Clinical course and long-term outcomes in autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy.

Background: The aim was to describe the clinical course and long-term outcomes of the French cohort of patients with glial fibrillary acidic protein (GFAP) astrocytopathy.

Methods: Patients with positive CSF GFAP antibody test were identified between May 2017 and February 2023. Those whose clinical presentation occurred < 2 years before the initiation of the study, with other diagnosis than GFAP astrocytopathy, and with missing clinical information were excluded.

Results: Among the 74 patients included, 71 were alive at last follow-up. The median age at onset was 43 years (range 6-84), 44 patients were male (62%), and 11 (15%) had a neoplasia. The main initial syndrome was meningo-encephalitis (n = 41, 58%). The median follow-up was 28 months (range 1-129). The median mRS at presentation was 4 (range 1-5) and at last follow-up was 1 (range 0-4). Forty patients reported disability at last follow-up (56%). The most frequent sequelae were cognitive complaints (20/40, 50%) and gait disorder (19/40, 48%). 38/55 patients (69%) returned to school/work. Long-term immunoactive treatment was introduced in 40 patients (56%); the most commonly administered were oral corticosteroids (n = 35, 49%). Relapses were documented in 10 patients (14%) and occurred after a median follow-up of 9 months (range 3-46). The presence of concomitant tumor at onset was associated with relapse (HR 4.55, 95% CI 1.28-16.14, p = 0.03).

Conclusions: This study suggests a greater impact than previously described in long-term outcomes of patients with GFAP astrocytopathy and reports concomitant tumor at presentation as a risk factor for relapse.