HIV: Immune system's 'codes' discovered to suspend treatment

"A group of adolescents and young adults born with HIV and treated since early childhood showed a remarkable ability to control the infection, maintaining the virus in a nearly inactive state". This is what emerges from a study conducted by researchers at the Bambino Gesù Children's Hospital, in collaboration with the University of Rome 'Tor Vergata' and the MIT in Boston, published in the journal 'Cell Reports Medicine' .

The patients involved, part of the cohort called Leukohiv, were subjected to early and continuous antiretroviral therapy for an average of 20 years. The study identified specific signals of the immune system (biomarkers) that are associated with an extremely reduced presence of the HIV virus in the body (a condition known as minimal "viral reservoir"). This parameter is very important from a clinical point of view, because it can help to recognize those patients for whom it is possible to safely evaluate the suspension of antiretroviral therapy.

The in-depth immunological analysis was made possible by using a leukopheresis procedure, which allowed the collection of large quantities of lymphocytes in a safe manner, allowing an advanced characterization of the immune system. The data obtained highlighted an almost total absence of intact proviruses (the active and replicating forms of the virus) and the presence of highly functional natural killer (NK) cells even after decades, a sign of enhanced innate immunity.

Who can suspend therapy

To date, we do not have clear clinical criteria to decide in which patients, even if under virological control for years, a suspension of therapy can be evaluated" explains Professor Paolo Palma , head of Clinical Immunology at Bambino Gesù: "This study contributes to filling this gap, providing useful scientific tools to select candidates for therapeutic suspension in a safe, personalized and monitored manner".

Another important observation concerns the localization of the residual virus: in some cases, HIV is present in genetically inactive areas of the human genome, where it has minimal possibilities of replicating. This could be the result of the pressure exerted by early therapy, which would push the virus towards silent and less dangerous areas. According to Professor Nicola Cotugno , associate professor of Pediatrics at the University of Rome Tor Vergata, "the results suggest that a treatment started very early can deeply modulate the immune system, making it capable of controlling the virus even in the absence of active therapy".

Why is study important?

The study represents an important step forward in understanding the mechanisms that allow long-term control of HIV, paving the way for personalized and sustainable therapeutic strategies that, in the future, could reduce drug dependence in selected patients. At the Bambino Gesù Children's Hospital - National Reference Center for pediatric HIV - approximately 80-100 patients are followed every year. Most have contracted the virus through vertical transmission (from mother to child) and receive effective therapy, capable of ensuring a good quality of life and a low viral load.