Li Cai1, Xi Zhou1, Miao Wang2, Heng Mei1, Lisha Ai1, Shidai Mu1, Xiaoyan Zhao1, Wei Chen3, Yu Hu4, Huafang Wang5. 1. Institute of Hematology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China. 2. Department of Urology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China. 3. Beijing Institute of Biotechnology, Beijing, China. Electronic address: cw0226@foxmail.com. 4. Institute of Hematology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China. Electronic address: huyu@126.com. 5. Institute of Hematology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China. Electronic address: whf2019@hust.edu.cn.
To the Editor:We have read with interest the comments by Mungmunpuntipantip and Wiwanitkit, and we agree that cytokines are associated with disease severity and have an effect on the underlying disease. We would like to share our understanding of the role of cytokines in coronavirus disease 2019 (COVID-19).It is well known that an uncontrolled immune response to viral infection may lead to extensive cytokine release, called “cytokine storm,” consisting of a collection of proinflammatory cytokines (such as IL-6, IL-5, IL-8, and IL-1β) and chemokines. The cytokine storm plays a major role in the development of acute respiratory distress syndrome and multiple organ failure in patients with COVID-19. Intensive care with sufficient hospital resources may reduce the mortality rate of severely ill patients. However, invasive intervention in those patients with irregular immunity may lead to other complications, and death is inevitable in some patients. Monitoring these cytokines provides clinicians with early signs of an overactive immune response and enables timely intervention. Nowadays, the use of anti-inflammatory agents (corticosteroid, tocilizumab, and so on) to suppress the cytokine storm is undergoing multiple trials and some results are encouraging. Nevertheless, the impact of these agents on antiviral immunity and the appropriate timing of their use remain to be studied.In our study, cytokine analysis was performed in 21 patients with COVID-19 (8 nonsevere and 13 severe) and showed that IL-6 and IL-10 levels were significantly higher in the death group than those in the recovery group. No significant difference, except for IFN-α, was observed between the nonsevere and severe groups, which may due to a decreased level of cytokine during the recovery stage of COVID-19 or the small sample size.Many thanks for allowing us to reply to the comment on our article.