Association of antibodies to ganglioside complexes and conduction blocks in axonal Guillain‐Barré syndrome presenting as acute motor conduction block neuropathy

A close relationship between acute motor conduction block neuropathy and antibodies against the complex of GM1 and GalNAc‐GD1a has been reported. This study investigates the hypothesis that conduction block at the early phase of axonal Guillain‐Barré syndrome (GBS) is also associated with such ganglioside complexes. Sera were obtained from seven French patients with initial evidence of isolated conduction blocks that resolved or progressed to acute motor axonal neuropathy. Serum IgG to asialo‐GM1 and gangliosides of LM1, GM1, GM1b, GD1a, GalNAc‐GD1a, GD1b, GT1a, GT1b, and GQ1b as well as their complexes were measured. Five of seven patients progressed within the first month of disease to AMAN. One patient had IgG antibodies against the complex of asialo‐GM1 and each of the other ganglioside antigens. Another patient carried IgG antibodies against GM1 complex with GM1b, GD1a, and GT1a as well as asialo‐GM1 complex with GD1a and GT1a. None had IgG antibodies against GM1/GalNAc‐GD1a complex. Six patients had IgG against single antigens GM1, GD1a, GalNAc‐GD1a, GD1b, and asialo‐GM1. In three patients, a reduced reaction against GM1/GalNAc‐GD1a complex was observed. The presence of conduction block in axonal GBS is not always associated with anti‐GM1/GalNAc‐GD1a complex antibodies.