Tocilizumab in COVID-19: Factors Associated With Mortality Before and After Treatment Sarabia de Ardanaz, Luis Andreu Ubero, José María Navidad Fuentes, Miriam Ferrer González, Miguel Ángel Ruiz del Valle, Víctor Salcedo Bellido, Inmaculada Barrios Rodríguez, Rocío Cáliz Cáliz, Antonio Rafael Requena Méndez, María del Pilar COVID-19 Immunosupression Tocilizumab Mortality Risk factor Platelet We thank Pablo Lardelli Claret for his helpful advice in statistical methods. We also acknowledge the staff of Hospital Universitario Virgen de las Nieves who took (and are taking) care of the COVID-19 patients. Tocilizumab (TCZ) has been administered in SARS-CoV-2 pneumonia but the factors associated with mortality before and after treatment remain unclear. Cox regression models were used to estimate the predictors of time to death in a cohort of hospitalized patients with COVID-19 receiving TCZ. In addition, the mean differences between discharged and deceased patients in laboratory parameters measured before and 3, 6 and 9 days after TCZ administration were estimated with weighted generalized estimation equations. The variables associated with time to death were immunosuppression (Hazard Ratio-HR 3.15; 95% confidence interval-CI 1.17, 8.51), diabetes mellitus (HR 2.63; 95% CI 1.23–5.64), age (HR 1.05; 95% CI 1.02–1.09), days since diagnosis until TCZ administration (HR 1.05, 95% CI 1.00–1.09), and platelets (HR 0.27; 95% CI: 0.11, 0.69). In the post-TCZ analysis and compared to discharged patients, deceased patients had more lactate dehydrogenase (p 0.013), troponin I (p 0.013), C-reactive protein (p 0.013), neutrophils (p 0.024), and fewer platelets (p 0.013) and lymphocytes (p 0.013) as well as a lower average PaO2/FiO2 ratio. In conclusion, in COVID-19 diagnosed patients receiving TCZ, early treatment decreased the risk of death, while age, some comorbidities and baseline lower platelet counts increased that risk. After TCZ administration, lower platelet levels were again associated with mortality, together with other laboratory parameters. 2021-09-14T10:15:58Z 2021-09-14T10:15:58Z 2021-07-01 info:eu-repo/semantics/article Sarabia De Ardanaz L... [et al.] (2021) Tocilizumab in COVID-19: Factors Associated With Mortality Before and After Treatment. Front. Pharmacol. 12:620187. doi: [10.3389/fphar.2021.620187] http://hdl.handle.net/10481/70202 10.3389/fphar.2021.620187 eng http://creativecommons.org/licenses/by/3.0/es/ info:eu-repo/semantics/openAccess Atribución 3.0 España Frontiers Research Foundation