Antibody glycosylation in neuroimmune diseases

Glycosylation, a critical post-translational modification of proteins, is particularly evident in immunoglobulins (Ig), also known as antibodies, and plays a significant role in various neuroimmune diseases. Of particular importance is the N-glycosylation of the crystallizable fragment (Fc) of IgG. It has a straightforward structure and directly impacts antibody effector functions, thus making it a focal point in antibody glycosylation studies. This review systematically summarizes characteristic IgG glycosylation patterns in neuroimmune disorders, including multiple sclerosis (MS), neuromyelitis optica spectrum disorders (NMOSD), Guillain–Barré syndrome (GBS), chronic inflammatory demyelinating polyradiculoneuropathies (CIDP), and myasthenia gravis (MG). A prevailing pattern of reduced IgG galactosylation, sialylation, and core fucosylation has been consistently observed across these diseases, and these alterations are intricately linked to a pro-inflammatory shift in antibody functionality. Beyond pathological mechanisms, this review further explores the potential clinical value of IgG glycosylation, emphasizing its applications as a biomarker and as a target for innovative therapeutic strategies, such as the design of engineered therapeutic monoclonal antibodies and the use of glycosidases. The specific alteration of IgG glycosylation is a hallmark of neuroimmune diseases, contributing to their pathogenesis and offering substantial translational promise. Harnessing this knowledge for the development of glycosylation-based diagnostics and therapeutics represents a significant frontier in the management of neuroimmune diseases.