Bengaluru: A woman who was diagnosed with HIV in 1992 may be the first person ever to be rid of the virus without any medication or the risky bone marrow transplant, according to researchers.
The study, that announced the findings in the journal Nature, also stated that an additional 63 individuals were able to control the infection without drugs by isolating the virus in their bodies in viral reservoirs and preventing replication.
The researchers state that such individuals may have acquired a “functional cure” for HIV, which is coming to light only now because of newer genetic technology.
The 66-year-old female patient Loreen Willenberg, who is based in California, was already well-known in the HIV-related medical community for having successfully suppressed the virus for decades after infection.
So far, only two people have been cured of HIV. In 2008, Timothy Ray Brown from California, who came to be known as the ‘Berlin Patient’, was the first to be cured of AIDS. His identity was revealed in 2010.
Adam Castillejo, who was known as the ‘London Patient’ was the second to be cured, in 2019. Both men had painful bone marrow transplants for cancer which also included antiretroviral therapy.
HIV is a retrovirus that inserts itself into the human genome, making copies of itself and also tricks the immune system.
Willenberg is the third patient to be cured of HIV but is the first to recover without any surgery or medication.
‘Functional cure’ found in only 0.5% HIV patients
HIV is a particularly hard pathogen to combat because it primarily targets the immune system, which is responsible for fighting off infectious, disease-causing pathogens.
In some individuals, the immune system catches up over time and destroys infected cells.
However, according to the new paper, some are capable of blocking and locking away the part of the genome that is infected by HIV.
Such individuals are rare and this kind of “functional cure” is found in less than 0.5 per cent of infected individuals. The researchers have dubbed these unique individuals as ‘elite controllers’.
Elite controllers have been studied intensively in the past three to four decades, and Willenberg herself has been enrolled in such studies for over 15 years.
The researchers state that except for her diagnosis and a test many years ago that confirmed the presence of HIV in her body, the virus was not found in any of her tissues in subsequent tests, even with new sophisticated methods of testing samples from her rectum and intestines. This indicates that her body has efficiently locked the virus away inside her genome.
The scientists found that individuals with this “functional cure” do not carry antibodies, but their memory immune cells do recognise the pathogen. Their T cells — killer cells that attack infected cells as part of the immune response — were able to eliminate the cells that were infected in laboratory settings.
The immune system was also able to lock the virus away in a place in the genome where it cannot be copied.
Another patient, a 36-year old man in Brazil was reportedly cured of HIV using a drug cocktail and without surgery in July this year, but researchers have urged caution in interpreting the results as long-term remission.
The researchers of the new Nature paper state that this natural mechanism of ‘locking’ the virus away to unreplicable parts of the genome can be possibly tapped into and anti-viral therapies can be tailored in such a way that this functional cure becomes theoretically achievable.