[Anti-GM1 gangliosides antibodies in multifocal motor neuropathies].

In a study on 67 chronic neuropathies, we have shown that anti-GM1 antibodies are particularly frequent in multifocal motor neuropathies (MMN) with conduction blocks (17/24 cases). The detection of these antibodies by ELISA necessitates a confirmation by immunodetection on thin-layer chromatography, so as to distinguish the anti-GM1 antibodies present in MMN from natural antibodies which are polyreactive and of low affinity. There is no direct correlation between the anti-GM1 antibody titer, the immunosuppressive treatment and the clinical evolution. Nevertheless, the detection of high titer of anti-GM1 antibodies is an additional argument in favor of treatment by IVIg.