Severe COVID-19 despite or even due to the strong immunity

Date:
September 1, 2020
Source:
Ruhr-University Bochum
Summary:
Critically ill patients present a similar or even stronger immunity
against the virus than convalescent patients. This supports the
theory that severe infections might be linked to an exaggerated
immune reaction.



FULL STORY ==========================================================================
A weak immune response isn't the cause of dangerous lung failure in severe Covid-19 infections. Such infections seem, on the contrary, to be caused
by an overreaction of the immune system. This is the conclusion made by
a research team from Ruhr-Universita"t Bochum (RUB) and the university
hospital of Duisburg-Essen led by Professor Nina Babel, Head of the
Centre for Translational Medicine at the RUB clinic Marien Hospital Herne.


==========================================================================
The team from Marien Hospital and the department of Virology of Ruhr- Universita"t Bochum (RUB) as well as the Clinic for Infectious Diseases,
the Clinic of Anesthesiology and the Institute for Virology of University Medicine Essen studied specific antibodies and T cells occurring in
recovered, seriously ill and deceased Covid-19 patients. The researchers identified comparable immune reactions in clinical follow up. They report
their findings in the journal Cell Reports Medicine from 29 August 2020.

How the immune system fights viruses Antibodies and T lymphocytes
are among the most important elements of the immune defence against
viruses. The antibodies prevent viruses from entering the host cell
by binding to certain virus receptors. They also mark the infected
cells for other players in the immune system, which are able to kill
the infected cells. Virus-specific T lymphocytes, on the other hand,
can kill infected cells directly and highly efficiently.

During the last weeks, some studies have been published on the analysis
of these cell-killing Sars-Cov-2 specific T cells in patients with
Covid-19. The studies demonstrated detection of such cells in patients recovered from Covid- 19 suggesting their protective antiviral effect. On
the other hand, some studies indicate that an excessive immune response
might be the cause of severe Covid-19. The role of Sars-Cov-2 specific
T-cells in this exaggerated immune response is unclear.

Critically ill patients have the same or stronger immunity as recovered patients In the current study, the research team analysed immune
responses in Covid-19 patients during the disease progress. "This is
how we wanted to investigate the role of T cells and antibodies in
controlling the infection and the disease," explains Nina Babel, who
headed the study. "The novel aspect of our study is that we analysed
Sars-Cov-2 specific T-cells and antibodies in relation to disease
progression and viral clearance. We found that a strong T-cell and
antibody response could be detected not only in patients with mild
Covid-19 patients who had recovered from the virus infection." Similar
or even stronger immunity to Sars-Cov-2 was found in patients who had
been critically ill and who suffered Covid-19-related lung failure.

"The total number of specific immune cells as well as their functionality
was not better in patients who survived Covid-19 than in those who died
from it," says Dr. Ulrik Stervbo, head of laboratory at the Centre for Translational Medicine. There was also no difference in the strength and functionality of the immune response between patients who still suffered
from and those who had cleared a Sars-Cov-2 infection.

Excessive immune response plays an important role "Even though further
studies will be necessary to understand the specific mechanism of Covid-19 development, our data suggest that excessive Sars-Cov-2- specific T cell response can cause immunopathogenesis leading to Covid-19- related lung failure," points out Nina Babel. "The results of current studies on
the successful application of immunosuppressive therapies in Covid-19
support this hypothesis," concludes Professor Timm Westhoff, Director
of Medical Clinic I at Marien Hospital Herne.


========================================================================== Story Source: Materials provided by Ruhr-University_Bochum. Original
written by Meike Driessen; translated by Donata Zuber. Note: Content
may be edited for style and length.


========================================================================== Journal Reference:
1. Constantin J. Thieme, Moritz Anft, Krystallenia Paniskaki, Arturo
Blazquez-Navarro, Adrian Doevelaar, Felix S. Seibert, Bodo Hoelzer,
Margarethe Justine Konik, Thorsten Brenner, Clemens Tempfer,
Carsten Watzl, Toni L. Meister, Stephanie Pfaender, Eike Steinmann,
Sebastian Dolff, Ulf Dittmer, Timm H. Westhoff, Oliver Witzke,
Ulrik Stervbo, Toralf Roch, Nina Babel. Robust T cell response
towards spike, membrane, and nucleocapsid SARS-CoV-2 proteins is
not associated with recovery in critical COVID-19 patients. Cell
Reports Medicine, 2020; 100092 DOI: 10.1016/j.xcrm.2020.100092 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/09/200901112227.htm

--- up 1 week, 1 day, 6 hours, 50 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1337:3/111)