Preliminary Study on the Effect of Impaired Glucose Tolerance on Blood-Brain Barrier Permeability in Non-Neurosyphilis Patients

Background: Blood-brain barrier (BBB) is frequently disrupted in patients with diabetes mellitus (DM) and/or neurosyphilis (NS). Clinical cases reflect a trend that non-neurosyphilis (non-NS) patients with impaired glucose tolerance (IGT) are likely to develop NS and/or DM. Objective: To investigate whether IGT promotes BBB disruption in patients with non-NS. Methods and Material: A total of 21 subjects were enrolled, including six with IGT, nine with non-NS, and six with both IGT and non-NS. BBB permeability was evaluated by dynamic contrast-enhanced (DCE) MRI and the secretion of biomarkers from cerebrospinal fluid (CSF) were measured by colorimetric method, immune turbidimetric method, and enzyme-linked immunosorbent assay (ELISA) method. Results: The non-NS patients with IGT have higher BBB permeability at cortex superior frontal gyrus, white matter, and thalamus than non-NS patients without IGT or IGT patients without non-NS. The CSF-serum albumin-quotient (Qalb) levels and CSF secretion are highest in non-NS patients with IGT, including matrix metalloproteinase 9 (MMP9), soluble intercellular cell adhesion molecule-1 (sICAM-1), and soluble vascular cell adhesion molecule-1 (sVCAM-1). Conclusions: Significant correlations between CSF biomarkers and BBB permeability were found.