Tryptophan-immobilized column adsorbs immunoglobulin G anti-GQ1b antibody from Fisher's syndrome: A new approach to treatment.

Sera from patients with Fisher's syndrome in the acute phase contain immunoglobulin (Ig)G anti-GQ1b ganglioside antibody. Removal of the autoantibody should lead to earlier recovery with less residual neurologic involvement. A tryptophan- or phenylalanin-immobilized polyvinyl alcohol gel column (IM-TR 350 or IM-PH 350) semiselectively adsorbs such autoantibodies as rheumatoid factor, anti-DNA antibody, or anti-acetylcholine receptor antibody. A batchwise adsorption test showed that an IM-TR gel adsorbed a larger amount of the IgG anti-GQ1b antibody than did an IM-PH column. Several patients with Fisher's syndrome therefore were given immunoadsorbent therapy using the IM-TR column without adverse reactions. An ex vivo plasma perfusion study done with the IM-TR column confirmed that it effectively adsorbs the IgG anti-GQ1b antibody. Results of adsorption tests done with various amino acid-immobilized gels suggest that both the hydrophobic force of the side chain and the anionic charge of the carboxylic acid in tryptophan are important in the adsorption of the autoantibody by the IM-TR gel. Immunoadsorption using the IM-TR column, which does not need replacement fluids, offers an alternative type of plasmapheresis for Fisher's syndrome.