Prominent urinary dysfunction and delayed antibody detection in patients with glial fibrillary acidic protein astrocytopathy: a case series analysis

BACKGROUND: Glial fibrillary acidic protein astrocytopathy (GFAP-A) is a rare central nervous system (CNS) autoimmune disorder with highly heterogeneous presentations. This study aims to describe the clinical and diagnostic features in a Chinese case series. METHODS: Six patients at a single tertiary center with positive GFAP antibody were included, the patients' data were retrospectively analyzed. RESULTS: The cohort included 3 males and 3 females, with a median age of 56 years (range 30-75). Prominent urinary dysfunction was observed in four patients (66.7%). Brain or spinal cord MRI abnormalities were present in only 50% (3/6) of patients. All patients exhibited CSF-specific oligoclonal bands and elevated indices of intrathecal IgG synthesis. A notable finding was the delayed detection of CSF GFAP antibody in five patients (83.3%), who tested negative at disease onset but turned positive upon follow-up testing weeks to months later. CONCLUSION: This case series underscores the high frequency of autonomic urinary dysfunction and the potential for delayed antibody detection in Chinese GFAP-A patients. These findings suggest that clinical suspicion should remain high even with initial negative antibody testing, warranting repeat CSF analysis in suspected cases to avoid diagnostic delay.