Evolution in anti-myelin oligodendrocyte glycoprotein antibody detection and its clinical significance: a narrative review

Myelin oligodendrocyte glycoprotein (MOG) is a protein exclusively expressing on the surface of myelin sheaths and oligodendrocyte plasma membrane in the central nervous system of mammals, and it has a highly conserved nucleotide and amino acid structure between species. Evidence from animal research support that anti-MOG antibodies (MOG-Abs) are pathogenic antibodies rather than a bystander secondary to myelin destruction. Similarly, immunoglobulin-G against myelin oligodendrocyte glycoprotein (MOG-IgG) is considered a demyelinating disease-associated autoantibody in human beings. In clinical studies, several detection methods, including ELISA, immunoblot, radio immunoprecipitation assays and Cell-based assays (CBAs), have been applied in identifying MOG-Abs in idiopathic inflammatory demyelinating diseases (IIDDs) of human beings. CBAs method is recommended by many proposed diagnostic criterions for MOG-Abs-associated disorders (MOGAD). This method involves transfection of mammalian cells with MOG antigen, binding of MOG-Abs to MOG antigen, binding of secondary antibodies to MOG-Abs and quantification method. However, the reliability for CBAs systems of MOG-Abs detection can be influenced by numerous factors, such as length of MOG antigen, expression vectors, cell lines, secondary antibodies, and read-out systems. In addition, there arc controversial results on the studies of IIDDs with MOG-IgG positive. Nowadays, more and more evidence suggests that patients positive for MOG-IgG share common features, but further clinical and laboratory researches are needed to clarify if MOGAD is an independent disease entity. In this review, we intend to summarize the detection methods of MOG-Abs and their sensitivity and specificity to MOGAD in human.