Effects of Tocilizumab on Inflammation and Iron Metabolism in Critically Ill Patients with COVID-19.

COVID-19 produces cytokine-mediated persistent inflammation and is associated with elevated iron stores and low circulating iron. It is believed that central to the pathophysiological mechanism is interleukin 6 and hepcidin. A state of iron overload, termed hyperferritinemia, and inflammatory anemia take place. Both conditions are linked to a worse result in critically ill patients. Blocking the interleukin 6-hepcidin pathway with Tocilizumab could present favorable outcomes. The aim of this study was to evaluate if Tocilizumab influences survival, the occurrence of sepsis, anemia and transfusions in critically ill patients suffering from COVID-19. This prospective observational study focused on levels of interleukin 6, hepcidin and blood iron parameters in patients treated with Tocilizumab. Data were compared before and after therapy as well as between treated and control groups. Results indicate that there is no difference in terms of survival nor in the rate of anemia or sepsis occurrence. Hepcidin was elevated and anemia ensued after treatment, which could indicate alternative pathways. In conclusion, when the classic interleukin 6-hepcidin pathway is blocked, inflammation seems to use alternative routes. Further understanding of these pathways is required and new pharmacological therapies need to be developed to treat persistent inflammation.

Hyperferritinemia, Low Circulating Iron and Elevated Hepcidin May Negatively Impact Outcome in COVID-19 Patients: A Pilot Study.

Inflammation in COVID-19 produces intracellular iron overload with low circulating iron available for metabolic processes. The accumulated intracellular iron generates reactive species of oxygen and results in ferroptosis, a non-programmed cell death. Since no organ is spared, iron dysmetabolism increases the mortality and morbidity. Hepcidin and the mediator interleukin 6 are believed to play a role in the process. Our aim is to evaluate the predictive values of serologic iron and inflammatory parameters in COVID-19 critically ill patients. Hence, 24 patients were included. Hepcidin and interleukin 6, along with routine blood parameters, were determined and outcomes, such as death, multiple organ damage (MOD), anemia, and need for transfusions, were assessed. The results of this pilot study indicate that iron metabolism parameters individually, as well as models consisting of multiple laboratory and clinical variables, may predict the outcomes. Further larger studies are needed to validate the results of this pilot stud. However, this paper identifies a new direction for research.