First sustained remission of HIV infection in the absence of protective mutations after bone marrow transplant

A total of seven people worldwide (two patients in Berlin, and patients in London, Dusseldorf, New York, City of Hope and Geneva) are thought to be likely cured or in long-term remission of HIV infection after receiving bone marrow transplants to treat blood cancer.

Romuald, a Geneva patient monitored at the Geneva University Hospital (HUG), is the only patient to have experienced HIV remission after a bone marrow transplant without the CCR5-delta32 mutation, a rare genetic mutation known to confer natural resistance to HIV in CD4 cells.

Unlike previous cases in which the presence of the CCR5-delta32 mutation seemed to play a decisive role in the HIV outcome, the published study shows that the Geneva patient's cells are still susceptible to HIV infection. Nevertheless, almost three years after antiretroviral treatment was stopped, the virus has still not been detected in the patient.

By closely monitoring patients over time, the scientists were able to demonstrate that after transplant, the virus-carrying cells gradually declined: viable virus-carrying cells that were easily detectable before transplant were no longer detectable by modern analyses.

paper, Published In the journal Nature Medicinepresents these results together with a hypothesis that the teams from UNIGE, HUG and the Institut Pasteur are working on to explain why this patient went into remission.

The presence of innate immune cells with strong anti-HIV capabilities may prevent the virus from reactivating, even if some infected cells still remain in the body. The immunomodulatory treatments that patients receive to suppress the graft-versus-host reaction they have experienced repeatedly since transplantation may also help prevent viral reactivation.

Finally, these graft-versus-host responses may have effectively eliminated the viral reservoir, making the CCR5-delta32 mutation unnecessary because no replicative virus remains in the body. These hypotheses open promising avenues for research aimed at achieving remission of HIV infection.