Relapsing Autoimmune GFAP Astrocytopathy: Case Report

Introduction. Glial fibrillary acidic protein (GFAP) is the main component of intermediate astrocyte filaments. In 2016, anti-GFAP antibodies (Ab) were identified as the specific biomarker for the first established CNS inflammatory disorder subsequently called autoimmune astrocytopathy associated with anti-GFAP Ab (A-GFAP-A). Since GFAP is localized intracellularly, GFAP Ab do not appear to be directly pathogenic though serve as a biomarker of immune inflammation. Although presence of GFAP-Ab in the serum (but not in the CSF) could be observed in various CNS immune-mediated diseases, detection of GFAP-Ab in CSF is only characteristic for A-GFAP-A. A-GFAP-A usually develops after the age of 40 and mostly manifests acutely or subacutely with symptoms of meningoencephalomyelitis or its focal forms. Linear perivascular radial cerebral white matter enhancement is a specific MRI finding of A-GFAP-A. Concomitant neoplasms or autoimmune disorders, as well as co-expression of other antineuronal antibodies are not uncommon in A-GFAP-A. Usually, disease responds well to immunotherapy, and prolonged remission could be achieved, however recurrent disease course and fulminant cases are also described in the literature. In these cases, long-term immunosuppression is required. Data on epidemiology, etiological factors, and precise pathogenesis of A-GFAP-A are still limited. Due to the lack of long-term follow-up data, diagnostic criteria, generally accepted treatment strategies or prognostic risk factors for relapse and outcome of the disease have not yet been established and precised. We present the first description of a case of relapsing A-GFAP-A in Russia and an analysis of the current data on the pathogenesis, clinical features, as well as the diagnostic challenges and treatment approaches for A-GFAP-A.