Tocilizumab in SARS-CoV-2 Patients with the Syndrome of Cytokine Storm: A Narrative Review

Abstract

Introduction: Corona virus is a group of viruses that cause diseases in mammals and birds. In humans, these families of viruses can cause respiratory infections from a mild form to fatal. It is preferably called coronavirus. Formally, it is known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or 2019 novel coronavirus (2019-nCoV) and this disease is called coronavirus disease 2019 (COVID-19). SARS-CoV-2 is infectious in humans and the world health organization has announced COVID-19 as pandemic disease. Tocilizumab is a biological agent that inhibits the cytokine, interleukin 6 (IL-6 inhibitor). As SARS-CoV-2 infection leads to the development of cytokine storm syndrome, the drug, tocilizumab, seems to have a positive effect on patients with COVID-19.

Aim: To analyze and review the possible effects and efficacy of the tocilizumab (monoclonal antibody against IL-6 receptors) in SARS-CoV-2 patients.

Materials and methods: A search was carried out for all recent review articles, which were used to study the SARS-CoV-2 disease and their characteristics. Furthermore, we have analyzed the most recent research articles on monoclonal antibody against IL-6 receptors (tocilizumab) and their possible clinical effects in COVID-19 and its' clinical trials.

Results: COVID-19 is a disease caused by SARS-CoV-2 infection. It is a life threatening condition, which can give rise to fatal outcomes if left untreated. However, there are no approved treatments for COVID-19 globally. Furthermore, we can conclude that SARS-CoV-2 is associated with the worsening of lung conditions, characterized by interstitial pneumonia with acute respiratory distress syndrome as a result of cytokine storm syndrome. According to available research data, tocilizumab, a recombinant humanized anti-human monoclonal antibody of IgG1τ (gamma 1, kappa), can improve patient's condition from cytokine storm syndrome by inhibiting the IL-6 (Interleukin 6) receptors.

Conclusion: The rational use of the tocilizumab in severe and critically ill COVID-19 patients can prevent the development of irreversible lung injury and death of the patient. Three retrospective studies of Xiaoling Xu et al., Pan luo et al., and Paola Tonaiti et al. have shown the efficacy of tocilizumab in severe and critically ill COVID-19 patients. However, we need more randomized research studies with a significant number of patients which can confirm the promising results on tocilizumab treatment in COVID-19 patients. Moreover, ongoing clinical trails such as TOSCA, COVACTA results have not been published yet which are expected to give better and more significant results on tocilizumab's effectiveness and safety.

Keywords: Covid-19; SARS-CoV-2; acute respiratory distress syndrome; cytokine release syndrome; cytokine storm; interleukin 6 (IL-6); interstitial pneumonia; tocilizumab.