Woman's own immune system believed to have cured her of HIV

A 30-year-old Argentine woman has reportedly become the second documented person in the world whose own immune system may have cured her of HIV. Speaking on condition of anonymity due to the stigma associated with the virus, the woman—who was first diagnosed with HIV in 2013—told NBC News in Spanish over email: "I enjoy being healthy. I have a healthy family. I don't have to medicate, and I live as though nothing has happened. This already is a privilege." Researchers have dubbed the young mother the "Esperanza patient" after the town in Argentina where she lives. "Esperanza" means "hope" in English.

In a study published in the Annals of Internal Medicine this week, researchers said they believe their findings will bring hope to the estimated 38 million people across the world who are living with the virus and to the ever-expanding HIV-cure research field. The "Esperanza patient" case serves as one of two proofs of concept that "a sterilizing cure of HIV-1 infection" is possible through natural immunity. "This is really the miracle of the human immune system that did it," said Dr. Xu Yu, a viral immunologist at the Ragon Institute in Boston, who led the exhaustive search for any viable HIV in the woman's body in partnership with Dr. Natalia Laufer, a physician-scientist at INBIRS Institute in Buenos Aries, Argentina.

"Now we have to figure out the mechanisms," said Dr. Steven Deeks, a prominent HIV cure researcher at the University of California, San Francisco, who was not involved with the study. "How does this happen? And how can we recapitulate this therapeutically in everybody?" Yu was also the lead author of a paper published in August 2020 that analyzed 64 people who—like the "Esperanza patient"—are so-called elite controllers of HIV. 1 in 200 people with HIV are estimated to have immune systems that are somehow able to suppress the virus’s replication to very low levels without antiretrovirals.

The authors of the study found that these individuals' immune systems appeared to have preferentially destroyed cells that harbored HIV capable of producing viable new copies of the virus. One of those analyzed for the study, a now-67-year-old Californian named Loreen Willenberg who was diagnosed with HIV in 1992, stood out from the others as having an immune system that had apparently vanquished the virus entirely. Scientists could not find any intact viral sequences even after sequencing billions of her cells. Yu explained that Willenberg's case is quite similar to the Esperanza patient's.

The virologist theorized that both these women may have mounted a particularly potent killer T-cell response to the virus. "I'm very keen to learn more about this seemingly new phenomenon of extraordinary elite control" of HIV, Rowena Johnston—director of research at amfAR: The Foundation for AIDS Research—said of how the two cases have inspired her. "There's really a lot to know." Scientists did an extensive search for any viable HIV in 1.2 billion of the Esperanza patient's blood cells and also searched 500 million placenta-tissue cells after she gave birth to an HIV-negative baby in March 2020.

Yu and her team found no intact viral sequences in the elite controller they were studying despite using highly sophisticated and sensitive genetic-sequencing techniques that have only recently become available. "The study sets the standard for demonstrating that the Esperanza patient has no replication-competent proviral DNA within her cells," said Carl Dieffenbach, director of the Division of AIDS at the National Institute of Allergy and Infectious Diseases—a division of the National Institutes of Health, which funded the study along with the Bill & Melinda Gates Foundation. "The more of these patients we uncover and work up, the more complete our understanding of what a cured patient looks like."

"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."