A woman in Argentina has become only the second documented person whose own immune system may have cured her of HIV.
Researchers have dubbed the 30-year-old mother, who was first diagnosed with HIV in 2013, the “Esperanza patient,” after the town in Argentina where she lives.
In English, “esperanza” means “hope.”
“I enjoy being healthy,” the Esperanza patient, who spoke on condition of anonymity due to the stigma associated with the virus, told NBC News in Spanish over email.
“I have a healthy family. I don’t have to medicate, and I live as though nothing has happened. This already is a privilege.”
The co-authors of the study, which was published Monday in the Annals of Internal Medicine, said they believe their findings will indeed bring hope to the estimated 38 million people globally living with the virus and to the ever-expanding HIV-cure research field.
The case serves as one of two proofs of concept that a so-called sterilising cure of the virus is apparently possible through natural immunity.
‘Miracle’ of the immune system
“This is really the miracle of the human immune system that did it,” said Xu Yu, a viral immunologist at the Ragon Institute in Boston.
“Now we have to figure out the mechanisms,” said Steven Deeks, a prominent HIV cure researcher at the University of California in San Francisco, who was not involved with the study.
“How does this happen? And how can we recapitulate this therapeutically in everybody?”
Scientists are pursuing the task of curing HIV on multiple fronts.
This includes gene therapy, “kick and kill” efforts to flush the virus from its so-called reservoir, “block and lock” methods to keep it trapped in cells, and therapeutic vaccines that would enhance the body’s immune response to the virus.
To date, researchers have successfully cured two other people therapeutically — in both cases through complex and dangerous stem cell transplants.
HIV has proved extraordinarily difficult to eradicate from the body because it will infect certain immune cells, known collectively as the viral reservoir, that can spend long periods in a resting state.
This keeps the viral DNA, known as provirus, encoded into those cells under the radar of standard antiretroviral treatment.
Antiretroviral treatment can only attack the virus in infected cells when they are actively churning out new copies of HIV.
Yu was also the lead author of a paper published in Nature in August 2020 that analysed 64 people who, like the Argentine woman, are so-called elite controllers of HIV.
These are among the estimated one in 200 people with HIV whose own immune systems are somehow able to suppress the virus’s replication to very low levels without antiretrovirals.
That study’s authors found that these individuals’ immune systems appeared to have preferentially destroyed cells that harboured HIV capable of producing viable new copies of the virus.
Left over were only infected cells in which the viral genetic code was spliced into a kind of genetic dead zone — regions of the cellular DNA that were too distant from the levers that propel viral replication.
Vanquishing the virus
One member of that cohort, Loreen Willenberg, a now-67-year-old Californian who was diagnosed with HIV in 1992, stood out as having an immune system that had apparently vanquished the virus entirely.
Even after sequencing billions of her cells, scientists could not find any intact viral sequences.
Willenberg’s case of an apparent natural cure of HIV is quite similar to the Esperanza patient’s, according to Yu.
After the Esperanza patient began partnering with Yu’s team in 2019, the scientists searched mightily for any viable HIV in 1.2 billion of her blood cells.
They also searched 500 million placenta-tissue cells after the woman gave birth to an HIV-negative baby in March 2020.
Using highly sophisticated and sensitive genetic-sequencing techniques that have only recently become available, Yu and her team once again found no intact viral sequences in the elite controller they were studying.
“We’re never going to be 100 percent sure there’s absolutely no intact virus, no functional virus anywhere in her body,” Yu said of the Esperanza patient.
“To bring what we learn from these patients to a broader patient population is our ultimate goal.”