Effect of tocilizumab treatment in mildly-obese patients with coronavirus disease 2019: a case series

BACKGROUND: The coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is an increasingly widespread international medical problem. Several randomized trials and observational studies in patients with COVID-19 have been performed. However, the standard treatment strategy has not yet been established. The purpose of this study is to report effect of tocilizumab treatment combined with remdesivir, dexamethasone, and heparin on obese Japanese patients with COVID-19. Tocilizumab is a monoclonal antibody against the interleukin-6 (IL-6) receptor. Obesity, characterized by systemic enlarged adipocytes, promotes proinflammatory cytokine expression in adipose tissue. More specifically, obesity induces detrimental adipocytokine production including tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), and IL-6. In addition, its production in the adipose tissue is associated with body mass index (BMI) and adipocyte size. IL-6 can promote inflammation not only in the adipose tissues but also in endothelial cells and triggers systemic inflammation. METHODS: A cross-sectional observational study was conducted. The study sample consisted of 96 patients between August 2020 and January 2021 at Showa University Fujigaoka Hospital. RESULTS: Overall, 56.3% (54 of 96) were administered with remdesivir, 54.2% (52 of 96) with dexamethasone, 19.8% (19 of 96) with anticoagulant therapy with heparin. Of the patients, nine were administered tocilizumab with remdesivir, dexamethasone, and heparin. The current study indicated that single-dose treatment of tocilizumab in combination with remdesivir, dexamethasone, and heparin is beneficial for obese Japanese patients with COVID-19. CONCLUSIONS: We believe that the severity of obesity is related to the anti-IL-6 treatment sensitivity in patients with COVID-19.