Immunological criteria for the diagnosis of multisystem inflammatory syndrome associated with MERS-COV-2 and infectious diseases with sepsis in children

Multisystem inflammatory syndrome associated with SARS­CoV­2 in children is a potentially life–threatening condition that develops several weeks after COVID­19 and is characterized by a hyperinflammatory response with damage to ≥2 organs and systems. At the moment, there is no understanding of how the mechanisms of development and course of this disease differ from other more studied similar conditions, for example, sepsis in infectious diseases. The aim is to compare immunological parameters in multisystem inflammatory syndrome associated with SARSCoV­2 and infectious diseases with sepsis in children. Materials and methods . The concentration of cytokines, chemokines and growth factors in serum was determined in 14 children with multisystem inflammatory syndrome associated with SARS­CoV­2, 19 children and 16 healthy children (control group) with IHS. Results . Both common and distinctive signs of inflammation were found in patients with MVS­D and IHS. Patients with MVS­D, unlike healthy children, were characterized by a decrease in Basic FGF, IFN­a2, IL­1a, IL­1b, IL­2, IL­3, IL­4, IL­5, IL­9, IL­12(p40), IL­13, IL­18, PDGF­BB, RANTES, TRAIL and Boost G­CSF, HGF, IL­1ra, IL­2Ra, IL­6, IL­10, IL­16, IP­10, MCP­1, M­CSF, MIG. Statistically significant in MVS­D was a decrease in IL­2 and IL­5 levels compared with the control group, but significantly less pronounced than in IS (8.0 times and 3.5 times, respectively), a pronounced increase in MIG levels (12.0 times compared with children with IS). The RANTES index (a proinflammatory chemokine that attracts leukocytes to the focus of inflammation) decreased with MVS­D, while it increased with IS compared with the control group. Conclusions . Immunological features of MISC have been found that distinguish the pathogenesis of the syndrome from infectious diseases occurring with sepsis. The identified markers can be used as criteria for the differential diagnosis of these diseases.