Some patients with Covid-19 have, between the sixth and the eighth day of the disease, severe respiratory impairment, responsible for almost all stays in the intensive care unit.
Caregivers must then help them breathe, under pain of death. This is the second viral phase, that of inflammation.
" In some people, the inflammation, necessary to fight the virus, drifts, misses its target, becomes too great and triggers lung damage Explains the Professor Olivier Epaulard, infectiologist at CHUGA, the Grenoble-Alpes Hospital Center.
It's disproportionate inflammation that kills
" In fact, people are not sick because the virus destroys cells, but because the virus triggers very significant respiratory inflammation. ” adds Professor Epaulard.
This inflammation is the response, the defense of our body, of our immune system, to viral attack.
" With the Covid-19, the immune system is racing, the defense is inappropriate, disproportionate. It is she who has a deleterious effect. "
In summary, it’s not the virus that kills, it’s the "inflammatory storm". What the Anglo-Saxons have baptized "Cytokine storm", thunderstorm or cytokine shock.
Basically, cytokines are proteins that alert our immune system to viral attack. And which in this case trigger an overreaction.
Like a little breeze that announces … the storm.
(embed) https://www.youtube.com/watch?v=hdCpRGY5u48 (/ embed)
Cytokines, "biomarkers" of inflammation
The study by Grenoble researchers identified these cytokines as "biomarkers" of inflammation, that is to say, of the worsening of the disease.
These scientists from CHUGA and of the UGA were particularly interested in the cytokine called Interleukin 6 or "IL6".
It’s the one that alarms the immune system. It stimulates the secretion of proteins in the acute phase of inflammation. It plays a key role in regulating this phenomenon.
The researchers therefore established a correlation between a certain dosage of this IL6, taken from the blood of patients as soon as they enter the hospital, and the worsening of the disease.
In this sense, this protein proves to be a "Bio-marker" inflammation. Its presence can betray the excitement of the immune system.
If we spot IL6, we can therefore predict the phenomenon. And anticipate it.
Predict the storm to better control it
This is the whole point of this research. Anticipate the aggravation, from the third or fourth day. To better manage the patient.
" It is a question of knowing which are the patients to be absolutely monitored to start without delay an active treatment, to modulate the inflammation, with for example corticoids ” comments Professor Epaulard.
" The idea is to identify the aggravation early, to break down the inflammation, this harmful process that will send the patient to resuscitation "He adds.
Corticosteroids, well known as "Anti-inflammatory", are a first resort.
But Professor Epaulard also talks about the use of an antibody, the "Tocilizumab", which would directly attack the IL6 protein to regulate its disproportionate alert, by blocking its receptors.
This antibody is used in particular in the treatment of rheumatoid arthritis.
Doctors at the CHU, they are also researchers at the University
The blood analyzes which made it possible to measure the "bio-marker", the famous protein IL6, related to the samples of more than 200 Covid-19 patients hospitalized in Grenoble since March 7, 2020.
They were carried out at the IBP, the Institute of Biology and Pathology, the giant laboratory at Michallon hospital.
A building of over 13,000 square meters, where two medical biologists, 11 laboratory technicians and two engineers worked hard to achieve these results.
Everything took place in the Protein Biochemistry laboratory, under the joint direction of the Professor Olivier Epaulard, infectious disease specialist at CHU Grenoble Alpes, Dr Audrey Le Gouellec and Professor Bertrand Toussaint, both medical biologists at CHUGA and researchers in the TIMC-IMAG laboratory (CNRS / UGA / Grenoble INP-UGA).
In the coming weeks, this research should be published in a very prestigious international journal.
Research supported by the "Université Grenoble Alpes" Foundation
In addition to contributions from university and hospital institutions, the UGA Foundation mobilized to allow this research to start immediately.
In early March, in an emergency, the Foundation managed to collect 160,000 euros in donations from its patrons: Air Liquide, Caisse d'Epargne Rhône-Alpes, bioMérieux, MGEN, Banque Populaire AURA, Compagnie de Chauffage and GEG.
The purpose of the Foundation is to unite companies, teacher-researchers and students around projects of general interest.
In addition to this research, the Grenoble University Hospital Center has participated in many other clinical trials since the appearance of the coronavirus.
To learn more about the research in progress throughout France, avoiding in addition the fake news, don't hesitate to visit INSERM website, the National Institute of Health and Medical Research.