Doctors at the Hospital Clínic in Barcelona, Spain, determined that a woman who received an immunostimulant regimen in 2006 is in a state of what they characterize as viral remission, that is, she still has the human immunodeficiency virus (HIV) but his immune system has controlled the replication of the virus for more than 15 years.
The results of this exceptional case were presented on July 27, during the World AIDS 2022 Conference. According to the newspaper The country, Through a clinical trial, the Spanish researchers were able to understand the innate characteristics in the woman’s immune system, which allowed her to keep the disease at bay and defeat parts of the virus present in her body. Because of this, she managed to live 15 years without drugs.
Baptized as “Patient Barcelona”, the identity of the woman remains anonymous, but it is known that she would be 59 years old. She contracted the acute infection in 2006 and was later singled out along with 20 other patients for drug treatment.
Antiretroviral treatment, the standard for controlling AIDS, is effective in suppressing virus replication within the body and blocking transmission, but HIV persists in reservoirs and reappears after stopping therapy. Very few people manage to maintain undetectable viral loads without taking medication.
Of all of them, she was the only one in the group to pass more than 50 viral load tests in the last 15 years. The novelty of her research on her immune system is that it was possible to characterize which subpopulations were involved in the peculiar process of defense against HIV.
They turned out to be Natural Killer (NA) cells, which are part of the innate immune system and constitute the first line of defense against other pathogens, and CD8+ T lymphocytes, key agents in the innate immunity of cells against viruses and bacteria. The patient has very high levels of both.
The great novelty of the work is that we have characterized the cells that achieve control of the virus. The patient has very high levels of the two cells that could block the virus or kill infected cells.
– Núria Climent, researcher of the IDIBAPS HIV group
Until now, it was a mechanism never before observed in very few patients who also control the disease, but that is not all, since, over the years, the woman’s “viral reservoir” is reducing and the time may come when that it reaches zero.
It is an exceptional case, not only because there are very few people with long-term post-treatment control, but also because of the mechanism of control of HIV, different from those described so far.
This permanent cure for AIDS occurs in a very small group of people, called “aftercare controllers.” Other cases of cure are related to bone marrow transplantation or to people who have defective viruses or genetic factors associated with a strong immune response to HIV, known as elite controllers.
The researchers point out that the next step is to understand the mechanisms that occur in this patient and see if it is possible to replicate them in other patients. If successful, it will be possible to extend the functional cure of AIDS, that is, the patients will continue to have the virus, but their immune system will completely control its replication.
For Juan Ambrosioni, a doctor who led the research of the HIV group at Hospital Clínic, it is more feasible to obtain this type of cure than that offered by bone marrow transplants.