Can we talk about a complete cure for HIV infection
Olga Lukinskaya
Yesterday the world has spread the news about a nine-year-old girl, which defeated HIV infection without treatment, it is true, after a deeper study of the issue, it becomes clear that the therapy was carried out, although quite a long time ago, and English-speaking sources accurately call the child's condition remission, and not cure. We tried to figure out whether it is possible at all to talk about complete recovery from infections with hepatitis viruses or HIV and whether the body is able to cope with them on its own.
The problem with viruses is that they are all very different and, unlike bacteria, do not have a cellular structure. To destroy bacteria, it is enough to destroy their shell, that is, the outer wall of the cell itself - this is how the very first antibiotic, penicillin, works. There are antibiotics that interfere with protein synthesis inside bacteria and prevent them from multiplying; Be that as it may, bacteria are independent organisms. The virus, in fact, is a carrier of genetic information - DNA or RNA - in a protein shell with several auxiliary molecules like enzymes. The virus DNA can be inserted into the cell of a human or animal body in the place of the “master” - that is why it is so difficult to develop drugs that destroy viruses and do not damage the cells of the body.
It should be understood that the viability of bacteria and viruses in the body and beyond is not the same - the same hepatitis viruses can be easily destroyed by high temperature, for example, when sterilizing dental or manicure instruments. And not all means of influence are applicable equally inside and outside our body: the skin can be treated with an antiseptic, but it cannot be introduced into the blood if bacteria reproduce in it uncontrollably. Fragile, rapidly dying in the air, HIV becomes powerful and dangerous when it enters the blood - and worst of all, it destroys immune cells designed to fight infections. Still, scientists are working not in vain, and there are already quite effective medicines that have made HIV infection a chronic disease - and the life expectancy of patients receiving therapy is 70-80 years.
These drugs are called highly active antiretroviral therapy, they affect different components of the infection and are used in combination with each other. For example, one drug can inhibit a virus enzyme that acts on proteins in human cells, and another can block receptors on immune cells, preventing the virus from contacting them. While a person is taking medications, the amount of virus in the blood may drop to the minimum, but after some time after stopping treatment, the HIV infection usually manifests itself again. This period can be several months or a couple of years - or it can be much longer. It happens even without treatment: for some people, HIV infection does not progress eight to ten years after infection, and scientists still cannot name the exact reason for this.
It is important to understand that there is practically no “zero” in virology: if a virus is not detected, it is possible that the sensitivity of the equipment simply does not allow it to be found in such low numbers
What is considered a cure - is also an ambiguous question. For example, in the practice of treating infections with hepatitis viruses, they consider the so-called sustained virological response. If within twelve weeks after completion of therapy, relapse did not occur, the patient is considered cured. If the hepatitis C virus is detected after a considerable period of time thereafter, it is likely that reinfection has occurred (this is not uncommon, for example, people who inject drugs). It is important to understand that there is practically no “zero” in virology: if a virus is not detected, it is possible that the sensitivity of the equipment simply does not allow it to be found in such low numbers. Another thing is that the organism is able to cope with single virus particles even of such dangerous infections on its own.
HIV infection is even more difficult: in some studies, the number of viral copies is less than five thousand per milliliter of blood, in others it is less than fifty. If we do not see the virus, can we say that it is completely destroyed? After how many years of remission can we assume that the patient has healed and stop the observation? If a person dies in a period of remission for reasons other than HIV, can we assume that there would never be a relapse? These are not only medical, but also philosophical questions - and so far the case of a long remission in an African girl says only that it is necessary to continue to study the question and try to understand whether this effect can be achieved in other patients.
In principle, it has been known for quite some time about mutations that make the body resistant to HIV infection. It is possible that, in addition to forty weeks of antiretroviral therapy, conducted shortly after birth, some unique feature of the body helped the child - it is not yet known which one. At the moment, complete remission, without the ability to detect viral particles in the blood, was achieved in three children - and one of them still had a relapse. Today, we can only trust doctors and scientists and hope for the success of new developments - and for children in complete remission, we can expect it to last a lifetime. Statements such as “The child’s immune system coped with HIV infection on its own” should be treated with great care: no one has managed to cope with HIV without treatment, and, unfortunately, such loud headlines can cause failure of therapy when it is needed.
Photo: Kateryna_Kon - stock.adobe.com, Kateryna_Kon - stock.adobe.com