Fig. 5.

A SARS-CoV-2 infection produces an abnormal increase of circulating ECFCs and impairs iron metabolism increasing the levels of ferritin and decreasing erythropoiesis, resulting in a decrease in hemoglobin levels. Additionally, SARS-CoV-2 causes digestion of hemoproteins, decreasing the levels of hemoglobin and resulting in iron cell leakage, which increase ferritin levels. B Post-COVID-19 patients with lower numbers of ECFC had lower levels of hemoglobin and higher levels of ferritin, suggesting that those patients presented a higher inflammatory response, possibly as a result of an insufficient ECFC mobilization that could act as a protective mechanism. Long-COVID syndrome was associated with higher ferritin levels, lower hemoglobin levels and with female gender. ECFC endothelial colony-forming cells. Created with BioRender.com