Circulating extracellular vesicles in Systemic Lupus Erythematosus: physicochemical properties and phenotype

Area of Science:

• Biomedical research
• Immunology
• Nanotechnology

Background:

• Systemic lupus erythematosus (SLE) is a chronic autoimmune disease.
• Extracellular vesicles (EVs) are implicated in intercellular communication and disease pathogenesis.
• Identifying reliable biomarkers for SLE is crucial for diagnosis and management.

Purpose of the Study:

• To characterize the physicochemical and phenotypic properties of circulating EVs in SLE patients.
• To investigate the potential of these EVs as biomarkers for SLE, with or without lupus nephritis (LN).

Main Methods:

• Plasma EVs were isolated from SLE patients (n=38) and healthy controls (n=18) using differential centrifugation.
• EVs were analyzed for size, morphology, surface charge, and phenotype (e.g., EV-CD45+, EV-CD14+, EV-IgM+) using electron microscopy, dynamic light scattering, and flow cytometry.
• Energy Dispersion Spectrum (EDS) was assessed for elemental composition.

Main Results:

• SLE-EVs were larger and more numerous than control EVs (p<0.0001).
• SLE-EVs exhibited altered EDS (p<0.001) and reduced electronegativity (p<0.0001).
• Increased frequencies of EV-CD45+, EV-CD14+, and EV-IgM+ were observed in SLE patients (p<0.001, p<0.05, p<0.001).

Conclusions:

• Circulating EVs in SLE patients display distinct physicochemical and phenotypic characteristics compared to controls.
• Larger EV size and the presence of surface IgM are promising features for discriminating SLE patients.
• These findings highlight the potential of EVs as diagnostic biomarkers for SLE.