Atypical Inflammatory Syndrome Triggered by SARS-CoV-2 in Infants with Down Syndrome

Area of Science:

• Pediatric Immunology
• Infectious Diseases

Background:

• Adults with Down syndrome (DS) face higher risks for severe COVID-19 pneumonia.
• COVID-19 in children with DS is not well understood, though SARS-CoV-2 can cause severe pneumonia or multisystem inflammatory syndrome in children (MIS-C) in the general pediatric population.

Observation:

• Two infant girls with DS developed an atypical, severe form of MIS-C requiring prolonged hospitalization (>4 months).
• Immunological assessments revealed significant neutrophilia, B cell depletion, elevated IL-6, IL-8, ICAM1, and FcɣRI.

Findings:

• Children with DS, even when uninfected, showed similar but less pronounced immune alterations at baseline.
• These baseline immune characteristics may predispose children with DS to exaggerated inflammation post-SARS-CoV-2 infection.

Implications:

• A severe, atypical MIS-C presentation is possible in infants with Down syndrome.
• Understanding these immune dysregulations is crucial for managing COVID-19 and MIS-C in children with DS.