Seropositivty: a word that since its creation, brings a lot of fear, especially beacuse of the dire expectations it brings. This because HIV, or Human Immunodeficiency Virus causes the so called AIDS, or Acquired ImmunoDeficiency Syndrome, causing the fall of immunitary defenses thus making the infected subject much more susceptible to infections, Like most viruses, it needs in order to replicate a cellulare host In most cases, every virus has a preference, or tropism, towards a specific kind of cells, and the disease they cause is in fact the consequence of this preference. However, HIV presents a tropismo as much particular as Dangerous: CD4+ T lymphocytes, also known as T Helper, which task is to assist immune response with the production of molecules known as cytokines, capable of inducing the activation of other cells of the immune system such as macrofages.
Because of that, this virus is the perfect sapper, attacking the immune system directly But in order for this to happen completely the virus needs to spread to most lymphocytes, not an easy task since in a single milliliter of water there can be as much as 5000, this is why we need to study the staging of the disease, and because of that, the behaviour of the HIV. It all starts with the virus access to the circulatory system. Viral particles are located in the blood and the semen, and this limits the infection to events such as using dirty Needles, unprotected sex and pregancy with transplacentar transfer The virus is not found neither in the saliva nor in the sweat, thus it is possible to kiss and share the bathroom with an infected person without risk of infection, especially because the virus is really fragile and even in an ideal enviroiment it can’t survive more than 72 hours more than 72 hours.
Once it enters the body, the virus comes in contact with the firs line of defens of the organism: Memory T lymphocytes and macrophages, starting the acute fase.
Hold on, didn’t we say that….. exactly. This happens because the HIV presents some variants, or strains, or strains, called M-trophic or T.trophic, beacuse they are capable of attacking macrophages and T lymphocytes. These cells attack the virus with bravery and determination obvlious to the fact that this will bring their doom, since the virus during its replication process creates a protein called VPU capable of destroying their membrane, bringing to the mass Death of the lymphocytes. Since Mucose membranes are the main placing for CD4+ T lymphocytes, this causes a great reduction in their number, as low as 500 units per cubic millimter, against the regular 1000. Simultaneously there is the spreading of the pathogen in the circulatory system, process also known as viraemia. Thi causes the activation of primary immune response with the starting of a condition knwon as “flu-like disease” with symptoms like, fever, malaise and enlarged lymphonodes that all begin 3-6 weeks after contagion and last for about a week.
This is a critical phase for the infection because it is often ignored, especially because of what happens next. The immune system counts in its ranks a divison of cells calle APC or “Antigen Presenting Cells” capable of isolating and expose on their Surface pathogens’ antigens. They serve as a “search & recovery” team, since once gathered this antigens they reach the various lymphonodal stations to allow B lymphocytes to produce specific antibodies so that they can reduce the viraemia, allowing the partial recovery of the leukocytes count and the disappareance of the symptoms. This is the phase where the subject becomes “seropositive”, because in its serum, the liquid part of the blood after the removal of the coagulative factors, presents anti-HIV antibodies, sign of an happened infection.
In most cases this is the end of the disease, but the HIV is different. It is a retrovirus, meaning its genetic code is made of an RNA filament that, inside the cells, is converted into DNA that will be inserted in the gentic code of the host cell This terrible but fascinating mechanism not only renders the cell incapable of removing the infection of removing the infection, but as long as it will be vital it will produce viral particles, delocating energy from its vital processes, risking Death. The virus the, reaches the various lymphonodal station thanks to the APCs, where it will infect all the T lymphocytes. However when there is the antibody respons Something peculiar happens that is still not fully understood. For some reason, the viraemia resetting causes the viral replication to decrease to the poinf where infected cells are capable of surving, even though they keep producing other viruses. This is the start of the “latency phase” phase where the virus slowly spreads in the whole body, albeit without giving off any sign, except a slow reduction in the number of lymphocytes, estimated in the range of 1-2 Billions per day.
This phase can last many years, until for reasons not fully undestood, viral replication steps up, causing a massive fall in leukocytes count because of the extent of the infection When T lymphocytes fall below 200 units per cubic millimeter, the subject is affected by opportunitsts pathogen, that are pathohens normally not strong enough to cause disesae, but in immunodeficient subjects can reproduce easily This includes fungal infections li candidiasis or pneumonia by Pneumocisti Jirovecii extended bacterial and parasitic infections, and the beginning of tumoral diseases like kaposi sarcoma, because the immune system also protects against tumors, and kidney diseases and neural diseases caused by the virus itself.
Not long ago, this phase usually ended with the Death of the patient, because there was not a way og blocking the virus, today however there is the HAART, an Highly Active Anti-Retroviral Therapy that uses a mixture of drugs capable of inhibiting viral replication This therapy however is effective only in the early stages, since it does not remove the virus from the organism, this if it is started in late stages when there are reduced leukocytes, their distruction cannot be reverted, thus it is imperative in case there is the suspect of being infected, to do all the needed tests, so to eventually be able to start the therapy early nad avoiding AIDS onset thus conducting a normal life And that is the end for today, I hope it was instructive and pleasing, if yes push the like button and subscribe to the channel, this tells me i am doing a good job Don’t forget to follow us on facebook and and Instagram, and, if you like our designs, you can finde these beautiful shirts in the link down below.
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