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

Abstract

Introduction: Coronavirus is a group of viruses which causes diseases in mammals and birds. In humans, these family of viruses can cause the respiratory infections from mild form to fatal forms. It is preferably called as coronavirus. Formally it known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or 2019 novel coronavirus (2019- nCoV) and this disease is called as coronavirus disease 2019 (COVID-19). SARS-CoV-2 is infectious in humans and world health organization has announced that Covid-19 as a pandemic disease. Tocilizumab is a biological agent which 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 positive effect in patients with covid-19. Purpose of the Study: 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: The search strategy on recent research and review articles is used for the SARS-CoV-2 disease and their characteristics. Furthermore we have analyzed most recent research article on monoclonal antibody against IL-6 receptors (tocilizumab) and their possible clinical effects in Covid-19 and their clinical trials on Covid-19 patients. Results and Conclusion: 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 treatment for covid-19 globally. Furthermore we can conclude that SARS-CoV-2 is associated with 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. 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. has shown the efficacy of tocilizumab in severe and critically ill covid-19 patients. However we need more randomized research studies with significant number of patients which can confirm the promising results on tocilizumab treatment in covid-19 patients and even ongoing clinical trails such as TOSCA, COVACTA results has not been published yet which are expected to give better and more significant results on tocilizumab’s effectiveness and safety.

When Does the Cytokine Storm Begin in COVID-19 Patients? A Quick Score to Recognize It

“…The treatments proposed in various studies have included corticosteroid therapies (commonly used to suppress inflammation), Janus kinase (JAK) inhibitors (IL-1 family antagonists) or IL-6 receptor blockade (IL-6 antagonists), and TNF blockers. The randomized controlled COVACTA trial NCT04320615 (A Study to Evaluate the Safety and Efficacy of Tocilizumab in Patients With Severe COVID-19 Pneumonia)failed to meet its primary end point of improved clinical status [43], but evidence in the literature, instead, reports efficacy with tocilizumab [44][45][46]. Care should be taken in interpreting data from the COVACTA study, one consideration is that something must be done about the timing of the administration, because the immunosuppression (with glucocorticoids or IL-6 blockade) needs to intervene when the immune response makes the patient sick.…”

PMX-DHP Therapy for Dyspnea and Deoxygenation in Severe COVID-19 Pneumonia: A Case Series

“…Although tocilizumab has been shown in some studies to reduce mortality risk in patients with severe COVID-19, 9 , 10 in other studies, its effects were less clear. 11 , 12 However, in the present study, both patients improved after PMX-DHP therapy, although the mechanism through which this was achieved remains unclear. However, the reason why patients who did not respond to tocilizumab responded well to PMX-DHP is that PMX-DHP has been suggested to act by reducing the levels of several inflammatory cytokines in addition to IL-6.…”

Current treatment strategies for COVID‑19 (Review)

“…Of the 77 patients, 61 achieved significant improvement as indicated by chest X-ray. As such, the therapeutic efficacy of tocilizumab for COVID-19 is rapid, sustained and associated with significant clinical improvement (82,83).…”