Background: With the increasing life expectancy of people living with HIV (PLWH) following antiretroviral therapy (ART), there is a growing prevalence of chronic diseases such as osteonecrosis of the femoral head (ONFH). Compared with the more accessible blood, the viral infection profile in bone marrow and necrotic femoral heads in PLWH remains inadequately characterized.
Methods: Femoral head and bone marrow were collected from 15 PLWH undergoing total hip arthroplasty. For each femoral head, samples were obtained from the subchondral, necrotic, sclerotic, and normal areas. HIV DNA and HIV RNA assays were employed to evaluate disparities in viral load and reservoir between bone marrow and blood, as well as to quantify viral infection in distinct regions of the necrotic femoral head.
Results: Blood HIV RNA dropped below detectable levels in 8 patients (below 20 copies/mL). The median of bone marrow HIV RNA was 255.89 copies/mL. HIV DNA in blood and bone marrow was 296.35 and 454.31 copies/10⁶ cells. HIV DNA in necrotic area was about half that in sclerotic area, HIV RNA was about twice that in normal area, the difference was statistically significant.
Conclusion: Despite using ART, there is still substantial active HIV and a potential reservoir in the bone marrow. Viral transcription was most active in the necrotic area of the femoral head, which may indicate that HIV itself is directly involved in ONFH.

Keywords: HIV, AIDS, bone marrow, femoral head, reservoir