Anti-GM1b IgG antibody is associated with acute motor axonal neuropathy and Campylobacter jejuni infection.

Anti-GM1 and anti-GM1b antibodies are frequently present in patients with Guillain-Barré syndrome (GBS) and accordingly, the two antibodies often coexist in the same patient. In order to study clinical and laboratory features of anti-GM1b-positive GBS, we analyzed the data of patients with anti-GM1b IgG antibody but no anti-GM1 IgG antibody. Of 86 consecutive patients, 10 had anti-GM1b antibody alone and frequently had acute motor axonal neuropathy (AMAN, 80%) and Campylobacter jejuni infection (60%). Of 10 patients with anti-GM1 antibody alone, four had AMAN, and two had C. jejuni infection. These results showed that GM1b could be a target molecule of autoantibody in the AMAN form of GBS subsequent to C. jejuni infection.