UW study finds tie between inflammation and long COVID symptoms

Three years after long COVID was first documented, the mysteries behind what causes it are starting to be unraveled.

Driving the news: Some of the mental symptoms of long COVID like brain fog and memory issues are likely sparked by inflammation, according to a new study published this month by researchers with the University of Washington School of Medicine, the Veterans Affairs Puget Sound Health Care System, and Oregon Health & Science University.

The big picture: While the relationship between long COVID and inflammatory diseases is still being studied, there is a growing body of work suggesting a link between the virus and inflammatory diseases that affect the brain.

• "(COVID) may make it worse, bring it on sooner, or it may cause its own version of cognitive impairment," said researcher William Banks, a professor with the UW Division of Gerontology & Geriatric Medicine and associate chief of staff for research and development at the VA Puget Sound Health Care System.

Details: Researchers administered SARS-CoV-2 to mice.

• The study showed that the S1 protein, the virus' characteristic spike protein, readily passes through the blood-brain barrier.
• Once there, the protein generates inflammation that can spur problems with learning and memory and accelerate the effects of Alzheimer's and other cognitive impairments, Banks said.

It's still not clear why some people get long COVID and others do not, according to the CDC, but among those at higher risk include those who either got severely sick from COVID or had underlying conditions prior to infection.

• People who experienced multisystem inflammatory syndrome (MIS) during or after COVID are also at higher risk.

What's next: Banks said the next steps for study include examining animals to see the long-term effects of inflammation on a brain that's been infected with COVID-19 and testing drugs that might block or prevent certain kinds of neuroinflammation.