A new hope of treatment for children affected by HIV comes from the Bambino Gesù Pediatric Hospital on the eve of the World Day against AIDS. Physicians and researchers have succeeded in developing a new procedure capable of characterizing the residual viral load and the associated protective immune response present in patients, identifying those children in which the viral residue is dormant and those in which this residue carries, if not adequately treated, a risk of recurrence of the disease. The results of this new procedure will be presented in the next edition of the Conference on Retroviruses and Opportunistic Infections, which will take place in Seattle during the following month of February. During 2023, the first trial for the suspension of antiretroviral therapy in children with “dormant” viral reserve will start at the Bambino Gesù.
THE RESIDUAL VIRAL LOAD
Residual viral load (or viral reserve) indicates the amount of virus that remains in some cells (CD4) located on the T lymphocytes of HIV-infected people. Today it still represents the main obstacle to complete recovery: the presence of residue, in fact, is what renders lifelong antiretroviral therapy necessary. In children who have inherited the virus from their mother (vertical infection) and who start antiretroviral therapy early, the amount of this residue is reduced. However, to understand the real possibilities of treatment, a diagnostic procedure is fundamental – the cellular characterization of the residue – which requires the withdrawal of a considerable amount of blood, often difficult in the case of children. Approximately 150.000 new paediatric infections are recorded in the world every year, for a total of approximately 1.700.000 children infected with HIV. Vertical HIV infection affects about 95% of new pediatric cases each year.
THE NEW PROCEDURE
To overcome the problem of the reduced amount of blood that can be drawn from a child, the researchers of the areas of Clinical Immunology and Vaccinology directed by prof. Paolo Palma and Complex and Perinatal Infections by Dr. Stefania Bernardi, in collaboration with the Aphaeresis unit of Dr. Giovanna Leone of Transfusion Medicine of Bambino Gesù, studied the application of a procedure with which to obtain an optimal quantity of cells ready for characterization. That is leukapheresis which, through a special machine, allows to take only the white blood cells, then re-introducing the rest of the blood into the circulation. The procedure was found to be safe for small patients and effective, with a cell yield up to 150.000 times greater than traditional sampling techniques.
The cellular material obtained with leukapheresis has, therefore, allowed physicians and researchers of Bambino Gesù to pursue a new molecular characterization of the viral reserve in collaboration with the laboratory of prof. Mathias Lichterfeld of Boston’s MIT, among the world’s leading experts in this field. In this research, the protective immune response associated with the specificity of the individual patient’s viral reserve was investigated: through the characterization and typing of the residual virus it was thus possible to identify the children in which this reserve is dormant and those in which this reserve carries, if not adequately treated, a risk of recurrence of the disease.
The results of the research will be presented during the 30th edition of the Conference on Retroviruses and Opportunistic Infections (CROI) which will be held from the 19th to the 23rd of February 2023 in Seattle where they have already been considered of extreme interest by the scientific evaluation commission, awarding Dr. Nicola Cotugno with the scholarship to participate in the event. It is the annual scientific meeting dedicated to understanding, preventing and treating HIV/AIDS and associated infections which brings together hundreds of researchers and clinicians from all over the world.
THE THERAPEUTIC SUSPENSION
“Thanks to the results obtained by two studies pursued by Bambino Gesù it is now possible to determine the viral reserve’s characteristics in children with HIV vertical infection, identifying whether the virus still present in their cells has more or less the capacity to replicate, i.e. whether it is dormant or active – professor Paolo Palma explains, head of the Clinical Immunology and Vaccinology research unit of the Hospital – In children in whom this reserve turn out to be completely dormant, it will be possible to proceed with the therapeutic suspension in the context of a controlled experimental study. A goal pursued for years by doctors and researchers who deal with HIV”.
During the course of 2023, an experiment already approved by the Ethics Committee of the Hospital will start at the Bambino Gesù which will allow for the first time the therapeutic suspension in children whose analysis of the viral residue reveals only the presence of dormant virus. Currently, around 100 HIV-infected children and young people are being followed up at the Holy See Pediatric Hospital, almost all with vertical infection.