The Coronavirus Attacks Fat Tissue, Scientists Find - The New York Times

The research may help explain why people who are overweight and obese have been at higher risk of severe illness and death from Covid.

Patients who were overweight or obese were more likely to develop severe Covid-19 and more likely to die.

Now researchers have found that the coronavirus infects both fat cells and certain immune cells within body fat, prompting a damaging defensive response in the body.

The study’s authors suggested the evidence could point to new Covid treatments that target body fat.

Blish, with colleagues at Stanford and in Germany and Switzerland, carried out experiments to see if fat tissue obtained from bariatric surgery patients could become infected with the coronavirus, and tracked how various types of cells responded.

The fat cells themselves could become infected, the scientists found, yet did not become very inflamed.

But certain immune cells called macrophages also could be infected, and they developed a robust inflammatory response.

Even stranger, the pre-adipocytes were not infected, but contributed to the inflammatory response.

The research team also obtained fat tissue from the bodies of European patients who had died of Covid and discovered the coronavirus in fat near various organs.

The coronavirus appears to be able to evade the body fat’s immune defenses, which are limited and incapable of fighting it effectively.

And in people who are obese, there can be a lot of body fat.

The coronavirus “can infect that tissue and actually reside there,” he said.

As the inflammatory response snowballs, cytokines trigger even more inflammation and the release of additional cytokines.

“This paper is another wake-up call for the medical profession and public health to look more deeply into the issues of overweight and obese individuals, and the treatments and vaccines we’re giving them,” said Barry Popkin, a professor of nutrition at University of North Carolina at Chapel Hill, who has studied the heightened risk that Covid poses to those with obesity