Obesity is a known risk factor for more severe COVID-19
Obesity is a known risk factor for more severe COVID-19. One likely reason may be that the virus can infect fat cells, researchers have discovered.
In lab experiments and in autopsies of patients who died of COVID-19, they found the virus infects two types of cells found in fat tissue: mature fat cells, called adipocytes, and immune cells called macrophages.
"Infection of fat cells led to a marked inflammatory response, consistent with the type of immune response that is seen in severe cases of COVID-19," said Dr Catherine Blish of Stanford University School of Medicine, whose team reported the findings on bioRxiv on Monday ahead of peer review.
A separate new study has found that genes explain why some young, healthy adults die from COVID-19.
A gene that helps the coronavirus reproduce itself might contribute to life-threatening COVID-19 in young, otherwise healthy people, new findings suggest.
Genetic analysis identified five genes that were significantly "upregulated", or more active, in COVID-19 patients with critical illness, of which the most frequent was a gene called ADAM9.
As reported on Tuesday in Science Translational Medicine, the researchers saw the same genetic pattern in a separate group of COVID-19 patients.
Later, in lab experiments using human lung cells infected with the coronavirus, they found that blocking the activity of the ADAM9 gene made it harder for the virus to make copies of itself.
More research is needed, they say, to confirm their findings and to
determine whether it would be worthwhile to develop treatments to block ADAM9.