Does the COVID-19 cytokine storm exist?

Inflammatory proteins, also known as cytokines, play a crucial role in the immune reaction. If this immune response is too powerful, a phenomenon called”cytokine storm”, it can result in harm to the patient. It’s been believed that a cytokine storm contributes to disease severity in patients with COVID-19.

Following the measurement of several important cytokines in patients with COVID-19 and various other severe diseases, researchers at Radboud university medical center now show that COVID-19 is not characterized by a cytokine storm. This might have consequences for the treatment of the patients, the investigators write in JAMA.

The cytokine storm in COVID-19 sufferers is not clearly defined. Oftentimes, different cytokines are evaluated and no comparison was made with different diseases. Therefore, uncertainty and doubt exists concerning the cytokine storm in these patients.

Various patient groups
Researchers from the Intensive Care (IC) department at Radboud university medical center have measured the concentration of three essential cytokines in the blood of patients admitted to the IC with several different conditions. They performed these measurements in patients with COVID-19 who met the criteria for a serious acute respiratory infection (ARDS), patients with bacterial septic shock (with and without ARDS), and patients who had been admitted to the IC after a cardiac arrest or severe trauma. The cytokines were measured using the same techniques for each of the groups of patients.

From the above described five individual groups, the concentration of tumor necrosis factor alpha (TNF-?) And interleukins 6 and 8 (IL-6, IL-8) was quantified. Chemical Matthijs Kox:”The degree 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 exhibited markedly lower levels of IL-6 and IL-8. The cytokine concentrations in COVID-19 patients were comparable to people in IC patients with trauma or cardiac arrest, conditions which aren’t noted for a cytokine storm.”

The results from this study show 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. This means that critically ill COVID-19 patients likely will not benefit from specific anti-cytokine therapies.”-Peter Pickkers, Professor of Intensive Care Medicine