BACKGROUND AND AIM: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), a novel coronavirus, has caused a pandemic with a clinical course ranging from asymptomatic infection to pneumonia, Acute Respiratory Distress Syndrome (ARDS), and death. This study analyzes the effectiveness of tocilizumab (TCZ) in treating hospitalized Coronavirus Disease 2019 (COVID-19) patients.

METHODS: We included 141 patients with Macrophage Activation Syndrome (MAS) admitted to our hospital and treated with tocilizumab in addition to standard care. We examined laboratory parameters before and after TCZ treatment and assessed changes in clinical and radiological images.

RESULTS: The median time to start TCZ treatment was 6.5 days post-admission. Eighty patients received the first dose of TCZ within 6.5 days post-admission, while 61 patients received it after 6.5 days post-admission. Among the group who received TCZ within 6.5 days, 22 (27.5%) out of 80 patients died, whereas 30 (49.3%) out of 61 patients died in the group who received TCZ after 6.5 days post-admission (p=0.008). According to the laboratory results on the first day of hospitalization, the day of TCZ initiation, and the third and fifth following days; the median C-Reactive Protein (CRP), lymphocyte, and fibrinogen levels of patients returned to normal after TCZ treatment.

CONCLUSIONS: Several risk factors, such as older age and comorbidities, can cause mortality in severe COVID-19 patients. We observed that administering TCZ in the early stages of MAS decreased the necessity for both invasive and non-invasive mechanical ventilation, assisted in clinical recovery, and lowered the mortality rate.