Why tocilizumab could be an effective treatment for severe COVID-19?

Abstract

A severe pneumonia-associated respiratory syndrome caused by a new coronavirus was identified in December 2019 , spread rapidly and has become a world-wide public health challenge. About 25% of COVID-19 patients experienced severe complications including acute respiratory distress syndrome (ARDS), and even progressed into an intensive care unit (ICU) admission and died. The exploration for the mortality causes and advancing novel therapeutic development of severe COVID-19 is crucial at the moment. The biopsy samples analysis at autopsy suggested that increased alveolar exudate caused by aberrant host immune response and inflammatory cytokine storm probably impedes alveolar gas exchange and contributes to the high mortality of severe COVID-19 patients. Our research has identified that pathogenic T cells and inflammatory monocytes incite inflammatory storm with large amount of interleukin 6, therefore monoclonal antibody that targets the IL-6 pathways may potentially curb inflammatory storm. Moreover, Tocilizumab treatment that blocking IL-6 receptors showed inspiring clinical results including temperature returned to normal quickly and respiratory function improved. Therefore, we suggest that Tocilizumab is an effective treatment in severe patients of COVID-19 to calm the inflammatory storm and reduce mortality.

Impact of Corticosteroids and Immunosuppressive Therapies on Symptomatic SARS-CoV-2 Infection in a Large Cohort of Patients with Chronic Inflammatory Arthritis

“…The improvement in knowledge on COVID-19related ARDS pathogenesis has pointed out the central role of the abnormal immune response to SARS-CoV-2 leading to a massive release of pro-in ammatory mediators known as cytokine release storm [52,53]. This has actually paved the way for the use of biological drugs and small molecules in the treatment of the most severe subsets of COVID-19 [13,[54][55][56][57][58][59]. Although the apparent bene cial therapeutic effects of immunomodulatory agents cannot be translated into any speculation on their prophylactic role, the possibility that chronic use of ts/bDMARDs may dampen exaggerated immune reactions, thus mitigating COVID-19 progression into more symptomatic patterns, deserves further investigation.…”

An Update on Current Therapeutic Drugs Treating COVID-19

“…A study published in April 2020 reported that 21 severe or critical COVID-19 patients in China were treated with the compound, with 20 of them recovered at the time of publication and 1 on the way to recovery (but still in ICU). Encouraged by these results, a larger multicenter clinical trial was launched (ChiCTR2000029765) and had about 500 patients treated with tocilizumab already enrolled [109,110].…”

Dramatic improvement after tocilizumab of severe COVID‐19 in a child with sickle cell disease and acute chest syndrome

“…Tocilizumab, that targets IL-6 receptors, was suggested to be effective on clinical evolution as well as on immune dysregulation. 6 After a single TCZ injection, serum IL-6 level first increases rapidly before decreasing. In the absence of significant clinical improvement with persistence of an elevated IL-6 level, a second and a third dose of TCZ can be administered after 12 and 24-36 hours respectively.…”