Frederick National Laboratory scientists were part of a multi-institutional collaboration that has identified a second patient whose natural immune response to HIV infection appears to have cured her of the disease, raising the question: Can this be replicated?
Only three other patients have ever been declared fully cured, but each of these outcomes was accomplished medically. Most patients live symptom-free taking antiretroviral drugs, but it is a lifelong regimen and they are not cured. Fewer than 1% of patients hold symptoms at bay without drugs, but they, too, are not cured.
In the current case, scientists identified a 30-year-old woman from Esperanza, Argentina, who tested positive for HIV in 2013, received antiretroviral drugs for six months and has since been free of detectable virus.
Researchers analyzed more than 1.5 billion of the patient’s blood cells using multiple sophisticated techniques and found no evidence of active or latent HIV. Their results were reported recently in the Annals of Internal Medicine.
An accompanying editorial speculated about what this means.
“If the Esperanza patient has indeed achieved a sterilizing cure, defining the mechanisms responsible for it becomes important,” wrote Joel Blankson of Johns Hopkins Medicine, noting that Esperanza means “hope” in English. “If a spontaneous sterilizing cure of HIV is in fact a possibility, we may eventually be able to do more than just hope that we can replicate this phenotype on a large scale.”
The study used peripheral blood voluntarily given by the Esperanza patient in October 2017, January 2018 and August 2019. White blood cells were obtained in September 2020. Placental tissues were collected in March 2020 following the birth of her child, who did not get the virus.
To see if HIV had persisted in her cells, the scientists examined 1.188 billion peripheral blood cells, 503 million placental cells and 150 million white blood cells using multiple, highly sensitive analytical techniques. They did find evidence of past HIV infection, but they did not see a single remaining HIV particle capable of replicating.
“The mechanisms that enable such a remarkable disease outcome are difficult to ascertain,” wrote the group led by Xu G. Yu of the Ragon Institute and Brigham and Women’s Hospital, with collaborators including FNL’s Mary Carrington, Yuko Yuki and Maureen Martin.
But determining those mechanisms, as Blankson noted, would open a new line of investigation toward a possible cure for others, as well.
An earlier collaboration identified an individual in 2020 who appeared to have self-cured. The only other complete HIV cures to date include a recently reported case of a woman who received a relatively new transplant method involving umbilical cord blood. And in separate cases, two men were cured after bone marrow transplants from donors with a rare genetic mutation that blocks HIV.