Autoantibodies in central nervous system and neuromuscular autoimmune disorders: A narrative review

Abstract

The discovery of novel autoantibodies in neurological disorders contributes to a better understanding of its pathogenesis, improves the accuracy of diagnosis, and leads to new treatment strategies. Advances in techniques for the screening and detection of autoantibodies have enabled the discovery of new antibodies in the central nervous system (CNS) and neuromuscular diseases. Cell-based assays using live or fixed cells overexpressing target antigens are widely used for autoantibody-based diagnosis in clinical practice. Common pathogenic autoantibodies are unknown in most patients with multiple sclerosis (MS) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Novel pathogenic autoantibodies to aquaporin-4 and myelin oligodendrocyte glycoprotein (MOG) have been identified in neuromyelitis optica spectrum disorder and MOG antibody-associated disease, respectively. These diseases have clinical similarities to MS, but with the discovery of pathogenic autoantibodies, they are now recognized as distinct disease entities. Antibodies to paranodal membrane proteins such as neurofascin-155, contactin‑1, contactin‑associated protein‑1 in CIDP and muscle-specific kinase and low-density lipoprotein receptor–related protein 4 in myasthenia gravis were added to the profiles of autoantibodies in neurological disorders. Despite the relatively low frequency of seropositivity, autoantibody detection is currently essential for the clinical diagnosis of CNS and neuromuscular autoimmune disorders, and differential approaches to seropositive patients will contribute to more personalized medicine. We reviewed recent discoveries of autoantibodies and their clinical implications in CNS and neuromuscular disorders.

Clinical characteristics of myelin oligodendrocyte glycoprotein antibody-associated disease according to their epitopes

“…The clinical significance of MOG-Ab has been studied thoroughly with the discovery of reliable cell-based immunoassay for MOG-Ab using full-length human MOG protein and IgG1 antibody ( 9 ). The detection of MOG-Ab became an essential part of the differential diagnosis of CNS demyelinating diseases ( 5 , 10 ), and it has helped to expand our understanding of the clinical diversity of MOGAD; the clinical syndromes of MOGAD include single/recurrent or bilateral ON, TM, ADEM, brain or brainstem syndrome, and cortical encephalitis ( 2 , 5 , 11–13 ). In our study, patients with MOGAD also showed diverse clinical syndromes, and ON was the most common presenting clinical syndrome (38/55, 69.1%), which was in line with the results of previous studies ( 3 , 14 , 15 ).…”