Overview
- B2, a 60-year-old man in Berlin, has remained free of detectable HIV for more than seven years after stopping ART following a stem cell transplant from a donor with only one CCR5Δ32 allele.
- The case is the seventh reported long-term HIV remission and only the second without a homozygous CCR5Δ32 donor, pointing to mechanisms beyond complete CCR5 resistance, such as graft-versus-reservoir effects.
- A UCSF-led Nature study found that 7 of 10 participants maintained low-level viremia for months after stopping ART following a therapeutic vaccine plus broadly neutralizing antibody regimen, with one person controlling for over 18 months.
- Separate Nature research linked sustained post-treatment control to pre-existing HIV-specific CD8+ T cells with stem-like proliferative and cytotoxic capacity, suggesting these features could predict who benefits from antibody-based strategies.
- Researchers caution that stem cell transplants are high risk and the immunotherapy trial was small and uncontrolled, underscoring heterogeneous outcomes and the need for larger studies to translate these insights into scalable cures.