Abstract
A 30-year-old Chinese male diagnosed with autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy presented with cerebrospinal fluid (CSF) eosinophilia. Magnetic resonance imaging (MRI) revealed no significant abnormalities; however, CSF analysis demonstrated the presence of GFAP-immunoglobulin G (IgG) antibodies. Notably, the CSF showed marked eosinophilia, which declined following methylprednisolone therapy and was accompanied by clinical improvement. The proportion of eosinophils in the CSF of this patient exceeded previously reported levels in cases of autoimmune GFAP astrocytopathy. These findings suggest a potential relationship between eosinophil infiltration and the pathogenesis of autoimmune GFAP astrocytopathy, indicating that eosinophils may contribute to disease progression.