Blood Neutrophils from Children with COVID-19 Exhibit Both Inflammatory and Anti-Inflammatory Markers

Background: Perhaps reflecting that children with COVID-19 rarely exhibit severe respiratory symptoms and often remain asymptomatic, little attention has been paid to explore the immune response in pediatric COVID-19. Here, we analyzed phenotype function of circulating neutrophils from COVID-19. Methods: One seventy-four COVID-19, 21 multisystem inflammatory syndrome (MIS-C), 40 healthy were studied. Neutrophil was by flow cytometry blood samples. Cytokine production plasma levels IgG antibodies directed spike protein SARS-CoV-2 measured ELISA. Cell-free DNA quantified fluorometry. Findings: Compared controls, showed a lower expression CD11b, CD66b, L-selectin but higher activation markers HLA-DR, CD64 PECAM-1 inhibitory receptors LAIR-1 PD-L1. No differences pattern cytokine NETs observed when compared Interestingly, not only distinguished asymptomatic mild moderate also positively correlated serum concentration SARS-CoV-2. Interpretation: Acute lung injury is prominent feature adults. A low adhesion molecules together high might prevent tissue infiltration preserving function. Funding: FONCyT- ANPCyT, UBA, Argentina. Declaration Interests: The authors have declared no conflict interest exists. Ethics Approval Statement: Institutional Review Board at institutions participants reviewed approved sample collection overall study.