Objective:

To describe a case of autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy, highlighting the importance of considering this entity in the differential diagnosis of presumed central nervous system infections.

Background:

GFAP astrocytopathy is a rare autoimmune neuroinflammatory disorder with a broad spectrum of clinical manifestations including meningitis, encephalitis, and/or myelitis. Its presentation can closely mimic infectious meningoencephalomyelitis, particularly when meningitis is the presenting feature.

Design/Methods:

N/A

Results:

A 24-year-old man with no significant medical history presented with several days of fever, headache, meningismus, and photophobia. Cerebrospinal fluid (CSF) analysis showed lymphocytic pleocytosis (320 cells/µL), elevated protein (186 mg/dL), and low glucose (35 mg/dL). Varicella-zoster virus (VZV) DNA was detected by a multiplex meningitis/encephalitis PCR panel. Despite prompt initiation of intravenous acyclovir, he developed progressive encephalopathy, seizures, respiratory failure, and quadriparesis. MRI of the brain and spine revealed multiple linear T2-hyperintense lesions in the periventricular white matter, a cytotoxic lesion of the corpus callosum (CLOCC), and a longitudinally extensive spinal cord lesion spanning the upper cervical to lower thoracic segments. High-dose intravenous corticosteroids were initiated, followed by plasma exchange and intravenous immunoglobulin, resulting in gradual neurologic improvement. CSF GFAP-IgG later returned positive at high titer (1:64) by cell-based assay, confirming a diagnosis of autoimmune GFAP astrocytopathy. The patient was transitioned to a prolonged oral corticosteroid taper over several months, with continued functional recovery. A stand-alone (non-multiplex) CSF VZV PCR later returned negative, suggesting a false-positive result on the initial multiplex assay.

Conclusions:

Autoimmune GFAP astrocytopathy can closely mimic viral meningoencephalomyelitis, and false-positive multiplex PCR results may confound the diagnosis. This entity should be considered in patients with presumed infectious meningitis and/or encephalomyelitis unresponsive to antiviral therapy, as early recognition and immunotherapy can lead to substantial recovery.