Biomarkers.

Area of Science:

• Neuroscience
• Biochemistry
• Medical Diagnostics

Background:

• Alzheimer's disease (AD) diagnosis relies on biomarkers like amyloid-beta and phosphorylated tau (p-tau).
• Glial fibrillary acidic protein (GFAP) shows potential in reflecting and predicting disability in neurodegenerative diseases.
• Exploring novel biomarkers like GFAP is crucial for validating pathological mechanisms and improving clinical data reliability in AD.

Purpose of the Study:

• To measure glial fibrillary acidic protein (GFAP) and phosphorylated tau (p-tau) levels in human blood.
• To evaluate the correlation between GFAP and p-tau levels for Alzheimer's disease (AD) diagnosis.
• To assess the diagnostic potential of these biomarkers using a magnetic bead-based electrochemical sensor.

Main Methods:

• Magnetic beads coated with specific antibodies were used for GFAP and p-tau detection.
• Blood samples from normal controls (NC), mild cognitive impairment (MCI), and AD patients were analyzed.
• Impedance change rates of GFAP and p-tau were compared to differentiate between NC, MCI, and AD groups.

Main Results:

• Both GFAP and p-tau showed low impedance change rates in normal controls.
• MCI patients exhibited slightly elevated impedance change rates compared to controls.
• AD patients displayed the highest impedance change rates, approximately double that of controls, indicating significant astrocyte activation.
• Multi-biomarker analysis demonstrated superior diagnostic reliability (higher Area Under Curve values) compared to single biomarkers.

Conclusions:

• GFAP and p-tau blood levels, measured via a magnetic bead-based electrochemical sensor, correlate with Alzheimer's disease (AD) status.
• GFAP effectively indicates astrocyte activation in individuals across the NC, MCI, and AD spectrum.
• Combining GFAP and p-tau enhances diagnostic accuracy for AD, suggesting potential for improved prognosis and point-of-care applications.