Coronavirus: What is the “storm” of the immune system

Scientists are now raising serious doubts about what causes the so-called “cytokine storm”, a self-destructive immune system reaction that severely worsens the condition of several patients with Covid-19. Doubt focuses on a cytokine (or cytokine) 6 (IL-6), which has been blamed primarily for the body’s defense boomerang reaction against SARS-CoV-2 coronavirus, but recent research does not confirm this. This, according to the New York Times, inevitably raises doubts about the effectiveness of coronavirus-based therapies, which focus on interleukin-6 in order to calm the “storm”. It also holds the mystery of what ultimately causes certain deaths from Covid-19 and how they can be prevented. The “cytokine storm,” as an explanation for some coronavirus deaths, began with early reports from China, where drugs were first tested. block IL-6, followed by similar reports from Italy. This immune overreaction is sometimes seen in severe infections, even if patients show a small to negligible amount of coronavirus, which indicates that their body has “got rid” of it. However – according to the theory of “storm” – the body’s defenses can become uncontrollable, releasing massive cytokines, which cause serious damage to tissues and organs. Some drugs that block interleukin-6 and are already used (e.g. for the treatment of rheumatoid arthritis), have been used in many hospitals around the world to treat patients with Covid-19. But newer studies, some scientists say (not everyone agrees), show that IL-6 is not the main culprit in “storms”, nor do the latter always happen the same way. New research has failed to show that interleukin-6 drugs are really effective in Covid-19, and in some cases IL-6 levels are not even higher in patients with coronavirus than in other patients in serious condition for another reason. Three studies in American medical journals (two in the JAMA Internal Medicine and one in the New England Journal of Medicine) found no evidence that a common IL-6 drug, tocilizumab for rheumatoid arthritis, reduces the risk of death in patients with Covid -19 in critical condition. The drug company Roche itself did its own testing and found that this did not really help in the case of Covid-19. Some scientists, such as Dr. Caroline Calfi, an intensivist at the University of California, San Francisco, have a problem with it. the term “cytokine storm” which, as he says, “has no specific definition”. The term may be imaginative and has caught the attention of the media and the public, but “without definition, there are no diagnostic criteria to show that there really is such a thing.” But even if the “storm” exists, interleukin -6 is more of a passenger than a driver, as hundreds of cytokines are released when the immune system is activated and interacts with each other through complex processes. “It’s like a spaghetti tangled in so many different ways. “It is over-optimistic that IL-6 will be the answer to everything,” said Dr. Bruce Walker, director of immunology at the Ragon Institute of Massachusetts General Hospital and MIT and Harvard Hospitals. to assess whether IL-6 levels are abnormally elevated in patients with Covid-19. But a new study, led by infectious disease specialist Jonathan Parr of the University of North Carolina, shows that it is not and that it is often lower than in other severe cases (eg sepsis). A second study, led by Calfi, which evaluated five studies in more than 900 patients with severe Covid-19, found that interleukin-6 levels ranged from normal to only slightly elevated. Pulmonologist-intensivist Dr. William Fisher of Carolina pointed out that the idea of ​​a cytokine storm “comes to the fore in any serious viral infection, such as AIDS, Ebola, influenza, Lassa fever, SARS and MERS.” But, as he said, “it is difficult to distinguish what guides the pathology, whether it is only the virus or both the virus and the overreaction of the immune system trying to clear the virus.” Apart from IL-6, other factors, such as ferritin and CRP proteins, may be involved in the self-destructive defense response. In any case, Calfi said, new findings on the role of IL-6 and the usefulness of drugs against it teach doctors a lesson: “We need to be really humble about biological complexity.” ΑΠΕ – ΜΠΕ Follow it on Google News and be the first to know all the news See all the latest News from Greece and the World, at

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