Localization of GM1 and GD1b antigens in the human peripheral nervous system

Serum antibodies against ganglioside GM1 and/or GD1b are frequently detected in autoimmune neuropathies such as multifocal motor neuropathy, IgM paraproteinemic neuropathy and Guillain-Barré syndrome. Some of them bind to GM1 or GD1b monospecifically but others cross-react with both of the antigens. In order to investigate the respective localizations of GM1 and GD1b antigens in the human peripheral nervous system, an immunohistochemical study was performed using two mouse monoclonal antibodies, each monospecific to GM1 and GD1b. GGR12, monospecific to GD1b, bound to neurons in dorsal root ganglia and sympathetic ganglia, and some parts of the peripheral myelin, mainly the paranodal areas. However GMB16, monospecific to GM1, did not bind to either neurons or myelin. GD1b antigen present on neurons and paranodal myelin in the peripheral nervous system can be a target antigen of serum antibodies in autoimmune neuropathies. Further effort should be made to reveal the localization of GM1 antigen in the human peripheral nervous system.