In this work, we revealed that: (1) the CSF and serum sTREM2 levels are higher in MOG-AD pediatric patients; (2) the CSF sTREM2 levels are correlated with CSF WBC count and CSF protein concentration; (3) the CSF sTREM2 levels are correlated with mRS score; and (4) the CSG sTREM2 levels could be a biomarker for MOG-AD diagnosis. Here, MOG is linked to Alzheimer disease.