GM1B IS A NEW MEMBER OF ANTIGEN FOR SERUM ANTIBODY IN GUILLAIN-BARRE-SYNDROME

Serum antibody from some patients with Guillain-Barre syndrome recogni zed an antigen of a minor component in human brain monosialogangliosid e fraction. We purified that antigen, which migrated at a position sli ghtly lower than that of GM1 on a thin-layer chromatogram (TLC), by us ing Iatrobeads column chromatography and preparative TLC. Structural a nalyses, including fast atom bombardment mass spectrometry, showed it to be GM1b. An enzyme-linked immunosorbent assay (ELISA) using purifie d GM1b showed that anti-GM1b antibody was present in 22 of 104 cases t ested, No anti-GM1b antibody was present in the sera from control pati ents with other diseases or from the normal controls. Four sera recogn ized only GM1b among the 11 ganglioside antigens tested. The other 18 sera had antibodies to other antigens, most of which shared no termina l epitope with GM1b. Eight of nine sera samples with anti-GalNAc-GD1a antibody also had anti-GM1b antibody. Antibody to a minor monosialogan glioside, GM1b, was found to be a useful diagnostic marker for Guillai n-Barre syndrome. Further study is needed to determine whether this an tibody plays a role in the pathogenetic mechanism of the syndrome.