Anti-GQ1b antibody: Recent topics

Studies on antibodies against glycolipids, mainly gangliosides, have advanced the understanding of the pathophysiology of Guillain–Barré syndrome. Glycolipid antibody research began with the study of isolated ganglioside antigens, and further expanded that area with the discovery of antibodies against complex antigens of two glycolipids. In Fisher syndrome-related disorders, immunoglobulin G (IgG) anti-GQ1b antibody is detected at a high rate, but 10–30% of the cases are antibody-negative. Recently, an antibody that requires Ca²⁺ to react with ganglioside GQ1b (Ca²⁺-dependent GQ1b antibody) was discovered in the antibody-negative cases. Ca²⁺ interacts with the disialosyl group (NeuAc[α2-8]NeuAc[α2-])of GQ1b, and the antibody is thought to recognize the structure to which Ca²⁺ is bound. Anti-GQ1b antibody is considered to be more involved in Fisher syndrome-related disorders than was previously shown.