Clinical Characteristics and Outcomes in Patients with COVID 19 Received Tocilizumab in Wuhan, China: A Multicentre Retrospective Cohort Study

Background: Coronavirus Disease-2019 (COVID-19) has caused considerable morbidity and mortality. Hence, there is an urgency to find effective treatment. Tocilizumab, an inhibitor of IL-6, has been widely proposed as a treatment of severely ill patients without robust evidence supporting its use. Methods: In this multicentre, retrospective, cohort study, we included 5,235 adult patients who were admitted to 3 hospitals in Wuhan, China with confirmed COVID-19 from January 20 to March 18, 2020 . 65 patients in tocilizumab group and 130 patients in non-tocilizumab group were propensity score matched at a ratio of 2:1 based on age, sex, and comorbidities. Detailed demographic data, comorbidities, radiological and laboratory parameters, complications and treatments were compared between tocilizumab group and non-tocilizumab group. Furthermore, univariable and multivariable Logistic and Cox regression models were used to explore the risk of complications and in-hospital death associated with tocilizumab. Findings: During the follow-up, patients in non-tocilizumab group were more likely to develop into death (42 [32·31%] vs 14 [21·54%]). After adjusting for confounding, the detected risk for in-hospital death was lower in the tocilizumab group versus the non-tocilizumab group (HR=0·47; 95% CI=0·25-0·90; p=0·023). In the multivariable logistic regression model, use of tocilizumab was associated with a lower risk of ARDS (OR=0 · 23; 95% CI=0·11-0·45; p<0·0001). Before treatment the patients had heightened inflammation and more dysregulated immune cells, which might aggravate disease progression. However, abnormally elevated IL-6, CRP, fibrinogen and APTT decreased in COVID-19 patients after treatment. And the counts of lymphocytes and immune cells subset in peripheral blood, which decreased in patients, returned to normal after treatment. No obvious complications were observed. Interpretation: Tocilizumab may be of value in improving outcomes in severe patients of COVID-19, which provided a novel strategy for COVID-19-induced cytokine release syndrome (CRS). Our preliminary data could inform bedside decisions until more data from randomized, controlled clinical trials becomes available. Funding Statement: SARS-CoV-2 Pneumonia Emergency Technology Public Relations Project of Tongji Medical College, Huazhong University of Science and Technology (No. 2020kfyXGYJ043) and National Key Research and Development Plan for the Emergency Management of Novel Coronavi rus Pneumonia, China (No. 2020YFC0845100). Declaration of Interests: The authors report no conflicts of interest. Ethics Approval Statement: This study was approved by the Ethics Committee of Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology (TJ-C20200108) and granted a waiver of informed consent from study participants.