Griffin and colleagues (Griffin JW, Li CY, Ho TW, Tian M, Gao CY, Xue P, Mishu B, Cornblath DR, Macko C, McKhann GM, Asbury AK. Pathology of motor-sensory axonal Guillain-Barré syndrome. Ann Neurol 1996;39:17-28 ) proposed that acute motor axonal neuropathy (AMAN) and acute motor-sensory axonal neuropathy (AMSAN) are part of the spectrum of a single type of immune attack on the axon. In contrast, IgG anti-GM1 antibody is associated closely with AMAN, but whether other IgG anti-ganglioside antibodies are associated with this neuropathy is not clear. We investigated whether IgG anti-ganglioside antibodies can be used as immunological markers to differentiate AMAN from acute inflammatory demyelinating polyneuropathy (AIDP) and whether these autoantibodies are present in AMSAN. The frequencies of anti-GM1, anti-GM1b, and anti-GD1a IgG antibodies in 21 AMAN patients were significantly higher than in 19 AIDP patients. Anti-GM1b and anti-GD1a IgG, as well as anti-GM1 IgG antibodies, therefore are immunological markers for AMAN. The patients with AMSAN had anti-GM1, anti-GM1b, and anti-GD1a IgG antibodies, indicative that AMAN and AMSAN share a common immunological profile.