Overlapping syndrome of MOG-IgG-associated disease and autoimmune GFAP astrocytopathy.

Antibodies against myelin oligodendrocyte glycoprotein (MOG-IgG) have been considered to be closely relevant to an inflammatory demyelinating disease of the central nervous system (CNS). Glial fibrillary acidic protein (GFAP) immunoglobulin G (IgG) has been identified as a biomarker for a novel autoimmune astrocytopathy. However, coexistence of MOG-IgG and GFAP-IgG is extremely unusual and only one patient has been described with simultaneous presence of MOG-IgG in serum and GFAP-IgG in cerebrospinal fluid (CSF). Herein, we reported the first case of overlapping syndrome of MOG-IgG-associated disease (MOG-AD) and autoimmune GFAP astrocytopathy in whom MOG-IgG and GFAP-IgG were detected both in serum and CSF. A 20-year-old male patient was referred to our department with the presentation of decreased vision, diplopia and weakness of right limb with unknown reasons. Magnetic resonance imaging (MRI) revealed multiple intracranial lesions presenting hypointensity on T1-weighted images, hyperintensity on T2-weighted and FLAIR images and patchy contrast enhancement. MOG-IgG and GFAP-IgG were detected both in serum and CSF, and the titers of both antibodies fluctuated with the severity of disease. Treatment strategy employing intravenous methylprednisolone pulse therapy followed by oral prednisone with slow tapering resulted in an improvement of his symptoms and a sustained remission. Coexistence of MOG-IgG and GFAP-IgG with distinct underlying pathogeneses necessitates the recommendations to screen all recognized pathogenic antibodies against CNS antigens when an autoimmune disease is suspected, since it shows great significance for definite diagnosis of disease and treatment strategy options.