Abstract
The coronavirus disease 2019 (COVID-19) may cause cytokine storm and respiratory illness such as pneumonia and progressive respiratory failure. Tocilizumab (TCZ), a monoclonal antibody that targets the interleukin-6 (IL-6) receptor, was approved as an alternative treatment for severe COVID-19 patients despite limited real-world clinical data in China. In the present study, we will discuss and evaluate the treatment response of TCZ therapy in patients with COVID-19. The clinical characteristics, treatment, laboratory parameters of IL-6, C-reactive protein (CRP), lymphocyte counts before and after TCZ therapy, and clinical outcomes in the 13 patients with COVID-19 were retrospectively evaluated according to the related medical records. The results showed that 13 patients with COVID-19 were totally included in this study. One of them was moderately ill, 8 were seriously ill, and 4 were critically ill. Eleven patients received TCZ administration once, while the other 2 patients received it twice. The median level of IL-6 before TCZ administration was 27.91 (7.42–210.90) pg/mL. Serum IL-6 level tended to further spike firstly and then gradually decreased after TCZ therapy in 10 patients. A persistent and dramatic increase of IL-6 was observed in 2 patients who were finally dead. The CRP levels of 76.92% (10/13) of the patients were above the normal range before the start of TCZ therapy and gradually declined after the TCZ treatment. No. 1 and No. 10 patients finally died accompanied by the corresponding lymphocyte counts persistently dropping. No. 13 patient became exacerbated possibly due to inducing severe bacterial infection after TCZ treatment, while the other 10 patients showed clinical improvement. In summary, the study revealed that TCZ may have a certain therapeutic effect on severe COVID-19 patients with a risk of the cytokine storm. It is necessary to further evaluate the efficacy and safety of TCZ by rigorous randomized controlled trial in the next step.
Highlights
Since December 2019, an outbreak of a novel coronavirus disease 2019 (COVID-19) was reported in Wuhan, China, which has subsequently affected more than 200 countries, areas, or territories worldwide
One clinical trial, using the IL-6 receptor-targeted monoclonal antibody tocilizumab (TCZ), which blocks IL-6-mediated signals by inhibiting IL6 binding to transmembrane and soluble IL-6 receptors, Canadian Journal of Infectious Diseases and Medical Microbiology reported quick control of fever and an improvement of respiratory function in 21 patients with severe COVID-19 treated in Anhui, China [6]. erefore, TCZ is recommended in seriously ill patients with elevated IL-6 by the Diagnosis and Treatment Protocol for COVID-19 (Trial Version 7) issued by the National Health Commission of China [7]
Based on laboratory data in our hospital, the level of IL-6 was defined as elevated when it was higher than 7.00 pg/mL. e C-reactive protein (CRP) was defined as elevated when it was higher than 10.00 mg/L, while the lymphocyte count declined as it was less than 1100/μL. e patients whose laboratory data of IL-6 or CRP or lymphocyte count were completely missed before or after TCZ administration were considered as study withdrawal. e latest laboratory values before TCZ administration were selected as the value before TCZ therapy, and the changes in the value after TCZ administration were observed for one week. e clinical outcome of the patients was evaluated when discharged or died according to the related medical records
Summary
Since December 2019, an outbreak of a novel coronavirus disease 2019 (COVID-19) was reported in Wuhan, China, which has subsequently affected more than 200 countries, areas, or territories worldwide. Ese severe COVID-19 patients show substantially elevated serum levels of proinflammatory cytokines, including interleukin-6 (IL-6) and IL2, as well as IL-1, IL-8, and tumor necrosis factor, characterized as cytokine storm, which may lead to respiratory failure or even death [3–5]. One clinical trial (https:// clinicaltrials.gov/ct2/show/ChiCTR2000029765), using the IL-6 receptor-targeted monoclonal antibody tocilizumab (TCZ), which blocks IL-6-mediated signals by inhibiting IL6 binding to transmembrane and soluble IL-6 receptors, Canadian Journal of Infectious Diseases and Medical Microbiology reported quick control of fever and an improvement of respiratory function in 21 patients with severe COVID-19 treated in Anhui, China [6]. Erefore, TCZ is recommended in seriously ill patients with elevated IL-6 by the Diagnosis and Treatment Protocol for COVID-19 (Trial Version 7) issued by the National Health Commission of China [7]. In the retrospective observational study, we will present the therapeutic response of TCZ in these 13 patients with COVID-19 and provide some experience for the clinical application
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
