Sustained HIV-1 remission after heterozygous CCR5Δ32 stem cell transplantation

Researchers have recently reported that HIV infection in a patient with leukemia has remained in a state of sustained remission for more than six years following an allogeneic hematopoietic stem cell transplant. This achievement represents the seventh documented case of HIV remission worldwide and is particularly significant due to the unique genetic characteristics of the patient.
In previous cases, patients achieved durable remission because the donor cells were homozygous for the CCR5 Δ32 mutation, which prevents HIV from entering host cells. In contrast, this patient received donor cells with a heterozygous CCR5 genotype, meaning the transplanted cells did not confer complete immunity against the virus. Nevertheless, after discontinuing antiretroviral therapy three years post-transplant, HIV has remained undetectable in the patient’s body, and extensive testing indicates that the active viral reservoir has been eradicated.
Analyses suggest that immune mechanisms, such as antibody-dependent cellular cytotoxicity (ADCC), may have played a critical role in clearing the viral reservoirs. These findings indicate that complete CCR5 deletion in donor cells is not strictly necessary for achieving long-term HIV remission, and that reduction of viral reservoirs may be a key factor in establishing durable viral control.
This report provides new hope for the development of advanced HIV therapeutic strategies and enhances our understanding of the role of stem cell transplantation and the immune system in eradicating the virus. It also clarifies the direction of future research toward long-term and sustained HIV remission strategies.
 

Publish date: 1404/10/17