Decreasing Levels of Neurofilament Light Chain in Relapsing Glial Fibrillary Acidic Protein Astrocytopathy – A Case Report
Victoria Dai1, Elizabeth Verter2
1Albert Einstein College of Medicine, 2Montefiore Einstein
Objective:
We review usage of neurofilament light chain (NfL) as a biomarker for disease activity in glial fibrillary acidic protein astrocytopathy (GFAP-A).
Background:
GFAP-A is a monophasic or relapsing immune mediated meningoencephalomyelitis associated with IgG antibodies against GFAP. NfL, a product of axonal breakdown detected in cerebrospinal fluid (CSF) and serum, is an established biomarker of neuroinflammation/neurodegeneration. Elevated CSF and serum NfL (sNfL) were reported during acute GFAP-A.
Design/Methods:

We describe a case of acute exacerbation of GFAP-A without increased sNfL levels.

Results:

A 41-year-old female presented to an outside hospital with generalized weakness, altered mental status, painful spasms, and urinary retention. MRI revealed multiple confluent supratentorial and infratentorial lesions with associated radial perivascular enhancement, and diffuse longitudinal cervical and thoracic cord signal hyperintensity, with edema and patchy enhancement. CSF revealed lymphocytic pleocytosis and elevated protein. Patient was diagnosed and treated for multiple sclerosis with 3 days of high dose intravenous steroids and 300mg of ocrelizumab. Patient then presented to our center with relapsing disease and was diagnosed with CSF confirmed GFAP-A. Patient had significant clinical improvement after plasma exchange and steroid taper, with resolved perivascular enhancement and reduction in parenchymal T2 hyperintensities. sNfl was measured (390 pg/mL, normal <17.3 pg/mL) ~2 months after relapse and steadily declined over 7 months. At 8 months, while on 8mg prednisone, she developed expressive aphasia. Imaging revealed recurrent perivascular enhancement. Despite clinical and radiographic evidence of relapse, sNfL further decreased (31.5 pg/mL). Patient was treated with intravenous steroids, plasma exchange, and rituximab. sNfL 2 months post-treatment was stable.

Conclusions:
To our knowledge, no reports exist of declining NfL in acute GFAP-A. These findings suggest NfL levels may not be a reliable marker of disease activity in GFAP-A, possibly representing delayed neurodegeneration after acute inflammatory process. Further studies are needed to understand NfL trajectory throughout this disease course.
Generative AI Usage
No, did not use generative AI in the drafting or editing in this abstract.
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