A woman has been controlling HIV for 15 years without taking drugs, an exceptional case of a functional cure for AIDS. The team at the Hospital Clinic in Barcelona, Spain, announced that the patient, after discontinuing antiretroviral treatment, has complete control of HIV replication, with an undetectable viral load and without taking drugs against the virus.
This case, which will be presented this week at the 2022 World AIDS Conference taking place in Montreal, Canada, is different from those known with patients from Berlin and London who achieved complete cure because the virus disappeared after a stem cell transplant. to treat the hematological diseases they suffered from.
This new case from Spain is also different from the Argentine patient known as “Patient Esperanza”, who achieved a “sterilizing cure” of the virus. This means that HIV is not detected in the blood or in the cells, that it was deactivated by the action of its own immune system. “I have no trouble believing that I am cured at all. It’s just that I learned to live with this and to have to change my mentality, ”explained the patient Esperanza when her case became relevant worldwide.
The case of the so-called “Barcelona patient” is a functional cure, since the woman still has the virus, but her immune system can completely control its replication 15 years after stopping AIDS treatment, according to the Hospital Clinic of Barcelona, in charge of the study.
Acquired Immunodeficiency Syndrome (AIDS) is the most serious form of infection caused by the human immunodeficiency virus (HIV). Antiretroviral treatment, the standard for controlling the disease, is effective in suppressing viral replication within the body and blocking transmission to others, leaving the patient with such a low blood level of HIV that it becomes undetectable in a conventional analysis. But HIV persists in reservoirs, so if therapy is stopped, it has the ability to replicate and can attack the patient again.
However, like the Barcelona patient, “there are few people, like the ‘post-treatment controllers’, who maintain undetectable viral loads without taking medication, being a realistic model for functional HIV care. Other cases of cure are related to bone marrow transplantation or in exceptional patients who have defective viruses or genetic factors associated with a potent immune response to HIV from a type of lymphocyte, CD8+ T cells, in so-called elite controllers.” the research team explained in a statement.
Josep Mallolas, director of the HIV unit at Hospital Clinic, stressed that the Barcelona case “is exceptional not only because there are very few people with long-term post-treatment control (15 years), but also because of the HIV control mechanism, which is different to that described in ‘elite controller’ patients and other cases documented so far”.
“The functional cure of HIV is a much more realistic goal on a larger scale than the sterilizing cure, which is why it is so important to understand the underlying mechanisms,” added Juan Ambrosioni, an Argentine infectologist who is part of the medical team at the Hospital Clinic in Barcelona.
More than 15 years ago, the patient was diagnosed in the stage of acute HIV infection and was included in a clinical trial with antiretroviral treatment for 9 months and various immunomodulatory interventions with cyclosporine A, an immunosuppressant.
“The patient did not have classic genetic factors associated with HIV control, she was not an elite controller of the disease and even more, she presented a severe primary infection, something that is not common in post-treatment controllers either,” said Josep M. Miró , specialist in infectious diseases at Hospital Clinic, head of the AIDS and HIV infection group at the August Pi i Sunyer Biomedical Research Institute (IDIBAPS) and professor of Medicine at the University of Barcelona.
Other cases of cure are related to bone marrow transplantation -Berlin and London- or to exceptional cases that have defective viruses or genetic factors associated with a strong immune response to HIV from a type of lymphocyte, patients who are known by the name of elite controllers
In this sense, “the patient from Barcelona” does not have classic genetic factors associated with disease control or defective viruses, since the researchers isolated samples in the laboratory and verified that her HIV had the conditions to replicate. The researchers also confirmed that their T-lymphocytes – key immune system agents – are susceptible to HIV infection, suggesting that other cell populations in the blood were blocking infection and could help control the disease.
The great discovery of the researchers lay in characterizing two populations of cells that manage to control HIV: the “natural killer” (NK) cells, which are part of the innate immune system and constitute the first line of defense against different pathogens, and the CD8+ T lymphocytes, which play a key role in defending cells against viruses and bacteria.
“Compared to other people, the patient has very high levels of these two populations that may be blocking the virus and destroying infected cells”, highlighted researcher Núria Climent, researcher of the AIDS and HIV infection group at IDIBAPS.
The next objective is to decipher in detail the success model of this patient’s immune system, of which details have not been disclosed at the express request of the patient, to determine if it is possible to replicate it in other people with HIV, which would be a step of giant in the control of the great pandemic of the second half of the 20th century.