Researchers have identified a second HIV patient who can clear the virus from the body – without the use of antiretroviral drugs.
According to a report published Monday in Annals of Internal Medicine, a 31-year-old woman was diagnosed with HIV in 2013 on antiretroviral therapy alone for six months during her pregnancy to prevent transmission of the disease to her baby. Dr. Xu Yu, who led the research team that reported the case, said many complex tests looking for genetic evidence of HIV in the patient’s blood showed no intact virus in the cells. hers. She is a principal investigator at the Ragon Institute of Massachusetts General Hospital, MIT, and Harvard, and an associate professor of medicine at Harvard Medical School. The findings suggest that a patient’s immune system can even clear out HIV reservoirs that allow the virus to continue to multiply for decades. Current anti-HIV drugs can reduce virus levels to undetectable levels, but cannot completely eliminate residual virus reservoirs in the body.
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“There is no way to say that we have evidence that there is not a single virus in this patient,” Yu said. “The only thing we can say is that after analyzing a large number of cells from the patient, with the technology in our laboratory, we cannot disprove the hypothesis that the patient can achieve natural immunological cure for sterility.”
There have been previous reports of patients who stopped taking anti-HIV drugs and achieved undetectable levels of the virus for years, including Timothy Ray Brown, also known as the “Berlin patient” and Adam Castillejo, “London patient”. However, both have been diagnosed with cancer and benefit from stem cell transplants for treatment, which will replace their immune cells with cells from donors. consists of cells that can prevent HIV infection. They are also likely to continue to nurture latent, cleared reservoirs of HIV in the patient Yu is describing.
The woman is the second patient to have apparently cleared the virus this way. Yu’s team described the first, called the “San Francisco patient,” in 2020. The second patient, from Esperanza, Argentina, is working with Yu’s team and continues to provide blood samples to him. ongoing research. She is currently pregnant with her second child and Yu and the patient’s doctors are discussing whether her remarkable, clear virus-free condition means she won’t need to take it. anti-HIV medication before and during delivery (current guidelines recommend for pregnant women who have HIV). Patient Esperanza will also provide the research team with samples of her breast milk so that scientists can determine if it contains any viruses.
Yu’s team has been analyzing 1.5 billion blood cells and tissues from Esperanza patients since 2017, looking for any sign of the entire viral genetic material that suggests a virus is likely to survive. active and regenerated. But they found no such evidence. However, they did find viral gene fragments indicating that the patient had been infected with HIV at one point. They found similar clues in the San Francisco patient.
Yu cautioned that the findings may not be universal for most HIV patients. Both of her patients belong to the group of so-called elite controls, or those with very low levels of HIV suppression, often undetectable by their immune systems without the need for further investigation. help of anti-HIV drugs. Researchers around the world are studying these people in-depth; It’s not clear what percentage of people infected with the virus can naturally suppress it with their immune systems, but Yu believes the two patients she describes suggest there may be more to it. She hopes that hearing about the first two will encourage others to get tested and researched, so scientists can better understand which aspects of their immune systems are providing an effective response. effective in preventing HIV.
“Many immune factors may play a role,” she said. “Now that we have a second case, there are probably many cases out there who may not know they have a cure for sterilization. Some may not even know that they are infected. We hope to attract more patients; if we had a cohort of these extremely rare cases, that would allow us to really analyze their immune responses more deeply and more broadly and hopefully give us suggest which immune factors contribute the most to this condition. Then we can apply what we learn to the general population.”
Since the first elite controls were identified among sex workers in Africa in the 1990s, scientists have been studying their immune systems, looking at everything from The antibodies they produce to the immune system’s highways are made up of white blood cells. So far, they haven’t determined what is keeping these people protected from serious illness, but Yu says more sophisticated ways of looking for even the slightest hint of HIV’s genes are helping. see people like the San Francisco and Esperanza patients. That could turn the work of elite controllers forward. For example, one thing Yu hopes to do is compare the immune responses between these two patients with the immune responses of people taking anti-HIV drugs. It’s possible that the cocktail produced a weaker immune response than the one produced by these two patients, and scientists could find a way to boost that response.
