Table 1.

Markers of Cytokine Storm

Marker	Source	Association with Cytokine Storm	Normal Range	COVID-19 Marker Cut-Off	References
Ferritin	Serum Chemistry	Cellular ferritin leaks from damaged cells	18–350 ng/mL	≥ 400 μg/L*	[85]
D-dimer	Serum Chemistry	Defective plasma coagulation	250–500 ng/mL	≥ 1000 ng/mL*	[86]
Lactate dehydrogenase	Serum Chemistry	Lactic acidosis	140 −280 U/L	≥ 450U/L *	[83]
C-Reactive Protein	Serum Chemistry	Associated to IL-6 stimulation	0.3 to 1.0 mg/dL	≥ 20 mg/dL*	[87]
ALT	Serum Chemistry	Damage of hepatocytes	19 to 33 IU/L	67 (47–100) IU/L*	[88]
Cytokines	Serum Chemistry
	IL-1beta	Pro-inflammatory activity	0.10 pg/mL	0.67 pg/mL	[89]
	IL-6	Pro-inflammatory activity	0.5 to 5 pg/mL	<25 pg/mL*	[90,91]
	TNF-α	Pro-inflammatory activity	0 to 8.1pg/mL	< 35pg/mL*	[92]
Neutrophil/Lymphocyte Ratio	Hematological	Increased neutrophil counts and lymphopenia.	1.0–3.0	6.6 (2.1–11.1)*	[7,93]
Erythrocyte Sedimentation Rate	Hematological	Platelet destruction	0 to 29 mm/hr	>100 mm/hr*	[94]

Notes: *Marker levels suggest a remarkable increase from the normal range. They are not to be taken as fixed as they do vary as the disease progresses due to several other factors.