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U.S. Department of Health and Human Services NATIONAL INSTITUTES OF HEALTH NIH News National Heart, Lung, and Blood Institute (NHLBI) <https://www.nhlbi.nih.gov>
For Immediate Release: Thursday, February 17, 2022 CONTACT: NHLBI Engagement and Media Relations Branch, 301-496-5449, <e-mail:nhlbi_news@xxxxxxxxxxxxx> MEDIA AVAILABILITY SCIENTISTS PINPOINT MECHANISMS ASSOCIATED WITH SEVERE COVID-19 BLOOD CLOTTING WHAT: After studying blood samples from 244 patients hospitalized for COVID-19, a group of researchers, including those who work at the National Institutes of Health, identified “rogue antibodies” that correlate with severe illness and may help
explain mechanisms associated with severe blood clotting. The researchers found circulating antiphospholipid antibodies <https://www.nhlbi.nih.gov/health-topics/antiphospholipid-antibody-syndrome>, which can be more common among people with autoimmune disorders,
such as lupus. However, these “autoantibodies,” which target a person’s own organs and systems, can also be activated in response to viral infections and activate other immune responses. Scientists compared the blood samples to those from healthy controls and found the COVID-19 samples contained higher levels of the antibody IgG, which works with other immune cells, such as IgM, to respond to immune threats. Higher levels
of IgG were also associated with COVID-19 disease severity, such as in patients who required breathing assistance. The researchers observed similar patterns, but to a lesser extent, after analyzing blood samples from 100 patients hospitalized for sepsis, which
can leave the body in inflammatory shock following a bacterial or viral infection.
IgG helps bridge a gap between innate and adaptive immune responses – a process that helps the body recognize, respond to, and remember danger. In normal cases, these features help protect the body from illness and infection. However, in
some cases, this response can become hyperextended or altered and exacerbate illness. A unique finding from this study is that when researchers removed IgG from the COVID-19 blood samples, they saw molecular indicators of “blood vessel stickiness” fall. When
they added these same IgG antibodies to the control samples, they saw a blood vessel inflammatory response that can lead to clotting.
Since every organ has blood vessels in it, circulating factors that lead to the “stickiness” of healthy blood vessels during COVID-19 may help explain why the virus can affect many organs, including the heart, lungs, and brain. A query
of this study was evaluating “upstream” factors involved with severe blood clotting and inflammation among people with severe COVID-19 illness. The researchers note future studies could explore the potential benefits of screening patients with COVID-19 or other forms of critical illness for antiphospholipids and other autoantibodies and at earlier points of infection. This may
help identify patients at risk for extreme blood clotting, vascular inflammation, and respiratory failure. Corresponding studies could then assess the potential benefits of providing these patients with treatments to protect blood vessels or fine-tune the
immune system. WHO: Yogen Kanthi, M.D., a co-corresponding author, is available to discuss this research. Dr. Kanthi is a cardiologist, Clinical Lasker Research Scholar, and leads the Laboratory of Vascular Thrombosis and Inflammation <https://www.nhlbi.nih.gov/science/vascular-thrombosis-and-inflammation#Research-Interests>at
the National Heart, Lung, and Blood Institute. He is also an assistant professor of cardiovascular medicine at the University of Michigan, Ann Arbor.
ARTICLE: Endothelial cell-activating antibodies in COVID-19. Arthritis & Rheumatology, 2022. DOI: https://doi.org/10.1002/art.42094. ###
About the National Heart, Lung, and Blood Institute (NHLBI): NHLBI is the global leader in conducting and supporting research in heart, lung, and blood diseases and sleep disorders that advances scientific knowledge, improves public health,
and saves lives. For more information, visit <>. About the National Institutes of Health (NIH): NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting
and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit <https://www.nih.gov>. NIH...Turning Discovery into Health -- Registered, U.S. Patent and Trademark Office ### This NIH News Release is available online at: <https://www.nih.gov/news-events/news-releases/scientists-pinpoint-mechanisms-associated-severe-covid-19-blood-clotting> To subscribe (or unsubscribe) from NIH News Release mailings, go to <http://service.govdelivery.com/service/subscribe.html?code=USNIH_1>. If you subscribed via the NIH LISTSERV, go to <https://list.nih.gov/cgi-bin/wa.exe?A0=nihpress>. |
