Ferritin and Severe COVID-19, from Clinical Observations to Pathogenic Implications and Therapeutic Perspectives

BACKGROUND A virally-induced cytokine storm syndrome, associated with a massive and overwhelming systemic inflammation, burdens a subgroup of patients with severe coronavirus disease-2019 (COVID-19), which leads to pulmonary inflammation and extensive lung damage. These severe COVID-19 patients are characterized by high ferritin levels. These findings mirror what was previously reported about the prognostic role of this iron storage protein in other inflammatory diseases included in the hyperferritinemic syndrome. The latter suggests that ferritin could be a further pathogenic mediator in enhancing the inflammatory process, stimulating inflammatory pathways, and thus perpetuating a vicious pathogenic loop. Considering its activity as an immune activator, a therapeutic approach targeting ferritin may be also postulated in these diseases. Considering these observations, high ferritin levels characterize severe COVID-19 and other diseases included in the hyperferritinemic syndrome. Because ferritin could enhance the inflammatory process, it could be tested as a possible new therapeutic target to improve the outcome of these patients.