Changes in Inflammatory Markers after Administration of Tocilizumab in COVID-19: A Single-Center Retrospective Study

The COVID-19 pandemic requires the development of effective methods for the treatment of severe cases. We aimed to describe clinical outcomes and changes in inflammatory markers in Polish patients treated with tocilizumab. The medical charts of SARS-CoV-2-positive patients treated in the Department of Infectious Diseases between 4 March and 2 September 2020 were retrospectively analyzed. The patients who received tocilizumab according to the Polish Association of Epidemiologists and Infectiologists guidelines were selected for the study. We identified 29 individuals who received tocilizumab, out of whom 11 (37.9%) died. The individuals who died had significantly higher maximal interleukin-6 (IL-6) and lactate dehydrogenase (LDH) serum levels than survivors. After administration of tocilizumab, further increase in LDH and IL-6 was a prognostic factor for unfavorable outcomes. Among inflammatory markers, 7-day mean of IL-6 serum concentration was the best predictor of death (cut-off: ≥417 pg/mL; area under ROC curve = 0.81 [95% Confidence Interval: 0.63-0.98]). The serum concentrations of inflammatory markers before administration of tocilizumab did not predict the outcome, whereas IL-6 and LDH measurements after administration of tocilizumab seemed to be of predictive value.