Scientists in the University of Harvard, have identified the second person, known as the ‘Esperanza Patient’ whose body has been able to get rid of HIV on its own without the use of antiretroviral drugs.
Scientists reported in the Annals of Internal Medicine that they were unable to find intact HIV genomes from 1.19 billion blood cells and 500 million tissue cells from the second untreated person living with HIV.
Xu Yu of the Ragon Institute at Massachusetts General Hospital (MGH), Massachusetts Institute of Technology (MIT) and Harvard University said the case represents the second instance of a sterilising cure.
Loreen Willenberg, a 67-year-old California woman, was the first such person, who maintained control of the virus for nearly three decades without antiretroviral drugs.
The research team identified Willenberg as having no intact HIV sequence in her genome, suggesting that her immune system may have eliminated the HIV reservoir.
Researchers may be able to develop HIV treatments that mimic these immune responses if the immune mechanisms underlying this response can be understood.
“We are now looking toward the possibility of inducing this kind of immunity in persons on ART through vaccination, with the goal of educating their immune systems to be able to control the virus without ART,” Yu said.
Yu’s team sequenced billions of cells from the San Francisco Patient, Willenberg, looking for HIV sequences that could be used to produce new viruses, but it could not find any.
The extraordinary discovery, the first known case of sterilising cure without stem cell transplantation, was reported in the journal Nature in 2020.
“These findings, especially with the identification of a second case, indicate there may be an actionable path to a sterilising cure for people who are not able to do this on their own,” said Yu, who is also a physician investigator at MGH.
HIV inserts copies of its genome into cells’ DNA during infection, forming a viral reservoir. This state allows the virus to hide from anti-HIV drugs and the body’s immune system.