Serious forms of Covid-19 infection would be the result of an exaggeration of the immune response. This is the thesis that seems to be confirmed by a study conducted by German researchers.
- A strong T cell and antibody response was detected in patients with severe forms of the disease.
- Excessive response of SARS-CoV-2-specific T cells can cause immunopathogenesis that leads to lung failure.
A weak immune response is not the cause of lung failure in severe Covid-19 infections. Such infections, on the contrary, seem to be caused by an overreaction of the immune system, concludes a study carried out by a team of German researchers from the Ruhr-Universität Bochum (RUB) and the University Hospital of Duisburg-Essen. The results were published on August 29 in the journal Cell Reports Medicine.
Critically ill patients have the same or stronger immunity than recovered patients
Antibodies and T lymphocytes are among the most important elements of the immune defense against viruses. Antibodies prevent viruses from entering the host cell by binding to certain viral receptors. Virus-specific T cells can directly kill infected cells. Previous studies have demonstrated the protective antiviral effect of these T cells. On the other hand, other studies have indicated that an excessive immune response could be the cause of severe Covid-19 and the role of T cells in this exaggerated immune response still remains murky.
In this study, the research team analyzed immune responses in Covid-19 patients during disease progression. “This is how we wanted to study the role of T lymphocytes and antibodies in the control of infection and disease.says Professor Nina Babel, who led the study. The novel aspect of our study is that we analyzed SARS-CoV-2 specific T cells and antibodies in relation to disease progression and viral load. We have found that a strong T-cell and antibody response can be detected elsewhere than in patients with a mild form of Covid-19 infection who have recovered from viral infection..”
The overresponse of T cells in question
Immunity similar to, or stronger than, that of patients with mild disease has been found in patients who have been critically ill and have lung failure related to Covid-19. “The total number of specific immune cells and their functionality are no better in patients who survived Covid-19 than in those who died.continues Dr. Ulrik Stervbo, head of laboratory at the Center for Translational Medicine. There is also no difference in the strength and functionality of the immune response between patients who are still in pain and those who are no longer infected..”
The key to serious infections lies in the excessive response of T cells.”Although further studies will be needed to understand the specific mechanism of Covid-19 development, our data suggest that an excessive response of SARS-CoV-2-specific T cells may cause immunopathogenesis leading to lung failure related”, reveals Nina Babel. “The results of current studies on the successful application of immunosuppressive therapies in Covid-19 support this hypothesis.”, concludes Professor Timm Westhoff, who participated in the study.
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