Some patients developed Guillain-Barre syndrome (GBS) after the admini
stration of bovine gangliosides. Patients with GBS subsequent to Campy
lobacter jejuni enteritis frequently have IgG antibody to GM1 ganglios
ide. Fisher's syndrome (FS), a variant of GBS, is associated with IgG
antibody to GQ1b ganglioside. We showed the existence of molecular mim
icry between GM1 and lipopolysaccharide (LPS) of C. jejuni isolated fr
om a GBS patient, and that between GQ1b and C. jejuni LPSs from FS pat
ients. Several lines of evidence suggest a pathogenic role for anti-ga
nglioside antibodies. Some patients developed sensorimotor polyneuropa
thy after anti-GD2 antibody administration. Anti-GM1 antibody can bloc
k motor nerve conduction. The molecular mimicry between infectious age
nts and gangliosides may function in the production of anti-gangliosid
e antibodies and the development of GBS and FS. Anti-GQ1b IgG antibody
is detected also in Bickerstaff's brainstem encephalitis and acute op
hthalmoparesis, which suggests that these conditions are categorized a
s autoimmune diseases related to FS. Since a tryptophan-immobilized co
lumn effectively adsorb anti-GQ1b IgG antibody, immunoadsorption with
the column should be considered as an alternative form of plasmapheres
is for the anti-GQ1b IgG antibody syndrome.