Background and Aims:

Autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy is a steroid-responsive meningo-myelo-encephalitis characterized by anti-GFAP Antibodies and specific morphological findings such as linear perivascular radial gadolinium enhancement on brain-MRI.

Methods:

Two cases of myelo-meningo-encephalitis with some common features are herein described.

Results:

Case-1:45-year-old woman, with acute urinary retention, gait ataxia, mental slowness and headache.
Case-2:45-year-old man, with acute urinary retention, cerebellar ataxia and progressive paraparesis.
The two cases shared:
- a post-infectious onset (febrile urinary tract infection);
- spine MRI with linear leptomeningeal gadolinium enhancement, brain MRI with linear perivascular radial enhancement and FLAIR parenchimal and leptomeningeal hyperintensities (figure).
- CSF: high cellularity (204 and 177 leukocytes/mcl, respectively), high proteins (123 and 177 mg/dl, respectively) and intrathecal oligoclonal IgG production.
- no other CSF/serum investigations suggesting autoimmune-inflammatory, metabolic or infectious disorders.
- response to IV corticosteroids.

Case-1 only, showed CSF and serum anti-GFAP IgG1 antibodies, revealed by home-made cell-based-assay.

Conclusions:

Two cases of myelo-meningo-encephalitis with perivascular linear enhancement have been described, although definite diagnosis of autoimmune anti-GFAP astrocytopathy could be reached in Case-1 only. Nevertheless, anti-GFAP antibodies more likely represent an epiphenomenon accompanying a predominant T-cell mediated process.

Noteworthy, in both cases new MRi findings not typical of other disimmune CNS disease, as leptomeningeal FLAIR hyperintensities in cerebral sulci, brainstem and perivascular spaces, were also observed, suggesting a novel “autoimmune astrocytopathy spectrum disease (AASD)”. Considering that seronegative patients with histological features consistent with anti-GFAP-astrocitopathy have been described, in the second case the same diagnosis could be hypothesized even in absence of anti-GFAP antibodies.