COVID-19 May Not Be Characterized by Cytokine Storm

The findings of a preliminary analysis suggest that coronavirus disease 2019 (COVID-19) may not be characterized by cytokine storm and therefore the benefit of anticytokine therapies remains to be determined, according to a research letter published in JAMA.¹

An abnormally strong proinflammatory response known as “cytokine storm” may play an important role in the pathophysiology of COVID-19, although to what extent is unclear.¹ Previous data demonstrated that although interleukin (IL)-6 levels are elevated in severe COVID-19, they are lower than levels usually observed in non-COVID-19 acute respiratory distress syndrome (ARDS).²

Therefore, researchers compared cytokine levels in critically ill patients with COVID-19 with levels in patients with other critical illnesses who were admitted to the intensive care unit of Radboud University Medical Center.¹ There were 46 patients with COVID-19 with ARDS, 51 with septic shock with ARDS, 15 with septic shock without ARDS, 30 with out-of-hospital cardiac arrest (OHCA), and 62 with multiple traumas. In COVID-19, cardiovascular insufficiency was more common, overall disease severity and leukocyte counts were lower, and lung injury was more severe compared with the other groups.

Results demonstrated that levels of all 3 cytokines were significantly lower in patients with COVID-19 than in patients with septic shock with ARDS. Patients with COVID-19 also displayed significantly lower IL-6 and IL-8 concentrations compared with patients with septic shock without ARDS. Tumor necrosis factor levels in patients with COVID-19 were higher than those in trauma patients, whereas no differences between patients with COVID-19 and OHCA or trauma were present for IL-6. Lower concentrations of IL-8 were found in patients with COVID-19 compared with patients with OHCA, while no differences compared with the trauma group were observed.

“In this study, critically ill patients with COVID-19 with ARDS had circulating cytokine levels that were lower compared with patients with bacterial sepsis and similar to other critically ill patients,” the authors concluded.¹

References

1. Kox M, Waalders NJB, Kooistra EJ, Gerretsen J, Pickkers P. Cytokine levels in critically ill patients with COVID-19 and other conditions. Research letter. JAMA. Published online September 3, 2020. doi:10.1001/jama.2020.17052

2. Sinha P, Matthay MA, Calfee CS. Is a “cytokine storm” relevant to COVID-19? JAMA Intern Med. 2020;180(9);1152-1154.

This article originally appeared on Pulmonology Advisor