The difference of the inflammatory milieu in MIS-C and severe COVID-19

Background Coronavirus disease 19 (COVID-19) may have a severe course in children. Multisystem inflammatory syndrome in children (MIS-C) is the post-COVID complication characterized by an exaggerated inflammation, observed in children. However, data on the underlying pathophysiology are sparse. We therefore aimed to assess the cytokine and chemokine profiles of children with MIS-C and compare these to life-threatening severe SARS-CoV-2 and healthy controls (HCs) to shed light on disease pathophysiology. Methods Samples of 31 children with MIS-C, 10 with severe/critical COVID-19 and 11 HCs were included. Cytokine and chemokine profiles were studied and compared in between groups. Results Most cytokines and chemokines related to IL-1 family and IFN-gamma pathway (including IL-18 and MIG/CXCL9) and IL-17A were significantly higher in the MIS-C group when compared to the severe/critical COVID-19 group and HCs. IP-10/CXCL10 and IL-10 were higher in both MIS-C patients and severe/critical COVID-19 compared to HCs. Conclusion Our results suggest that IL-1 and IFN-gamma pathways play an important role in the pathophysiology of MIS-C. Impact This study defines a pattern of distinctive immune responses in children with MIS-C and in patients with severe/critical COVID-19. As the COVID-19 pandemic continues, biomarkers to identify MIS-C risk are needed to guide our management that study results may shed light on it.

Automated summary

This study investigates the cytokine and chemokine profiles of children with MIS-C and compares them to severe/critical COVID-19 cases and healthy controls. The results suggest that IL-1 and IFN-gamma pathways play a significant role in the pathophysiology of MIS-C. These findings contribute to our understanding of immune responses in children with MIS-C and severe/critical COVID-19.