Table 3. Laboratory characteristics of MIS-C with or without hyperferritinemia

	MIS-C with hyperferritinemia (n = 11)	MIS-C without hyperferritinemia (n = 11)	P value
Hemoglobin, g/dL	12.1 (9.6–14.9)	12.1 (10.5–13.2)	0.693
Total WBC count, μL	7,110 (2,350–20,390)	7,290 (2,940–14,660)	0.718
ALC, μL	854 (198–2,260)	1,020 (414–6,890)	0.450
Platelet count, 103 /μL	103 (62–431)	181 (103–389)	0.010
ESR, mm/h	22 (2–120)	36 (11–105)	0.211
CRP, mg/dL (normal < 0.5)	13.8 (3.2–25.5)	5.1 (3.3–9.4)	0.130
AST, U/L	52 (40–579)	57 (33-94)	0.843
ALT, U/L	54 (34–232)	61 (13–120)	0.412
Albumin, g/dL	2.8 (2.5–3.2)	3.4 (2.3–4.1)	0.048
NT-proBNP, pg/dL	1,044 (421–23,858)	1,676 (299–3,662)	0.577
Ferritin, ng/mL	1,145 (690–10,364)	286 (148–443)	< 0.001
Tn elevation	7 (63.6)	1 (11.1)	0.028
Abnormal TG or fibrinogen1)	8 (72.7)	9 (81.8)	1.000
Coagulopathy: INR > 1.1	7 (63.6)	8 (72.7)	1.000
Pyuria: ≥ 10 WBC/hpf	5 (45.4)	2 (18.2)	0.361
Met 2016 MAS criteria2)	11 (100.0)	0.0 (0.0)	< 0.001

Data are presented as frequency (%) or median (range). MIS-C: multisystem inflammatory syndrome in children; WBC: white blood cell; ALC: absolute lymphocyte count; ESR: erythrocyte sedimentation rate; CRP: C-reactive protein; AST: aspartate transaminase; ALT: alanine transaminase; NT-proBNP: N-terminal pro-brain natriuretic peptide; Tn: troponin; TG: triglyceride; INR: international normalized ratio; hpf: high-power field; MAS: macrophage activation syndrome.
TG >156 mg/dL or fibrinogen ≤360 mg/dL.
MAS is diagnosed when ferritin > 684 ng/mL and 2 of 4 criteria (platelets ≤ 181,000/μL, AST > 48 U/L, TG > 156 mg/dL, or fibrinogen ≤ 360 mg/dL) [16].