ABSTRACT
Background: The treatment of COVID-19 caused by SARS-CoV-2 posed serious challenges to health care systems. In 8-10% of patients with severe COVID-19 have a cytokine storm syndrome, highlighting the importance of host immune response in pathogenesis. Objectives: Our aim was to evaluate the effect of tocilizumab treatment in COVID-19 patients with severe cytokine storm who were refractory to standard of care therapy. To determine the prognostic factors that indicate the success of treatment in these patients. Methods: Fifty-three patients were treated with tocilizumab during waves 2 and 3 of the pandemic due to a cytokine storm associated with SARS-CoV-2 infection. All patients underwent physical examination, saturation monitoring, laboratory examination, blood gas analysis and chest CT examination. Deteriorating clinical status, elevated IL-6 and other acute phase protein levels observed in patients treated with standard therapy suggest cytokine storm syndrome. The treatment of these patients was supplemented with 8 mg/kg (max. 800 mg) tocilizumab (1 or 2 times within 24 hours). We assessed the clinical and laboratory response of these patients to IL-6-R inhibitor therapy, the need for ventilation, the need for intensive care and mortality. Results: Immunological consultations were performed in 31 patients, of whom 21 (68%) were successfully treated. Eleven patients of them (22%) died. In the 22 non-consulted patients, this rate was reversed: 7 (22%) were successful and 15 (68%) were treatment failures. The success of the treatment was mainly influenced by the well-established indication, the recognition of contraindications, and the condition that did not require invasive ventilation method. The 29 tocilizumab therapies initiated in the non-intensive care unit avoided intensive care unit treatment in 18 patients. Eleven patients were admitted to the intensive care unit, but 7 patients required temporary respiratory support and recovered, 4 patients required invasive mechanical ventilation and later died (14%). In contrast, 24 treatments initiated in the intensive care unit saved the lives of only 3 patients, and 21 patients were lost (87.5%). The effectiveness of treatment was not affected by age, with survival rates of 40%, 44%, 57% and 55% for the 40-49, 50-59, 60-69, 70-79 age groups, respectively. Interestingly, the extent of lung involvement also did not show a signifcant difference. Although it was a prerequisite for initiating tocilizumab treatment to have fresh alveolitis on the CT image of the chest. Conclusion: Use of tocilizumab is most effective in patients with COVID-19 who have high levels of infammatory activity and IL-6, who are at an early stage of lung involvement and who do not respond to high-dose corticosteroid therapy, who have no bacterial superinfection and require not invasive mechanical ventilation. It is also important that specialist who has immunological approach and routine with biological treatment be also involved in the care of patients with severe COVID-19 disease.