COVID-19 ‘may not be characterized by cytokine storm’
COVID-19 may not be characterized by the presence of a cytokine storm, an abnormal strong proinflammatory response, according to results published in JAMA.
“Critically ill patients with COVID-19 with acute respiratory distress syndrome (ARDS) had circulating cytokine levels that were lower compared with patients with bacterial sepsis and similar to other critically ill patients,” Matthijs Kox, PhD, of the department of intensive care medicine at Radboud University Medical Center in Nijmegen, Netherlands, and colleagues wrote. “These findings are in line with lower leukocyte counts observed in patients with COVID-19, and are possibly due to lower overall disease severity, despite the presence of severe pulmonary injury.”
Kox and colleagues examined characteristics of 46 patients with COVID-19 and ARDS, 51 with septic shock with ARDS, 30 with out-of-hospital cardiac arrest and 62 with multiple traumas admitted to the ICU at Radboud University Medical Center. They excluded patients with immunological insufficiencies, which they defined as chronic or concomitant immunosuppressive medication use.
Levels for all cytokines were lower in COVID-19 patients than in patients with septic shock with ARDS, with geometric averages of 22pg/mL (95% CI, 18-27) v 40 pg/mL (95% CI, 30-55) for TNF, 27 pg/mL (95% CI, 23-33) v 215 pg/mL (95% CI, 133-347) for IL-8 and 48 pg/mL (95% CI, 35-66) v 376 pg/mL (95% CI, 190-744) for IL-6. Additionally, patients with COVID-19 had significantly lower IL-8 and IL-6 concentrations than patients with septic shock and no ARDS.
The authors their study’s major limitations included a small sample size, a single center and thidentical assays without data on lot-to-lot variability.
“The findings of this preliminary analysis suggest COVID-19 may not be characterized by cytokine storm,” the researchers wrote. “Whether anticytokine therapies will benefit patients with COVID-19 remains to be determined.”