COVID-19 and liver dysfunction in children: Current views and new hypotheses

Table 3 Immune features in pediatric patients with varying degrees of coronavirus disease 2019

Biomarker	Severe	Moderate	Mild/asymptomatic
T lymphocyte[45-47]	CD3+↓; CD4+ ↓; CD8+ ↓; CD3+CD4+ ↓; CD3+CD8+ ↓	CD3+ →; CD4+ →/↑; CD8+ →	CD3+ →; CD4+ →; CD8+ →
B lymphocyte[23,46]	↓	→/↑	→/↑
Innate cell[23,46]	Monocytes ↑; Neutrophils ↑; NK cells ↓	Monocytes ↑; NK cells ↑; Neutrophils ↓	Monocytes →; Neutrophils →; NK cells →
Immunological parameters[23,46]	IgE ↑; IgG ↓; IgA ↑; IgM ↓; C3 ↑/↓; C4 ↑/↓	IgE →/↑; IgG →/↑; IgA →/↑; IgM →; C3 ↑/↓; C4 ↑	IgE →/↑; IgG →/↑; IgA →/↑; IgM →; C3 ↑/↓; C4 →
Inflammatory cytokine[23,46,47]	IL-2 ↑; IL-4 ↑; IL-6 ↑; IL-10 ↑; IFN-γ ↑; TNF-α ↑	IL-2 →; IL-4 →; IL-6 →; IL-10 ↑; IFN-γ →; TNF-α →	IL-2 →; IL-4 →; IL-6 →; IL-10 →; IFN-γ →; TNF-α →
Chemokines[49]	CXCL10 →; CXCL8 →; CCL2 →	CXCL10 →; CXCL8 →; CCL2 →	CXCL10 →; CXCL8 →; CCL2 →

↑: Increased; ↓: Decreased; →: Unchanged.

NK: Nature killer; Ig: Immunoglobulin; C: Complement; IL: Interleukin; IFN: Interferon; TNF: Tumor necrosis factor; CXCL: Chemokine (C-X-C motif) ligand; CCL: CC chemokine ligand.