Case1:

A 41-year-old female presented with dizziness, headache, emesis, and dysarthria. Examination revealed nystagmus, dysmetria, and brisk reflexes. MRI showed T2 hyper-intensities with enhancement. CSF showed elevated WBCs, protein, immunoglobulin, oligoclonal bands, and GFAP antibodies. Intravenous methylprednisolone resolved her symptoms. She had three relapses and developed seizures despite methylprednisolone. She was treated with levetiracetam and started on mycophenolate mofetil. Her symptoms resolved after four months.

Case2:

A 53-year-old female presented with confusion, dysarthria, and hallucinations after reported meningitis. MRI showed cerebritis. CSF had elevated WBCs and protein. No infection was discovered, and she was unchanged despite antimicrobials. Meningeal biopsy showed perivascular lymphocytic infiltrates consistent with AE. She improved with IVIG, but later relapsed. CSF found GFAP antibodies. She improved with methylprednisolone followed by rituximab. Weeks later, she developed status epilepticus with increased enhancement on MRI. After improving with plasmapheresis and cyclophosphamide, she returned 14 months later with seizures and enhancing lesions. She returned to normal after cyclophosphamide followed by mycophenolate mofetil.

 AE is newly recognized, with a number of antibodies discovered since the early 2000’s. CNS targeted antibodies can be divided by cellular location. These cases had antibodies to GFAP, a cytoplasmic protein, which likely result in antibody production after T-cell mediated damage. While GFAP related AE is steroid responsive, steroid-sparing agents may be necessary. No randomized trials exist, but clinical improvement in AE has been reported with maintenance therapies.

Our cases demonstrate effectiveness of T-cell targeted therapies in a likely T-cell mediated AE. The first with mycophenolate mofetil, and the second with cyclophosphamide followed by mycophenolate mofetil. The second patient relapsed after rituximab therapy, raising the hypothesis that T-cell directed therapy may be preferable in GFAP related AE.