Paris (AFP)

A protein produced by the body in the context of inflammation could play an important role in severe forms of Covid-19, and targeting it could therefore help fight against the worsening of the disease, according to a study conducted by researchers French.

According to this work, published Thursday in the journal Cell, there is "a very high rate" - 100 to 1,000 times more than normal - of this protein, calprotectin, in patients with a severe form of Covid-19.

"Our results suggest that calprotectin may be responsible for the worsening of Covid-19," said lead author of the study, immunology researcher Aymeric Silvin, in a statement.

Much work around the world seeks to better understand the mechanisms of the "cytokine storm", an uncontrolled and excessive inflammatory reaction implicated in severe forms of Covid-19.

"The sharp increase in calprotectin in the blood could occur before the cytokine storm associated with the inflammatory runaway in patients developing a severe form," continued Aymeric Silvin.

In theory, we could therefore perhaps identify patients at risk of developing a severe form of the disease, by testing the level of calprotectin in their blood, according to the press release from the French organizations behind this research (Gustave Roussy, AP -HP, Inserm), in collaboration with foreign teams (Singapore, China, Israel).

In addition, this lead could offer "a novel therapeutic approach", since blocking the calprotectin receptor could help fight the aggravation.

"These strategies are to be evaluated by clinical trials", according to the press release.

The study was based on the analysis of blood samples from 158 patients admitted to the emergency room on suspicion of Covid-19.

In the most affected patients, in addition to the high calprotectin level, the tests revealed abnormal functioning of some white blood cells, which seems to weaken the immune response.

Carrying out analyzes on these two markers when a patient is admitted could therefore help identify the risks of serious forms upstream.

"The early diagnosis of a severe form of Covid-19 can be made on a blood tube", hoped another of the researchers, Prof. Michaela Fontenay, head of the biological hematology service at Cochin hospital in Paris, cited in the press release.

© 2020 AFP