London: Challenging an earlier assumption, new research has shown that disease severity in patients with Covid-19 may not be due to cytokine storm.
Inflammatory proteins also known as cytokines play a crucial role in the immune response. If this immune response was too strong, a phenomenon known as “cytokine storm” can cause harm to the patient. It has been thought that a cytokine storm characterizes Covid-19 although it was not clearly defined.
In many cases, different cytokines were evaluated and no comparison has been made with other diseases. Therefore, uncertainty and doubt exist concerning the cytokine storm in these patients. The new study published in the journal JAMA may have consequences for the treatment of these patients.
Researchers from Radboud University Medical Centre in the Netherlands have now measured the concentration of three essential cytokines in the blood of patients admitted to intensive care with several distinct conditions. They performed these measurements in patients with Covid-19 who met the criteria for a severe acute respiratory infection (ARDS), patients with bacterial septic shock (with and without ARDS) and patients who had been admitted to intensive care after a cardiac arrest or severe trauma.
The cytokines were measured using the same methods for each group of patients.
“The level of cytokines was significantly less elevated in Covid-19 patients than in patients with septic shock and ARDS. Compared to patients with septic shock without ARDS, so without severe pulmonary disease patients with Covid-19 also displayed markedly lower levels of IL-6 and IL-8,” said a researcher Matthijs Kox.
The cytokine concentrations in Covid-19 patients were similar to those in IC patients with trauma or cardiac arrest, conditions that were not noted for a cytokine storm.
“The results from this study showed that Covid-19 is not characterized by a cytokine storm.”
The severe disease observed in critically-ill Covid-19 patients is, therefore, not explained by strongly elevated levels of inflammatory proteins in the blood, said Professor Peter Pickkers.
“This means that critically-ill Covid-19 patients likely will not benefit from specific anti-cytokine therapies.”