Cytokine Storm May Not Be the Chief Culprit for the Deterioration of COVID-19

Abstract

COVID-19 is spreading and ravaging all over the world, and the number of deaths is increasing day by day without downward trend. However, there is limited knowledge of pathogenesis on the deterioration of COVID-19 at present. In this study we aim to determine whether cytokine storm is really the chief culprit for the deterioration of COVID-19. The confirmed COVID-19 patients were divided into moderate group (n = 89), severe group (n = 37), and critical group (n = 41). Demographic data were collected and recorded on admission to ICU. Clinical data were obtained when moderate, severe, or critical COVID-19 was diagnosed, and then compared between groups. The proportion of enrolled COVID-19 patients was slightly higher among males (52.5%) than females (47.5%), with an average age of 64.87 years. The number of patients without comorbidities exceed one third (36.1%), and patients with 1, 2, 3, 4 kinds of comorbidities accounted for 23.0%, 23.0%, 13.1%, and 4.9%, respectively. IL-6, IL-10, TNF, and IFN-γ, including oxygenation index, sequential organ failure assessment score, white blood cell count, lymphocyte count, lymphocyte percentage, platelet, C-reaction protein, lactate dehydrogenase, creatine kinase isoenzyme, albumin, D-Dimer, and fibrinogen showed significant difference between groups. Some, but not all, cytokines and chemokines were involved in the deterioration of COVID-19, and thus cytokine storm maybe just the tip of the iceberg and should be used with caution to explain pathogenesis on the deterioration of COVID-19, which might be complex and related to inflammation, immunity, blood coagulation, and multiple organ functions. Future studies should focus on identification of specific signaling pathways and mechanisms after severe acute respiratory syndrome coronavirus 2 infections (IRB number: IRB-AF/SC-04/01.0).

Keywords: COVID-19; IFN-γ; IL-10; IL-6; SOFA score; TNF; cytokine storm; hypercytokinemia.