Myelin flow cytometry assay detects enhanced levels of antibodies to human whole myelin in a subpopulation of multiple sclerosis patients

Antibodies directed against myelin components have been described in multiple sclerosis (MS). Accumulating evidence suggests that pathogenically relevant anti-myelin antibodies bind conformational and post-translationally modified epitopes. However, the current methods to detect anti-myelin antibodies often do not allow recognition of such epitopes.We developed a flow cytometry-based assay to detect antibodies to whole human myelin (including conformational and post-translationally modified epitopes). MS patients (n = 152) showed enhanced serum levels of anti-myelin antibodies (total Ig, IgG and IgM) when compared to healthy donors (HD, n = 40). Strikingly, approximately 50% of MS patients showed enhanced anti-myelin IgG levels. Anti-myelin IgG levels were not correlated with clinical parameters of disease. In the same population, serum antibody responses to recombinant myelin oligodendrocyte glycoprotein were comparable in MS patients and HD.