PhD Scientific Days 2021

CL_III_L: Clinical Medicine III. Lectures

Laboratory parameters predicting in-hospital mortality of adult in-patients with COVID-19 associated cytokine release syndrome treated with high-dose tocilizumab – experiences from the national COVID-19 centre of Hungary

Text of the abstract

Introduction
A recent large randomized clinical trial in Coronavirus Disease 2019 (COVID-19) patients with hypoxia and elevated C-reactive protein levels has proven efficacy of high-dose (8 mg/kg) intravenous tocilizumab, a monoclonal antibody targeting the interleukin-6 receptor.

Aim
Our aim was to describe the laboratory parameters predicting in-hospital mortality of patients with tocilizumab administration in COVID-19 associated cytokine release syndrome (CRS).

Methods
We evaluated high-dose intravenous tocilizumab administration in a single centre observational cohort study of critically ill COVID-19 adult patients fulfilling predefined strict CRS criteria. A single-centre, prospective, observational cohort study was carried out among consecutive adult (≥18 years of age) in-patients with COVID-19 at our centre between April 1 and December 31, 2020. Primary endpoints were 28-day all-cause mortality and ICU admittance. Changes from baseline in laboratory parameters on day 7 and 14 after administration of tocilizumab were noted.

Results
In total, 1801 patients were admitted to our centre during the study period. One hundred and six patients received tocilizumab, and among them 62 (58.5%) required intensive care unit (ICU) admittance while 25 (23.6%) deceased. At day 7 after tocilizumab administration, inflammatory markers (CRP, IL-6, ferritin) and lactate dehydrogenase (LDH) values were significantly lower among survivors. Subsequently, at day 14, differences of IL-6 and LDH levels has become more pronounced between subgroups. Restoration of absolute lymphocyte count (ALC) by day 7 and 14 was insufficient among patients who died.

Conclusion
In the studied cohort, administration of high-dose tocilizumab for COVID-19 patients with cytokine release syndrome demonstrated clinical and sustained biochemical parameter improvement in 76.4%. In this patient population high and increasing LDH, IL-6, and low ALC may have a predictive role for mortality.

University and Doctoral School

Semmelweis University, Károly Rácz Doctoral School of Clinical Medicine