AB0700 TOCILIZUMAB DID NOT REDUCE MORTALITY IN SEVERE COVID-19 PATIENTS BUT CAUSED THROMBOCYTOSIS

Background:TCZ is a monoclonal antibody against Interleukin-6 receptor (IL-6R) which is used for relieving inflammation and reducing mortality in COVID-19 patients. Safety and efficacy of Tocilizumab (TCZ) in Covid-19 pneumonia is uncertain yet. In this study, we aimed to determine clinical outcomes in patients treated with TCZ.Objectives:In this study we aimed to share our retrospective results which we had obtained from patients with COVID-19 diagnosis received TCZ.Methods:We performed a retrospective case control study between May and August 2020 in Turkey. We compared outcomes in patients who received TCZ with those who did not. Death in hospital and intensive care unit (ICU) requirements were evaluated as endpoints. Demographic data, comorbidities, additional treatment, treatment side effects, laboratory and clinical results were retrospectively assessed. There are no significant differences between groups according to age, gender and Charlson Comorbidity Index (CCI).Results:12 (27.3%) patients died in standard group and eight (18.6%) patients died in TCZ group (p=0.150).Days of staying in the hospital were eight days in standard treatment group and 12 days in TCZ group (p=0.03). 10 of 43 patients in TCZ group were admitted to ICU. MV support was needed in 8 of these patients. 18 of 44 patients (40.9%) within the standard group were admitted to ICU and 12 patients (27.3%) were intubated (p=0.125,p=0.480). Significant IL-6 decrease was not observed post treatment in TCZ group according to pretreatment period (p=0.60). Significant decreases were examined in CRP and ferritin values through TCZ treatment. However, D-dimer and thrombocyte values increased.Conclusion:TCZ may not be an effective treatment for reducing ICU requirement, to prevent intubation or death, for shortening period for staying in hospital. The patients should be followed up closely for possible thrombosis because of increased D-dimer and thrombocytes with TCZ treatment.References:[1]Sharma A, Tiwari S, Deb MK, Marty JL. Severe acute respiratory syndrome coronavirus-2 (SARS-Cov-2): A global pandemic and treatment strategies. IntJ Antimicrob Agents. 2020 Aug; 56(2):106054.[2]Singhal T. A rewiev of coronavirus Disease-2019(COVID-19). Indian J Pediatr. 2020 Apr;87(4):281-286.[3]Mehta P, McAuley DF, Brown M, Sanchez E, Tattersall R.S, Manson J.J. COVID-19: consider cytokine storm syndromes and immunosuppression. Lancet. 2020;395(10229):1033-[4]Teijaro J.R. Cytokine storms in infectious diseases. SeminImmunopathol. 2017;39:501–503.[5]Zhang Y, Li J, Zhan Y, Wu L, Yu X, Zhang W et al. Analysis of Serum Cytokines in Patients with Severe Acute Respiratory Syndrome. Infect Immun 2004 Aug;72(8):4410-4415.[6]Zhang C, Wu Z, Li JW, Zhao H, Wang GQ. Cytokine release syndrome in severe COVID-19: interleukin-6 receptor antagonist tocilizumab may be the key to reduce mortality. Int J Antimicrob Agents. 2020 May; 55(5):105954.[7]Xu Z, Shi L, Wang Y, Zhang J, Huang L, Zhang C et al. Pathological findings of COVID-19 associated with acute respiratory distress syndrome. Lancet Respir Med. 2020;8(4):420–2[8]Fu B, Xu X, Wei H. Why tocilizumab could be an effective treatment for severe COVID-19? J Transl Med 18,164 (2020).[9]Guaraldi G, Meschiari M, Cozzi-Lepri A, Milic J, Tonelli R, Menozzi M et al. Tocilizumab in patients with severe COVID-19: a retrospective cohort study. Lancet Rheumatol. 2020 Aug;2(8):e474-e484.[10]Gupta S, Wang W, Hayek S.S, Chan L, MathewsK.S, Melamed M.L et al. Association Between Early Treatment With Tocilizumab and Mortality Among Critically Ill Patients With COVID-19. JAMA Intern Med. 2021 Jan1;181(1):41-51.[11]Campochiaro C, Della-Torre E, Cavalli G, De Luca G, Ripa M, Boffini N et al Efficacy and safety of tocilizumab in severe COVID- 19 patients: a single-centre retrospective cohort study. Eur J Intern Med. 2020 Jun;76:43-49.Disclosure of Interests:None declared