Scientists at the Karolinska Institute in Sweden have shown that patients with severe COVID-19 have high levels of specific immune cells called myeloid suppressor cells. The presence of these cells may explain the development of complications in coronavirus infection. A new high risk factor for death is reported in an article published in the Journal of Clinical Investigation.
It is known that M-MDSC suppressor cells suppress the activity of T cells, which are involved in the body's defense against viral infections. To better uncover the role of M-MDSC in the progression of COVID-19, the researchers examined blood samples and swabs from 147 coronavirus patients who had had mild illness or who died of complications. The results were compared with a group of healthy people or those with the flu.
It turned out that in patients with severe COVID-19, the level of M-MDSC in the blood is significantly increased compared with lighter cases and healthy people. At the same time, patients with COVID-19 had fewer T cells in their blood. In addition, scientists have linked high levels of M-MDSC in the early stages of the disease with severe complications later on.
