Autoimmune Meningoencephalomyelitis Associated with Glial Fibrillary Acidic Protein IgG Antibodies

Mayo Clinic laboratories have identified 134 cases positive for glial fibrillary acidic protein immunoglobulin G (GFAP IgG) autoantibodies among more than 100,000 patients being evaluated for autoimmune and paraneoplastic disorders as part of routine clinical care. This report details the clinical course in 16 patients, along with details on the assay.

Patients typically present with subacute onset of headache, confusion, behavioral changes, lethargy, blurred vision, and difficulty walking. Exam may be notable for papillitis, cranial nerve palsies, and signs of myelopathy. Spinal fluid can reveal moderate inflammation with elevated white blood cells (4/μL–500/μL), increased protein, oligoclonal bands, and elevated IgG index. Magnetic resonan…