New Cause of COVID-19 Blood Clots Identified
A study reveals the virus triggers production of antibodies circulating through the blood, causing clots in people hospitalized with the disease.
https://labblog.uofmhealth.org/lab-repo ... identified
Blood clots continue to wreak havoc for patients with severe COVID-19 infection, and a new study explains what may spark them in up to half of patients.
The culprit:
an autoimmune antibody that’s circulating in the blood, attacking the cells and triggering clots in arteries, veins, and microscopic vessels. Blood clots can cause life-threatening events like strokes. And, in COVID-19, microscopic clots may restrict blood flow in the lungs, impairing oxygen exchange.
Outside of novel coronavirus infection, these clot-causing antibodies are typically seen in patients who have the autoimmune disease antiphospholipid syndrome. The connection between autoantibodies and COVID-19 was unexpected, says co-corresponding author Yogen Kanthi, M.D., an assistant professor at the
Michigan Medicine Frankel Cardiovascular Center and a Lasker Investigator at the
National Institutes of Health’s National Heart, Lung, and Blood Institute.
“
In patients with COVID-19, we continue to see a relentless, self-amplifying cycle of inflammation and clotting in the body,” Kanthi says. “Now we’re learning that autoantibodies could be a culprit in this loop of clotting and inflammation that makes people who were already struggling even sicker.
”
‘Some of the worst clotting we’ve ever seen’
Co-corresponding author
Jason Knight, M.D., Ph.D., a rheumatologist at Michigan Medicine, has been studying antiphospholipid syndrome antibodies in the general population for years.
“Half of the patients hospitalized with COVID-19 were positive for at least one of the autoantibodies, which was quite a surprise,” says
Knight, also an associate professor of internal medicine and a leading expert on diseases caused by autoantibodies.
In the new
Science Translational Medicine publication, they found about half of the patients who were very sick with COVID-19 were exhibiting a combination of high levels of both the dangerous antibodies and super-activated neutrophils, which are destructive, exploding white blood cells.
In April, the team was the first to report that patients hospitalized for severe COVID-19 had higher levels of neutrophil extracellular traps in their blood.