Research shows that many children with PANS have dysfunctional immune systems. When conventional psychiatric medications fail, treatments such as intravenous immunoglobulin (IVIG) have shown some success; however, IVIG is short-term, costly, and invasive. Further research into such treatments is impeded by lack of knowledge about PANS biomarkers. Using RNA sequencing of whole blood, this team identified a transcriptomic signature of immune dysfunction in children with PANS, whose features are modifiable with IVIG and associated with clinical improvements. This study aims to validate this signature in a larger cohort of children with PANS, examine it at a cellular level, and explore how IVIG modifies this signature at a cellular level. The results from this study will provide the first evidence for a signature of immune dysfunction in children with PANS, increasing our potential at finding effective treatments.