The Role of Intestinal Epithelial Permeability in Multisystem Inflammatory Syndrome in Children: A Case–Control Study.

Background: Multisystem inflammatory syndrome in children (MIS-C) occurs after SARS-CoV-2 infection, with gastrointestinal symptoms a prominent feature. This syndrome has been proposed to be triggered by persistent SARS-CoV-2 antigenemia due to increased intestinal epithelial permeability. We obtained evidence for this in this study. Methods: In a single-centre study, we recruited 83 children and analysed blood samples to quantify the circulating markers of increased intestinal permeability following SARS-CoV-2 infection. Publicly available proteomics MIS-C datasets were also accessed to assess the evidence for increased intestinal permeability. We further quantified SARS-CoV-2 antigenemia and the humoral response to SARS-CoV-2 spike protein. Results: Following SARS-CoV-2 infection, healthy children demonstrated no dysregulation of the intestinal epithelial barrier. In MIS-C, considerable increases in markers of epithelial dysfunction were observed, with similar increases noted in febrile controls. Furthermore, we found little evidence of persistent SARS-CoV-2 antigenemia in MIS-C. Conclusions: Our results suggest that although increased intestinal epithelial permeability is a feature of MIS-C, it is not unique to the condition, and persistent SARS-CoV-2 antigenemia does not occur. [ABSTRACT FROM AUTHOR]