Sensory neuropathy associated with monoclonal immunoglobulin M to GD1b ganglioside.

A 67-year-old woman with a sensory polyneuropathy was shown to have a serum monoclonal immunoglobulin M lambda antibody with a titer of 1:10,000 toward GD1b ganglioside. The immunoglobulin M also reacted with some other gangliosides containing disialosyl groups such as GD2, GD3, and GQ1b, but it did not react with GM1, LM1, or GD1a. The principal reactive ganglioside in human cauda equina was GD1b.