Monospecific
IgG antibodies to
GD1b ganglioside (GD1b-specific antibodies) have been found in patients with acute ataxic neuropathy and
Guillain-Barré syndrome, but the association of the GD1b-specific
antibodies with specific neurological conditions has yet to be established. We tested sera from more than 10,000 patients with various
neurological disorders, and found six sera, which contained
IgG antibodies to GD1b, but not to LM1, GM1,
GM1b, GD1a,
GalNAc-GD1a, GT1a, GT1b and GQ1b. All six patients who carried GD1b-specific
antibodies presented with acute onset of
ataxia and monophasic course of the illness, of whom five demonstrated cerebellar-like
ataxia. Four patients had antecedent symptoms of
upper respiratory tract infection. The six patients demonstrated areflexia, and four complained of distal
numbness. All the six patients who had the GD1b-specific
antibodies carried
IgG antibodies to complex of GQ1b/GM1 and GT1a/GM1. GD1b-specific
antibodies were significantly absorbed by GQ1b/GM1 and GT1a/GM1 and anti-GQ1b/GM1 and -GT1a/GM1
antibodies were absorbed by GD1b. In conclusion, the GD1b-specific
antibodies, which recognizes GQ1b/GM1 or GT1a/GM1 complex, are associated with acute
ataxia.