAg in OBI, informing NRTI-sparing ART selection.