Plasma glial fibrillary acidic protein as a biomarker of blood-brain barrier integrity in patients with occult cerebral small vessel disease.

Objective: To investigate the association between plasma glial fibrillary acidic protein (GFAP) levels and blood-brain barrier (BBB) integrity in patients with occult cerebral small vessel disease (CSVD).

Methods: This retrospective study included patients with occult CSVD (CSVD group, n = 68) and age-matched individuals without CSVD (control group, n = 61). Demographic and clinical characteristics were compared between groups. Cognitive function was assessed using the Montreal Cognitive Assessment-B (MoCA-B). Plasma GFAP levels were measured, and all participants underwent sequential magnetic resonance imaging (MRI) to evaluate BBB integrity. Patients were stratified based on total MRI burden of CSVD into moderate/severe and none/mild load groups. Risk factors associated with moderate/severe CSVD load were analyzed.

Results: The prevalence of hyperlipidemia was significantly higher in the CSVD group than in the control group (P = 0.020), and MoCA-B scores were significantly lower. In the CSVD group, plasma GFAP levels were negatively correlated with total cholesterol (r = -0.281, P = 0.020) and low-density lipoprotein (r = -0.282, P = 0.020), as well as with MoCA-B scores (r = -0.440, P = 0.0002). MRI analysis revealed that brain regions showing significant correlations with elevated plasma GFAP levels exhibited BBB disruption and cortical thinning.

Conclusion: Elevated plasma GFAP levels are associated with cognitive impairment and BBB disruption in patients with occult CSVD. GFAP may serve as a potential biomarker for evaluating BBB integrity in this population.