Serum autoantibodies to cell surface determinants in multiple sclerosis: a flow cytometric study

Area of Science:

• Neuroimmunology
• Autoimmune diseases
• Cellular immunology

Background:

• Multiple sclerosis (MS) is traditionally viewed as autoimmune and inflammatory.
• Evidence suggests autoantibodies may contribute to MS pathogenesis.
• Previous studies on antibodies to myelin basic protein and myelin-oligodendrocyte glycoprotein yielded inconclusive results.

Purpose of the Study:

• To investigate the presence of antibodies targeting cell surface determinants on oligodendrocyte and neuronal cells in MS patients.
• To compare antibody binding in MS sera with sera from other inflammatory central nervous system (CNS) diseases and healthy controls.

Main Methods:

• Flow cytometry was used to detect antibody binding to intact cultured human cell lines.
• Sera from MS patients (relapsing-remitting and secondary progressive subtypes), other inflammatory CNS diseases, and healthy individuals were analyzed.
• Antibody binding was assessed on oligodendrocyte precursor (OPC)-derived cell lines and a neuronal cell line (SK-N-SH).

Main Results:

• Significant IgG or IgM antibody binding to OPC cell lines was observed in 50% of MS sera, with no difference between RRMS and SPMS.
• Antibody binding to the neuronal cell line SK-N-SH was significantly higher in SPMS (70%) compared to RRMS (25%) (P < 0.001).
• No significant antibody binding differences were found when OPCs were differentiated, cells were permeabilized, or in patients with 'benign' MS.

Conclusions:

• Antibodies targeting accessible cell surface antigens on OPCs and neurons are present in a subset of MS patients.
• These findings support the hypothesis that autoantibody-mediated processes may be relevant in specific MS patient subgroups.
• Identifying these specific cell surface targets could reveal new therapeutic strategies for MS.