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A more surprising symptom of COVID-19 is a blood clot that many patients, including young children, experience infection with. Clogging has in some cases caused dangerous obstruction in the lungs, leading to stroke and even death, even in people without a history of circulatory conditions.
In a paper published in Science Earlier this week, researchers gave a glimpse of what could drive clots provoked by a COVID-19 infection. The group found that a specific group of antibodies called an antibody – which are rogue versions of cells that protect the body from pathogens, but instead attack its own cells (in this case the body’s own blood vessel cells) may be partly responsible. . Risk of clots associated with the disease. Of the 172 patients admitted to the hospital in COVID-19, they found that half had produced these one antibody. In addition, when scientists injected lantibodies into lab rats, the animals developed blood clots.
In April, a similar group of scientists reported that inflammation associated with COVID-19 can clot in small vessels in the lungs, and that these clots are mostly filled with immune cells called neutrophils. In COVID-19 patients, these neutrophils can explode into tiny blood vessels, forming sticky molecular traps that attract other clotting factors circulating in the blood. “Developed, we think this is to trap things like bacteria or viruses,” says Yogi Kanthi, a researcher and author of the study at the National Heart, Lung and Blood Institute, an assistant professor at the University of Michigan. “Even if [neutrophils] When further stimulated, they can grow and block blood vessels and cause blood clots to form. “In a previous study, Kanthi and his colleagues found that COVID-19 patients who have more of these” traps “in their blood system are more likely to develop serious disease or respiratory failure.
“Inflammation produces waste, and clotting causes more inflammation,” he says. “It becomes an endless self-amplifying loop of inflammation and clotting that results in patients falling ill.”
Their latest Science In the paper, researchers found that tontibodies trigger this cycle of inflammation and clotting. The antibodies found in COVID-19 patients are the same as those found by doctors in patients with im tomimun disease called antiphospholipid syndrome, in which antibodies cause seed clots that attract clotting factors that eventually block blood flow. To understand how these antibodies contribute to the risk of clotting in patients with that syndrome, study antiphospholipid disease such as Jasin Knight, who predicts similar clotting in COVID-19 patients. “By May, all of the Covid-19 patients were talking,” says Knight, one of the study authors at the University of Michigan. “When we started doing aut tops, we noticed microvascular clots in the lungs.”
Such clots in small vessels – often too small to be picked up by a CT scan – are a symptom of a blockage in the blood flow associated with COVID-19. Patients in large vessels, including veins and arteries, not only develop so-called macrovascular clots, which can lead to deep vein thrombosis and stroke, but the infection also appears to clot in small vessels in the lungs that can cause respiratory problems. And tontibodies may be the reason for that, as they can bind blood vessel cells everywhere.
In fact, Kanti says, COVID-19 can be seen as “an extreme version of many diseases, one of which is antiphospholipid syndrome.” This means that studying these patients can lead to a better understanding of COVID-19 and how coronaviruses contribute to clotting. To begin with, Knight is already studying a drug, dipyridamole, approved to treat stroke and prevent blood clots in people receiving mechanical heart valves, to see if it can reduce the risk of clotting in COVID-19 patients. . The drug is relatively inexpensive and directly interferes with neutrophil activation, which can reduce the formation of hyperactive neutrophil traps in vessels. Testing for tontibodies is already available for doctors to order, so eventually, Knight says, COVID-19 patients can be tested for antibody levels and then triad to receive more aggressive blood thinners or other drugs such as dipyridamole, If it proves effective. , To prevent them from clotting.
The team says the team is currently enrolling COVID-19 patients for an anti-clotting drug study and may have its answers by the end of the year. Those findings could open up new insights into how viruses affect the body’s coagulation processes; Kanti says the body’s autoantibodies can cause such widespread clots. “We knew that antibodies could be like this [from our knowledge of antiphospholipid syndrome] But no one ever saw if they cause clots to form. “
It is not yet clear at what stage during infection these form faeces begin to form, and people are more likely to have them. Heredity, a person’s history of previous viral and bacterial infections, as well as the rave-up immune response initiated by Covid-19 probably all contribute to that risk. But the fact that half the patients can produce these potential clot-stimulating antibodies means that they have a better understanding of what these risk factors are, and that the people who treat them are more serious and potential. Can experience a fatal COVID-19 infection.
