COVID-19 and Iron Metabolism: Traditional Review

Viruses invade cells to reproduce, and they require an iron-filled cell for efficient reproduction. Together with other viruses, the coronavirus disease-2019 (COVID-19) virus can alter the expression of proteins involved in iron homeostasis. For example, in COVID-19 patients, an increase in pro-inflammatory cytokines such as interleukin-6 may stimulate the synthesis of hepcidin, the regulatory hormone of iron metabolism, thereby suppressing ferroportin-mediated cellular iron export. Increased serum levels of ferritin in COVID-19 virus infection is associated with a poor prognosis and may be partly due to the virus itself. Some viruses selectively infect iron acceptor cells (e.g. macrophages) by binding to transferrin receptor 1 during cell entry. Moreover, human airway secretions in the major route of entry of COVID-19 include transferrin and lactoferrin, and this glycoproteins can bind iron and maintain a chemically inert form. Understanding how iron metabolism and viral infection interact in the COVID-19 outbreak may suggest new ways to control the disease.