Two new examples of individuals considered cured or in prolonged remission from HIV infection, after undergoing stem cell transplants, will be presented at an international AIDS conference held in Rio de Janeiro.
Total Cases and Presentation
With the inclusion of these new records, the global number of patients classified as cured of the viral infection reaches 13. The cases, named Ascent patient and Kansas City patient, will be detailed on Wednesday (29) during a session focused on research into HIV eradication.
Christian Gaebler, an immunologist at Charité Universitätsmedizin Berlin, anticipated this news during the pre-conference HIV Cure Without Borders: Science, Community and the Latin America and Caribbean Perspective. Gaebler stated that Ascent patient would be number 12 and the Kansas City patient would be number 13, describing the findings as 'truly fascinating.'
Limitations and Clinical Context
Specific clinical information about the Kansas City patient was not disclosed by the researcher. The two new cases are part of a very limited group of people who have managed to eliminate or control HIV without continuous medication, thanks to stem cell transplantation.
It is important to note, however, that despite scientific progress, experts warn that this procedure does not constitute a therapeutic alternative for the majority of people living with HIV. This is because all patients considered cured or in prolonged remission required a bone marrow transplant due to the development of leukemia or other hematological cancer, a complex and high-risk procedure reserved for potentially fatal diseases.
Gaebler emphasized the importance of 'learning from all these cases.'
Global Epidemic Perspective
Since the beginning of the epidemic, it is estimated that around 90 million people have lived with or are living with HIV. The 13 transplant-related cases represent only a small fraction of this amount, but they provide crucial data for developing methods that allow for virus control without the need for constant treatment.
The first recognized cure case was that of Timothy Ray Brown, nicknamed the 'Berlin patient', presented in 2009. At that time, Brown received a transplant from a donor carrying two copies of the CCR5-delta32 mutation, a genetic alteration that blocks the function of the CCR5 co-receptor, a primary entry point for HIV into immune system cells. For years, the scientific community believed this mutation was essential to achieving a cure.
New Mechanisms of Viral Control
The most recent cases, however, suggest that factors other than the genetic mutation may be involved in controlling the infection. Gaebler mentioned the case of the Geneva patient, who entered remission even when receiving cells from a donor without the CCR5-delta32 mutation. He also cited a second patient from Berlin whose donor possessed only one copy of this genetic alteration.
According to the specialist, these results point to the contribution of immunological mechanisms, in addition to genetics, in controlling HIV. In the second Berlin patient, researchers detected antibodies capable of neutralizing the virus and stimulating NK cells, vital components of the immune system responsible for destroying infected cells. According to Gaebler, this immune response may have helped in the gradual reduction of viral reservoirs, which are cells where HIV hides and represent the biggest obstacle to a definitive cure.
Research into Alternative Therapies
In addition to stem cell transplants, various research teams are working on developing treatments that can benefit a much larger number of people with HIV. Strategies under study include broadly neutralizing antibodies (bNAbs), CAR-T cell therapies, genetic editing of the CCR5 gene, and new immunotherapy approaches.
Gaebler reported that several clinical trials with bNAbs show similar results: between 10% and 20% of participants manage to maintain partial or total viral control after suspending antiretroviral therapy under supervision.
The immunologist also presented preliminary data from an experimental therapy using CAR-T cells modified to recognize HIV and edited in the CCR5 gene. In a group of ten participants, one managed to keep the virus controlled for about 90 weeks without treatment, while five others experienced a smaller than expected viral increase. Although the findings are still initial and come from small studies, scientists believe that this research will guide the development of future treatments that allow people with HIV to keep the virus under control without continuous dependence on medication.
