Dramatic Response of Multi-System Inflammatory Involvement (Mis-N) in Neonates Treated with IvIg and Methylprednisolone

Severe acute respiratory coronavirus-2 (SARS-CoV2) has shown its impending impact by causing multisystem inflammatory syndrome in children. MIS-N is an evolving entity with a skeptical presentation. Its progression is very unforeseeable and fatal. Recent studies have speculated vertical transmission of immunoglobulins (IgG) to the fetus. Along with the antibodies, some cytokines might cross the placenta and induce a systemicinflammatory response in the newborn. Infection and subsequent hyperinflammatory process appears to have occurred in two different individuals (i.e. infection in mother and Mis-N in neonates). It typically occurs 2-6 weeks after acute SARS-CoV-2 infection. Angiotensin-converting enzyme II (ACE2) was known to be the cell receptor for SARS-CoV.1 It is speculated that children were less sensitive to 2019-nCoV than adults due to the immaturity and binding ability of ACE2 in children.2 Additionally, children have a higher levels of antibody against virus than adults. Furthermore, children’s immune systems are still developing and may respond to pathogens differently from adult immune systems. However, it has been found that the proportion of severe and critical cases was 10.6%, 7.3%, 4.2%, 4.1%, and 3.0% for the age groups <1, 1 to 5, 6 to 10, 11 to 15, and >15 years, respectively.3 These results suggest that young children, particularly infants, were vulnerable to 2019-nCoV infection. Therefore, the mechanism for the difference in clinical manifestations between children and adults remains to be determined.