Protein microarray analysis reveals BAFF-binding autoantibodies in systemic lupus erythematosus

Area of Science:

• Immunology
• Autoimmunity
• Proteomics

Background:

• Autoantibodies targeting cytokines, chemokines, and growth factors disrupt immune function, contributing to autoimmune and immunodeficiency disorders.
• Detecting these autoantibodies is crucial for understanding and diagnosing immune-related diseases.

Purpose of the Study:

• To develop a high-throughput, unbiased method for detecting autoantibodies against serum factors in patient samples.
• To identify autoantibody targets in Systemic Lupus Erythematosus (SLE) and assess their correlation with disease characteristics.

Main Methods:

• Construction of a multiplex protein microarray on a nitrocellulose surface containing various human cytokines, chemokines, and circulating proteins.
• Validation of the microarray's specificity for detecting serum factor-binding autoantibodies (Abs).
• Application of the microarray to analyze serum samples from patients with autoimmune polyendocrine syndrome type 1, chronic mycobacterial infection, and SLE.

Main Results:

• The protein microarray successfully detected specific autoantibody reactivity to various serum factors.
• Elevated immunoglobulin G (IgG) autoantibody reactivity to B cell-activating factor (BAFF) was identified in SLE patients compared to controls.
• BAFF autoantibody levels correlated with the severity of SLE, particularly with interferon-alpha (IFN-α)-driven disease manifestations.

Conclusions:

• Multiplex protein microarrays are effective tools for detecting autoantibody reactivity to serum factors in human samples.
• Increased autoantibody reactivity to BAFF may indicate an elevated inflammatory state within the spectrum of SLE.
• This approach aids in understanding the role of autoantibodies in autoimmune and immunodeficiency diseases.