this article has no bearing on COVID but does show how ferritin can affect those certain cells.
https://jprsolutions.info/files/final-file-5ec958f16ddfa0.73615335.pdf
The Lung Dr who got this early on and had to be hospitalized had insane Ferritin levels. The article about him was either on Slate or Salon.
Ferritin is a nonspecific acute phase reactant. It is a reasonable marker of inflammation and can help us understand the prognosis but thats about the end of it from a clinical standpoint.
https://www.salon.com/2020/04/05/what-it-feels-like-to-survive-covid-19s-dreaded-cytokine-storm/
“In the current context, we believe we have a biomarker of this condition, a serum level of a non-specific but is an acute phase reactant called serum ferritin. It looks like it may be to be one of the more reliable biomarkers of cytokine dysregulation. A serum ferritin is normally below 400 in our lab, mine was 18,000!”