Abstract: Page 1 of 30 1 Efficacy of diammonium glycyrrhizinate combined with vitamin C for treating hospitalized 2 COVID-19 patients: a retrospective, observational study 3 4 Ruoming Tan1, Xiaogang Xiang2, Wei Chen3, Zhitao Yang4, Weiguo Hu5, Hongping Qu1*, Jialin 5 Liu1* 6 7 1 Department of Critical Care Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of 8 Medicine, Shanghai, 200025, China; 2 Department of Infectious Diseases, Ruijin Hospital, 9 Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China; 3 Department of 10 Pulmonary and Critical Care Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of 11 Medicine, Shanghai, 200025, China; 4 Department of Emergency, Ruijin Hospital, Shanghai Jiao 12 Tong University School of Medicine, Shanghai, 200025, China; 5 Department of Surgery, Ruijin 13 Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China. 14 15 *Correspondence: 16 Jialin Liu*, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, 17 China, Email:ljl11243@rjh.com.cn, Phone: +86 21 53305091, Fax: +86 21 54500671. 18 Hongping Qu*, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 19 200025, China, Email:hongpingqu0412@hotmail.com. 20 21 22 23 24 25 26 27 28 29 30 © The Author(s) 2021. Published by Oxford University Press on behalf of the Association of Physicians. All rights reserved. For Permissions, please email: journals.permissions@oup.com 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Manuscripts submitted to QJM: An International Journal of Medicine Manuscripts submitted to QJM: An International Journal of Medicine 31 Abstract: 32 Background: The current global coronavirus disease 2019 (COVID-19) pandemic caused by severe 33 acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has shown limited responses to medical 34 treatments. 35 Aims: To observe the effect of combination treatment of giammonium glycyrrhizinate and vitamin 36 C （DV）on the prognoses of patients with COVID-19. 37 Methods: This retrospective observational study recruited 207 COVID-19 patients from Tongji 38 Hospital，patients were assigned to DV and non-DV groups on the basis of the DV treatment. To 39 make the results more credible, a propensity-score matching (PSM) approach was adopted at a 1:3 40 ratio to determine the participants. Logistic analysis was used to assess the effect of DV therapy in 41 the progress of COVID-19. 42 Results: In the DV group, the new onset incidence rate of acute respiratory distress syndrome 43 (ARDS) after admission was clearly lower than that in the non-DV group (DV vs non-DV groups, 44 15.2% vs 35.7%; P=0.002). Compared with the non-DV group, the DV group showed fewer new 45 onset of complications (such as ARDS, acute liver injury and acute myocardial injury) (DV vs non- 46 DV groups,19.6% vs 46.1%; P=0.000). Moreover, DG+VC may help to recover the count of NK 47 cells and decrease the level of sIL-2R. 48 Conclusions: DG+VC might be a promising candidate for preventing the deterioration of COVID- 49 19 patients, which is worthy to be studied in large and perspective..