Table 1.

Clinical and laboratory abnormalities of «hyperferritinemic syndromes» and patients with COVID-19 severe infection (modified from Rosario C. et al. [1]).

	Severe COVID-19 *	Septic shock	AOSD	MAS	CAPS
Hyperferritinemia	++	++	+++	+++	++
Ferritin range (ng/ml)	>300 (300–5000)	>300 (300–5000)	>300 (even >5000)	>300 (even >10,000)	>300 (300–5000)
Hypercytokemia	+++	+++	+++	+++	+++
Infection as trigger	+++	+++	++	++	++
Fever	+++	+++	+++	+++	++
Multi organ involvement	+++	+++	+++	+++	+++
ARDS	+++	+	+	+	+
Hepatomegaly	NR	rare	++	++	NR
Splenomegaly	NR	rare	++	++	NR
Hemophagocytosis	NR	+	+	+++	NR
Trombocytopenia	+/−	+	−	+	+
Anaemia	+	+	+	+	+
Leukopenia	++	+	−	++	NR
Low/absent NK activity	+	+	+	+	NR
Sol IL-2R > 2400 U/ml	+	+	+	+	NR
Hyper TG	NR	+	−	++	NR
Abnormal Liver function	++	++	++	++	++
Coagulopathy	++	++	+	++	+++
ESR/CRP (↓↑)	+++ (↑ESR ↑CRP)	+++ (↑ESR ↑CRP)	+++ (↑ESR ↑CRP)	++ (↓ESR ↑CRP)	++ (↑ESR ↑CRP)

Legend: * [54,[65], [66], [67]]; ARDS = acute respiratory distress syndrome; NK = natural killer; Sol IL-1R = soluble interleukin-2 receptor; TG = triglycerides; ESR = erythrocytes sedimentation rate; CRP = C-reactive protein.