Loss of Smell and Cytokine Storm: What Happens in the Body with COVID-19

THE NEW SARS-COV-19 VIRUS IS BECOMING MORE KNOWN , and the recommendations for the treatment of COVID-19 are constantly updated. Even doctors do not keep up with new data, and individual facts reach the layman, often in a modified form or without explanation. Is it true that coronavirus infection deprives a person of their sense of smell? Does the virus cause vascular thrombosis? Why is COVID-19 being tried to treat malaria, rheumatoid arthritis and HIV? Let’s try to answer these questions. 

Why does the sense of smell disappear?

On anosmia (loss of sense of smell), first mentioned as a possible symptom of the new coronavirus infection – it can be assumed that in the background of other complaints disappearance of the sense of smell does not seem important or doctors are not asked this question patients. Now that a lot of data has accumulated, experts are already saying that sudden anosmia can be one of the characteristic manifestations of the disease.        

Now we know about two proteins that work as receptors for the new coronavirus – that is, help it enter cells. Scientists from Harvard discovered that there are cells in the nose with both of these proteins on the surface, which means that the virus infects them easily . These cells surround the olfactory neurons and are involved in their “support” – apparently , when they cease to function normally, the sense of smell disappears. Such anosmia can last for several weeks, and the situation returns to normal along with a general recovery from the disease.                    

Why does the disease occur less often in children ? 

Children are traditionally at risk of various infections, including respiratory infections – all the more surprising since the incidence of COVID-19 in general and the number of severe cases among children remains much lower than among adults. In an attempt to explain why this is happening, scientists have put forward several hypotheses. It is known that too strong immune response to infection leads to severe complications in adults . Perhaps children immunity works at the optimal level of intensity – that is, the immune response in children is not too weak and not too strong. However, in babies, it may still be insufficient: according to one Chinese study , most severe cases of COVID-19 among children were observed under the age of five .                                 

Another possible explanation is the increased readiness of the children’s immune system to combat coronaviruses. This is explained by the fact that children in schools and kindergartens constantly communicate with a large number of people and, as you know, often get sick with ARVI. True, this theory also has opponents – perhaps antibodies to other coronaviruses, on the contrary, help SARS-CoV-2019 enter cells, and then this does not explain the advantage that children clearly have . More rare cases of COVID-19 in children may also be due to the fact that they have fewer receptors called ACE2, through which the virus enters lung cells (although this hypothesis is controversial). As Whatever it was, it is important to remember that children, even very little , can hurt COVID-19 and transmit the infection to others, and therefore must comply with all measures of hygiene and isolation, which are applicable to adults.                               

What is Kawasaki disease and is it related to COVID-19   

In recent years there have been reports about the syndrome occurs in children, possibly in connection with SARS-CoV-2019. Kawasaki syndrome (or disease) is a rare condition that has existed before. At the same time , an inflammatory process develops in the walls of the vessels, the temperature rises, a rash appears, the skin and mucous membranes turn red . The reasons for this process are not exactly clear, and the virus, apparently , can become a trigger for such manifestations – but by themselves, unlike the virus, they are not contagious.                   

Such expressions are manifestations accompanying COVID-19 have some babies, called multi-system inflammatory disease – and it is similar with Kawasaki disease, and with the toxic shock syndrome (surely you have heard about it in the context of the dangers of superabsorbent tampons). In severe cases, this can lead to heart complications . Do children also experience symptoms of the gastrointestinal tract: nausea, vomiting and diarrhea.                  

Nevertheless , experts are still cautious and do not talk about an unequivocal connection between the syndrome and the new coronavirus – for example, the leadership of the British Royal College of Pediatrics and Children’s Health has the wording “pediatric multisystem inflammatory syndrome, temporally associated with COVID-19.” Light rashes on the skin or abdominal pain without other symptoms (for example, high fever) are not a reason to call an ambulance, but the child’s condition should be monitored.               

What happens with pneumonia

The new coronavirus damages the so-called ciliary cells of the lungs (from the Latin cilia – “eyelashes”); on the surface of these cells there are mobile cilia that constantly cleanse the lungs, “sweeping” unnecessary fragments out of them , including pollen, viruses or particles of dead cells. If they do not work, particles and fluid accumulate in the lungs and it becomes difficult for a person to breathe.           

When the immune system turns on and begins to fight the virus, the intensity of this response may be too high – and then the tissue damage increases. In severe cases, the process can leave traces in the lungs, similar in shape to a honeycomb. Due to the inflammatory process, the permeability of the membranes between the alveoli of the lungs and blood vessels increases – as a result, a liquid appears in the lungs, which prevents a person from breathing.            

What is a cytokine storm

In severe cases COVID-19 disease manifests itself and for outside light: suffering liver (may be seen at a certain blood test indicators), changing the number of white blood cells and in platelet blood drops blood pressure, increasing the likelihood of thrombosis . Sometimes acute renal failure and cardiac arrest develop – all body systems simply cannot withstand the load. But this does not mean that all these places are affected by a virus. The reason is too strong a reaction of the immune system.              

Cytokines are substances whose appearance serves as a kind of alarm signal, and in response, the immune system begins to attract cells to fight the disease. If too many cytokines are released uncontrollably, the immune response also increases and attacks not only infected, but also healthy cells. This release of cytokines is called a cytokine storm ; it leads to inflammation, weakening the walls of the vessels, the fluid from which enters the lungs.             

Inflammation develops in a wide variety of organs and, in combination with a lack of oxygen, can lead to their failure. There is still no definitive answer to the question of why some patients with COVID-19 are so severe – in part this may be due to concomitant diseases, although it is known about severe cases in otherwise healthy people.             

Why are antibiotics and antimalarial drugs prescribed? 

At today is not registered with any one drug that would act specifically on SARS-CoV-2019 and in official recommendations on the first place – supporting measures. These include hemodynamic support (vasoconstrictor if blood pressure drops) and respiration (supplemental oxygen and various types of mechanical ventilation).              

Chloroquine and hydroxychloroquine, remdesivir, azithromycin, which are now much talked about, have not yet been recommended for use outside of clinical trials – they may be effective, but this has not yet been proven. The antibiotic azithromycin may have antiviral and anti-inflammatory effects, while chloroquine may inhibit the entry of the virus into cells, interfere with its binding to receptors, and lower levels of cytokines (substances that increase inflammation). These mechanisms operate in a laboratory setting, but how effective they are in patients with COVID-19 remains to be understood. Antiviral drugs (those commonly used against HIV infection) can theoretically inhibit some of the proteins of the new coronavirus, preventing it from functioning normally, although the results have not been particularly encouraging so far .                           

At the same time, research is underway on immunotherapeutic agents – from the plasma of those who have been ill with COVID-19 to various antibodies that are being studied or already registered for the treatment of leukemia, lymphoma, rheumatoid arthritis. These drugs, with names ending in -mab (from the English mAb, monoclonal antibody, that is, monoclonal antibody), usually act on a specific target among the very cytokines that cause the inflammatory cascade. One or more of these drugs may help save the lives of the most severe patients.

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