Currently, antiretroviral drugs require continuous, uninterrupted use to prevent the virus from circulating in the blood again.
By Fernanda Bassette, Agência Einstein
In the 1990s, being diagnosed with HIV infection (which causes AIDS) was like a “death sentence”. There was no treatment available and it was the natural course of the patient. But as soon as the first drugs against HIV appeared, the scenario began to change and Brazil became a pioneer and a world reference in public policies for the treatment of the disease.
According to David Lewi, infectious disease specialist at the Israelita Albert Einstein Hospital, the treatment of HIV has evolved a lot since the arrival of the first drug, the famous AZT, which is now in disuse. “AZT has had a great history in fighting disease, but over the years the drugs have improved in terms of safety and toxicity, side effects have diminished, and today most patients don’t take only one pill. Abroad, there are already cases of patients receiving monthly injections”, explains the doctor, who is also a retired professor at the Federal University of São Paulo (Unifesp).
Currently, antiretroviral therapy aims to make the viral load undetectable – which does not leave the person free from the virus. HIV, but stops the transmission of the virus. For the treatment to be truly effective, it is necessary to make continuous and uninterrupted use of the drug, otherwise the latent virus will circulate again.
This is because existing drugs only work on viruses that are circulating in the blood – they cannot reach those that are latent in cells. “When the virus is dormant in the cells, without activation, it does not cause damage to immunity and the drug cannot reach them. If the patient stops taking the drug, at some point these viruses that “ hibernate “will recirculate”, explains the doctor.
Cure in the future?
Since the lack of good medication compliance is one of the greatest difficulties encountered in the fight against HIV, researchers have been looking for a fixed-term treatment for ten years, and no longer for life. “Instead of taking the drug for an indefinite period, what is sought is that this latent virus be expelled from the “sanctuary” and, once released in the blood, extinguished under the action of the drug. And then, in the future, we could stop the medication and the patient would actually be cured,” explains Lewi.
Another attempted cure that has been sought is the total elimination of the virus – as happened in the case of the so-called “Berlin patient”. Timothy Ray Brown, believed to be one of the few people to be cured of HIV infection, was diagnosed with acute myeloid leukemia. and received, in 2007, a bone marrow transplant a donor carrying a genetic mutation that would guarantee resistance against the virus.
“The doctors chose a compatible bone marrow donor, who had this genetic deletion that prevented the HIV virus from entering the cells. And it worked. Since then, there have been a few other cases like this around the world, but no one is thinking of making it a clinical practice because, in addition to being an expensive procedure, bone marrow transplantation itself carries a risk of mortality,” he says. .
The use of cell therapy against the disease is also being studied. In a survey conducted by Unifesp, with the Istituto Superiore di Sanità, in Rome (Italy), the scientists carried out the genetic sequencing of the virus circulating in the cells of each patient. These cells were then processed and reinfused, as in an autologous bone marrow transplant (when the patient’s own cells are collected and used later). Two of the study participants ended up with undetectable viral RNA in the experimental protocol, showing a possible avenue for personalized HIV cell therapy, taking into account both the patient’s immune system and viral profile. of the individual. The results were published in scientific journal AIDS research and therapy.
The development of an HIV vaccine is also another attempt by researchers. “HIV is a virus that undergoes several mutations and to date, no center has succeeded in creating an antibody through a vaccine that could eliminate it. HIV creates subterfuges against these antibodies. Unfortunately, not all vaccines tried so far have induced sufficient immunity against HIV,” says Lewi.
According to the infectiologist, several centers around the world are looking for a cure for HIV, but, for him, the most promising is the development of a definitive treatment. “What I am highlighting today is the ease with which the patient takes his medication, with increasingly simple treatment regimens and with very low side effects. At this precise moment, it is still essential that the patient adheres to the treatment. But I envisage that in the future, perhaps in five years, we will be able to speak of definitive treatment, for a predetermined duration, until the patient can suspend the medication and consider himself cured, “he said. he concluded.
AIDS in Brazil
Even though the number of new cases is decreasing in Brazil, it remains very high. The most recent data from epidemiological bulletin of the ministry of health point out that in the last five years the annual average of cases is around 36.8 thousand new diagnoses and has increased in young men. Worldwide, there are approximately 1.5 million new cases per year.
(Source: Einstein Agency)
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