By Marisa Iati
A 30-year-old Argentine woman appears to have become the second documented person whose body may have eliminated her HIV on its own, a new study says.
Scans of more than 1 billion of the woman's cells detected no viable virus, even though for most of the time she was not undergoing antiretroviral therapy meant to keep the virus from replicating.
The finding raises the possibility that a person's own immune system may in rare cases provide a sterilizing cure - the elimination of virus capable of copying itself - the researchers wrote.
"What happened is unique," said Steven Deeks, an HIV researcher at the University of California at San Francisco, who was not involved in the study. "It's not that she's controlling the virus, which we do see, but that there's no virus there, which is quite different."
The study, published on Monday in the Annals of Internal Medicine journal, contributes to research with major implications for the 37.7 million people worldwide living with HIV, which can lead to Aids if left untreated. HIV spreads through bodily fluids, usually after unprotected sex or needle-sharing.
While HIV has no known cure, the virus has been eliminated in three people who received stem cell transplants to treat their cancer. But transplants are dangerous and frequently fraught with complications, making them unrealistic tools for curing a disease that can be treated with a daily pill regimen and a recently approved injection.
Scientists are seeking a cure for HIV through four main branches of research: activating the body's immune response to the virus, gene therapy, "shock-and-kill" attempts to force the virus from cells so the immune system can try to eradicate it, and "block-and-lock" efforts to keep the virus lodged in cells so it can't replicate.
The Argentine woman in the new study joins Loreen Willenberg, the other woman whose immune system is known to have eradicated HIV. Willenberg, of Northern California, may have been the first person to have been cured without a bone-marrow transplant or medication.
Deeks, who worked on a study of Willenberg last year, said both women may have been cured because they had unusually powerful T cells, a component of the body's immune system. Understanding that mechanism, he said, could be key to developing therapeutic vaccines that could clear out HIV without negative long-term consequences.
It is also possible that the Argentine woman had developed an HIV-specific immune response before becoming infected, because her partner had died of Aids, Joel Blankson, an HIV researcher at Johns Hopkins Medicine, wrote in an editorial published in the Annals of Internal Medicine. Researchers could use the woman's cells to replicate her immune system in mice and study the effects of infecting the rodents with HIV, he posited.
The Argentine woman was diagnosed with HIV in March 2013. Over eight years of follow-up, the researchers wrote, 10 tests found no detectable levels of the virus in her blood or tissue.
She was not receiving antiretroviral therapy until taking a pill regimen during her second and third trimesters of pregnancy in late 2019 and early 2020. The woman stopped therapy after delivering an HIV-free baby, and the researchers said they were still unable to detect the virus in her body. The scientists did find fragments of HIV, indicating that she had previously been infected and that the virus had replicated, they wrote.
While the researchers said they cannot prove that the woman was cured, they said it is probable. They referred to her in the study as the "Esperanza patient," after the city in Argentina where she is from. "Esperanza" is also the Spanish word for "hope."
"In line with her wishes," the researchers wrote, "we propose to refer to her as the 'Esperanza patient' to send a message of hope for finding a cure for HIV-1 infection."