Elevated ITGAX/CD11c in CSF-Derived Extracellular Vesicles Reflects Disability Progression in Multiple Sclerosis

Area of Science:

• Neuroimmunology
• Extracellular Vesicle Biology
• Biomarker Discovery

Background:

• Extracellular vesicles (EVs) are implicated in neuroinflammation and neurodegeneration, but their role in multiple sclerosis (MS) is unclear.
• Identifying unique EV characteristics in MS is crucial for understanding disease pathogenesis.

Purpose of the Study:

• To identify distinctive protein characteristics of EVs in the cerebrospinal fluid (CSF) of patients with MS.
• To explore the potential of CSF-derived EVs as biomarkers for MS disease severity and prognosis.

Main Methods:

• EVs were isolated from CSF using phosphatidylserine affinity methods.
• Mass spectrometry was employed to analyze protein content in CSF and EVs from discovery and validation cohorts.
• Cohorts included patients with MS, other neurologic diseases (ONDs), and neuromyelitis optica spectrum disorders.

Main Results:

• Significant increases in 33 CSF proteins and 100 EV proteins were observed in MS patients.
• Specific proteins (ITGA4, ITGAX, MS4A1, CD3E) were elevated in MS patient EVs compared to ONDs.
• ITGAX levels in EVs correlated with confirmed disability worsening and showed potential for prognosis prediction.

Conclusions:

• CSF-derived EVs reflect immunologic changes characteristic of MS and other neuroimmune diseases.
• Myeloid cell and lymphocyte alterations may contribute to MS pathogenesis.
• CSF-derived EVs show promise as future biomarkers for MS disease severity and prognosis.