Background: The potential role of interleukin-6 (IL-6) in coronavirus disease 2019 (COVID-19) pneumonia provides the rationale for investigating IL-6 signaling inhibitors.
Objectives: To evaluate and report treatment responses to tocilizumab (TCZ) in COVID-19 patients and compare mortality outcomes with those of standard care.
Material and methods: Patients hospitalized with a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, diagnosed with reverse transcription polymerase chain reaction (RT-PCR) between March 2020 and April 2021, were enrolled in this single-center retrospective cohort study. Propensity score matching was performed in order to reduce confounding effects secondary to imbalances in receiving TCZ treatment.
Results: A total of 364 patients were included in this study. Two hundred thirty-six patients received standard care, while 128 patients were treated with TCZ in addition to standard care (26 (20.3%) patients received a dose of 400 mg intravenously once, while 102 (79.7%) patients received a total dose of 800 mg intravenously). In the propensity score-matched population, less noninvasive mechanical ventilation (p = 0.041) and mechanical ventilation support (p = 0.015), and fewer deaths (p = 0.008) were observed among the TCZ-treated patients. The multivariate adjusted Cox regression model showed a significantly higher survival rate among TCZ patients compared to controls (hazard ratio (HR): 0.157, 95% confidence interval (95% CI): 0.026-0.951; p = 0.044). The hazard ratio for mortality in the TCZ group was 0.098 (95% CI: 0.030-0.318; p = 0.0001 using log-rank test).
Conclusions: This study determined that TCZ treatment in COVID-19 patients was associated with better survival, reduced need for mechanical ventilation and reduced hospital-associated mortality.
Keywords: COVID-19; cytokine storm; mortality; pneumonia; tocilizumab.