The human immunodeficiency virus, or HIV, operates by replicating its own DNA into its hosts. This means it takes over the organism a cell at a time, altering its immune system and bodily functions. To suppress the disease, people infected receive treatment called anti-retroviral therapy (ART). This keeps the amount of virus in the body extremely low at undetectable amounts, allowing them to lead normal healthy lives. Although, there is a small reservoir left in the body which ART cannot eliminate.

Less than one percent of people are termed ‘elite controllers,’ meaning they can fight off the virus due to the natural mechanics of their immune system. In these rare instances, patients have a type of immune cell called killer T cells, which fight off the virus without the need for medication. Although again, elite controls still have reservoirs of HIV still present in their bodies.

In order for patients to completely clear out HIV, stem cell transplantation treatment needs to occur. In extremely rare cases, some humans can say good riddance to the virus without this treatment. This occurrence has only been recorded once before, in a study published in Nature last year. Now, for the second time, a person has again eliminated the infection completely by natural means.

The woman from Argentina was first diagnosed with the retrovirus in 2013. After eight years of treatment and checkups, doctors found no signs of the disease in her body. The study looking into this woman was published in Annals of Internal Medicine by Xu Yu’s research group. They analyzed over 1.19 billion blood cells and 500 million tissue cells from her body, searching for any traces of viral DNA, though none was found. This phenomenon of natural viral removal has been termed a ‘sterilizing cure.’

A similar killer T cell response has been identified in both people which carry this ability. “These findings, especially with the identification of a second case, indicate there may be an actionable path to a sterilizing cure for people who are not able to do this on their own,” commented Yu.

When scientists understand how individuals achieve a sterilizing cure in further detail, the hope is to harness their natural ability and mimic it to treat other people. Yu added, “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.”

Source study: Annals of Internal Medicine – A Possible Sterilizing Cure of HIV-1 Infection Without Stem Cell Transplantation