Autoimmune inflammatory meningoencephalitis in a patient negative for glial fibrillary acidic protein-specific immunoglobulin G

In this study, we describe clinical findings in a patient with autoimmune inflammatory meningoencephalitis who was negative for antibodies against glial fibrillary acidic protein (GFAP-IgG).

Serum and cerebral spinal fluid (CSF) samples were collected from the patient as part of a study of 520 patients with neurological syndromes. Antibodies against GFAP and other proteins associated with neurological disorders were measured by rat brain- and cell-based indirect immunofluorescence assays.

A 42-year-old female was diagnosed with autoimmune inflammatory meningoencephalitis. She experienced a subacute and relapsing course with decreased vision, fever, headache, ataxia, hemiplegia, and disturbance of consciousness. Brain magnetic resonance imaging showed extensive lesions in the white matter along the ventricle, brainstem, right internal capsule, and meninges. The patient responded well to steroid treatment. Examination of CSF revealed a normal white blood cell count and protein level. Serum and CSF were negative for GFAP-specific antibodies and all other autoantibodies tested. Immunohistochemical staining of a brain biopsy collected during relapse revealed chronic inflammation and severe edema. Extensive and strong staining of CD163+ macrophages were evident throughout the lesions; however, CD3+ cells were rare and CD138+ and CD20+ cells were absent.

We describe a case of subacute corticosteroid-responsive nonvasculitic autoimmune inflammatory meningoencephalitis in the absence of GFAP-IgG. The pathological features were distinct from those of patients with GFAP-IgG-positive meningoencephalitis, suggesting that nonvasculitic autoimmune inflammatory meningoencephalitis is a heterogeneous neurological syndrome.