Researcher of the Department of Immunology of the Scientific Research Institute of Physical and Chemical Biology of Moscow State University Andrei Kruglov developed a new method for detecting antibody responses to viral proteins and studied the cause of the severe course of the disease that occurs during new coronavirus infection.

Cytokine storms are actively discussed as the main cause of the severe course of the disease that occurs in patients with coronavirus infection. This is a situation when too many pro-inflammatory cytokines are produced - peptide molecules that alert the human body to danger. Proinflammatory cytokines act as a stimulator of immune responses to eliminate infectious pathogens, which leads to an excessively violent activation of inflammation and immunopathology. The use of blockers of this excessive inflammation helps only a few people with severe COVID-19.

Andrei Kruglov, a researcher at the Moscow State University Research Institute of Physical Chemistry, developed a new method for detecting the antibody response to viral proteins. It turned out that in severe COVID-19 patients, the antibody response switches, and in the later stages of the disease, immunoglobulin A (IgA2), which is not specific to the virus, begins to be produced. This is due to the fact that in the severe course of the disease, there is a large release of a suppressor molecule, a cytokine, TGF-b1.

“The significance of this work lies in the fact that the severe course of COVID-19 is not associated with a cytokine storm, but with the induction of a more complex pattern of cytokines, including those with immunosuppressive activity, which suppress the body's specific defense against the virus. Thus, our study offers a new way of treating severe COVID-19 by blocking TGFb1, ”concluded Andrey Kruglov.

The authors point out that, while in the usual case, plasmablasts secreting antibodies can be detected in the blood about 7 days after the onset of an acute immune response and only within 1-2 days, in the case of a severe form of COVID-19, their release was detected in during the entire duration of therapy (up to 60 days), which is also typical for autoimmune diseases mediated by antibodies. The transforming growth factor TGF-β is said to be the source of this reaction.

This TGF-β is also indicated as one of the important factors in cancer, cardiovascular disease (atherosclerosis), and renal failure.