A Spanish woman living with HIV has had an undetectable viral load for more than 15 years without taking medication, a case similar to that of “patient Esperanza” in Argentina . This case of spontaneous control of the virus will be presented at the 24th edition of the International AIDS Conference, which is being held in Montreal, Canada.
The case of the woman, whose identity is preserved anonymously but is already known as “the patient from Barcelona” was studied by doctors from the Hospital Clínic, in that city.
“This woman has been without medication for more than 15 years. After having been with her for a short period of time, she completely controls the AIDS virus and this has a very important aspect: we have been able to find out what the possible mechanism is that allows this," he announced during a press conference in the Catalan capital. Dr. Josep Mallolas, head of the Clínic’s HIV-AIDS Unit.
Despite advances in the control of HIV, a cure has not yet been found. Antiretrovirals are effective in suppressing viral replication, but HIV persists in reservoirs and recovers after stopping treatment. There are very few exceptions to this rule: a few people called “aftercare controllers” are able to keep the virus at bay after they are taken off medication. In addition, there are also so-called “elite controllers”, who achieve the same despite not having started antiretroviral therapy. These are also rare: less than 1% of those infected.
But according to the Spanish newspaper El PAÍS, the “Barcelona patient” does not belong to these two groups, since she was diagnosed in 2006 with an acute infection, something that is not typical of any of them. This woman was included in a clinical trial directed by José M. Miró that sought to know if the immune system could be strengthened so that it controlled viral replication.
Of a cohort of patients, one group received only antiretrovirals and the other received a series of additional immunomodulatory treatments, including an immunosuppressant, cyclosporine A. “Nine months after stopping treatment, this patient no longer had a detectable viral load in the HIV in plasma,” described Dr. Núria Climent, researcher in the AIDS and HIV infection group at the August Pi i Sunyer Biomedical Research Institute (IDIBAPS), during an interview between several members of the medical team and EL PAÍS.
In fact, this woman was the only one of the 20 individuals who reacted like this. She “did not rebound the virus, and she has not rebounded for 15 years and more than 50 viral load tests; Not that she sometimes had any small low-level presence. She has always been undetectable,” completes Miró.
Once this patient’s immunological reaction was discovered, the next step was to infect the CD4+ T lymphocytes, which are the main target of HIV. And it was proven that they were capable of replicating the virus. On the other hand, when Climent and Sonsoles Sánchez Palomino, another doctor on the team, performed cultures with other subpopulations of blood cells, they found that there was a very drastic control of virus replication.
This suggested that these other subpopulations were the ones involved. With in vitro tests we demonstrated that they were cells called Natural Killer (NK, or “natural killers” in Spanish) and also CD8+ T lymphocytes,” describes Dr. Sonsoles Sánchez-Palomino. These NK cells are what our body uses to trigger an immune reaction when it comes into contact with HIV and, if it is powerful, it can control it.
The great novelty of this research, which makes it unique, is that it has been possible to characterize which subpopulations of NK and which subpopulations of CD8+ T lymphocytes are those that could be involved in this phenomenon: they are some NK cells that have memory and also others that They are called T Gamma-Delta, and they are one of those that provide innate immunity. “The patient has very high levels of both, and they could be blocking or destroying the ones that are infected,” described Dr. Climent.
“If we were able, through treatment, to repeat or replicate that innate immune capacity that this woman has, the advantages would be enormous,” said Dr. Mallolas during the video call.
The next step of this research is to identify exactly what combination of the patient’s own factors, along with those that Dr. Miró administered to her in the clinical trial, led to this control of the virus in her, but not in the rest of the participants.
The first step is to analyze the rest of the clinical trial cohort to see what “the patient from Barcelona” has compared to the other nine participants who were treated with the same thing.
Although the woman’s age is unknown, it is known that she is in excellent health, and that her immune system and tests are perfectly normal. But Dr. Mallolas emphasized that “we have to be very cautious, we could have 15 years of success, but not 16.”
