Researchers have been trying to figure out what's going on.By Dr. Maria Simbra

PITTSBURGH (KDKA) — With coronavirus, people can have blood clots throughout the body.

This clotting, called thrombosis, can happen in big and small blood vessels, as well as in veins and arteries.

“Thrombotic complications are commonly associated with this disease. Moreso in severe disease but also mild disease. It suggests that there’s clearly a relationship there,” says Dr. Ashis Tayal, a stroke neurologist at the Allegheny Health Network.

Researchers have been trying to figure out what’s going on.

“One of the early things that we were recognizing in some of the patients with severe COVID was these derangements in laboratory studies,” says Dr. Tayal, “suggesting there were changes in people’s normal coagulation.”

Because some people have been noted to have something called antiphospholipid antibodies, researchers wanted to look into this further.

“Antiphospholipid antibodies are autoimmune antibodies,” Dr. Tayal said. “We are frequently diagnosing these in people sometimes with rheumatologic conditions, like lupus, also cancer, and infections are also associated with these antiphospholipid antibodies.”

They checked the blood of 172 patients hospitalized with COVID-19, looking for these immune system proteins that attack a person’s own body.

“These circulating antibodies can actually interact with normal clotting mechanisms and can activate our normal clotting mechanisms unnaturally, and therefore cause spontaneous clotting,” says Dr. Tayal.

More than half of the patients had them and a high level was associated with more clotting, more inflammatory cells, more severe lung disease and poorer kidney function.

“I think it’s an important finding because you wouldn’t normally expect to see that many laboratory abnormalities in other populations,” says Dr. Tayal. “So there’s something unique about COVID that is generating these antiphospholipid antibodies and in a much higher percentage of patients that you might expect.”

A step towards understanding why the clotting happens.

“When people are hospitalized with COVID, some people are started on anticoagulant medications to reduce the risk of clotting,” Dr. Tayal adds.

Dr. Maria Simbra